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Test Mic

E

ebackscheider

Active Member
I have installed a 2nd Com (Dynon) and I hear great, but no transmit. TX does light up, and the radio does take the air, my portable shows rx. Is there an easy way to test the mic side? I have a multimeter, no other special equipment.

Not sure if the problem is in the Audio Panel coming out, or going into the 2nd com.
 
If your push-to-talk switch is working (the TX lighting seems to confirm), and your portable shows RX, then my guess would be that something is mis-wired on the microphone jack side.

Here would be my likely list of things to check, with the caveat that I'm no electrical guru:
- Visually check all connections around the jack and make sure that they're all correct and that none of those connections is touching a metal surface
- Use a multimeter to check all connections from the jack to the plug on the audio panel
- Confirm you have the insulator washers on the mic jack. If missing or installed incorrectly, they can cause "dead air" when transmitting
- Make sure only one end of the shielded wire is grounded
 
The Jacks are the same on Com1 vs Com2 in the Audio Panel. I'm not sure the Mic is getting out of the Audio Panel, which is what I'm trying to test. I'm great with the +- 12, but this audio stuff is killing me!




D-Dubya said:
If your push-to-talk switch is working (the TX lighting seems to confirm), and your portable shows RX, then my guess would be that something is mis-wired on the microphone jack side.

Here would be my likely list of things to check, with the caveat that I'm no electrical guru:
- Visually check all connections around the jack and make sure that they're all correct and that none of those connections is touching a metal surface
- Use a multimeter to check all connections from the jack to the plug on the audio panel
- Confirm you have the insulator washers on the mic jack. If missing or installed incorrectly, they can cause "dead air" when transmitting
- Make sure only one end of the shielded wire is grounded
Click to expand...
 
Test steps

Since you mentioned 2nd com I assume #1 still works (?).
1. Look carefully at the audio panel pins. Is the mike wire going to #2 connected to the correct pin?
2. Look at radio #2. Is the mike wire from the audio panel on the ‘mike in’ pin?
These pin numbers are hard to see. Use a magnifying glass, or count pins from the end, to make sure.
Are there any mike jacks that by-pass the audio panel? These are very easy to mis-wire.
Is shielded wire used? (Should be ‘yes’). Look very carefully for a single stray strand of the shield which may be touching the inner wire, or the inner wire crimp connection. These are very hard to see. If you pull the pins you can test for a short with an ohmmeter.
 
ebackscheider said:
The Jacks are the same on Com1 vs Com2 in the Audio Panel. I'm not sure the Mic is getting out of the Audio Panel, which is what I'm trying to test. I'm great with the +- 12, but this audio stuff is killing me!
Click to expand...

To test this, you’ll need a pin-puller. Remove the audio panel connector, pull the mike and PTT pins going to both radios (4 pins). Reinsert the radio1 pins into the #2 holes (swap com1 with com2, ptt1 with ptt2). Reconnect, power up, set audio panel to #2, test transmit. If radio1 transmits audio, the audio panel is working properly.
My best guess is that your #2 mike wire has a stray bit of shield touching the center conductor or its pin. Pull both ends of this wire from the AP and radio connectors, use an ohmmeter to test for short to the shield.
Edit. Or the mike wire to #2 is simply in the wrong hole. The numbers are impossible to see, count the pins from the end. Make sure you’re looking at the same side as the schematic.
 
Last edited:
COM RADIO Setup
To adjust Squelch, Sidetone, and Microphone Gain, go to SETUP MENU > COM RADIO SETUP:
SIDETONE VOLUME – Adjust for your personal preference of how much microphone audio is heard in the headset when transmitting.

Good luck
 
Hope to test this weekend

Thanks for the tips folks. I should have time this weekend to test.

Eric

BobTurner said:
To test this, you’ll need a pin-puller. Remove the audio panel connector, pull the mike and PTT pins going to both radios (4 pins). Reinsert the radio1 pins into the #2 holes (swap com1 with com2, ptt1 with ptt2). Reconnect, power up, set audio panel to #2, test transmit. If radio1 transmits audio, the audio panel is working properly.
My best guess is that your #2 mike wire has a stray bit of shield touching the center conductor or its pin. Pull both ends of this wire from the AP and radio connectors, use an ohmmeter to test for short to the shield.
Edit. Or the mike wire to #2 is simply in the wrong hole. The numbers are impossible to see, count the pins from the end. Make sure you’re looking at the same side as the schematic.
Click to expand...
 
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