From personal_submersibles at psubs.org Thu May 1 13:30:25 2025 From: personal_submersibles at psubs.org (Rick Patton via Personal_Submersibles) Date: Thu, 1 May 2025 07:30:25 -1000 Subject: [PSUBS-MAILIST] (no subject) Message-ID: I had to look at the starboard battery bank and discovered this! Has anyone else had this problem? It?s natural for a battery to percolate while being charged and maybe there is no way around this but A) my battery charger isn?t backing off when it senses that the batteries are topping off or B) the level of acid was too high in the batteries or C) it isn?t avoidable?? Is there a good coating that I can apply on the bottom of the pods that resists battery acid? So close to launching but things just keep popping up! Rick -------------- next part -------------- A non-text attachment was scrubbed... Name: IMG_3974.jpg Type: image/jpeg Size: 1513985 bytes Desc: not available URL: -------------- next part -------------- Sent from my iPhone From personal_submersibles at psubs.org Thu May 1 19:08:55 2025 From: personal_submersibles at psubs.org (via Personal_Submersibles) Date: Fri, 2 May 2025 11:08:55 +1200 Subject: [PSUBS-MAILIST] 1. Re: OTS and motor controller noise In-Reply-To: References: Message-ID: <023501dbbaee$04fca2d0$0ef5e870$@gmail.com> Hi all, For that very reason I have made a housing attached to the motor with the controller and canbus interface all within. I used a Kelly controller and the housing for all the components is about 100 mm diameter and about 50mm deep. So I have my 72 volt power cord and a CANbus cable into the housing. Hopefully no noise with my OTS. All 11 motors configured in the same way. Hugh -----Original Message-----Si about 100 mm diameter and about 50mm deep From: Personal_Submersibles On Behalf Of via Personal_Submersibles Sent: Wednesday, 30 April 2025 1:40 PM To: personal_submersibles at psubs.org Subject: Personal_Submersibles Digest, Vol 136, Issue 33 Send Personal_Submersibles mailing list submissions to personal_submersibles at psubs.org To subscribe or unsubscribe via the World Wide Web, visit http://www.whoweb.com/mailman/listinfo.cgi/personal_submersibles or, via email, send a message with subject or body 'help' to personal_submersibles-request at psubs.org You can reach the person managing the list at personal_submersibles-owner at psubs.org When replying, please edit your Subject line so it is more specific than "Re: Contents of Personal_Submersibles digest..." Today's Topics: 1. Re: OTS and motor controller noise (Jon Wallace via Personal_Submersibles) ---------------------------------------------------------------------- Message: 1 Date: Wed, 30 Apr 2025 01:39:18 +0000 (UTC) From: Jon Wallace via Personal_Submersibles To: Personal Submersibles General Discussion Subject: Re: [PSUBS-MAILIST] OTS and motor controller noise Message-ID: <90593753.3387481.1745977158206 at mail.yahoo.com> Content-Type: text/plain; charset="utf-8" Lol, just saw your comment about the Theremin.? So maybe we can give a rendition of the 1812 Overture from 100 feet??? ?:)? :) Jon On Tuesday, April 29, 2025 at 08:31:52 PM EDT, Alec Smyth via Personal_Submersibles wrote: Just finished another round of experimentation. This is fun. 1) Changing channels did absolutely nothing at all. All four were equally?noisy.2) Turning on squelch was the opposite, it was so effective it completely eliminated the noise. There was not even minimal white noise and I wondered if the comms box was still on. However, I do not expect it to work that well in the water. I know I've tried it on dives and it was?an improvement, but not to this extent. My guess is that it's because with the props spinning in air, thruster currents are drastically lower.3) Shielding with aluminum foil was super interesting. I could hear the attenuation go up and down just as I held a sheet of foil in my hand and moved it in and out of the space between one of the controllers and the comms box. D'you guys know what a Theremin is? Wrapping the OTS box in foil certainly did help attenuate the noise, but isn't a complete solution because of small gaps remaining, for instance for the cables. I'd say the noise reduction was probably 50-75%. Conclusion... I'll plan to both relocate the OTS box to the quietest area, and use squelch. Maybe get fancy by making an aluminum pocket into which I'll slide the SSB-2010, as a method of mounting it to the hull.? Alec On Tue, Apr 29, 2025 at 4:46?PM Jon Wallace via Personal_Submersibles wrote: Alec, can you also test channel 3.? I'm literally getting no interference on Channel 3 which is 31.25khz upper side band.? Using this channel would be a good work around until an electronic fix can be achieved that protects all channels. Jon On Tuesday, April 29, 2025 at 01:01:03 PM EDT, Alec Smyth via Personal_Submersibles wrote: I happen to have my former sub Snoopy back in the shop because her current owner has engaged me to recommission her. The job is about 99% done, and the comms already installed, so I just conducted an experiment. I have the same setup as Dave; SSB-2010 inside the cabin running on its own dry cell batteries, connected to the transducer by a cable that is potted through a penetrator without cutting. I had left that cable longer than needed, in case the owner decided he wanted the OTS unit somewhere different.? I turned on the thrusters and started moving the OTS all around inside, and also routing the cable along different paths. Here are the conclusions: 1) As one would expect, there is much less noise when the thrusters are at either zero throttle or full throttle. All the noise is in between, when the signal is choppy.2) The noise is completely insensitive to the position of the cable. BTW the cable I'm using?was the OEM cable on another comms system similar to OTS. It's a small diameter shielded single conductor, where the shield is not grounded but used as a second conductor.3) Almost all of the variation in noise comes from proximity of the OTS unit to the speed controllers. There is also a bit of noise if its placed close to the battery cables, but it's nothing compared to the noise emanating from the controllers. So... the conclusion, at least in my case, is to place the OTS unit as far from the speed controllers and battery cables as possible. David, does that match the location of your OTS unit? Best,Alec On Tue, Apr 29, 2025 at 12:54?AM David Colombo via Personal_Submersibles wrote: Jon, youve got me thinking on this one. In the VAST, i have the diver unit inside the sub, a continuous non cut cable potted to the thru hull penetrator. The diver unit has its own 6 AA battery pack. With the pair of 36v 101's, and wearing the headset, i have not had any issues with bleed over noise. I am planning on adding the topside unit inside as a new comms like you. My 101's are controlled by their own minnkota pwm which are on the 36v lipo4 battery pack.? The hotel loads are on their own 12v lipo4 battery pack, which is where i plan on connecting the topside unit.? I will run a test to see if i can find any signal interferance using the hotel load battery vs its own 2-6v battery pack, and let you know what i find. On Mon, Apr 28, 2025, 4:24?PM Alec Smyth via Personal_Submersibles wrote: I've had mine to 250', but it was inside the sub. That said, the effect on the audio quality was remarkable. It was perfectly clear, but if you ever talked to your friends through a long garden hose as a kid, that was exactly how it sounded. Which was great, because it made it feel spooky and deep! On Mon, Apr 28, 2025 at 4:35?PM Sean T. Stevenson via Personal_Submersibles wrote: I have had a SSB-2010 a bit deeper than 130 as a diver without flooding the housing, but I don't know how deep it will go without compensation.? That limit is the standard recreational diving depth limit for no-mandatory-decompression-stop diving, and it is likely that it was both designed and rated accordingly.?? These units have no helium speech descramblers, so they are of limited utility for ambient pressure divers as you go deeper. The donald duck voice on top of the limited bandwidth of ultrasonic comms at all makes intelligibility a challenge. I had the unit to ~165 fsw, and I suspect that you could push it deeper, but you would void any warranty.? I'm using PowerCom 3000D units now, and these have similar depth ratings. Sean -------- Original Message -------- On 2025-04-28 10:59, Jon Wallace via Personal_Submersibles wrote: SB-2010 is rated to 130 feet by OTS.? Has anyone tested one to deeper depths? On Monday, April 28, 2025 at 01:15:01 PM EDT, hank pronk via Personal_Submersibles wrote: Jon, put the whole unit outside the hull.? I have zero issues with this.? I just put fresh batteries in for each diveHank Sent from my iPhone On Apr 28, 2025, at 10:16?AM, Jon Wallace via Personal_Submersibles wrote: ? Not a lot of room to work with of course inside the cabin.? My controllers are mounted up near the top of the hull, the coax comes in from the bottom and is probably only about 18 inches laterally from the controllers.? The coax cable thru-hull is only 5/8 inch diameter (15.8 mm) so PL259's won't fit through it to allow me removal for maintenance which is why I opted for SMA.? I suppose I could try it since I won't be removing the cable regularly but it's definitely going to be a PIA change. No I'm not sure whether the noise is electrical or acoustic in source but now that you've asked I can tell you that the controllers make an audible tone when the PWM is active, even with the OTS off.? The tone changes of course depending upon the PWM frequency I select, but it is always there.? The same tone comes out the OTS, but amplified. Jon On Monday, April 28, 2025 at 11:51:58 AM EDT, Sean T. Stevenson via Personal_Submersibles wrote: Two things I would look at: 1) Relative location and shielding between the motor controller and the transducer cable.? Is additional shielding (conduit?) possible? 