Buzzing sound with wouxun

[Near miss]

For anyone that does have experience with chinesium radios..

On one private range I get a Wouxun 70Mhz radio to use for safety purposes.

But pushing the PTT or tangent usually causes loud buzzing sound at the recipient.

I have tested that the fault happens without my headset and microphone. Just the radio, Peltor PTT and Peltor headset wires & splitter are enough. The fault can happen on PTT alone, but is nearly impossible to recreate / recreates very rarely. Connecting the rest of the wire makes it very likely to reoccur.

Without the wires or headset connected, the radio works fine by itself.

The problem itself manifests by the wire being very sensitive to pressure under hot mic depending on how the cables and radio are laid out.
Yesterday I had the whole unit on the floor and just bringing a torque wrench nearby the radio antenna with hot mic was enough to cause it to buzz.

If I take the antenna out of the wouxun, it works without problems with the rest of the wire and TX goes through.

I figured it is the antenna but I have another wouxun that has longer antenna that should be also better quality and it behaves the same.

I think the wouxuns maybe have a problem with signal / grounding? Too bad I have not been able to yet test any PMRs on this rather new setup yet since I only own 1 radio myself. In few weeks I will be able to test PMR radio with multiple receivers.

Or maybe the fault is in Peltor wires/devices not being protected enough? I have measured all the wires and PTT to be good to go.

And I regret having to bring problems made in china over here but I ain't going to buy them new radios to solve this problem and this also intrigues me since on their own their radios do work well. Maybe there is another lesson to be learned here.

I was given 2 wouxons to test this problem so if you have any suggestions to test, I am open to it.

 

[Char'ed Cuterie]

Couple things cross my mind here:

- Most U.S. based folks don't have access to 4M/70MHz frequencies. Not a ton of gear over here for that, and as such, makes it a little tricky to recommend alternatives. No idea what the surplus commercial radio market is like over there.

- Headsets, PTTs, and connectors are typically manufactured to work well with a certain range of electrical impedence. In very, very broad strokes, there's military, commercial (Motorola and similar), and Chinese. Broader stroke yet, most professional systems do NOT match impedence well with chinese radios. This issue of impedence matching may not even be your issue, but it certainly can be.

- If the intended use is non-tactical range safety comms, I would just use the radio alone, especially because you mentioned that was a known-good configuration.

- If you need to communicate more often and it's a pain digging this thing out of a pouch all the time, you could just get the highest quality speaker mic that's compatible (and available in Finland) and leave it at that.