Antique Army Surplus Receiver Restored

If you’ve ever been to a hamfest in the United States, you probably have at least seen an ARC 5 Command set. These were very rugged receivers and there were a ton of them made. Hams have been reworking them for years. In a recent video [Tom N3LLL] shared some of his tips for restoring them.

You might think these are just like a regular old radio, but there are some unique challenges, including capacitors filled with beeswax and strange threaded screws. [Tom] made several custom boards to replace the dynamotor with a solid-state inverter, replace odd capacitors, and provided a faceplate. He also 3D printed some replacement studs to replace the often decayed anti-vibration studs for the dynamotor.

The teardown at the end shows how rugged these things are. Tom’s restoration philosophy is to modernize the set while keeping the outward aesthetics. The receivers perform well, and as you might expect are built like tanks.

If you want to try your hand at restoration, these are not very expensive because there were so many of them made. Often the shipping is about the same price as the radio, but one in good shape can cost a bit more. We think the real fun is getting one that is not in such good shape and making it better.

Everyone has their own style and we know some restorers are more purists, but as a practical matter, [Tom’s] restorations look great, sound great, and preserve these great old radios so that someone might still be using them in another 75 years.

We’ve covered the ARC 5 before, unsurprisingly, and that restoration was a bit more traditional if you prefer it that way. If you need something to listen to on the AM band, try a matching transmitter.

16 thoughts on “Antique Army Surplus Receiver Restored

    1. Like that solid state receiver in QST in 1972?

      Or the time someone built an SSB transmitter in either a Command Set transmitter or receiver?

      There was a time when some cut down the transmitter chassis to make them shorter, keeping the VFO butnnot the high power stages, to feed an existing transmitter. They were very stable variable oscilkators, monster variable capacitor with a great reduction drive, and a very stable coil.

      I paid ten dollars in Canada for my Command Set transmitter in 1972, they were still cheap and plentiful then. It was still in original wrapping.

      But nobody put a Raspberry Pi in one.

      1. I guess that’s more like $50 in todays money. I think you had to be careful at flea markets in the 1980s that you didn’t leave too late or someone would load one in your car when you weren’t looking or hand you one as you walked out the door.

        As I’ve said before I think it was less that they finally sold out from warehouse stock in the late 80s as much as the surplus places sent them for actual scrapping or landfill to make room for cheap Russian stuff or newly ended Cold war surplus from all parties. Same goes for a lot of things like gensets and rangefinders and other “OMG that belongs in a museum!” small equipment of WWII vintage.

  1. The problem with these HF command sets is that the individual transmitters and receivers cover a limited bandwidth and none of the stock HF radios go above 9.1 MHz maximum.[1] There are 5 separate receivers that cover 0.19-9.1 MHz and 8 separate transmitters that cover 0.5-9.1 MHz. To get continuous transmit/receive coverage from 0.52-9.1 MHz you would need 12 stock boxes, and that’s not including the separate dynamotor power supplies.

    Over the years amateur radio operators figured out all sorts of hacks for these command sets to increase the frequency coverage above 9.1 MHz and/or add multi-band amateur coverage. For example, take a look at “The ARC-5 Pages” by W7EKB for more.[2]

    * References:

    1. AN/ARC-5 – Wikipedia

    2. “The ARC-5 Pages” – W7EKB

    1. I was going to write the same thing. A bench full of equipment to get coverage that doesn’t quite make it to 10 MHz! Not to mention how much power it would consume. These are beautiful pieces of equipment though. I first attended the Hamvention in 1974, and you could get one of these in decent condition for about five or ten bucks. I’m still regretting setting the mil spec version of the Collins 51-J3 receiver I picked up at the Hamvention and restored. The mechanical racks of tuning slugs doing a ballet as the bands changed was quite a thing to watch. I kept a National HRO-1 though and it is still a great sounding and sensitive receiver, though limited by having only a BFO.

      There is something about the small of warm shellac and capacitor wax that adds a little extra satisfaction to the radio experience.

      My museum of electronic obsolescence also contains a Tektronix 551 dual beam oscilloscope, outboard power supply, cart, plug-ins, probes, manuals, etc. Boasting two distributed vertical amplifiers, if I recall just the ‘scope contains something like 112 vacuum tubes. It makes a good space heater when operating.

    1. They were very light, so a ton of them could amount to a lot.

      They were small and made of aluminum,and no built in power supply.

      When I got mine in 1972, I carried it home. I can’t remember if I walked or took the subway.

  2. I have a CCT-46129, which is similar to the R23/ARC-5, which *should* cover 0.19 to 0.55 MHz, but someone modified it to cover the broadcast band.

    I’m seriously interested in UNmodifying it, back to the original band, but the only things I can see that don’t look original are some bodge wires to put all the filaments in parallel so as to use 12V instead of 24V for the LV supply, a change that I might keep.

    I’m now thinking that maybe removing (or smallening) a capacitor could raise the LO frequency, which might achieve the (unwanted) band change. So maybe I’m looking for something that’s missing?

    Slogging through mediocre quality pdf scans of 354 page manuals hasn’t yielded any result yet. If anyone knows how these units were mod’d for band changes, sure would appreciate a tip

    1. The ones that covered the broadcast band were the rarest. They just weren’t made in big numbers, it’s not that they became rare after the war.

      The ones that tuned below 550KHz were useful since they had an 85KHz IF, which meant better selectivity than the average receiver. As someone mentioned, they could be tuned to the 455KHz IF of many a low end receiver to add selectivity.

      The interesting thing about the Command Set receivers is that while the general circuitry was constant, the IF frequency varied with the tuning range. So the ones above the AM broadcast band had IFs in the low MHz range, and relatively broad selectivity (made for easy tuning). So if you try shifting their frequency range, the results will be less than optimum.

      1. Yes, I also have a BC-454-B that does 3-6mc, and that has 1415kc IFs, and I’ve seen 2830kc IFs in some one of these. Really would like to get the navigation receiver back on band so that, like you said I could feed it 455kc from other radios, or try for the BBC LW broadcasts on 197.

        Also I noticed, the plate on top says Feb 1942, but there’s faded yellow printing on the back next to J3 that says May 1943, which I’d assume is when this particular unit was accepted.

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