I have a very early AL-80A (S/N 0095) in which I also had a very
early internal QSK-5 switch (S/N 0005). I had similar problems with
it, but finally got it under control by increasing the reverse bias
current in the PIN diodes. However, about a year ago, the old
internal QSK-5 finally developed a non-repairable problem, so I
purchased the new version of the internal QSK-5 switch. Its operation
has been absolutely flawless from the moment I installed it.
At least for me, it's been free of any problems.
Kim N5OP
At 10:33 AM 8/10/2012, you wrote:
Years ago I tried to get the QSK-5 to play with my Omni VI+ and an Ameritron
Amp, which also had a slow open-frame TR-relay. I started buying
replacement protection lamps by the dozens. I never got it to work.
In my opinion, the best thing to do is to swap out the old relay circuitry
in the Amp for a 12v circuitry, and then use a 12v Vacuum relay. Actually
you will need a couple of relays. It's a lot of work but probably a better
solution than the QSK-5. IMHO
MFJ sells two models of inexpensive vacuum relays: 408-8100 (DPST-NO), and
408-8500 (DPST - one pole NO, one pole NC). Use an open collector
transistor to keyed from the TX OUT signal to key the relay. Use a small
reed relay to send the TX EN signal back to the transceiver.
73
Rick, DJ0IP
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