[Boatanchors] sx-88 manuals and schematics

[Rodger Singley]

Doug,



I have the original manual with mine and there is no resistance table in the manual.  As far as I know one wasn’t produced.



After I went through mine including replacement of all of the tubular capacitors and a very few out-of-spec resistors followed by a careful alignment it worked perfectly except for intermittent noise on the highest frequency range.  I traced it to a coil connection that was never soldered although like all of the other connections in the receiver it did have a little dot of red paint indicating it had been inspected ??



As you may already know if the 4H4C ballast tube goes open it can be replaced with a standard 6V6.  A “bad” 6V6 is fine as long as the filament is still intact. The same is true of the 4H4C ballast also used in National NC-300, 303, and 400 receivers and if your line voltage is pretty stable the difference will not be noticeable, particularly on the lower bands.



Rodger WQ9E



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From: McDonald, J Douglas<mailto:jdmcdona at illinois.edu>
Sent: Monday, October 17, 2016 11:39 AM
To: Boatanchors at mailman.qth.net<mailto:Boatanchors at mailman.qth.net>
Subject: [Boatanchors] sx-88 manuals and schematics



I'm restoring my Hallicrafters SX-88.  I've got all the data I found on the net,
which is almost "fine". Two problems:

There is no resistance table. Is there one?

While the best schematic I have  (the djvu one from BAMA) is perfectly readable
for the actual schematic part, the wording is too low resolution to be
sure of the listed pin assignments, part values, and especially voltages.

Does anybody have a better schematic and/or a resistance check table?

Oh yes ... I find it amazing that this set ever worked reliably. Wiggling
the 1st RF tube causes intermittent shorts of the plate and filament lugs on the tube socket.
The solder blob on the filament, clearly original, is too big. Easily fixed by bending
the plate terminal very slightly. (It was straight, now bent, so this was not a post-manufacture problem.)

Doug McDonald


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