Are,
Do you have anything attached to J13 (Xverter Interface)? If not a
resistance measurement between pin 7 of one of the relays K1, K2 etc and
ground with the K2 switched OFF, and W6 removed, should read a very high
value, I would expect > 1 Megohm.
There is also the remote possibility that one of the relays is stuck with
its pin 7 connected to its pin 8, something which could be checked with a
resistance measurement with the K2 turned off.
73,
Geoff
GM4ESD
Are, LB3SA, wrote on Saturday, May 17, 2008 6:44 PM
I recently completed my K2 and everything seemed to work OK. All tests are
ok
with exception of a slightly low 8V regulator output (7.59V).
The sensitivity seems low however (my KX1 is much better at this point).
Tracing the receiver revealed that sensitivity is top notch at certain
points. This is where it gets weird...
When I inject a signal on the north side (according to schematic) of C7
(40m), C15 (80M), C24 (20M) and the same on all other bands, the
sensitivity
is great. But when I inject the signal on the other side of these
capacitors
(pin 8 on the relays), the level drops (at least 20db) to the same as
what
it is at antenna, W6, W1,D2/D3, D3/D4 and all other points along the
signal
path.
I removed W6 and RFC7 to isolate the problem and to see if anything in the
T-R switch or Low Pass filters could pull the signal down but there is no
change. I still only hear a weak signal when I inject a signal at pin7 or
8
on the respective relays. But as soon as I touch either side of C6 for
40m,
L7 for 80m, C22 for 20m etc, it is as strong as it should be.
I have measured all the relays for potential shorts but they seem to be
fine.
Any ideas out there?
73,
Are - LB3SA
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