[Amps] Alpha 78 Control Circuit 'Issue'

[Paul Gerhardt]

Any Alpha 78 techs?

Am having trouble with the control circuitry.

TR switching works if in standby.  (it is putting out power in 'standby')

When CW OR SSB buttons are down the 78 stays in Transmit.

60 sec timers is working
HV is working and switching from Hi to Low
RF power output is good
Meters all seem good

Shorting Relay Jack in standby (both CW AND SSB buttons 'out') causes T/R
switching and RF Sensing (to inhibit T/R switching with input) works
in 'Standby' .

When CW OR SSB button is down T/R switching is 'locked' in Transmit Relay
Jack (open or shorted) makes no difference.




-- 
Paul Gerhardt
K3PG
http://pgerhardt.blogspot.com