2) I have encountered problems in the past with noise on coax due to impedance mismatch / partial signal reflection at any connectors. In my experience, this is solved by moving from RG58 up to RG8, but you don't have that option because the transducer is a potted assembly. If you have enough cable tail available to experiment, I wonder about swapping the SMA connectors for PL259 to see if that makes a difference. Are you certain that the noise you are hearing is being introduced electrically, and not acoustically in the ultrasonic range of the transducer? Sean -------- Original Message -------- On 2025-04-28 06:47, Jon Wallace via Personal_Submersibles wrote: Hey folks, My OTS STX-101 receiver is picking up some fairly significant and annoying electronic noise from my Roboteq PWM motor controllers.? I tried changing channels on the OTS hoping a different frequency might help but it didn't.? I also tried changing the controller PWM frequency between a range of 10khz and 24khz but nothing between those frequencies made a significant improvement.? The noise is enough to override the normal squelch setting but at the same time a strong communication signal through the OTS transducer is enough to override the noise. My configuration has the transducer outside the hull and receiver inside the hull which required cutting the cable.? I potted the cable in a thru-hull and reconnected the cable inside the cabin with RG-58 SMA connectors (soldered, not crimped). In talking with a couple other folks it seems I am not alone in this experience.? Some others have found that using local batteries instead of tying into the same batteries used by the motors has significantly reduced the noise, however in my case I am already using a separate battery isolated from the motor batteries.? Another choice that has seemed to make a difference is mounting an SB-1001 outside the hull and running the headset wires through the hull instead. Anyone else have similar experiences with OTS? Jon _______________________________________________ Personal_Submersibles mailing list Personal_Submersibles at psubs.org http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles _______________________________________________ Personal_Submersibles mailing list Personal_Submersibles at psubs.org http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles _______________________________________________ Personal_Submersibles mailing list Personal_Submersibles at psubs.org http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles _______________________________________________ Personal_Submersibles mailing list Personal_Submersibles at psubs.org http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles _______________________________________________ Personal_Submersibles mailing list Personal_Submersibles at psubs.org http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles _______________________________________________ Personal_Submersibles mailing list Personal_Submersibles at psubs.org http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles _______________________________________________ Personal_Submersibles mailing list Personal_Submersibles at psubs.org http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles _______________________________________________ Personal_Submersibles mailing list Personal_Submersibles at psubs.org http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles _______________________________________________ Personal_Submersibles mailing list Personal_Submersibles at psubs.org http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles -------------- next part -------------- An HTML attachment was scrubbed... URL: ------------------------------ Subject: Digest Footer _______________________________________________ Personal_Submersibles mailing list Personal_Submersibles at psubs.org http://www.whoweb.com/mailman/listinfo.cgi/personal_submersibles ------------------------------ End of Personal_Submersibles Digest, Vol 136, Issue 33 ****************************************************** From personal_submersibles at psubs.org Thu May 1 19:39:15 2025 From: personal_submersibles at psubs.org (hank pronk via Personal_Submersibles) Date: Thu, 1 May 2025 23:39:15 +0000 (UTC) Subject: [PSUBS-MAILIST] (no subject) In-Reply-To: References: Message-ID: <1173670339.425747.1746142755310@mail.yahoo.com> Sounds like a bad charger.Hank On Thursday, May 1, 2025 at 11:30:49 AM MDT, Rick Patton via Personal_Submersibles wrote: I had to look at the starboard battery bank and discovered this! Has anyone else had this problem? It?s natural for a battery to percolate while being charged and maybe there is no way around this but A) my battery charger isn?t backing off when it senses that the batteries are topping off or B) the level of acid was too high in the batteries or C) it isn?t avoidable?? Is there a good coating that I can apply on the bottom of the pods that resists battery acid? So close to launching but things just keep popping up! Rick Sent from my iPhone_______________________________________________ Personal_Submersibles mailing list Personal_Submersibles at psubs.org http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles -------------- next part -------------- An HTML attachment was scrubbed... URL: From personal_submersibles at psubs.org Thu May 1 19:58:50 2025 From: personal_submersibles at psubs.org (Alan James via Personal_Submersibles) Date: Thu, 1 May 2025 23:58:50 +0000 (UTC) Subject: [PSUBS-MAILIST] 1. Re: OTS and motor controller noise In-Reply-To: <023501dbbaee$04fca2d0$0ef5e870$@gmail.com> References: <023501dbbaee$04fca2d0$0ef5e870$@gmail.com> Message-ID: <1799571735.426692.1746143930568@mail.yahoo.com> Hugh, hopefully that won't be problematic in that good practice is to have a short run of wire from the battery to the controller & longer run from the controller to the motor you may be aware of this.... Why Short Battery Wires are Preferred: Long battery wires can increase inductance, which can lead to voltage spikes and damage to the controller's sensitive components. These spikes can be particularly problematic in high-power, fast-switching systems like RC controllers (ESCs). This can be mitigated by adding capacitors? between the wires. Cheers Alan Yahoo Mail: Search, organise, conquer On Fri, 2 May 2025 at 11:10 am, via Personal_Submersibles wrote: Hi all,? For that very reason I have made a housing attached to the motor with the controller and canbus interface all within.? I used a Kelly controller and the housing for all the components is about 100 mm diameter and about 50mm deep.? So I have my 72 volt power cord and a CANbus cable into the housing.? Hopefully no noise with my OTS.? All 11 motors configured in the same way.? Hugh -----Original Message-----Si about 100 mm diameter and about 50mm deep From: Personal_Submersibles On Behalf Of via Personal_Submersibles Sent: Wednesday, 30 April 2025 1:40 PM To: personal_submersibles at psubs.org Subject: Personal_Submersibles Digest, Vol 136, Issue 33 Send Personal_Submersibles mailing list submissions to ??? personal_submersibles at psubs.org To subscribe or unsubscribe via the World Wide Web, visit ??? http://www.whoweb.com/mailman/listinfo.cgi/personal_submersibles or, via email, send a message with subject or body 'help' to ??? personal_submersibles-request at psubs.org You can reach the person managing the list at ??? personal_submersibles-owner at psubs.org When replying, please edit your Subject line so it is more specific than "Re: Contents of Personal_Submersibles digest..." Today's Topics: ? 1. Re: OTS and motor controller noise ? ? ? (Jon Wallace via Personal_Submersibles) ---------------------------------------------------------------------- Message: 1 Date: Wed, 30 Apr 2025 01:39:18 +0000 (UTC) From: Jon Wallace via Personal_Submersibles ??? To: Personal Submersibles General Discussion ??? Subject: Re: [PSUBS-MAILIST] OTS and motor controller noise Message-ID: <90593753.3387481.1745977158206 at mail.yahoo.com> Content-Type: text/plain; charset="utf-8" Lol, just saw your comment about the Theremin.? So maybe we can give a rendition of the 1812 Overture from 100 feet??? ?:)? :) Jon ? ? On Tuesday, April 29, 2025 at 08:31:52 PM EDT, Alec Smyth via Personal_Submersibles wrote:? Just finished another round of experimentation. This is fun. 1) Changing channels did absolutely nothing at all. All four were equally?noisy.2) Turning on squelch was the opposite, it was so effective it completely eliminated the noise. There was not even minimal white noise and I wondered if the comms box was still on. However, I do not expect it to work that well in the water. I know I've tried it on dives and it was?an improvement, but not to this extent. My guess is that it's because with the props spinning in air, thruster currents are drastically lower.3) Shielding with aluminum foil was super interesting. I could hear the attenuation go up and down just as I held a sheet of foil in my hand and moved it in and out of the space between one of the controllers and the comms box. D'you guys know what a Theremin is? Wrapping the OTS box in foil certainly did help attenuate the noise, but isn't a complete solution because of small gaps remaining, for instance for the cables. I'd say the noise reduction was probably 50-75%. Conclusion... I'll plan to both relocate the OTS box to the quietest area, and use squelch. Maybe get fancy by making an aluminum pocket into which I'll slide the SSB-2010, as a method of mounting it to the hull.? Alec On Tue, Apr 29, 2025 at 4:46?PM Jon Wallace via Personal_Submersibles wrote: Alec, can you also test channel 3.? I'm literally getting no interference on Channel 3 which is 31.25khz upper side band.? Using this channel would be a good work around until an electronic fix can be achieved that protects all channels. Jon ? ? On Tuesday, April 29, 2025 at 01:01:03 PM EDT, Alec Smyth via Personal_Submersibles wrote:? I happen to have my former sub Snoopy back in the shop because her current owner has engaged me to recommission her. The job is about 99% done, and the comms already installed, so I just conducted an experiment. I have the same setup as Dave; SSB-2010 inside the cabin running on its own dry cell batteries, connected to the transducer by a cable that is potted through a penetrator without cutting. I had left that cable longer than needed, in case the owner decided he wanted the OTS unit somewhere different.? I turned on the thrusters and started moving the OTS all around inside, and also routing the cable along different paths. Here are the conclusions: 1) As one