2019-01-18, 01:46 AM
(2019-01-11, 08:45 PM)abarrow Wrote: Just an update on this. I just installed a new adjustable 12v to 5v buck converter. I moved it away from the radio equipment as much as possible, and grounded it to the boat's ground foil. I also grounded the metal case for my RPI, and installed a handful of ferrites on anything I could fined that was related to all this. My problem is mostly gone, although I can detect a slight change in VHF sensitivity when the OP system is powered up.
I guess the only other thing I could do would be to install a conventional voltage regulator instead of the buck converter, but it would consume considerably more current. So, for the moment, I'm going with this.
Here's the buck converter that I bought.
https://www.amazon.com/Regulator-DROK-Wa...B00CNXLDCQ
Andy, try a common mode choke. Normal DC/DC converters do not have filters to block switching noise
from the 12 V system. It may help to add capacitors or LC Filters but this is the wrong way.
Because the LC Filter can have influence to the DC/DC switcher. It works perfectly if it is designed by the
switcher developer himself. He has to add caps and Rs to stabilize the control loop.
What you can always do is to add a common mode choke. Two wires wound up to a ferrite/iron powder
ring. Add 10uF ceramic on both ends of the choke. This should reduce the switching noise dramatically.
All the best,
Chris