I finally got to do some touch and go's in my new to me Champ today. I realized real quick I have a significant noise problem in the radio. I am using an Icom A-24 Handheld with a David Clark headset hooked to an outside antenna. I am not connected to any external power just batteries. The plane has no electrics either. The engine is an 85-8 with Slick Mags.
I can hear ok when idleing but get nothing but noise while in cruise in the headset when transmitting and people on the ground said they couldn't make out anything in my transmissions.
What do I do first?
Thanks
Jim in Arkansas
Ignition Noise Problem
Radio Noise
Hi Jim, does your engine have shielded ignition? If not this is most likely where the noise is coming from. Shielded mag leads would be covered with a metal / rubberize cover on the wires and the spark plug and leads have threaded end connectors. Converting the system to a shielded mag harness and plugs can be spendy.
You could try moving the ant. aft away from the engine, toward the tail of the aircraft, you might try another radio and see if it works any better.
PS my Champ has a O-200 with slick mags and shielded harness etc I use a ICOM- A20 and it is clear and transmitts clear, the ant. is located on the RH wing fairing. I do have electrical system, generator, starter & battery the radio is wired to the aircraft electrical system.
You could try moving the ant. aft away from the engine, toward the tail of the aircraft, you might try another radio and see if it works any better.
PS my Champ has a O-200 with slick mags and shielded harness etc I use a ICOM- A20 and it is clear and transmitts clear, the ant. is located on the RH wing fairing. I do have electrical system, generator, starter & battery the radio is wired to the aircraft electrical system.
Last edited by Mnflyer on Sun Feb 04, 2007 21:54, edited 2 times in total.
GB MN.Flyer
Flying a Champ 7DC and a HKS Kitfox III
Flying a Champ 7DC and a HKS Kitfox III
The wires are shielded I think as they have a braided steel covering and the ends have caps that screw on the spark plugs. The kit is a Slick 4521 which came with the harness. THe mags are 4330's It was installed in 1991 and has about 500 hours on it. The plugs are REM40E's so they should be shielded or resistor type. The antenna is a Comant fiberglass type mounted on the top of ther cabin about mid wing. I wonder if the harnesses just get noisy after that many years and need to be replaced.
Thanks
Jim in Arkansas
Thanks
Jim in Arkansas
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kevin mielke
- Posts: 25
- Joined: Thu Mar 23, 2006 23:52
- Location: Wasilla Alaska
You can also try switching mags (left/right/both) while running about 1500 rpm or so and see if the sound changes and may help to isolate the problem if is a particular mag or wire. Trying the handheld antenna as Kevin suggested is also a good idea.
My experience is that you usually have very little engine noise with a shielded harness. I really haven't noticed much difference between using the external antenna or the 'rubber duck' antenna.
Hope this helps.
Mike Berg
My experience is that you usually have very little engine noise with a shielded harness. I really haven't noticed much difference between using the external antenna or the 'rubber duck' antenna.
Hope this helps.
Mike Berg
"If God had intended man to fly He would have given us more money"
Jim:
I have an Icom A6: With the headset connection you need an accesory PTT to transmit. If you use the handheld PTT your transmission will be noise only.
I also have an Icom A23: With the headset connection you do NOT need an accesory PTT, eventhough it will be clearer if you use one.
Also: if I use my Lightspeed ANR headsets, the ANR gets disconnected when I transmit (mainly with the rubber antenna). I have checked with them and their explanation is that the closeness of the origin of the transmission disables the ANR.
One more tip: if you are close to an ILS localizer, my radios pick up a horrible noise with the external antenna, but not with the rubber antenna.
Pablo
My Champ is a 7AC with slick shielded magnetos.
I have an Icom A6: With the headset connection you need an accesory PTT to transmit. If you use the handheld PTT your transmission will be noise only.
I also have an Icom A23: With the headset connection you do NOT need an accesory PTT, eventhough it will be clearer if you use one.
Also: if I use my Lightspeed ANR headsets, the ANR gets disconnected when I transmit (mainly with the rubber antenna). I have checked with them and their explanation is that the closeness of the origin of the transmission disables the ANR.
One more tip: if you are close to an ILS localizer, my radios pick up a horrible noise with the external antenna, but not with the rubber antenna.
Pablo
My Champ is a 7AC with slick shielded magnetos.
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Paul Agaliotis
- Posts: 2589
- Joined: Wed Dec 08, 2004 18:49
- Location: San Martin, California
- Contact:
Sometimes the wiring to the mag switch is the problem. Make sure they are shielded and the shield is grounded at both ends.
My TAC uses non-shielded ignition and the noise is manageable. I use an ICOM portable and fly from the back seat.
Paul
My TAC uses non-shielded ignition and the noise is manageable. I use an ICOM portable and fly from the back seat.
Paul
Mailing Adress : Paul Agaliotis 2060 E. San Martin, San Martin,Calif. 95046
I'll try the PTT button and see if that helps. I think the noise is just cabin noise and not ignition noise. I turned off the mags one at a time and didn't make any difference. It makes sense that when you push the PTT on the handheld it might be making the mike on the handheld hot as well as the headset mike. You guys are the best!
Jim in Arkansas
Jim in Arkansas