transmitting woes

[Johns]

Have a Microair radio. I can recieve great with no static but while transmitting I am barely understandable. It's the same with the engine running or not. My first thought is to check the mike wires but am wondering if anyone has other ideas.

John

[9GT]

Recheck your wiring at the radio. Have you pinged them out to make sure your pins are correctly located in the D-Subs? Its easy to mix one up or reverse the location of the pin in the connector. Double check and make sure you don't have a stray wire strand that is hanging out from the pin and touching another pin. Are you using a dedicated ground wire's or using the aircraft frame? I would stronly discourage the use of airframe as ground. And finally, are you using shielded wires for your headset jacks? If not, re-wire them with shielded. Double check the wiring points on the jacks and make sure all are correct. I screwed my jack wiring up the first time and also had a couple wiring issues in the D-subs (two radios and an audio panel) and had to do some re-wiring but I had absolutely no static or distortions when I got the wiring straightened out. Good luck!

[Johns]

Thanks Dave, will check everything listed. Funny thing though it was working great then started screwing up.

John

[Waiex 49]

Hi John,

I have two MicroAir radios installed in my Waiex and thought I would share my experiences on getting them to work properly.

My plane was built (by another guy) with one MicroAir radio. I got a good deal on a second MicroAir on the used market. With all the busy class C and B airspace where I fly in California having two radios is a good thing. I bought the dual radio harness from MicroAir and hooked everything up. Problem was that when I did my radio tests nothing worked. I'm not an avionics guy so I had to look for help. To my surprise, I found not too many folks want to work on these units as they don't have experience with them, nor do they have the tech manuals or parts.

I contacted the MicroAir factory in Austrailia but they were of no help. They will not work on the older model radios. If you have the newer radios you will find shipping costs to Austrailia and back are not cheap. And they will only work on the radio and will not help with any other issues such as wiring or antennas, etc.

A friend pointed me to MicroAir USA. This is an independent repair station not affiliated with MicroAir, but they specialize in working on MicroAir radios. Their website is www.microairusa.com. The owner is named Rick Lord, a real nice guy.

After talking with Rick, I shipped my entire comm system to him to check out. I sent both radios, the special wire harness, my intercom, headset jacks, etc. Rick tested everything for me. The radios were ok but needed tuning and service bulletin upgrades. The original wiring harness had some wiring mistakes and Rick fixed that for me. MicroAir USA did a great job for me, with a quick turn around time and ar a very reasonable rate. My comm system works great and I am a happy guy.

If you aren't able to resolve your radio problems locally you might want to consider MicroAir USA.

Don Bowen
Viking Waiex N49YX
www.mykiylog.com/donbowen

[Johns]

Thanks for the website Don, good to have a place to turn to!

John

[Jim B]

Don
I agree with your microairusa opinion. Several years ago I used them to repair my radio and they were great to work with. Glad to see they are still in business. I still have my microair radio and transponder installed and very happy with both.
Jim

[peter anson]

The guy at Microair USA sounds like a good person to contact, but there are a couple of things you can check yourself. I have had transmitting problems with my Microair twice. The first time I tracked it down to poor electrical connection in the BNC plug into the antenna. OK, you're receiving so that's not likely to be your problem. The second time it was a faulty PTT switch. The switch was not too hard to track down once I realized I had a problem. Maybe I should have paid more than $1.75 for the switch.
I also had difficulty getting it to work initially and had Microair Aust check the radio which I had bought second hand. It was OK and I tracked the problem to a mistake I had made in the wiring. The thing you'll notice about each of these Microair faults is that they were nothing to do with the radio itself.
The faulty PTT switch caused problems very like the ones you are experiencing, receiving OK but transmissions unintelligible.

Peter
Sonex 894

[builderflyer]

The guy at Microair USA sounds like a good person to contact, but there are a couple of things you can check yourself. The second time it was a faulty PTT switch. The switch was not too hard to track down once I realized I had a problem. Maybe I should have paid more than $1.75 for the switch.

The faulty PTT switch caused problems very like the ones you are experiencing, receiving OK but transmissions unintelligible.

Peter
Sonex 894

Peter makes a good point here..........a PTT switch that is not making good contact will make a mess out of transmissions. About five years ago my PTT switch did just that and I thought I was going to have to replace it but instead I first gave the internal workings a squirt of LPS 1. It's worked perfectly ever since without any additional attention. Worth trying!

Art,,,,,,,,,,,,,,,,,,,,,,Sonex taildragger #95,,,,,,,,,,,,,,,,,,,,,Jab3300 #261

[Johns]

Hey guys, great tips!! Think I'll check the ptt switch cause it was working.

John