would expect, there is much less noise when the thrusters are at either zero throttle or full throttle. All the noise is in between, when the signal is choppy.2) The noise is completely insensitive to the position of the cable. BTW the cable I'm using?was the OEM cable on another comms system similar to OTS. It's a small diameter shielded single conductor, where the shield is not grounded but used as a second conductor.3) Almost all of the variation in noise comes from proximity of the OTS unit to the speed controllers. There is also a bit of noise if its placed close to the battery cables, but it's nothing compared to the noise emanating from the controllers. So... the conclusion, at least in my case, is to place the OTS unit as far from the speed controllers and battery cables as possible. David, does that match the location of your OTS unit? Best,Alec On Tue, Apr 29, 2025 at 12:54?AM David Colombo via Personal_Submersibles wrote: Jon, youve got me thinking on this one. In the VAST, i have the diver unit inside the sub, a continuous non cut cable potted to the thru hull penetrator. The diver unit has its own 6 AA battery pack. With the pair of 36v 101's, and wearing the headset, i have not had any issues with bleed over noise. I am planning on adding the topside unit inside as a new comms like you. My 101's are controlled by their own minnkota pwm which are on the 36v lipo4 battery pack.? The hotel loads are on their own 12v lipo4 battery pack, which is where i plan on connecting the topside unit.? I will run a test to see if i can find any signal interferance using the hotel load battery vs its own 2-6v battery pack, and let you know what i find. On Mon, Apr 28, 2025, 4:24?PM Alec Smyth via Personal_Submersibles wrote: I've had mine to 250', but it was inside the sub. That said, the effect on the audio quality was remarkable. It was perfectly clear, but if you ever talked to your friends through a long garden hose as a kid, that was exactly how it sounded. Which was great, because it made it feel spooky and deep! On Mon, Apr 28, 2025 at 4:35?PM Sean T. Stevenson via Personal_Submersibles wrote: I have had a SSB-2010 a bit deeper than 130 as a diver without flooding the housing, but I don't know how deep it will go without compensation.? That limit is the standard recreational diving depth limit for no-mandatory-decompression-stop diving, and it is likely that it was both designed and rated accordingly.?? These units have no helium speech descramblers, so they are of limited utility for ambient pressure divers as you go deeper. The donald duck voice on top of the limited bandwidth of ultrasonic comms at all makes intelligibility a challenge. I had the unit to ~165 fsw, and I suspect that you could push it deeper, but you would void any warranty.? I'm using PowerCom 3000D units now, and these have similar depth ratings. Sean -------- Original Message -------- On 2025-04-28 10:59, Jon Wallace via Personal_Submersibles? wrote: SB-2010 is rated to 130 feet by OTS.? Has anyone tested one to deeper depths? ? ? On Monday, April 28, 2025 at 01:15:01 PM EDT, hank pronk via Personal_Submersibles wrote:? Jon, put the whole unit outside the hull.? I have zero issues with this.? I just put fresh batteries in for each diveHank Sent from my iPhone On Apr 28, 2025, at 10:16?AM, Jon Wallace via Personal_Submersibles wrote: ? Not a lot of room to work with of course inside the cabin.? My controllers are mounted up near the top of the hull, the coax comes in from the bottom and is probably only about 18 inches laterally from the controllers.? The coax cable thru-hull is only 5/8 inch diameter (15.8 mm) so PL259's won't fit through it to allow me removal for maintenance which is why I opted for SMA.? I suppose I could try it since I won't be removing the cable regularly but it's definitely going to be a PIA change. No I'm not sure whether the noise is electrical or acoustic in source but now that you've asked I can tell you that the controllers make an audible tone when the PWM is active, even with the OTS off.? The tone changes of course depending upon the PWM frequency I select, but it is always there.? The same tone comes out the OTS, but amplified. Jon ? ? On Monday, April 28, 2025 at 11:51:58 AM EDT, Sean T. Stevenson via Personal_Submersibles wrote:? Two things I would look at: 1) Relative location and shielding between the motor controller and the transducer cable.? Is additional shielding (conduit?) possible? 2) I have encountered problems in the past with noise on coax due to impedance mismatch / partial signal reflection at any connectors. In my experience, this is solved by moving from RG58 up to RG8, but you don't have that option because the transducer is a potted assembly. If you have enough cable tail available to experiment, I wonder about swapping the SMA connectors for PL259 to see if that makes a difference. Are you certain that the noise you are hearing is being introduced electrically, and not acoustically in the ultrasonic range of the transducer? Sean -------- Original Message -------- On 2025-04-28 06:47, Jon Wallace via Personal_Submersibles wrote: Hey folks, My OTS STX-101 receiver is picking up some fairly significant and annoying electronic noise from my Roboteq PWM motor controllers.? I tried changing channels on the OTS hoping a different frequency might help but it didn't.? I also tried changing the controller PWM frequency between a range of 10khz and 24khz but nothing between those frequencies made a significant improvement.? The noise is enough to override the normal squelch setting but at the same time a strong communication signal through the OTS transducer is enough to override the noise. My configuration has the transducer outside the hull and receiver inside the hull which required cutting the cable.? I potted the cable in a thru-hull and reconnected the cable inside the cabin with RG-58 SMA connectors (soldered, not crimped). In talking with a couple other folks it seems I am not alone in this experience.? Some others have found that using local batteries instead of tying into the same batteries used by the motors has significantly reduced the noise, however in my case I am already using a separate battery isolated from the motor batteries.? Another choice that has seemed to make a difference is mounting an SB-1001 outside the hull and running the headset wires through the hull instead. Anyone else have similar experiences with OTS? Jon _______________________________________________ Personal_Submersibles mailing list Personal_Submersibles at psubs.org http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles ? _______________________________________________ Personal_Submersibles mailing list Personal_Submersibles at psubs.org http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles _______________________________________________ Personal_Submersibles mailing list Personal_Submersibles at psubs.org http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles ? _______________________________________________ Personal_Submersibles mailing list Personal_Submersibles at psubs.org http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles _______________________________________________ Personal_Submersibles mailing list Personal_Submersibles at psubs.org http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles _______________________________________________ Personal_Submersibles mailing list Personal_Submersibles at psubs.org http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles _______________________________________________ Personal_Submersibles mailing list Personal_Submersibles at psubs.org http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles ? _______________________________________________ Personal_Submersibles mailing list Personal_Submersibles at psubs.org http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles _______________________________________________ Personal_Submersibles mailing list Personal_Submersibles at psubs.org http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles ? -------------- next part -------------- An HTML attachment was scrubbed... URL: ------------------------------ Subject: Digest Footer _______________________________________________ Personal_Submersibles mailing list Personal_Submersibles at psubs.org http://www.whoweb.com/mailman/listinfo.cgi/personal_submersibles ------------------------------ End of Personal_Submersibles Digest, Vol 136, Issue 33 ****************************************************** _______________________________________________ Personal_Submersibles mailing list Personal_Submersibles at psubs.org http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles -------------- next part -------------- An HTML attachment was scrubbed... URL: From personal_submersibles at psubs.org Thu May 1 20:36:45 2025 From: personal_submersibles at psubs.org (Jon Wallace via Personal_Submersibles) Date: Fri, 2 May 2025 00:36:45 +0000 (UTC) Subject: [PSUBS-MAILIST] (no subject) In-Reply-To: <1173670339.425747.1746142755310@mail.yahoo.com> References: <1173670339.425747.1746142755310@mail.yahoo.com> Message-ID: <2123225553.436659.1746146205593@mail.yahoo.com> It does sound like a charger issue, either not turning off or not cycling correctly from charge mode to maintenance mode.? Once you get the goop cleaned up and pod repainted you could lay down some heavy rubber to protect the steel in case it happens again.? I like the horse stall mats that Tractor Supply sells that are 1/2 inch thick but they also have some thinner material. Jon On Thursday, May 1, 2025 at 07:40:42 PM EDT, hank pronk via Personal_Submersibles wrote: Sounds like a bad charger.Hank On Thursday, May 1, 2025 at 11:30:49 AM MDT, Rick Patton via Personal_Submersibles wrote: I had to look at the starboard battery bank and discovered this! Has anyone else had this problem? It?s natural for a battery to percolate while being charged and maybe there is no way around this but A) my battery charger isn?t backing off when it senses that the batteries are topping off or B) the level of acid was too high in the batteries or C) it isn?t avoidable?? Is there a good coating that I can apply on the bottom of the pods that resists battery acid? So close to launching but things just