COS Voltage

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KB5AKO
Posts: 107
Joined: Sun Apr 03, 2005 8:57 pm

COS Voltage

Post by KB5AKO »

I have a GM-300 in VHF that is an 8 channel version with the masked logic board. The COS voltage is 0.03 volts with a signal; and 0.7 volts with no signal. I understand that the COS is active low. However, it seems to me that the no signal level would be higher than 0.7 volts. Does this sound like the correct voltage?

Victor, KB5AKO
Will
Posts: 6823
Joined: Tue Sep 04, 2001 4:00 pm

Post by Will »

Victor,

You need a 'pull-up resistor' to get a voltage swing from the open collector transistor that is in the GM radio.
KB5AKO
Posts: 107
Joined: Sun Apr 03, 2005 8:57 pm

Post by KB5AKO »

Will,

Thanks a lot. That worked for me. Anyway, once again; thanks a million batwings!

Victor, KB5AKO
Will wrote:Victor,

You need a 'pull-up resistor' to get a voltage swing from the open collector transistor that is in the GM radio.
Will
Posts: 6823
Joined: Tue Sep 04, 2001 4:00 pm

Post by Will »

Victor,

You are very welcome, Sir....
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