I'm on something of a roll when it comes to Hallicrafters I guess — I received a package on my porch the other day containing the rather suspect Hallicrafters SX-140 I took a chance on buying on eBay recently.
The SX-140 is a ham bands only, Novice level receiver, 80-6 meters, that was produced about 1961. It is designed to match the HT-40 Novice transmitter; the HA-5 VFO is what you added to the station after you upgraded to General.
Years ago I worked to assemble just that very station — SX-140, HT-40, HA-5 — and I have it here in the shack. The problem is the SX-140 had some major problems; for starters, it doesn't work, and from the looks of it, I'm not sure if it ever did. This receiver was offered as in kit form, and judging from the workmanship, I suspect this was one of those SX-140K models.
In aligning the thing, I found a damaged coil and a ferrite slug that's been destroyed. The transmitter is a very simple 3 tube affair, it either works or it doesn't. I have never had this station on the air; its been on my back burner for several years.
I decided to look for a different — functioning — SX-140 on eBay, but when I did remember to look, the good ones sold for way more money than I thought warranted. This receiver is a regenerative receiver, a very basic of the basic receivers.
I nearly decided to go ahead and sell it all a few weeks ago, but hestitated. I saw an SX-140 on eBay and watched it. It allegedly worked, though it had a broken AF Gain pot. Hmmm …
It looked like it was going to sell cheap, so I successfully sniped it. It finally arrived and I've had a chance to play with the receiver.
SX-140 FIRST IMPRESSIONS. For starters, I was surprised at how sensitive the receiver actually was. It didn't take long to warm up, and it is very stable. The bandswitch seems to be dirty, as the frequency seems to jump if you touch the bandswitch control.
Operating the rig takes a little getting used to. For best selectivity, you turn up the BFO/Selectivity (regeneration) to just past the point of oscillation. The selectivity wasn't like using DSP on my PROIII, but it was comparable to other vintage rigs, and better than others (like my Heathkit HW-16, for example).
On SSB, you crank the RF Gain back to keep the loud stations from overpowering the BFO in SSB mode. Some signals were so strong anyway that I had to detune the antenna trimmer to cut the signal strength back.
The missing AF Gain shaft was just that, the shaft was gone. The control is still there; to operate it, I simply inserted a small flat-bladed screwdriver and it worked like a charm.
I'm going to replace the AF Gain pot with a new one. The rcvr has had all the knobs replaced with incorrect ones, so I'll strip the other SX-140 of its knobs before I put it on eBay. I think this little station will be fun to play with on CW!
The rest of the receiver functions as it should. I'm sure it could use an alignment, but so far, it checks out nicely. The case is in good shape, the front panel is excellent. Even if I sell the station, I would at least like to make some contacts with it first!
The HT-40 also operates AM phone, so it could be used beyond the world of CW. I've not really considered that, but it could be fun to try.
The SX-140/HT-40 “twins” were followed several years later by the much nicer looking SX-146/HT-46 station. The value of these rigs hit the stratosphere after the QST article about them was published. Prices are still high for decent examples. I'm pleased to simply have a working SX-140 in the shack. Maybe when I get time I can try that station out this winter … we'll see!
73 … de KY4Z … dit dit …