The BC-474/SCR-288 field portable man-pack transceiver 

by Michael Starke

One of the radios one can’t find much information about is the BC-474 / SCR-288 transceiver. This is a field portable man-pack transceiver made for the US Signal Corps around 1940. According to some sources it was a "stop gap" set, to temporarily replace the SCR-131, 161 or SCR-171, for use by Field Artillery, Infantry & Signal Companies. This until sufficient quantities of the SCR-284 could be fielded. Not much background data can be gathered about this set, but the Midwest Military Communications Museum² provided the following:

The SCR-288 from the onset did not meet Signal Corps standards, but set was already in production by RCA for the Swedish government. The first five sets were delivered in March 1941. They were designed as a man-pack sets, to be carried by two men. The main components of this system (BC-474/SCR-288) shared common parts, such as circuits and design with other equipment being built by RCA, such as the AVT or AVR series, which were used in small aircraft for instance.









BC-474 transceiver with a hand-crank generator and accessories.


Though this little radio set was only adopted as an expedient, it saw significant service in WW-II even after it's successor, the SCR-284, became available. Most notably with Filipino Guerrilla forces, the China/Burma theater, and in the North African, & Italian campaigns, not to mention with various Allied countries (who all favoured it's small size & extremely simple operation). Do to this small size and weight (71lbs system weight / 2 man carry versus the 250 lbs / 3-6 man carry of the SCR-284), the SCR-288 was not truly replaced in many applications until the much more rugged and advanced SCR-694 became available late in the war. The only competitive system of it's time was the excellent Navy TBX series which had been in service since 1939. This set however was complicated to operate and it's extreme versatility sacrificed portability. Even after the introduction of the SCR-694, the BC-474/ SCR-288 continued to serve in the training of Signalmen at home.


The SCR-288 was the first radio set of it's type to be adopted that was capable of AM phone operation (though as a "Stop Gap", Limited Procurement and later as a Limited Standard). The system sacrificed several attributes in favour of light weight, small size and simplicity which in the end spelled it's success. These were mainly ruggedness and versatility. In the case of the latter, the SCR-288 could only be used as a field set, being powered by a hand crank generator and dry battery (for receive). No alternate power supplies or ancillary equipment are known of that would have allowed vehicular or semi-fixed operation as with it's successors." ²

Without any modification, it covers the entire 80-meter band using AM or CW. The transmitter VFO covers 3500 to 6300 kHz with an RF power output of 4 Watts. The receiver continuously tunes from 2300 to 6500 kHz. Supply voltage for the transmitter is 6.6VDC @1.65a for the heaters and 290VDC @ 100mA for the plates. Actually, any voltage between 240 and 320V will do. Originally power was supplied by a hand-crank generator. Receiver voltages require 1.5 VDC for the filaments and 90-240VDC (B+) either provided by a dry battery or the hand-crank generator. The watertight case of the BC-474 is painted in Army green, outside and inside. The front panel held in black with white lettering. It was indicated to me, that the BC-611 "Walkie-Talkie" frequencies align with the BC-474, therefore it is possible, that both were designed to be used together².


The set described here was given to me by my friend, Bob Allison (WB1GCM), who is an avid collector and operator of vintage military radio equipment. Mind you,- carrying the receiver on board through suspicious customs officers is another story…All in all the BC-474 is in a good physical state. The only flaw was, that the antenna current meter didn’t work. The set came without its legs, the hand-crank generator and the filter FL-10 when I got it. Apart from some "home-made" legs, the other bits, I learned, are very hard to find. A matching headset (ANB-H1), a CW-Key (J-38) and a hand-set (C-3) already existed.

The Receiver, a four tube superhet circuit, is used for the reception of AM or CW. The tubes have low power consumption. Power is provided by a battery pack, which fits inside the cabinet, just under the receiver section. I have used 4x 1,5V D-cells parallel and 20x 9V block batteries in series to provide the necessary power. The receiver plug is of a 4-pin type, originally made for use with a Burgess 6TA60 battery pack (or equal).

Front view

Inside view

The controls are somewhat limited, but sufficient. There are a Phone-CW switch, Receiver Tuning and Volume controls, and Receive-Transmit and Emission Selector (mode) switches. Two jacks are provided for two sets of earphones. The set only receives if the headphones are plugged into the main jack. Tuning stations needs a bit of skills, as there is no real "bandspread" available. However, when using the set it always surprises me how clear the stations come in,- almost no background noise,- fairly sensitive too. Considering its rather "simple" design and in comparison to one of my "modern" Watkins Johnson (WJ) receivers,- there is sometimes not much difference between the two,- perhaps a few more knobs to play with on the WJ…..


As for valves, the BC-474 has four of them located in the receiver compartment,- 1N5-GT, 1A7-GT, 1D8-GT, 3A8-GT,- easy to get on the surplus market. The 3-tube transmitter is supposed to have a range of about 15 miles for CW and 8 miles for AM phone, but I haven’t tested this yet. The manual recommends an antenna of 35 feet with a 35-foot counterpoise, but for reception any wire longer than 3 feet does it already.

The transmitter has all 6V6 type valves, one for the VFO, one for the power amplifier stage, and one for the AM plate modulator. The controls are standard for a transmitter of that time,- VFO Oscillator tuning, PA tuning, and Coarse and Fine antenna controls. To help with the tuning, a PA plate meter and Antenna Current meter are provided. Standard jacks the key and microphone are built in.

The binding posts for the antenna / ground are very close to the transmitter fine- tuning knob. When both are touched in operation it will for sure raise your heart-beat! What took a little effort was to repair the transmitter. The antenna current meter had shortened. By simply bridging it the transmitter would work again. Finding a replacement meter was the tough part. The manufacturer, Simpson Electric Co. in Chicago couldn’t help, nor could the known dealers like Fairradio Sales or Antique Radio Supplies and the likes.


I spent many evenings on the internet in finding this specific rectangular bakelite meter. After a lot of frustration I decided to have it professionally fixed at "any cost" by a German company specialized in such issues. After consulting the former owner of the company he mentioned an old ex-employee of his who could help… and he did. He had in his spares box a 40’s Siemens "converter / transducer" of some sort that now has the meter going again. This "miracle box" is out of white porcelain, has an in and output junction and can not be opened. I don’t know what happens in there and the older gentleman would not reveal it either. He gave it to me with a smile saying something like it was priceless and that he is happy to have an old radio going again….

Michael Starke, Kempen, Germany

² Dennis Starks, Midwest Military Communications Museum
³ John Dilks, QST 11/2001

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