Hallicrafters SX-122 Communications Receiver (1962)

     

This Hallicafters SX-122 was my very first "boatanchor," the name affectionately given to heavy old communications receivers. I bought this one in the mid-1990s.

After collecting tabletops, portables, and transistors for years, I found myself bitten by the boatanchor bug one day. Reading Chuck Dachis' Hallicrafters book had something to do with it. It's hard to look at all those great old beasts for very long, without wishing that you had one of your own.

Listening to shortwave broadcasts was a bigger factor. During the previous year, the Zenith TransOceanic 3000-1 had become my favorite bedside set. I spent many a pleasant late-night hour turning its dial to find stations all around the world.

Although the 3000 is a good performer, it still had a silicon heart, and I was itching to listen to worldband radio on a genuine "glow powered" tube set. With eleven tubes inside, the SX-122 definitely has plenty of glow power, yet it's modern enough to give very nice performance.

Description

Model SX-122 was made from 1962-1964 and it was the top-of-the-line Hallicrafters set of its day. The SX in the model designation indicates that it has a crystal filter, a feature shared by my other high-end Hallicrafters sets (SX-28, SX-42, and SX-88).

This radio has four bands, covering frequencies from .54-1600 Khz (the standard broadcast band) and 1.75-34 Mhz (shortwave and amateur).

As you can see from the first photo, this radio is in excellent cosmetic condition. On top of the radio is a matching model R-48 speaker, which I acquired a couple of years after buying the receiver.

The seller told me it was used by a German lady who came to the USA. Evidently, she used it only to listen to German shortwave broadcasts. There is virtually no wear around the dials, as you'd find if it had been used by a real "dial twister."

This is a dual-conversion receiver, meaning that it has two intermediate frequency (IF) stages at 1650 Khz and 50 Khz. Most consumer radios have a single IF stage. Additional circuitry lets you listen to amateur CW and SSB broadcasts.

The tubes are: 5Y3GT (rectifier), 0A2 (voltage regulator), 6DC6 (RF amplifier), 6AU6 (1st mixer), 6C4 (variable oscillator), 6DC6 (1650 Khz IF amplifier), 6BL8 (2nd mixer/crystal oscillator), 6BN8 (AVC amplifier/AVC rectifier/AM detector), 6BE6 (BFO/product detector), and 6GW8 (audio amplifier/audio output). The set also features an optional crystal calibrator, which takes a 6AU6 tube if present (mine is not). The crystal calibrator generates marker signals at every 100 Khz on the dial for checking the tuning accuracy.

The large left dial is the main tuner and the right dial is the bandspread, which allows finer tuning. Between the dials is a signal meter that shows the strength of the received signal.

The seven controls in the bottom row are:

  • RF Gain, to adjust the strength of the RF amplifier and 50-Khz IF amplifier
  • Band selector, to switch among the four bands
  • Antenna trimmer, a variable capacitor to compensate for loading effects of various antennas
  • CAL/OFF, which turns the optional crystal calibrator on and off
  • Selectivity, controls the receiver's selectivity: 0.5 for CW reception in crowded-band conditions, 2.5 KC for SSB, and 5 KC for best fidelity on AM
  • ANL/OFF, switches the automatic noise limiter circuit, which automatically limits noise from electrical interference
  • Audio gain, the volume control
  • BFO, the "beat frequency oscillator" used for CW and SSB listening
  • Function, turns on the power and chooses either AM or SSB/CW
  • Phones, the headphone jack

On the back of the receiver are terminals for attaching your antenna and speaker, and a small potentiometer for adjusting the signal meter's response.

This radio was built with quality and durability in mind. The main tuner includes a heavy flywheel, for smooth, fast tuning. And the tuning pulleys use thin steel cable instead of the usual wear-prone string.

Restoration

I bought this radio knowing that it needed some repair. From the look of things inside, it had never been touched electronically, except for some tube replacements. Most of the tubes still have the Hallicrafters brand name.

This radio is very easy to access. The top and bottom of the cabinet are large ventilated plates that you remove by loosening a few screws. Most servicing can be done without pulling the chassis out of the cabinet.

The next photo shows the set's roomy upper layout.

The rectifier and voltage regulator tubes are at the upper right. The other tubes are arranged roughly counterclockwise, starting with the RF amplifier at upper left. At the upper center is the empty socket where the crystal calibrator subassembly plugs in. At the lower left is the large, three-gang main tuner. To its right is the smaller two-gang capacitor for bandspread tuning.

The next photo shows the underside of the chassis, shortly after I had begun restoration.

The first steps in restoration, as with all tube radios, were to clean the controls with DeOxit and replace the old capacitors. Since this radio was made in the 1960s, many of its capacitors are the reliable ceramic type that don't normally need replacement.

After replacing one of the screen dropping resistors, the radio played like new. It has performed reliably for almost a decade.

Final Thoughts

If you are looking for a practical, easy to use receiver for shortwave listening, the SX-122 is an excellent choice. While it's not as feature-laden as some of my older boatanchors, it's a sensitive, stable receiver that has proved to be extremely reliable.

My only complaint about the SX-122 is that its audio quality doesn't measure up to the "push-pull" audio of my older SX models.

On the other hand, the SX-122 is more affordable, because there are lots of them in circulation, and some diehard radio collectors are not interested in anything from the 1960s. If you can't find a nice one in the $200-$300 range, you're simply not trying!

©1995-2014 Philip I. Nelson, all rights reserved