Radio Noise

[mike.smith]

I have the same issue, except that when I turn off the electronic ignition, the noise almost entirely goes away. I have the shielded p-leads that appear to be grounded at each end, but it's still very bad. I have an ICOM IC-A200 radio mounted just below my mag and electronic ignition switches. I can hear everyone else's transmissions, although the static is horrible. My transmissions are barely audible to others though. I wondered if it's because my plane has the headset jacks mounted just behind my shoulders, so there's 4-6 feet of un-shielded wiring that could be picking up the noise.

I have mine mounted there as well, but I used shielded wire. I've never had any noise get into my headset other than when one of the headset jack washers failed and there was metal to metal contact at the jack. So don't move your jacks just yet.

I bought a Sporty's SP-400 handheld radio to see if that worked any better, and I was amazed to find that the electronic ignition even feeds through into the handheld despite no connection to the plane at all. When I switch the electronic ignition off, the noise goes away in the handheld too. I'm going to try to get shielded wiring for the headset jacks and I'll move them under the panel to reduce the amount of wiring that's exposed to the electronic noise. If that doesn't work I'm not sure what to do short of ripping the entire panel out and starting over from scratch with a new radio and all new wiring to everything.

[WaiexN143NM]

Hi all,
Tom , first i would remake your headset jack harness and use shielded wire. All the other points mentioned good advice, ie p leads grounded one end only, isolation washers on jacks, etc.
i think you will like the results.
Efis throw out alot of RF also. We have a dynon skyview that emits alot. Ian from Xcom radio said that one of the worst is MGL. Not knocking their equipment, many people happy with their products. Just repeating what a radio mfgr told me.
We had the same problem, jacks mounted behind. Had to use shielded wire the second time around.
Dont forget to use shielded wire to the PTT buttons too.
We too tried a handheld in cockpit, lots of RF from the efis.
WaiexN143NM
Michael
Jab 3300

[mike.smith]

Hi all,
Dont forget to use shielded wire to the PTT buttons too.

As far as I know PTT wires are just an open/close "switch" circuit that carry no audio signals (at least that's how mine work) and so there is no need to shield them. Mine are not shielded and I've not had any issues.

[WaiexN143NM]

Hi mike,
Good yours working well. I bought a premade harness from xcom and the PTT wires were shielded. So i just followed what a mfgr. did when redoing the wiring harness on #143. Jacks are in the rollover /trurtledeck bulkhead. Cheers!

WaiexN143NM
Michael

[Titanium Cranium]

Hi all,
Tom , first i would remake your headset jack harness and use shielded wire. All the other points mentioned good advice, ie p leads grounded one end only, isolation washers on jacks, etc.
i think you will like the results.
Efis throw out alot of RF also. We have a dynon skyview that emits alot. Ian from Xcom radio said that one of the worst is MGL. Not knocking their equipment, many people happy with their products. Just repeating what a radio mfgr told me.
We had the same problem, jacks mounted behind. Had to use shielded wire the second time around.
Dont forget to use shielded wire to the PTT buttons too.
We too tried a handheld in cockpit, lots of RF from the efis.
WaiexN143NM
Michael
Jab 3300

I hadn't thought about the EFIS causing any of the noise. I have MGL stratomaster singles, but I'm considering upgrading to a Discovery Lite from MGL, which I would imagine might emit more. Where did you get your shielded wire for your headset jacks, and is there a particular size or brand I should get?

[WaiexN143NM]

Hi tom,
Good luck on eliminating your radio noise. I would think that anything from 16-22 ga wire would be fine. You can get shielded wire from a local electronics store. Our go to store in tucson is elliot electronics. You can also order from spruce, wicks, or b& c products . A good seperate ground also , not to a grounding block where alot of other electrical things are grounded. Let us know how things go.
Other tools to order : strippers, rachet crimpers, d-sub crimpers , remove/install pin tool for d-sub pins, d-sub pins male/female.
WaiexN143NM
Michael