I have made some repeaters with GM300 radios, Using a cable TX-RX to join both radios by the 16 pin.

Done it some years ago. But can't remember how I did to make the repeater stand up for a second after let the ptt.

I know I have used a small capacitor soldered in some place in the cable, but can't remember the right pins!

Wrong pins connections can burn pico fuse or even the crystal.. so it is not good do wrong connections!

Don't know if I have made me understand, or if anyone know how to do that in the repeater?


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    $\begingroup$ Is the logic level of the squelch on one of those 16 pins? $\endgroup$
    – Duston
    Commented Mar 18 at 19:20
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    $\begingroup$ clarifying: you're specifically asking how to cause the radio in repeater mode to keep TX on for 1 second after the incoming signal has ended? $\endgroup$
    – webmarc
    Commented Mar 21 at 0:53
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    $\begingroup$ I m making a real VHF repeater with 2 GM 300. So its to keep the TX for a second or less up, after any user around stop his ptt. $\endgroup$ Commented Mar 22 at 4:51
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    $\begingroup$ Just to we have time to hear the repeater takes down the PTT when we use it. Thats good to know if we are getting in range to the repeater. Hear hes response. $\endgroup$ Commented Mar 22 at 4:53


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