Batboard

I'm still trying to interface my ID-O-Matic CW ider with my GR300. I have all the controls working but I am having problem when the the audio output of the ider is connected to the accessory port of the RICK. With the ider connected, the audio from the receive radio passed to the transmit radio is extremely low. If I disconnect the ider, the audio is great. I put in a 10uf bypass cap, it helps, but the isolation isn't enough. I think I'm loading down the receive radio with the ider.

Any ideas on how to make the ider look like a high impedance to the receive radio?

Thanks,

Jerry

If you're using the standard GR300 configuration, i.e. rx audio out from the accy connector of the rx radio, through the RICK, then onto pin 3 of the tx radio, then the impedance at pin 3 of the accy connector is around 5-600 ohms. I'm not familiar with the ID unit that you're trying to use, but if you have a schematic, look at the audio output circuitry and see if the output is coming directly from an opamp or comparator. If it is, then the impedance looking back into the ID unit's output is likely very low(<100 ohms). If you have enough output level available from the ID unit, maybe 4 or 5 volts RMS, you can use a series resistor on the ID unit's output line(as a guess, around 5 k ohm) and increase the output level enough to still give you a respectable ID deviation.
If the above is not true, another option would be to use a dual or quad mosfet switch to select the tx audio input(rx audio or ID unit), and control the switch with the PTT output of the ID unit. Then, when ID time rolled around, rx audio would be cut(even if it was being used) the ID unit's audio output would be switched to the tx audio input for the duration of the ID time then the 'normal' switch(es) would be closed after ID to allow normal repeater use.