GM300 cross-band repeater setup questions

timkilbride · Post by **timkilbride** » Mon Apr 17, 2006 6:23 pm

I have built my cable required for the cross-band repeater with two GM300's. I am still waiting for my VHF radio so I can't test the cable yet.

I search the archives and found some reference to a 2.2uf cap on the mic line with the positive towards the radio. Is this a requirment or does your mileage vary from setup to setup? I could not find a detailed answer on it. I also installed a 5k taper potentionmeter on the RX Audio to Mic/ground line.

Tim

Will · Post by **Will** » Mon Apr 17, 2006 9:04 pm

Tim,

You NEED the cap in the line to the radio's MIC connection. There is a DC bias on the MIC lines in most all Motorola Mobiles built, GM300 is no exception. The capacitor blocks the DC bias from going to ground thru the pot or the other radio.

timkilbride · Post by **timkilbride** » Tue Apr 18, 2006 4:39 pm

Can a non-polarized capacitor be used?

Thanks,
Tim

Birken Vogt · Post by **Birken Vogt** » Tue Apr 18, 2006 7:59 pm

A non polarized cap can be used in place of a polarized one just don't do it the other way around

Birken