wrote in message
...
On Feb 2, 11:43�pm, wrote:
� � �hi guys,
� � �i am restoring an hq180a. �been a while since
i messed with tubes,
(abt 20 yrs) am in need of a little direction. �i
checked �& replaced
bad tubes, verified b+ v. �2 problems, may be related???
on top band,
very poor reception, & when u adj ant. control, u hit a
spot that
causes oscellation or motorboating. �prob #2...on top 2
bands, cw sigs
have a raspy note. �not t9 at all. �it is a high s/n
rcvr 6377. �kind
of neat, has spinner knobs, noise blanker, & 455 kc if
brought out to
rear apron. �i guess previous owner did mod, but it sure
looks
factory....solder connections, etc.
� � �would appreciate any and all guesses.
� � �tnx, pete, k2iqk

hi again, tnx for the replies..i did clean all wafer sws &
pots,
didn't clean main tuning cap..have bama prints for rx..will
try
voltage & resistance checks..full alignment sounds like a
good idea..i
have sig gen..1st & 2nd ifs would be difficult because sig
gen calib
not great..i dont think if alignment is my main prob..but
will do all
hf aligns..i'm glad to get back into tubes..its like
restoring a
classic car, but alot cheaper...hi hi. tnx agn..if u have
any more
ideas, pse email me.
73, pete

Again, I suspect the problem is bad capacitors.
Tunable hum is typical of feedback allowed by bad power
supply decoupling caps as is oscillation. I doubt if
alignment has anything to do with it.
Finding the bad caps may be a lot of work but you can
at isolate them to a particular stage of the RX. I don't
know what kind of caps Hammarlund was using when the HQ 180
was made. They evidently learned about Black Beauty paper
caps from the SP-600 and may have switched to ceramics. If
so the chances of bad ones is pretty small but even ceramic
caps don't last forever.
A capacitor checker would be very helpful.


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Richard Knoppow
Los Angeles, CA, USA