"COLIN LAMB" wrote in message
ink.net...
Hello:

I would like to make a comment - not to embarrass you but to prevent the
same type of mistake made by others. It is a common mistake, because I
have
acquired a number of receivers that suffered the same fate.

The mistake is aligning the radio when some malady occurs. The radio,
over
a period of years may age slightly, requiring a minor adjustment. But,
the
alignment will not jump dramatically in a manner that would be corrected
by
re-alignment. A jump in frequency is an indication that something else is
wrong. Instead of re-aligning the set, the problem must be located.

At this point, play like Sherlock Holmes. Use deductive reasoning. Test
the radio on each band. Make notes of what the malfunction is and home in
on the components which are common to the problem.

In the case at hand, a jump of frequency on two bands would not be
alignment. It could only be a component which is in common between the
malfunctioning bands. Since it happened suddenly, it would be a defective
component (or possibly a short created by opening the cabinet).

Now, in addition to finding the original problem, you will need to realign
the receiver, and each realignment can cause wear on those components. I
once got an HQ-145 where every if core was cracked and most of the
oscillator and rf section cores were damaged by using an improper
instrument
and some of those cores were cracked. I should have dumped the receiver
but
took it as a challenge and finaly got it restored.

Regarding the receiver, I believe the rf stage may be disconnected on the
broadcast band to prevent overload, so it is not uncommon to have a deaf
receiver.

73, Colin K7FM

I am sorry I was so harsh. Perhaps it is because I am working on my
helicopter rating and any minor mistake can kill you.


Not harsh at all.... I did inspect visually before aligning but should have
starting checking each component in common as you say. Perhaps a cap failed
somewhere. Also, the mediumwave band is not dead but just weaker than it
should be. That's a seperate issue however, as it was that way before I
screwed up the rig.

Thanks for your advice. Time to pull the schematic out again and take
another look.