keep popping up! Rick Sent from my iPhone_______________________________________________ Personal_Submersibles mailing list Personal_Submersibles at psubs.org http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles _______________________________________________ Personal_Submersibles mailing list Personal_Submersibles at psubs.org http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles -------------- next part -------------- An HTML attachment was scrubbed... URL: From personal_submersibles at psubs.org Thu May 1 22:02:56 2025 From: personal_submersibles at psubs.org (Rick Patton via Personal_Submersibles) Date: Thu, 1 May 2025 16:02:56 -1000 Subject: [PSUBS-MAILIST] (no subject) In-Reply-To: <2123225553.436659.1746146205593@mail.yahoo.com> References: <1173670339.425747.1746142755310@mail.yahoo.com> <2123225553.436659.1746146205593@mail.yahoo.com> Message-ID: Yeah I kind of figured that it was a charger issue. Riclk On Thu, May 1, 2025 at 2:41?PM Jon Wallace via Personal_Submersibles < personal_submersibles at psubs.org> wrote: > It does sound like a charger issue, either not turning off or not cycling > correctly from charge mode to maintenance mode. Once you get the goop > cleaned up and pod repainted you could lay down some heavy rubber to > protect the steel in case it happens again. I like the horse stall mats > that Tractor Supply sells that are 1/2 inch thick but they also have some > thinner material. > > Jon > > > On Thursday, May 1, 2025 at 07:40:42 PM EDT, hank pronk via > Personal_Submersibles wrote: > > > Sounds like a bad charger. > Hank > > On Thursday, May 1, 2025 at 11:30:49 AM MDT, Rick Patton via > Personal_Submersibles wrote: > > > I had to look at the starboard battery bank and discovered this! > Has anyone else had this problem? It?s natural for a battery to percolate > while being charged and maybe there is no way around this but A) my battery > charger isn?t backing off when it senses that the batteries are topping off > or B) the level of acid was too high in the batteries or C) it isn?t > avoidable?? > Is there a good coating that I can apply on the bottom of the pods that > resists battery acid? > So close to launching but things just keep popping up! > > Rick > > > Sent from my iPhone_______________________________________________ > Personal_Submersibles mailing list > Personal_Submersibles at psubs.org > http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles > _______________________________________________ > Personal_Submersibles mailing list > Personal_Submersibles at psubs.org > http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles > _______________________________________________ > Personal_Submersibles mailing list > Personal_Submersibles at psubs.org > http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles > -------------- next part -------------- An HTML attachment was scrubbed... URL: From personal_submersibles at psubs.org Sun May 4 17:19:37 2025 From: personal_submersibles at psubs.org (David Colombo via Personal_Submersibles) Date: Sun, 4 May 2025 14:19:37 -0700 Subject: [PSUBS-MAILIST] OTS and motor controller noise In-Reply-To: <1221880498.3451853.1745998986968@mail.yahoo.com> References: <776295123.2677993.1745856998926@mail.yahoo.com> <0F27FF3D-8274-4669-AB02-7D6AEE2F992B@yahoo.ca> <437686673.2728200.1745863199285@mail.yahoo.com> <8yHXkUBz7NWnskcymYb_3H_SCoy7at1QCjYXCclQ-0x2voN9BJsQoBlrZMgombU6K-vrh5m7_NzFGyhlmlb7aktNtmwsxCdg2t61dK5D_v0=@protonmail.com> <1478069852.3301778.1745959583330@mail.yahoo.com> <1068508737.3379385.1745974933686@mail.yahoo.com> <1221880498.3451853.1745998986968@mail.yahoo.com> Message-ID: Hi Jon, I've run some preliminary tests and the results are interesting. I'm going to rerun and try to document in better detail and frequencies. Here's my observations. To save me typing Topside unit =TS and Diver unit= DU. Ran the tests with the TU both sitting on my external fiberglass deck with the Transducer from the TU placed adjacent to my builtin transducer located externally at the rear of the hatch. Both Transducer cables are mfg full 25' cables with no cuts. Both TU and DU are on their own battery power. The DU is located on the starboard side, held with magnets onto the original VBT tank. Both Port and Starboard VBT have been cut open with a 16"x14" opening. Inside each of the VBT are located one PWM from MinnKota wired to the cutoff selector switch and then to the LiPo4 36v battery bank. Currently I have both the Minnkota speed selector switches adjacent to each other so they can lay over my knee to run the test. The DU is attached to my headset with channel set to 1, transmit: PUT, squelch on. The TU was sitting on my feet inside the sub, speaker on, and I set the TU to the same settings except the squelch was set to off on the rotation dial. The TU is about 30" from either PWM. With this setup I can hear my DU headset and the TU speaker at the same time. Test 1 with my DU only. Run each of the 4 channels through a series of starting out with one thruster and slowly running the speed scale in forward and then in reverse. Test 2 same test with both thrusters on and running the speed scale. Test 3 and 4 same test with the TU only Test 5 run both thrusters and both TU and DU. Note the DU is sitting closer to the PWM than the TU. TU is in its TU ABS case, with no additional shielding The thruster control cables are the mfg cables and I believe there is no shielding. Before I ran tests 1-5, I did a 6th test with the transducer of the TU into the sub and placed it near the PWM units, and then again adjacent to the thruster speed control wires. In Test 6,I found considerable frequency oscillation adjacent to the speed cable and less at the PWM units ( the PW units are incased in the mfg aluminum finned sealed case) all for channels (squelch off) I used this as a comparative baseline against the DU to see if Transducer proximity to the PWM made a difference and Initially I believe it does. So here are my observations: Test 1 & 2 DU: sometimes on start-up of a thruster I might get a short squelch burst and then no thruster noise for the rest of the speed scale. I believe that the DU which only has squelch on or off, is automatically compensating on all 4 channels, hence the reason I'm not getting any speed controller noise. No difference between test 1 & 2 Test 3 &4 TU: on all four channels with squelch off, there is a high frequency tone, each different on the 4 channels and when on test 4 with both thrusters double the db of the frequency tone. No difference if I ran one thruster forwards and one in reverse at the same time. Here is the interesting part: on each of the 4 channels there is a point on the squelch dial where you can eliminate the tone. approximately 25% on channel 1, 50 % on channel 2, 75% channel 3 and 100% on channel 4. So if I am using channel 1, preset the squelch to 25% +/- and you're good to go, same with the other channels. The other interesting thing is the proximity of the TU to the PWM. Outside the hull and about 3ft away from the PWM the intensity of the Tonal variation is substantially less, which might imply that additional shielding around the electronics of the TU could improve the reduction of the tonal frequencies. As I am planning to place the TU in the sub into one of the VBT with 1/2" thick steel on three sides, I'm hoping that will be enough shielding, only time will tell. Also I'm going to add some additional shielding on the thruster speed control wires based upon the test results of test 6. When I rerun the test, I will data log the frequency of each channel and try to calibrate the squelch position for the TU. Any thoughts on how best to filter out frequency noise besides the squelch? Anyway these are my current observations and I hope they give some insight into how to solve your problem. Best Regards, David Colombo 804 College Ave Santa Rosa, CA. 95404 (707) 536-1424 www.SeaQuestor.com On Wed, Apr 30, 2025 at 12:43?AM Alan James via Personal_Submersibles < personal_submersibles at psubs.org> wrote: > You could make clothing out of that Faraday fabric and make a million > selling it to our life cal Green community. > Alan > > Yahoo Mail: Search, organise, conquer > > > On Wed, 30 Apr 2025 at 1:04 pm, Cliff Redus via Personal_Submersibles > wrote: > _______________________________________________ > Personal_Submersibles mailing list > Personal_Submersibles at psubs.org > http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles > > _______________________________________________ > Personal_Submersibles mailing list > Personal_Submersibles at psubs.org > http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles > -------------- next part -------------- An HTML attachment was scrubbed... URL: From personal_submersibles at psubs.org Sun May 4 18:40:41 2025 From: personal_submersibles at psubs.org (Jon Wallace via Personal_Submersibles) Date: Sun, 4 May 2025 22:40:41 +0000 (UTC) Subject: [PSUBS-MAILIST] OTS and motor controller noise In-Reply-To: References: <776295123.2677993.1745856998926@mail.yahoo.com> <0F27FF3D-8274-4669-AB02-7D6AEE2F992B@yahoo.ca> <437686673.2728200.1745863199285@mail.yahoo.com> <8yHXkUBz7NWnskcymYb_3H_SCoy7at1QCjYXCclQ-0x2voN9BJsQoBlrZMgombU6K-vrh5m7_NzFGyhlmlb7aktNtmwsxCdg2t61dK5D_v0=@protonmail.com> <1478069852.3301778.1745959583330@mail.yahoo.com> <1068508737.3379385.1745974933686@mail.yahoo.com> <1221880498.3451853.1745998986968@mail.yahoo.com> Message-ID: <453019734.1266118.1746398441501@mail.yahoo.com> Thanks David.? It sounds like your tests confirm what others have said about using these units on their own internal batteries.? If you connect your STX-101 to an external battery with about 5-6 feet of wire you'll likely experience much worse results that match my experience.? One question about your controllers, were you testing with the minn-kota or Roboteq? Using squelch with internal batteries is likely a good option for some of the channels.? With external batteries I could also attenuate the noise by using squelch but only with the setting at 100%.? The problem with using too much squelch is that it attenuates the incoming comms signal as well as the noise thereby diminishing the effective range of communications.? If the incoming signal from the transducer isn't