[PSUBS-MAILIST] OTS and motor controller noise

[Jon Wallace via Personal_Submersibles]

 Hi James,
Very interesting.  You've got the SP-100D2 Buddy Phone, correct?  
Jon


    On Monday, April 28, 2025 at 03:51:14 PM EDT, James Frankland via Personal_Submersibles <personal_submersibles at psubs.org> wrote:  
 
 Hi Jon
I had this exact thing with mine.  I ran it initially with main power from the boat.  But the noise\interference from other things (cant remember what) made it hopeless.  I just did away with plugging it into the main power and used AA batteries in the unit.  
I also did the transducer the same as you.  
Once i switched to the internal standard AA batteries, i have no problems.
Kind Regards
James
On Mon, 28 Apr 2025 at 14:47, Jon Wallace via Personal_Submersibles <personal_submersibles at psubs.org> 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
  
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://www.whoweb.com/pipermail/personal_submersibles/attachments/20250428/c41b9939/attachment.html>