[Elecraft] K3: TRN5 failed

[Edward R Cole]

I was plagued by the K3 not transmitting in DATA-A mode on 1296 with 
a transverter.  I had the KXV3 programmed for 1296 transverter with 
XV5 which should send a HI output on BAND0 when TRN5 is 
programmed.  I first noticed I could transmit if I had 144 selected 
(XV1) which uses the same IF of 28-MHz.  Finally dawned on me that I 
was not getting BAND0=HI in 1296 which controls my INHIBIT=HI.  I 
reprogrammed XV5 to be TRN7 and everything works (TRN7 outputs BAND0=HI, also).

I am not using any of the other BANDn output lines at the present.

I guess there is failure in the K3 logic for TRN5.  That it a bit 
surprising as I feed BAND0 to the gate of a 2N2222 thru a high 
resistance.  The transistor is a relay driver that connects the 
INHIBIT line (ACC pin7) to a source of PTT which brings the inhibit 
line LO in transmit.  PTT is coming from a four-stage sequencer which 
is keyed by KEY OUT.

Since TRN5 was not outputting a logic=HI my INHIBIT line was holding 
the K3 transmitter off.  I guess someday I will need to  repair the 
logic ckt involved.

73, Ed - KL7UW
http://www.kl7uw.com
dubususa at gmail.com
"Kits made by KL7UW"