strong enough to override squelch, you're not going to hear it. The best solutions available to us are likely a combination of internal batteries, squelch, faraday cages, and filters.? If you can isolate your OTS into one of your VBT voids you are going to have a pretty good built-in faraday cage for it.? If you do end up connecting to an external battery, armored cables or metal conduit should help protect the wiring from EMI.? You have another advantage in that your Roboteq controllers are fully encased in a metal container and should vastly help contain EMI compared to my existing controllers which have a plastic cover. Filtering is something I am investigating.? I believe we would benefit from an LC filter, and better yet a Pi LC filter.? I've got parts on order to fabricate one with a cutoff frequency of 1.5khz and am looking forward to testing it however I won't be able to do any more work on this OTS issue until the end of the month due to other commitments.? If somebody is inclined in the meantime, Amazon sells automotive noise filters for radios that may (or may not) work for our purposes.? They are cheap at $10-12 and readily available however I haven't found any that specify the cutoff frequency so it's a crap shoot as to whether they would suffice.? However, automotive noise is typically in the same range (8-20khz) so I think it would be a valid test. This one has the best reviews I could find:https://www.amazon.com/Pipemans-Installation-Solution-Suppressor-Eliminator/dp/B07HZ4RSS7/ Jon On Sunday, May 4, 2025 at 05:21:33 PM EDT, David Colombo via Personal_Submersibles wrote: Hi Jon, I've run some preliminary tests and the results are interesting. I'm going to rerun and try to document in better detail and frequencies. Here's my observations. To save me typing Topside unit =TS and Diver unit= DU. Ran the tests with the TU both sitting on my external fiberglass deck with the Transducer from the TU placed adjacent to my builtin transducer located externally at the rear of the hatch. Both Transducer cables are mfg full 25' cables with no cuts. Both TU and DU are on their own battery power. The DU is located on the starboard side, held with magnets onto the original VBT tank. Both Port and Starboard VBT have been cut open with a 16"x14" opening. Inside each of the VBT are located one PWM from MinnKota wired to the cutoff selector switch and then to the LiPo4 36v battery bank. Currently I have both the Minnkota speed selector switches adjacent to each other so they can lay over my knee to run the test. The DU is attached to my headset with channel set to 1, transmit: PUT, squelch on.? The TU was sitting on my feet inside the sub, speaker on, and I set the TU to the same settings except the squelch was set to off on the rotation dial. The TU is about 30" from either PWM.? With this setup I can hear my DU headset and the TU speaker at the same time.Test 1 with my DU only. Run each of the 4 channels through a series of starting out with one thruster and slowly running the speed scale in forward and then in reverse.Test 2 same test with both thrusters on and running the speed scale.? Test 3 and 4 same test with the TU onlyTest 5 run both thrusters and both TU and DU.Note the DU is sitting closer to the PWM than the TU. TU is in its TU ABS case, with no additional shielding The thruster control cables are the mfg cables and I believe there is no shielding. Before I ran tests 1-5, I did a 6th test with? the transducer of the TU into the sub and placed it near the PWM units, and then again adjacent to the thruster speed control wires. In Test 6,I found? considerable frequency oscillation adjacent to the speed cable and less at the PWM units ( the PW units are incased in the mfg aluminum finned sealed case) all for channels (squelch off) I used this as a comparative baseline against the DU to see if Transducer proximity to the PWM made a difference and Initially I believe it does. So here are my observations:Test 1 & 2 DU: sometimes on start-up of a thruster I might get a short squelch burst and then no thruster noise for the rest of the speed scale. I believe that the DU which only has squelch on or off, is automatically compensating on all 4 channels, hence the reason I'm not getting any speed controller noise. No difference between test 1 & 2 Test 3 &4 TU: on all four channels with squelch off, there is a high frequency tone,? each different on the 4 channels and when on test 4 with both thrusters double the db of the frequency tone. No difference if I ran one thruster forwards and one in reverse at the same time. Here is the interesting part: on each of the 4 channels there is a point on the squelch dial where you can eliminate the tone. approximately 25% on channel 1, 50 % on channel 2, 75% channel 3 and 100% on channel 4.? So if I am using channel 1, preset the squelch to 25%?+/- and you're good to go, same with the other channels. The other interesting thing is the proximity of the TU? to the PWM. Outside the hull and about 3ft away from the PWM the intensity of the Tonal variation is substantially less, which might imply that additional shielding around the electronics of the TU could improve the reduction of the tonal frequencies.?As I am planning to place the TU in the sub into one of the VBT with 1/2" thick steel on three sides, I'm hoping that will be enough shielding, only time will tell. Also I'm going to add some additional shielding on the thruster speed control wires? based upon the test results of test 6.When I rerun the test, I will data log the frequency of each channel and try to calibrate the squelch position for the TU.Any thoughts on how best to filter out frequency noise besides the squelch?? Anyway these are my current observations and I hope they give some insight into how to solve your problem. Best Regards, David Colombo 804 College Ave Santa Rosa, CA. 95404 (707) 536-1424 www.SeaQuestor.com -------------- next part -------------- An HTML attachment was scrubbed... URL: From personal_submersibles at psubs.org Fri May 9 01:45:32 2025 From: personal_submersibles at psubs.org (Alan James via Personal_Submersibles) Date: Fri, 9 May 2025 05:45:32 +0000 (UTC) Subject: [PSUBS-MAILIST] OTS and motor controller noise In-Reply-To: <453019734.1266118.1746398441501@mail.yahoo.com> References: <776295123.2677993.1745856998926@mail.yahoo.com> <0F27FF3D-8274-4669-AB02-7D6AEE2F992B@yahoo.ca> <437686673.2728200.1745863199285@mail.yahoo.com> <8yHXkUBz7NWnskcymYb_3H_SCoy7at1QCjYXCclQ-0x2voN9BJsQoBlrZMgombU6K-vrh5m7_NzFGyhlmlb7aktNtmwsxCdg2t61dK5D_v0=@protonmail.com> <1478069852.3301778.1745959583330@mail.yahoo.com> <1068508737.3379385.1745974933686@mail.yahoo.com> <1221880498.3451853.1745998986968@mail.yahoo.com> <453019734.1266118.1746398441501@mail.yahoo.com> Message-ID: <592289637.3290134.1746769532214@mail.yahoo.com> Hi Psubbers, I downloaded Chat GPT AI search engine today to find a suitable voltage regulator & motor controller for a servo steering unit I made up. AMAZING, it came back with some options within the parameters I had defined; input more than 50V, H bridge reversing, Arduino compatible, output 12V and minimum of 10 Amps. So I thought I'd give it a go with our electrical noise problem, and this is what it came up with in super quick time. Electrical noise from a PWM motor controller is a common issue, especially in confined or electrically dense environments like a submarine, where RF interference and ground loops can seriously affect sensitive communication systems. Here?s a structured approach to mitigate the noise: --- 1. Shielding and Grounding Use shielded cables for both motor power and signal lines. Connect the shield to chassis ground at one end only to avoid ground loops. Ensure proper grounding: All systems should share a common ground reference point to avoid differential voltages that induce noise. Physically separate power and communication wiring?run them on opposite sides of the sub if possible. --- 2. Filtering the PWM Output Install ferrite beads or chokes on motor power lines close to the controller to suppress high-frequency noise. Use LC or RC low-pass filters on the motor outputs to smooth the PWM signal and reduce EMI. Consider a snubber circuit on the motor controller output if you're seeing voltage spikes. --- 3. Motor Controller Best Practices Decrease the PWM frequency slightly (if adjustable). High frequencies radiate more but low frequencies can produce audible hum?balance is key. Use soft start/stop settings to reduce large current surges. Keep motor leads short to minimize them acting as antennas. --- 4. Protecting Communication Systems If you're using serial comms (e.g., RS-232, RS-485), switch to differential protocols with optical or galvanic isolation. Add common-mode chokes on communication lines to reject interference. For Ethernet or digital comms, use isolated transceivers and TVS diodes to clamp any spikes. --- 5. Enclosure and Layout Put the motor controller in a metal (Faraday cage-style) enclosure to contain radiated noise. Ensure communication system components are in shielded boxes too, with proper EMI gaskets/seals if necessary. Alan Yahoo Mail: Search, organise, conquer On Mon, 5 May 2025 at 10:42 am, Jon Wallace via Personal_Submersibles wrote: Thanks David.? It sounds like your tests confirm what others have said about using these units on their own internal batteries.? If you connect your STX-101 to an external battery with about 5-6 feet of wire you'll likely experience much worse results that match my experience.? One question about your controllers, were you testing with the minn-kota or Roboteq? Using squelch with internal batteries is likely a good option for some of the channels.? With external batteries I could also attenuate the noise by using squelch but only with the setting at 100%.? The problem with using too much squelch is that it attenuates the incoming comms signal as well as the noise thereby diminishing the effective range of communications.? If the incoming signal from the transducer isn't strong enough to override squelch, you're not going to hear it. The best solutions available to us are likely a combination of internal batteries, squelch, faraday cages, and filters.? If you can isolate your OTS into one of your VBT voids you