radio mic to computer... follow up 1

So yesterday I wrote about interfacing a radio mic, specifically the microphone supplied with the TTI TCB-550 (Model number AMC-5011), as I'd wired the inteface with Uniden wiring the mic remained unmodified and would work as normal with a CB radio.

I removed the grey cables used for the test set, and built the unit into the box, the mic in at one end (any Uniden wired mic will plug in here, Cybernet wired ones won't, the connector is identical, just the pins used differ), inside the ground connects to the pre-amplifier board, the audio connects to two points, the pre-amp or a switch to bypass it, the TTI mic sounds better with the pre-amp bypassed as it turns out but it is there should other impedance mics need it, the TTI AMC-5011 is 1kΩ)

Output to the computer is renewed, in the shape of a stereo phono to TRS with the phono ends cut off and the tip wired to the switch common and the sleeve wired to the pre-amp ground, a red wire connects the pre-amp output to the switch, a small toggle switch that is mounted to the side of the box.

Tests on Echolink showed promise with the pre-amp out of circuit for the TTI CB mic, in circuit the audio was bad, suggesting pre-amp with this mic is not really needed, my next test will be a live on-air test on Echolink, preferably through GB3IR but at time of writing it is not currently connected to the Echolink system.

There is still the matter of keying up Echolink when I actually press the PTT, of course this is a job I'll have to deal with another day, the pre-amp board is also temporarily fixed in with hot melt glue, this will be renewed with nuts, washers, and bolts when the PTT control circuit gets added and the unit can then work as I would like, a real radio mic on an Amateur radio linking system, I know there is no RF involved at my end but in the shack making calls to another station using a computer mic is just awful.

73 de M6RSQ