I installed a KID controller on my boat a year ago, everthing worked good last season. This year I replaced my VHF marine radio, during testing I found that on some channels there is intermittent RFI. Even with the squelch set to max I still get intermittent reception, like some one has a mic keyed near by. I get the same thing on a handheld VHF, so that rules out a problem with the new radio or wiring issue to radio. I found that when I shut down the solar input to the controller, the RFI goes away after about 10 seconds in conjunction with a relay clicking inside controller. Nothing should have changed with the solar wiring. I ran short of time but, I want to check case ground to the controller. Am I on the right track, could a poor case ground be the culprit ?
Thanks is advance
Mike
or the new radio has fewer noise suppression circuits. Any chance of swapping the old one back for a test ?
I initially thought the same thing, however I get the same interference with a handheld VHF(that I've used for years). Based on that I think it's safe to assume the problem is not in the new radio.
Quote from: Mragan on May 28, 2019, 12:25:45 PM
I initially thought the same thing, however I get the same interference with a handheld VHF(that I've used for years). Based on that I think it's safe to assume the problem is not in the new radio.
You are saying that in the past your handheld radio did not get any noise from the Kid but now it does ? How far away from the Kid is the handheld radio when it starts to pick up the noise ?
Larry
Both radios, fixed mount and handheld where used at the helm approx. 5 feet away from charge controller. I often use the two radios at the same time, for example fixed mount scans multiple channels and is used for longer distance transmissions and held tuned to single channel for some one that I may talk to frequently at closer range. Again no problems in the past. I'm not sure what could have changed.
Check all your connections . And twist all the wires .
Take a listen through these sound samples of noise
http://www.arrl.org/sounds-of-rfi
Larry
In my experience VHF Ch 68 will pick up RF noise from the Classic if your VHF antenna is within approx. 12-15 ft. I'll get it when by ski boat is parked on the starboard stern side near the controller and is about 12ft from the controller in this position. It has a short 3ft antenna. My main VHF is at the helm and has a 13ft antenna mounted up on the upper railing about midway and maybe 30 ft from the controller at it's base and I have no problem with it. Also walking by the controller with hand-held on Ch 68 with pick it up.
It's most noticeable when Classic is charging.
There are a few ham operators on here and this has been discussed in the past, you might want to search these forums on what was discussed.
You might try running the two PV wires through a common mode ferrite clamp on or tubular core.
This would want to be added as close to the Kid as possible.
Something like this if the inside hole diameter is large enough for both wires to fit through.
https://www.digikey.com/product-detail/en/fair-rite-products-corp/0443164251/1934-1359-ND/8594062
You can also use more than one and even one on the battery plus and minus if you can.
If the hole is big enough, you can wrap both wires around for two (2) turns of both wires instead of just the one. If it's going to work, a single run through the middle with both +/- wires should help some at least.
If the ferrite is plenty big enough, you can run all the battery and PV wires through a single donut.
I kinda like the #31 material myself for wide bandwidth....
https://www.amazon.com/RF-Choke-31500-Ferrite-Material/dp/B00XDACVOM?ref_=fsclp_pl_dp_14
Or, in general....
https://www.amazon.com/slp/ferrite-bead/yfrvazvaeq9v4nz
Thanks for all the pointers every one. I will be able to get back on the boat this weekend, I will poke around and try to gather more specific details.
Resthome , You are correct it is pronounced on channel 68. Also on 16(and that's constantly monitored)
To clarify it is not like a back ground noise heard during normal transmit and receive. It is interpreted by the radios as a transmission when they are at rest , even with squelch set to max(just static).
Thanks again for all the advice!
I don’t recall having a problem with CH16. But I have a Chassic not a Kid so there may be some differences.
boB has good advice. As it is mostly on the PV cables.
I get the same thing with my handheld which is normally on ch.69. There's a Classic 200 in the area but my radio seems to start the noise when I walk by and remain near a Trace c-40 PWM controller.