are going to have a pretty good built-in faraday cage for it.? If you do end up connecting to an external battery, armored cables or metal conduit should help protect the wiring from EMI.? You have another advantage in that your Roboteq controllers are fully encased in a metal container and should vastly help contain EMI compared to my existing controllers which have a plastic cover. Filtering is something I am investigating.? I believe we would benefit from an LC filter, and better yet a Pi LC filter.? I've got parts on order to fabricate one with a cutoff frequency of 1.5khz and am looking forward to testing it however I won't be able to do any more work on this OTS issue until the end of the month due to other commitments.? If somebody is inclined in the meantime, Amazon sells automotive noise filters for radios that may (or may not) work for our purposes.? They are cheap at $10-12 and readily available however I haven't found any that specify the cutoff frequency so it's a crap shoot as to whether they would suffice.? However, automotive noise is typically in the same range (8-20khz) so I think it would be a valid test. This one has the best reviews I could find:https://www.amazon.com/Pipemans-Installation-Solution-Suppressor-Eliminator/dp/B07HZ4RSS7/ Jon On Sunday, May 4, 2025 at 05:21:33 PM EDT, David Colombo via Personal_Submersibles wrote: Hi Jon, I've run some preliminary tests and the results are interesting. I'm going to rerun and try to document in better detail and frequencies. Here's my observations. To save me typing Topside unit =TS and Diver unit= DU. Ran the tests with the TU both sitting on my external fiberglass deck with the Transducer from the TU placed adjacent to my builtin transducer located externally at the rear of the hatch. Both Transducer cables are mfg full 25' cables with no cuts. Both TU and DU are on their own battery power. The DU is located on the starboard side, held with magnets onto the original VBT tank. Both Port and Starboard VBT have been cut open with a 16"x14" opening. Inside each of the VBT are located one PWM from MinnKota wired to the cutoff selector switch and then to the LiPo4 36v battery bank. Currently I have both the Minnkota speed selector switches adjacent to each other so they can lay over my knee to run the test. The DU is attached to my headset with channel set to 1, transmit: PUT, squelch on.? The TU was sitting on my feet inside the sub, speaker on, and I set the TU to the same settings except the squelch was set to off on the rotation dial. The TU is about 30" from either PWM.? With this setup I can hear my DU headset and the TU speaker at the same time.Test 1 with my DU only. Run each of the 4 channels through a series of starting out with one thruster and slowly running the speed scale in forward and then in reverse.Test 2 same test with both thrusters on and running the speed scale.? Test 3 and 4 same test with the TU onlyTest 5 run both thrusters and both TU and DU.Note the DU is sitting closer to the PWM than the TU. TU is in its TU ABS case, with no additional shielding The thruster control cables are the mfg cables and I believe there is no shielding. Before I ran tests 1-5, I did a 6th test with? the transducer of the TU into the sub and placed it near the PWM units, and then again adjacent to the thruster speed control wires. In Test 6,I found? considerable frequency oscillation adjacent to the speed cable and less at the PWM units ( the PW units are incased in the mfg aluminum finned sealed case) all for channels (squelch off) I used this as a comparative baseline against the DU to see if Transducer proximity to the PWM made a difference and Initially I believe it does. So here are my observations:Test 1 & 2 DU: sometimes on start-up of a thruster I might get a short squelch burst and then no thruster noise for the rest of the speed scale. I believe that the DU which only has squelch on or off, is automatically compensating on all 4 channels, hence the reason I'm not getting any speed controller noise. No difference between test 1 & 2 Test 3 &4 TU: on all four channels with squelch off, there is a high frequency tone,? each different on the 4 channels and when on test 4 with both thrusters double the db of the frequency tone. No difference if I ran one thruster forwards and one in reverse at the same time. Here is the interesting part: on each of the 4 channels there is a point on the squelch dial where you can eliminate the tone. approximately 25% on channel 1, 50 % on channel 2, 75% channel 3 and 100% on channel 4.? So if I am using channel 1, preset the squelch to 25%?+/- and you're good to go, same with the other channels. The other interesting thing is the proximity of the TU? to the PWM. Outside the hull and about 3ft away from the PWM the intensity of the Tonal variation is substantially less, which might imply that additional shielding around the electronics of the TU could improve the reduction of the tonal frequencies.?As I am planning to place the TU in the sub into one of the VBT with 1/2" thick steel on three sides, I'm hoping that will be enough shielding, only time will tell. Also I'm going to add some additional shielding on the thruster speed control wires? based upon the test results of test 6.When I rerun the test, I will data log the frequency of each channel and try to calibrate the squelch position for the TU.Any thoughts on how best to filter out frequency noise besides the squelch?? Anyway these are my current observations and I hope they give some insight into how to solve your problem. Best Regards, David Colombo 804 College Ave Santa Rosa, CA. 95404 (707) 536-1424 www.SeaQuestor.com _______________________________________________ Personal_Submersibles mailing list Personal_Submersibles at psubs.org http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles -------------- next part -------------- An HTML attachment was scrubbed... URL: From personal_submersibles at psubs.org Fri May 16 09:23:15 2025 From: personal_submersibles at psubs.org (Douglas Suhr via Personal_Submersibles) Date: Fri, 16 May 2025 09:23:15 -0400 Subject: [PSUBS-MAILIST] Doug Suhr Obituary Message-ID: For those who may not have heard, my dad, Doug Suhr, passed away this monday, May 12th. Here is his obituary: https://www.morrisonhome.com/obituaries/Douglas-H-Suhr?obId=42532345#/obituaryInfo Mom and I are devastated, but we will carry on! ~ Douglas Suhr -------------- next part -------------- An HTML attachment was scrubbed... URL: From personal_submersibles at psubs.org Fri May 16 10:08:56 2025 From: personal_submersibles at psubs.org (Greg via Personal_Submersibles) Date: Fri, 16 May 2025 09:08:56 -0500 Subject: [PSUBS-MAILIST] Doug Suhr Obituary In-Reply-To: References: Message-ID: <98891E68-D466-4073-B310-0C853947B441@edison.tech> So sorry to hear that! His presence here will be missed! Please extend our deepest sympathies to your mother and family! Best personal regards, Greg Snyder > > On May 16, 2025 at 8:25 AM, wrote: > > > > For those who may not have heard, my dad, Doug Suhr, passed away this monday, May 12th. Here is his obituary: > > > https://www.morrisonhome.com/obituaries/Douglas-H-Suhr?obId=42532345#/obituaryInfo > > > > Mom and I are devastated, but we will carry on! ~ Douglas Suhr > > _______________________________________________ Personal_Submersibles mailing list Personal_Submersibles at psubs.org http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles > -------------- next part -------------- An HTML attachment was scrubbed... URL: From personal_submersibles at psubs.org Fri May 16 12:03:28 2025 From: personal_submersibles at psubs.org (Tim Novak via Personal_Submersibles) Date: Fri, 16 May 2025 09:03:28 -0700 Subject: [PSUBS-MAILIST] Doug Suhr Obituary In-Reply-To: <98891E68-D466-4073-B310-0C853947B441@edison.tech> References: <98891E68-D466-4073-B310-0C853947B441@edison.tech> Message-ID: Very sad to hear of this, Doug. Take care of your family. You have our deepest sympathies. Tim On Fri, May 16, 2025 at 7:09?AM Greg via Personal_Submersibles < personal_submersibles at psubs.org> wrote: > So sorry to hear that! > His presence here will be missed! > Please extend our deepest sympathies to your mother and family! > Best personal regards, > Greg Snyder > > > > On May 16, 2025 at 8:25 AM, > wrote: > > For those who may not have heard, my dad, Doug Suhr, passed away this > monday, May 12th. Here is his obituary: > > > https://www.morrisonhome.com/obituaries/Douglas-H-Suhr?obId=42532345#/obituaryInfo > > Mom and I are devastated, but we will carry on! ~ Douglas Suhr > _______________________________________________ Personal_Submersibles > mailing list Personal_Submersibles at psubs.org > http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles > > _______________________________________________ > Personal_Submersibles mailing list > Personal_Submersibles at psubs.org > http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles > -------------- next part -------------- An HTML attachment was scrubbed... URL: From personal_submersibles at psubs.org Fri May 16 23:02:58 2025 From: personal_submersibles at psubs.org (Alan James via Personal_Submersibles) Date: Sat, 17 May 2025 03:02:58 +0000 (UTC) Subject: [PSUBS-MAILIST] Doug Suhr Obituary In-Reply-To: References: Message-ID: <2016730524.1571785.1747450978959@mail.yahoo.com> Doug,I heard this on fb & it was very sad news.Your Dad was about a year younger than me,and the same age that my Dad passed on.Too young.He was an incredible host to Psubs at the Islamorada Psubs convention.?I remember him giving us free access to his beer fridge, crayfish snacks, meals & sub towing. A really generous guy.Keep in contact & look after your Mum.Regards Alan Yahoo Mail: Search, organise, conquer On Sat, 17 May 2025 at 2:38 pm, Douglas Suhr via Personal_Submersibles wrote: For those who may not have heard, my dad, Doug Suhr, passed away this monday, May 12th. Here is his obituary: https://www.morrisonhome.com/obituaries/Douglas-H-Suhr?obId=42532345#/obituaryInfo Mom and I are devastated, but we will carry on! ~ Douglas Suhr?