headset adaptor for Icom IC-A20 - wiring diagram?

[rusty sparrow]

any one able to help with a wiring diagram for one of the above? Or know where I can buy one in the UK?

TIA

RS

[jonkil]

Logging in from abroad, I have the wiring diaghram for the A20 at home, if you can wait for a week I will e-maıl ıt to you.

Regards,
Jon

[7AC]

Look up the "X-Com Radio " website.
I found a diagram there and it worked fine, I think it was among the FAQ's.

[rusty sparrow]

x-com site

Thanks - I couldn't find what I wanted though.. I've got an Icom IC-A20 MkII with two small jack sockets (2.5 mm and 3.5 mm) for mike and speaker.

[rusty sparrow]

Thanks Jon

I'll pm you my email address

RS

[rusty sparrow]

PTT problem

Making up a headset adaptor seems simple enough - but this isn't working. Do I have a problem with the transceiver?

I got this diagram from Icom quicktest1234789 - icom ic a20 headset

The PTT switch on the A20 body works fine. The 2.5 mm connector seems to click in securely and I'd assume that the input connections would be difficult to damage from any wrong input connections.

I got the transceiver from ebay - have I bought a duff one?

[GyroSteve]

That looks like a diagram for a PMR radio.

On the 2.5mm plug try the ring (centre section) for the mic and the tip for the PTT.

[znww5]

I don't know what the difference is between the MkI and MkII IC-A20, but if page 4 of your manual (Pre-operation) features an IC-CM9 speaker microphone then the following applies. BTW, I'm assuming you have an electret microphone.

The Icom manual shows a resistor permanently connected across the microphone and the PTT switch makes and breaks the common (ie screen) wire - the microphone screen and audio wires go to a mono 2.5mm plug.

By contrast, the quicktest site shows the microphone wired permanently across the common and tip connection, with the resistor being switched in and out of circuit across the two wires. It also shows a stereo 2.5mm plug.

If you are using a dynamic microphone, just leave out the resistor - however teh two switching schemes still differ.

I guess the first step is to check the manual for which circuit is applicable - good luck

[rusty sparrow]

I've tried putting a 33K resistor across from screen to tip, from screen to ring and from tip to ring (all three possible combinations). The right combination should cause the Icom to switch to transmit - or am I missing something?

I've not got a microphone attached - first want to check that the Icom will switch to transmit.