[Yaesu] FT-1000D and Alpha 87A
smlx at earthlink.net
Sun Jan 25 11:18:56 EST 2004
The D's circuit looks like this:
The Band Data connections come from the RF unit. S1002 switches the
collector of Q1029 to pin 2 of the Band Data connector. This device is
a FA1A4P (NPN). It is a 50v (Vceo) 100 ma device. This transistor also
operates the TX relay, RL 1005, at 12 volts. NEC device specs can be
If you don't turn the TX relay off, you will wire-or the FT1000D's 12
volt line through the relay coil to whatever is connected to Band Data
pin 2. NOT a good idea.
The circuit is designed to key only a positive voltage. Otherwise you
must use an external switching interface or you will pop the transistor
and then the TX relay won't work either.
I have been using a cable from pin 2 of the D directly to and the Alpha
87A "Relay" RCA connector for several years. I've never had a problem.
73, Steve WB6RSE
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