_______________________________________________ Personal_Submersibles mailing list Personal_Submersibles at psubs.org http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles -------------- next part -------------- An HTML attachment was scrubbed... URL: From personal_submersibles at psubs.org Tue May 20 13:43:23 2025 From: personal_submersibles at psubs.org (Rick Patton via Personal_Submersibles) Date: Tue, 20 May 2025 07:43:23 -1000 Subject: [PSUBS-MAILIST] Fwd: MY SUBMARINE IS MY CASTLE (HOME)! In-Reply-To: References: Message-ID: FYI. Wonder what depth she is rated for? ---------- Forwarded message --------- From: Bill Frizell Date: Tue, May 20, 2025 at 3:31?AM Subject: MY SUBMARINE IS MY CASTLE (HOME)! To: Rick Patton *Hey ADM Nemo, here is an idea for you just in case....Fuzzy* [image: 9fec8c36-3a3d-4580-8d55-2c57aceb1867.png] 22 Year Old Woman Couldn?t Afford Rent?So She Moved Into An Old Submarine - https://www.tips-and-tricks.co/home-and-garden/subhome/?utm_campaign=ikqbh0ld&utm_source=Taboola&utm_medium=native&utm_term=mainlinemedia-leadpatriot&utm_content=2mFdqkI52XeFXLqm1Tj2x35Ic0MzypJG-Q0R6mVeScE=&tclid=GiBDEitIn-kjdN5OEwKpT1JHv68Mh5hF_1wQFv-CKn2XmSCzhlIo-sq5zOnYk9mTATDzuWI -------------- next part -------------- An HTML attachment was scrubbed... URL: -------------- next part -------------- A non-text attachment was scrubbed... Name: 9fec8c36-3a3d-4580-8d55-2c57aceb1867.png Type: image/png Size: 566025 bytes Desc: not available URL: From personal_submersibles at psubs.org Tue May 20 15:10:42 2025 From: personal_submersibles at psubs.org (J. Foulkes via Personal_Submersibles) Date: Tue, 20 May 2025 15:10:42 -0400 Subject: [PSUBS-MAILIST] Fwd: MY SUBMARINE IS MY CASTLE (HOME)! In-Reply-To: References: Message-ID: As this is a lifeboat capsule and designed for SOLAS type compliance, probably 150m. On Tue, May 20, 2025 at 1:44?PM Rick Patton via Personal_Submersibles < personal_submersibles at psubs.org> wrote: > FYI. Wonder what depth she is rated for? > > ---------- Forwarded message --------- > From: Bill Frizell > Date: Tue, May 20, 2025 at 3:31?AM > Subject: MY SUBMARINE IS MY CASTLE (HOME)! > To: Rick Patton > > > *Hey ADM Nemo, here is an idea for you just in case....Fuzzy* > > [image: 9fec8c36-3a3d-4580-8d55-2c57aceb1867.png] > > 22 Year Old Woman Couldn?t Afford Rent?So She Moved Into An Old Submarine - > > > https://www.tips-and-tricks.co/home-and-garden/subhome/?utm_campaign=ikqbh0ld&utm_source=Taboola&utm_medium=native&utm_term=mainlinemedia-leadpatriot&utm_content=2mFdqkI52XeFXLqm1Tj2x35Ic0MzypJG-Q0R6mVeScE=&tclid=GiBDEitIn-kjdN5OEwKpT1JHv68Mh5hF_1wQFv-CKn2XmSCzhlIo-sq5zOnYk9mTATDzuWI > > _______________________________________________ > Personal_Submersibles mailing list > Personal_Submersibles at psubs.org > http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles > -------------- next part -------------- An HTML attachment was scrubbed... URL: -------------- next part -------------- A non-text attachment was scrubbed... Name: 9fec8c36-3a3d-4580-8d55-2c57aceb1867.png Type: image/png Size: 566025 bytes Desc: not available URL: From personal_submersibles at psubs.org Fri May 23 15:22:30 2025 From: personal_submersibles at psubs.org (Rick Patton via Personal_Submersibles) Date: Fri, 23 May 2025 09:22:30 -1000 Subject: [PSUBS-MAILIST] CO2 Message-ID: Someone posted a while ago that they sat or layed in their sub until the PPM got dangerous. Can't remember who that was? Wanted to get more information from them if possible. Thanks Rick -------------- next part -------------- An HTML attachment was scrubbed... URL: From personal_submersibles at psubs.org Wed May 28 17:23:04 2025 From: personal_submersibles at psubs.org (Rick Patton via Personal_Submersibles) Date: Wed, 28 May 2025 11:23:04 -1000 Subject: [PSUBS-MAILIST] CO2 In-Reply-To: References: Message-ID: Does anyone remember who sat in their sub with the hatch closed to see how long they could stay before the Co2 PPM became dangerous? Rick On Fri, May 23, 2025 at 9:22?AM Rick Patton wrote: > Someone posted a while ago that they sat or layed in their sub until the > PPM got dangerous. > Can't remember who that was? Wanted to get more information from them if > possible. > Thanks > > Rick > > -------------- next part -------------- An HTML attachment was scrubbed... URL: From personal_submersibles at psubs.org Wed May 28 19:08:21 2025 From: personal_submersibles at psubs.org (via Personal_Submersibles) Date: Thu, 29 May 2025 01:08:21 +0200 (CEST) Subject: [PSUBS-MAILIST] CO2 In-Reply-To: References: Message-ID: <1748473701776.78607.577f200a7e9a1982c95d2454d55b4b6c8e3469be@spica.telekom.de> I did such test some 40 years ago in the one man sub Sgt.Peppers in prone postion. It was about 400 Liter internal volume and 40 minutes before the headackse get to biolent.Vbr Carsten Gesendet mit der Telekom Mail App -- Original-Nachricht -- Von: Rick Patton via Personal_Submersibles < personal_submersibles at psubs.org > Betreff: Re: [PSUBS-MAILIST] CO2 Datum: 28.05.2025, 23:24 Uhr An: psubs chat room > Does anyone remember who sat in their sub with the hatch closed to see how long they could stay before the Co2 PPM became dangerous? Rick On Fri, May 23, 2025 at 9:22?AM Rick Patton > wrote: Someone posted a while ago that they sat or layed in their sub until the PPM got dangerous. Can't remember who that was? Wanted to get more information from them if possible. Thanks Rick -------------- next part -------------- An HTML attachment was scrubbed... URL: -------------- next part -------------- _______________________________________________ Personal_Submersibles mailing list Personal_Submersibles at psubs.org http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles From personal_submersibles at psubs.org Wed May 28 19:17:33 2025 From: personal_submersibles at psubs.org (Cliff Redus via Personal_Submersibles) Date: Wed, 28 May 2025 23:17:33 +0000 (UTC) Subject: [PSUBS-MAILIST] CO2 In-Reply-To: References: Message-ID: <1275795567.2487601.1748474253639@mail.yahoo.com> Rick, I did quite a bit of testing of the Life Support system on the R300.? During one test sequence, I sat in the R300 with the Scrubber turned off to see how long it would take to trigger 5000 ppm alarm.? It was 8 minutes.? Then, after turning the scrubber back on, it took 9 minutes for the CO2 level to drop back to 1500 ppm.? ?I would be glad to send you a copy of the report documenting the life support system testing over the years.? Send me your email offline to cliffordredus at sbcglobal.net. Best On Wednesday, May 28, 2025 at 04:23:58 PM CDT, Rick Patton via Personal_Submersibles wrote: Does anyone remember who sat in their?sub with the hatch closed to see how long they could stay before the Co2? PPM became dangerous? Rick On Fri, May 23, 2025 at 9:22?AM Rick Patton wrote: Someone posted a while?ago that they sat or layed in their sub until the PPM got dangerous.Can't remember who that was? Wanted to get more information from them if possible.Thanks Rick _______________________________________________ Personal_Submersibles mailing list Personal_Submersibles at psubs.org http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles -------------- next part -------------- An HTML attachment was scrubbed... URL: From personal_submersibles at psubs.org Wed May 28 22:50:16 2025 From: personal_submersibles at psubs.org (Alan James via Personal_Submersibles) Date: Thu, 29 May 2025 02:50:16 +0000 (UTC) Subject: [PSUBS-MAILIST] CO2 In-Reply-To: References: Message-ID: <1407897747.2546412.1748487016390@mail.yahoo.com> Hi Rick, no I don't remember but, there would be differing levels of danger. If you calculated the internal volume of your sub we could work it out for you. It's a lot easier to do this with the metric system. If you have the subs? cylindrical sections? diameter & length, & the diameter & depth? of the sperical sections, we can work out the area. Then subtract the estimated area of anything inside the sub. And finally estimate your volume by your weight & subtract that to give the volume of air. Then based on the CO2 output for the standard man ( In the book Manned Submersibles) we could produce some scenarios. Cheers Alan Yahoo Mail: Search, organise, conquer On Thu, 29 May 2025 at 2:30 pm, Rick Patton via Personal_Submersibles wrote: _______________________________________________ Personal_Submersibles mailing list Personal_Submersibles at psubs.org http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles -------------- next part -------------- An HTML attachment was scrubbed... URL: From personal_submersibles at psubs.org Thu May 29 08:48:53 2025 From: personal_submersibles at psubs.org (Jon Wallace via Personal_Submersibles) Date: Thu, 29 May 2025 12:48:53 +0000 (UTC) Subject: [PSUBS-MAILIST] CO2 In-Reply-To: References: Message-ID: <1902061324.2660618.1748522933384@mail.yahoo.com> Rick, Besides others, Steve McQueen ran that scenario in his K250 and reported on it at PC2021 in Orlando.? In a sealed hatch test without O2 or scrubber, he reached 5000ppm in 14 minutes and 10000ppm in 30 minutes.? The O2 had depleted to 19.5% at 34 minutes. You have slightly more volume in your K350 but should find similar results.? In the old days (before these measured tests) we used to say you could stay underwater in a K350 for about 30 minutes before surfacing to refresh the air inside, which seems to be confirmed by Steve's tests.? Important to understand that Steve's test represents one person, at rest with no stress.? Adding a passenger, moving around, and/or stressful situations will increase your breathing rate and reduce time to max/min levels.?? Jon On Wednesday, May 28, 2025 at 10:30:52 PM EDT, Rick Patton via Personal_Submersibles wrote: Does anyone remember who sat in their?sub with the hatch closed to see how long they could stay before the Co2? PPM became dangerous? Rick On Fri, May 23, 2025 at 9:22?AM Rick Patton wrote: Someone posted a while?ago that they sat or layed in their sub until the PPM got dangerous.Can't remember who that was? Wanted to get more information from them if possible.Thanks Rick _______________________________________________ Personal_Submersibles mailing list Personal_Submersibles at psubs.org http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles -------------- next part -------------- An HTML attachment was scrubbed... URL: From personal_submersibles at psubs.org Fri May 30 22:55:45 2025 From: personal_submersibles at