The AM Forum

Greetings from "old Shincracker Vt."

Does anyone have information on this very early non-phone airplane radio transmitter? I have had little luck on the internet engines.  Here are the specs" It uses (2) CG1984 Westinghouse glass tipped brass base tubes.  I believe these are 211"s. The name plate on the transmitter states: Type SE 1385A Transmitter for G.A.  "aircraft radio equipment" made for Navy Department (bu. eng).  Made by the ALLEN D.CARDWELL, Mfg. Corp. Dated 6/30/28.

It has a 4 position band switch ranging from 285KC-600KC The terminal board has 4 rows of 2 binding post marked REC, FLD,AC,& KEY. Its coupling coil has a bewildering amount of plug-in wires with strange slip on beads attached along the length of each plug wire. These wires appear like an old fasioned switchboard operator set.

Here are some pictures for review. I would like to get a schematic and hookup information. Maybe do some noninvasive clip leads to get it to run on 160!! CW. Any advise or references would be greatly appreciated.

Sincerely

Peter N2IDU

wow. is that cool or what? 

1929, right before the crash.- Looks like Cardwell made more than capacitors in those days.

Those beads are just ceramic insulators of the 'spinal column' type that are very flexible like a necklace.  Looks like you just hook up AC, a key, ant. and ground and your good to go,  At 500khz you might try a 1/4 wave wire, end fed first and see what happens....   ;D

Can you load a pix of the complete front panel?

What a great looking radio...
I too would like to see some additional pics

Here is a little history I found by googling:

http://earlyradiohistory.us/1963hw23.htm

"After the laboratory was moved to Anacostia, its staff was increased by several radio engineers and it was assigned the additional functions of design and development of complete aircraft radio systems. Two transmitters, the SE 1375 and SE 1385, which later became the backbone of naval airborne communications, were designed and developed. Both of these produced a clear 500-cycle note and neither was voice modulated. The SE 1375, 20 watts, which used four three-element tubes and operated on frequencies between 570 and 750 kc., was designed by Mr. F. B. Monar for use in small aircraft. The SE 1385, 500 watts, which used two 50-watt three-element tubes and covered the frequency range, 300-600 kc., was designed by Mr. L. A. Gebhard for use in large flying boats. One of the first radioteletype transmissions from aircraft to ground was made utilizing the SE 1385. It also became the transmitting component of the first aircraft radio transmitting system given a model designation, the GA. "

The transmitter appears on this list also:

http://pages.cthome.net/fwc/OLD-NAVY.HTM

Gee the date on that radio was my Father's second birthday.