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wa8yxm · 05-10-2009, 01:25 PM

Well, as I said up-thread I use it, or rather I will when I get my laptop compuer back.
(in shop just now)

Inerface is home brew, Compuer audio out (headphone) to isolation Transformer to L-Pad with a capacitor to load it some to balance power over the audio range to Radio

(Radio has 2 mic in-s it has 3 PTT's, which PTT you use chooses which mic in)

Radio audio out to isolation transformer to computer, same basic circuit both ways save for the "L" pad

PTT is an opto isolator on an RS-232 RTS or CTS line I used a pre-packaged LED assembly (As an indicator) a 2nd LED in series to form the control side of hte opto isolator a photo darlington is the other half and a switch in the PTT line to disable it for computer startup and other reasons.

05-10-2009, 01:25 PM	#7
wa8yxm Senior Member Join Date: Nov 2007 Location: Mobile, on the road Posts: 1,139	Well, as I said up-thread I use it, or rather I will when I get my laptop compuer back. (in shop just now) Inerface is home brew, Compuer audio out (headphone) to isolation Transformer to L-Pad with a capacitor to load it some to balance power over the audio range to Radio (Radio has 2 mic in-s it has 3 PTT's, which PTT you use chooses which mic in) Radio audio out to isolation transformer to computer, same basic circuit both ways save for the "L" pad PTT is an opto isolator on an RS-232 RTS or CTS line I used a pre-packaged LED assembly (As an indicator) a 2nd LED in series to form the control side of hte opto isolator a photo darlington is the other half and a switch in the PTT line to disable it for computer startup and other reasons.