iCom A200 wiring issue?

C

Corton750

Filing Flight Plan
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Oct 28, 2023
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Display name:
Carl
Hi, all; I previously only tested my Experimental Zenith iCom A200 installation once with a handheld comm and an old headset.

Yesterday, on one of my taxi tests, I called up ground for a radio check. They reported back loud and clear, so I done gud there.

However, I noticed that I only had sound in one ear (right ear), and there was no sidetone in the headset if I just spoke to myself. I only have one set of jacks wired. One thing I was never clear on, was if the intercom function is automatic, or must you install a comm/intercom switch on the panel, as the wiring instructions kinda imply?

Don't care too much about lack of sidetone; it *is* there when I push the PTT switch. Main concern is sound in only one ear. If I just jumper the headphone jack to connect both ears to one jack (it's a Lightspeed 20XL stereo headset that I love) will that mess with the impedance?

Thank You!;
 
First off, the A200 pinout says that the headset is mono and not stereo. Secondly, looks like the switch not only triggers the transmitter but also switches the mic between intercom and radio. If I read the circuit correctly, that would explain the lack of side tone. Without the switch, the mic never goes to pin K which is the intercom, hence no side tone.


1708560323818.png
 
I knew the comm was mono; the headset has a mono-stereo switch, and I had it set to mono. I’m just curious if I can jumper the two contacts in the panel jack to direct the sound to both sides. As noted, I believe that will change the impedance, but am unsure about that.

I only have a single-pole PTT, so nothing to trigger the intercom function. Guess I assumed that since I had no intercom switch that I’d have no intercom. But didn’t know that would impact the side tone. What you say makes sense. However, from the schematic, I’m confused about pins J and K. If K is the intercom connection, the switch diagram led me to believe that the intercom is connected only when the button is pressed. Which seems backwards to me. Obviously I need more knowledge. Thanks for educating me!
 
Corton750 said:
the headset has a mono-stereo switch, and I had it set to mono.
Click to expand...
If the headset is in mono mode then it wouldn't make sense that sounds is only coming from one ear.
 
Sorry for the delay in responding. Didn’t get back to the hangar til tday. Turns out with the switch in the mono position, sound was indeed coming out of the left ear. I just had to balance the volume a bit and lo and behold, it’s there.

still working the sidetone issue.
 
Also, I was confused about the schematic shown above. Turns out there’s a revised diagram with asterisked comment that says the schematic is shown with PTT pressed, which lears up my question about pin J vs K
 
i talked to icom yesterday. They say that regardless of what the schematic shows, there is no intercom capability in the A200. They also said there will be no side tone unless the PTT is pressed. Suggested I get a portable intercom.
 
Corton750 said:
i talked to icom yesterday. They say that regardless of what the schematic shows, there is no intercom capability in the A200. They also said there will be no side tone unless the PTT is pressed. Suggested I get a portable intercom.
Click to expand...
Slide out the A200 and slide in an A210 or A220?
 
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