Hallicrafters SX-62
The SX-62 is a single conversion general coverage receiver for AM, CW and FM. It fully covers
540 KHz to 110MHz in six bands. Introduced in 1948, it has 15 tubes. It was primarily intended
for the serious shortwave listener who also wanted FM and excellent sound. It is essentially an
SX-42 with a nice large slide rule style dial but without bandspread or S-meter.
Like the SX-42, the IF section is automatically switched using 455 KHz for the lower four bands
and 10.7 MHz for the upper two bands. Both it and the SX-42 are erroneously listed as a double
conversion receiver in several references. It has only converter for either of two IF frequencies,
one for AM broadcast and most shortwave and the other for the upper two bands primarily for
VHF and FM. Using a pair of 6V6 for 8 watts of push-pull audio output, the set is designed for
high fidelity when listening to FM but offers six bandwidth selections for various communication
needs.
Like all other Hallicrafters with the "X" in the model name, the SX-62 is equipped with a crystal
filter. It also has a crystal calibrator which the SX-42 does not have. The knob to the left of the
dial allows repositioning of the dial pointer to an accurate setting as indicated by the calibrator
signal.
The six bands on the dial are individually highlighted using a separate pair of dial lamps for each
band.
Like the SX-42, the SX-62 was known for excellent sound quality. Its output transformer has 500
and 5000 ohm impedance connections. A bass-reflex R-42 speaker came with this receiver and
matches any 500-600 ohm output.
Repair progress
The set was purchased at auction and was rather filthy. I started with a thorough cleaning inside
and out with white waterless hand cleaner. The cabinet was also cleaned but will need a re-paint
after the weather allows it. As usual, I sprayed deoxit on all accessible switch contacts and tube
sockets after pulling the chassis. I replaced the missing line cord. I restrung the dial cord
according to the diagram in the partial manual available on line. This was not a simple task. I
ended up putting the tension spring on the back side of the pulley. Works fine that way and is
easier to get to.
I found that a former owner had replaced practically every capacitor with quality Sprague caps.
The quality of soldering and wiring the replacements was just fair. In checking the cap
connections, I found and corrected several bad solder joints.
The R-42 speaker did not function at all. That turned out to be the Hi-fi - Communications switch
on the speaker. With the speaker on its back and the bat handle of the switch pointing up, I
sprayed a bit of deoxit at the base of the bat handle and worked the switch. The deoxit went into
the switch, cleaned the contacts, and solved the problem.
After electrical safety tests and reforming the electrolytics, I powered the set, but it barely picked
up a local AM station. Tube tests revealed a weak 6SG7 and a very worn 6SK7, both in the IF
chain. Replacing those and touching up the 455 KHz IF alignment (matching the crystal filter
frequency) brought the AM and shortwave bands to life. In fact, the AM broadcast band reception
sensitivity and selectivity rivaled that of my excellent and modern portable solid state Grundig
Yacht Boy 400 with, of course, much better sound by way of that R-42 bass-reflex speaker. The
sound from that speaker with the SX-62 on Hi-Fi or Bass settings when tuned to area AM oldies
stations reminded me of my favorite 1950's jukebox. Great sound. Shortwave reception was also
very good. FM reception barely worked however. The crystal calibrator also did not work.
The FM section
Found that the FM front end section was totally in need of realignment. It had likely never been
aligned after the caps were replaced. I also tweaked the FM limiter and discriminator adjustments.
After the alignment and attaching a proper antenna, the FM section came to life, performing
reasonably well for the era, again with that great "jukebox" sound by way of the push-pull 6V6
tubes and the R-42 bass-reflex speaker.
Crystal calibrator
The crystal caibrator did not work at all. My frequency counter with a loop of pickup wire did not
detect any oscillation at all. The circuit is very simple using a 6C4 triode and a crystal soldered
into the circuit right at the cathode and grid tube-socket connections. Its output is coupled to the
antenna terminal lead by a "gimmick", about a quarter inch of insulated wire wrapped around the
antenna terminal wire. The gimmick acts as a capacitor of a picofarad or two.
After tests, I concluded the crystal was bad. Clipped in a replacement which worked properly
according to both my frequency counter and the dial settings. Took the original crystal apart and,
sure enough, the tiny crystal was loose inside the mount. Could not repair it so soldered in the
replacement for the fix.
Overall I consider the SX-62 to be a very good and sensitive high-end SWL radio. I love the big
dial with separately-lighted bands and the adjustable tuning pointer. For ham bands, the lack of
bandspread capability makes use difficult. However, the quality of the sound and the ease of short
wave and broadcast band cruising make it a desirable set.
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