Dynon com low audio volume

[Edd]

Dynon com radio has low volume on receive, transmits seems to be ok, the intercom is plenty loud, in the setup screen the audio is set to maximum but no help. My headset is a Bose and it works perfectly in other aircraft. I returned the radio and intercom to Dynon, but they didn’t find any issues. Any help would be appreciated
Ed

 

[GKC Aviation]

Did this just start happening, or has it always been this way?
Do you just have the one com?
Your intercom is working fine, so that says that the audio wiring to the jacks from the intercom unit is ok.
I would surmise that you have a wiring problem between the com radio and the intercom unit.
Check that audio out of the com (phones HI) is not shorted to audio out LO (phones ground), and that the LO wire has good continuity to the intercom ground (pin 1)

 

[Rhino]

It is possible for an intercom to do this, but it's more likely to be wiring or connections, as GKC noted. You can narrow things down by temporarily connecting an audio line directly from the radio to the phone jack. That bypasses both your existing wiring and the mixer/volume circuitry in the intercom. I'd also be interested in knowing the answers to the questions GKC posed.

 

[Edd]

Did this just start happening, or has it always been this way?
Do you just have the one com?
Your intercom is working fine, so that says that the audio wiring to the jacks from the intercom unit is ok.
I would surmise that you have a wiring problem between the com radio and the intercom unit.
Check that audio out of the com (phones HI) is not shorted to audio out LO (phones ground), and that the LO wire has good continuity to the intercom ground (pin 1)

Yes one com radio and we have had this issue since new. I have checked the wiring several times every thing appears ok.

 

[Rhino]

I would try bypassing the intercom with a temporary jumper wire.

 

[Edd]

Is there a schematic on how to do that

 

[Rhino]

Installation manual, bottom of page 16-16. That shows you how to connect a radio directly to your headset jack when you have no intercom or audio panel. Make sure the intercom pin 14 is disconnected when you run the test. Alternatively, you could just power the intercom down, but you'll have to key the radio manually, unless your mic key line goes directly to the radio, and not through the intercom. You should get the full, available receive volume with this method.

 

[Edd]

Installation manual, bottom of page 16-16. That shows you how to connect a radio directly to your headset jack when you have no intercom or audio panel. Make sure the intercom pin 14 is disconnected when you run the test. Alternatively, you could just power the intercom down, but you'll have to key the radio manually, unless your mic key line goes directly to the radio, and not through the intercom. You should get the full, available receive volume with this method.

Thanks for the help, I’ll give it a try

 

[vlittle]

Is there a schematic on how to do that

Here is a simple bypass circuit that plugs into the intercom harness when it is removed. The rightmost image is the actual wiring. If you really want to go to the extreme, it’s also possible to incorporate the SkyView audio alerts into the design. I could tell you how, but it involves resistors, but you may not be able to resistor (joke).

 

[Rhino]

As usual, Vern rocks. Just remember, if you use a connector bypass on the intercom, you're only bypassing the intercom, and not the aircraft wiring itself. Still a great troubleshooting tool though. I need to build one of those. For your particular situation, since you only have one radio, I'd consider buiding a connector bypass at the radio end of the cable. That would not only bypass the aircraft intercom wiring, but you could also add a separate headset jack and PTT switch on the bypass itself, which would bypass all that wiring too. It would be similar to the diagram on page 16-16 of the install manual that's for planes that have no intercom.

 

[Edd]

Thanks so much for the suggestions I appreciate it

 

[Rhino]

I apologize. I edited my post without realizing you'd already responded.

 

[TrevorMills]

Thanks so much for the suggestions I appreciate it

Did you manage to resolve the problem Ed? If so what was the resolution?

 

[Edd]

Did you manage to resolve the problem Ed? If so what was the resolution?

I tried bypassing the intercom, but that didn’t help. I must have a wiring problem, I think what I’m going to do is remove the intercom, com panel and com radio and wire them up on the bench. If that works then I’m sure to have a wiring issue.

 

[TrevorMills]

I tried bypassing the intercom, but that didn’t help. I must have a wiring problem, I think what I’m going to do is remove the intercom, com panel and com radio and wire them up on the bench. If that works then I’m sure to have a wiring issue.

Thanks Ed. I've currently got a intermittent fault that sounds the same as the problem you have. It started after finding a broken wire on the power lines to the radio head that I have now fixed but I think I have another cable issue which is intermittently producing a low volume on receive. Tx is fine as reported by those on the frequency but sometimes I have to turn the volume to full and turn of squelch to be able to hear a response whilst other times it's fine. I've only had one flight with this issue but will investigate tomorrow. If I find a fix I'll post here...

 

[Edd]

Thanks Ed. I've currently got a intermittent fault that sounds the same as the problem you have. It started after finding a broken wire on the power lines to the radio head that I have now fixed but I think I have another cable issue which is intermittently producing a low volume on receive. Tx is fine as reported by those on the frequency but sometimes I have to turn the volume to full and turn of squelch to be able to hear a response whilst other times it's fine. I've only had one flight with this issue but will investigate tomorrow. If I find a fix I'll post here...

I’m thinking my problem must be in the wiring probably to the radio head, I’ll find out in a couple days.

 

[TrevorMills]

I’m thinking my problem must be in the wiring probably to the radio head, I’ll find out in a couple days.

I've found that it's not a wiring problem it seems to be an issue where the Rx doesn't seem to be tuned correctly when the frequency is dialled in. A restart of the radio resolved the problem. I've not flown much since I found the issue so will need to test on my next flights to see if I can replicate the problem. I seem to recall a Thread on here that mentions a similar issue.