Hallicrafters HT-32 Mark I

Joining the vintage radio collection this week is a Hallicrafters HT-32 Mark I transmitter I acquired from a local ham who wanted to see it go to someone who would put it back on the air.

The HT-32 works on 5 bands (80, 40, 20, 15, 11/10m selectable by crystal), does SSB, CW, and DSB (double side band, AM without the carrier). Maximum power output is 100 W in SSB/CW mode and 25 W in DSB mode.

At 50.7 cm (W) x 25.6 cm (H) x 43 cm (D) and weighing in at just under 40 kg, this radio is a BIG HEFTY beast. This is the kind of radio where you set it down somewhere in the house and built your shack around it. None of this “Oh, maybe I’ll move it over to this side of the room”. No. Once you’ve set it down that’s where it’s staying.

When I arrived to pick it up, the previous owner had it plugged in with a light bulb connected to the antenna connector for a dummy load. Everything seems to be in working order, and there was enough RF output coming through the antenna connector to light up the light bulb. The brightness of the light bulb modulated nicely when he spoke into the microphone, so that seemed like a good sign. Wasn’t able to verify what the transmitted RF sounded like, but once I get it on the air I’ll find out soon enough. The previous owner mentioned he had done a full alignment on the receiver, but that was quite a while ago. Hopefully nothing has drifted or changed in the meantime.

The radio is in pretty good condition for its age, with some light surface corrosion (what 70 year old radio wouldn’t). The top metal mesh cover flips open to reveal an assortment of tubes, capacitors, tuned inductors, and a big chunky transformer.

One of the three crystals in the radio can be used to set up the HT-32 to work in either the 11 m (CB now) or 10 m band.

The crystals are used to mix the SSB signal from the second mixer stage to produce the output frequency for that crystal’s band. The 11-10 m crystal can be switched out for operation in the 11 m band, or different 500 kHz segments of the 10 m band. The radio currently has a 30.9 MHz crystal which sets the radio up for operating in the 11 m band (26.96 – 27.23 MHz).

I haven’t pulled the radio out of the chassis yet to see how things look underneath. I expect that the rest of the radio will look fairly similar to the top.

I’ll have to figure out how to wire up a microphone to the radio. It looks similar to the connectors on the Heathkit IG-102 that I replaced with BNC connectors. A bit of research tells me that it’s an Amphenol 75-MC1F/Switchcraft 2501 connector. Wonder if I can find a working microphone with one of these connectors on it already.

Fortunately it also came with the manual, which I promptly scanned and made into a PDF. The manual also conveniently has the schematic for the radio. I’ll have to spend some time studying the manual to learn how to use it before I try to get this paired up with one of the Hammarlunds and get it on the air.

Looking forward to getting this radio set up and working.