psubs.org (Rick Patton via Personal_Submersibles) Date: Fri, 30 May 2025 16:55:45 -1000 Subject: [PSUBS-MAILIST] CO2 In-Reply-To: <1902061324.2660618.1748522933384@mail.yahoo.com> References: <1902061324.2660618.1748522933384@mail.yahoo.com> Message-ID: Thanks guys. The reason I asked is that my Co2 meter climbed up to a little over 4,000 Quicker than I thought it should but from what you have said, this seems normal. I was starting to wonder if my new Co2 meter was wrong. What I can't understand is that it climbed fast while laying down but when I sat upright, the meter walked slowly down to 1,000.?? Rick On Thu, May 29, 2025 at 2:51?AM Jon Wallace via Personal_Submersibles < personal_submersibles at psubs.org> wrote: > Rick, > > Besides others, Steve McQueen ran that scenario in his K250 and reported > on it at PC2021 in Orlando. In a sealed hatch test without O2 or scrubber, > he reached 5000ppm in 14 minutes and 10000ppm in 30 minutes. The O2 had > depleted to 19.5% at 34 minutes. > > You have slightly more volume in your K350 but should find similar > results. In the old days (before these measured tests) we used to say you > could stay underwater in a K350 for about 30 minutes before surfacing to > refresh the air inside, which seems to be confirmed by Steve's tests. > Important to understand that Steve's test represents one person, at rest > with no stress. Adding a passenger, moving around, and/or stressful > situations will increase your breathing rate and reduce time to max/min > levels. > > Jon > > > > On Wednesday, May 28, 2025 at 10:30:52 PM EDT, Rick Patton via > Personal_Submersibles wrote: > > > Does anyone remember who sat in their sub with the hatch closed to see how > long they could stay before the Co2 PPM became dangerous? > > Rick > > On Fri, May 23, 2025 at 9:22?AM Rick Patton wrote: > > Someone posted a while ago that they sat or layed in their sub until the > PPM got dangerous. > Can't remember who that was? Wanted to get more information from them if > possible. > Thanks > > Rick > > _______________________________________________ > Personal_Submersibles mailing list > Personal_Submersibles at psubs.org > http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles > _______________________________________________ > Personal_Submersibles mailing list > Personal_Submersibles at psubs.org > http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles > -------------- next part -------------- An HTML attachment was scrubbed... URL: From personal_submersibles at psubs.org Fri May 30 23:45:58 2025 From: personal_submersibles at psubs.org (irox via Personal_Submersibles) Date: Sat, 31 May 2025 03:45:58 +0000 Subject: [PSUBS-MAILIST] CO2 Message-ID: One consideration. CO2 is heavier than Nitrogen, so it may sink to the floor, if the meter is near the floor the reading may not be representative of the actual cabin CO2 level. Also if the meter is somewhere than CO2 can 'pool' around it reading may be higher. Moving around will also help mix up gases which may help give a more accurate CO2 reading. -------------- next part -------------- An HTML attachment was scrubbed... URL: From personal_submersibles at psubs.org Sat May 31 00:27:19 2025 From: personal_submersibles at psubs.org (Sean T. Stevenson via Personal_Submersibles) Date: Sat, 31 May 2025 04:27:19 +0000 Subject: [PSUBS-MAILIST] CO2 In-Reply-To: References: Message-ID: Per the ABS RULES FOR BUILDING AND CLASSING UNDERWATER VEHICLES, SYSTEMS AND HYPERBARIC FACILITIES (2024): Section 8 Life Support and Environmental Control Systems 8.5 Design Principles 8.5.5 Standard Person (2013) Carbon Dioxide (CO2) Produced: 0.0523 (0.115) kg (lbs) per hour at 1 atm. Sean -------- Original Message -------- On 2025-05-30 20:46, irox via Personal_Submersibles wrote: > One consideration. CO2 is heavier than Nitrogen, so it may sink to the floor, if the meter is near the floor the reading may not be representative of the actual cabin CO2 level. Also if the meter is somewhere than CO2 can 'pool' around it reading may be higher. > > Moving around will also help mix up gases which may help give a more accurate CO2 reading. -------------- next part -------------- An HTML attachment was scrubbed... URL: From personal_submersibles at psubs.org Sat May 31 11:00:21 2025 From: personal_submersibles at psubs.org (Jon Wallace via Personal_Submersibles) Date: Sat, 31 May 2025 15:00:21 +0000 (UTC) Subject: [PSUBS-MAILIST] CO2 In-Reply-To: References: Message-ID: <1898236432.3451103.1748703621260@mail.yahoo.com> Rick, If you haven't already I would install some fans to help circulate the air.? I have two 4inch computer fans, one fore, one aft, that work pretty good for this purpose and they draw negligible power. Jon On Friday, May 30, 2025 at 11:47:24 PM EDT, irox via Personal_Submersibles wrote: One consideration. CO2 is heavier than Nitrogen, so it may sink to the floor, if the meter is near the floor the reading may not be representative of the actual cabin CO2 level. Also if the meter is somewhere than CO2 can 'pool' around it reading may be higher. ? Moving around will also help mix up gases which may help give a more accurate CO2 reading. _______________________________________________ Personal_Submersibles mailing list Personal_Submersibles at psubs.org http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles -------------- next part -------------- An HTML attachment was scrubbed... URL: From personal_submersibles at psubs.org Sat May 31 11:11:29 2025 From: personal_submersibles at psubs.org (Jon Wallace via Personal_Submersibles) Date: Sat, 31 May 2025 15:11:29 +0000 (UTC) Subject: [PSUBS-MAILIST] CO2 In-Reply-To: References: Message-ID: <11643796.3454108.1748704289349@mail.yahoo.com> Alan will like this, ChatGPT says 0.0523 kg CO2 within 1217 liters (approx volume of K350) converts to 21,891 ppm.? That corresponds closely to the empirical results Steve McQueen got with his K-250. Jon On Saturday, May 31, 2025 at 12:28:47 AM EDT, Sean T. Stevenson via Personal_Submersibles wrote: Per the ABS RULES FOR BUILDING AND CLASSING UNDERWATER VEHICLES, SYSTEMS AND HYPERBARIC FACILITIES (2024): Section 8 Life Support and Environmental Control Systems 8.5 Design Principles 8.5.5 Standard Person (2013) Carbon Dioxide (CO2) Produced: 0.0523 (0.115) kg (lbs) per hour at 1 atm. Sean -------- Original Message -------- On 2025-05-30 20:46, irox via Personal_Submersibles wrote: One consideration. CO2 is heavier than Nitrogen, so it may sink to the floor, if the meter is near the floor the reading may not be representative of the actual cabin CO2 level. Also if the meter is somewhere than CO2 can 'pool' around it reading may be higher. ? Moving around will also help mix up gases which may help give a more accurate CO2 reading. _______________________________________________ Personal_Submersibles mailing list Personal_Submersibles at psubs.org http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles -------------- next part -------------- An HTML attachment was scrubbed... URL: From personal_submersibles at psubs.org Sat May 31 13:42:49 2025 From: personal_submersibles at psubs.org (Rick Patton via Personal_Submersibles) Date: Sat, 31 May 2025 07:42:49 -1000 Subject: [PSUBS-MAILIST] CO2 In-Reply-To: <1898236432.3451103.1748703621260@mail.yahoo.com> References: <1898236432.3451103.1748703621260@mail.yahoo.com> Message-ID: I had the monitor in the middle of the hull so it would give an accurate reading. I know that Co2 is heavy but what confuses me is the fact that it rose so fast when lying down and then started dropping when I sat up?? I have a fan installed in the back for atmosphere circulation while submerged but it is noisier than I would like but really moves the air around but might end up using a computer fan, just concerned that I will get the proper movement of air. Rick On Sat, May 31, 2025 at 5:01?AM Jon Wallace via Personal_Submersibles < personal_submersibles at psubs.org> wrote: > Rick, > > If you haven't already I would install some fans to help circulate the > air. I have two 4inch computer fans, one fore, one aft, that work pretty > good for this purpose and they draw negligible power. > > Jon > > > > On Friday, May 30, 2025 at 11:47:24 PM EDT, irox via Personal_Submersibles > wrote: > > > One consideration. CO2 is heavier than Nitrogen, so it may sink to the > floor, if the meter is near the floor the reading may not be representative > of the actual cabin CO2 level. Also if the meter is somewhere than CO2 can > 'pool' around it reading may be higher. > > > > Moving around will also help mix up gases which may help give a more > accurate CO2 reading. > _______________________________________________ > Personal_Submersibles mailing list > Personal_Submersibles at psubs.org > http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles > _______________________________________________ > Personal_Submersibles mailing list > Personal_Submersibles at psubs.org > http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles > -------------- next part -------------- An HTML attachment was scrubbed... URL: From personal_submersibles at psubs.org Sat May 31 17:12:05 2025 From: personal_submersibles at psubs.org (Alan James via Personal_Submersibles) Date: Sat, 31 May 2025 21:12:05 +0000 (UTC) Subject: [PSUBS-MAILIST] CO2 In-Reply-To: <11643796.3454108.1748704289349@mail.yahoo.com> References: <11643796.3454108.1748704289349@mail.yahoo.com> Message-ID: <1475430295.3543034.1748725926000@mail.yahoo.com> Jon, I get mixed results with chat GPT. I have the paid version & was advised by an expert to select the 03 variant that is a lot slower & more thorough, but requires you to be more specific in your requests. I asked it to design a scrubber for me but the result was pretty disappointing. It is very good at calculations. Some times it comes up with amazing results, other times you need to correct it several times. Alan Yahoo Mail: Search, organise, conquer On Sun, 1 Jun 2025 at 1:12 am, Jon Wallace via Personal_Submersibles wrote: _______________________________________________ Personal_Submersibles mailing list Personal_Submersibles at psubs.org http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles -------------- next part -------------- An HTML attachment was scrubbed... URL: