View Full Version : Converter ac noise

06-08-2018, 03:40 PM
Hi all
My new apex 26ft trailer converter is generating lots of noise.Just with trailer plugged in at house,It generates noise on my hf receiver in my hamshack.
Today i hooked up oscilloscope and my old ts440 txc in trailer.I monitored ac line on scope and get lots of noise when transmitting.without tx,the noise level in rcvr is s-8.I guess i need some good ac line filters to get rid of this noise.
Has anyone else had this problem?

06-11-2018, 08:55 PM
Welcome aboard. :hisign:

I haven't had any noise issues from the converter. Had one LED light that spewed some junk but it failed in short order. Are you running the rig off coach 12 VDC? I usually run my Kenwood TS570 off either a car battery or an Astron M35 power supply. No noise problems.

I have at one time or another on my ham radio career put ferrite chunks on just about everything.

06-12-2018, 07:44 AM
Doesnt make any difference if i connect directly to battery.this thursday i have a friend coming over with a few emi filters and isolation transformer.will see if they help.

08-01-2018, 09:01 AM
I have a progressive charger/converter that replaced the old liniar supply it's dead quiet I basically use it as my DC supply for the radio when plugged in depending on battery charge somewhere between 13.2 13.8 volts @ 40 amp possible output. Broad voltage range LED's make a lot of noise! I bought some very nice flush mount LED fixtures (5 to 30 volt) they totally wiped out my FM radio, complete desince! I had to remove the switching supplies and run them with a 10 volt regulator.

08-02-2018, 07:17 AM
My converter and battery charger were on the same 110v breaker.I installed another 110v breaker.now when im on the radio,i shutoff 110v breaker,for battery charger.
Noise is almost gone when using external 12v supply for radio.If I connect directly to 12v battery with 110v breaker shutoff the noise charger.At least i have a work around.Of course i can purchase a better battery charger.But im ok for now.
73 all bob

Another Mike
10-29-2018, 02:18 AM
Look at putting a big ferrite core or two on the charger output cable. Won't cost much and might be all you need.

11-20-2018, 06:17 PM
Hi all. Name here is Art and I'm brand spankin' new to the forum so I'm sure I'll do something silly in my learning. I have had major issues with converter noise in a trailer but I was able to solve mine with some basic troubleshooting. The new power converter I put in an old (new to us) trailer turned out to not be FCC Class B certified. The certification means it should not emanate any rf noise, however, mine did. I emailed the manufacturer and asked why it wasn't certified and they pretty much blew me off. I then removed the converter and installed a 40 amp ham radio supply and ran it through a battery isolator. The isolator was necessary as the meter lights and fan would continue to operate as long as there was 12 volts on the output terminals even with the trailer unplugged. The isolator prevented this.

Hope this helps as I know the frustration of the hash from a power converter. Especially when I found my problem, Field Day weekend.

11-21-2018, 03:04 AM
I never did solve my converter 100%.The 110v input for the converter and battery charger were on the same breaker.So i separated them and installed another breaker for the battery charger.when im on the radio i shutoff the breaker for the battery charger.Although this is not a solved problem,it is much better and a work around for me.

12-07-2018, 06:32 PM
Some older switchers were very noisy. My Progressive is very quiet it is however on it's own breaker because I back feed with an inverter and that would have diminishing returns!

12-31-2018, 09:05 AM
The converter that caused me so great a noise level in my 20' TT was a Progressive. Because of that, when I had to replace the converter in my fiver, I stayed away from them. Apparently they have quieted them down which is ideal.

Paul Stewart
01-09-2019, 10:11 AM
When the FCC certifies the unit will not cause interference is it certifying RFI over the air or AC line noise or both?

01-09-2019, 01:31 PM
FCC does not certify any such thing. The manufacturer certifies it, providing documentation from a properly accredited testing lab. Here are some links for info:

Link 1 (https://celectronics.com/training/learning/handout/fcc-class-b-verification.html)

Link 2 (https://compliancetesting.com/fcc-testing-and-verification/?gclid=Cj0KCQiA1NbhBRCBARIsAKOTmUs7wMm9n_sljoNogag luPH-5u9T8Af-ibQ17Q_oRUkOQH1f4vFMUUUaAoRfEALw_wcB)

Link 3 (https://en.wikipedia.org/wiki/FCC_Declaration_of_Conformity)

Paul Stewart
01-10-2019, 12:19 AM
Thank you, very informative.