An Aristo-Craft CR-1 Rangemaster Radio-Control Receiver. Price tag on the box says "Rileys of Hamilton $39.50"

Now you know about as much as I do. The brick is red plastic and 2 3/4 inches long. It's screwed together and has "Aristo-Craft Model CR-1 Carrier Receiver Made in Japan" in raised letters on the top. The two posts are presumably for power. The removable tube is about 2 1/8 by 5/8 inches and has seven pins. It is marked only as "304". The antenna is 21" long.

The wiring harness fits the other socket of course and it has an identical seven pin plug and five single pin plugs numbered "1,3,5,6,7". The numbers are hand painted and the wires are soldered to the main plug in a truly awful manner with some wires touching each other. Numbers 1 and 5 are black.

So what have I got here? Clearly it's a R/C receiver, but from when? Tube sets pre-date me and I cannot find anything at all on the net. The few outfits I've seen were larger and had metal cases. The size and build of this one makes me think it must have been at the start of the transistor era.

I believe Sony did the first fully transistorized TV in '59, so I'm guessing this unit is from the early sixties, maybe the late fifties.

Two related sites: Ron Ellis' collection, and the National Association Of Antique Radio Control Equipment Enthusiasts.

UPDATE: 12/11/00

Collector Rudy Ewert has provided a wonderful amount of information on this unit.

He found it advertised in the August 1965 issue of R/C Modeler:

A "NEVER AGAIN" OFFER! FROM POLK'S TO R/C USERS - This is a single, hard tube, carrier responsive unit designed with trouble-free simplicity of circuitry. High sensitivity and stability make it far superior to any other receiver of this type. It is light weight, compact and ruggedly designed. SPECIFICATIONS - Size: 1 1/4" x 1 5/8" x 2 3/4", Wgt. 2 ozs., completely encased. For use on latest F.C.C. Frequencies (26.995 thru 27.255). Hand crafted circuit, Hi-Fi quality components. Battery requirements: 67 1/2 VB - 1 1/2 VA. High current change.

Rudy points out that what I thought were battery posts on the top are actually tuning transformers to fine tune the reception of the receiver. He says these transformers will compensate for some atmospheric and ambient conditions, and also will compensate somewhat for the changes in the capability of the vacuum tube as it deteriorates (some of these tubes had a very short life, and one had to retune the receiver at the start of each flight). There is probably a plug, or pin that will accept an audio earphone - one usually tuned these receivers "by ear" by simply listening for the strongest signal reception while adjusting the receiver. The relay was triggered whenever the receiver "heard" a signal of sufficient strength to get a response out of the tube. Since there is no apparent crystal, this would be a super regenerative type of circuit, which means that it is basically open to all of the frequencies on the 26/27 MHz band. In practice, this unit would react to ANY signal of any sort. You wanted to be far off in the boondocks with this system.

Perhaps I should add a note for younger readers here. This is a simple ON/OFF single channel system. No nice analog servos. You built what was pretty much a free flight model and had a transmitter with a single button on it. Perhaps it should not be thought of as Radio Control, but as Radio Encouraged.