Inland Marine History Archive - Logo

  Radiomarine Corporation of America

Radiomarine Logo

Miniature of RMCA sign

In 1919 the government assisted by GE engineered the formation of RCA to take over the American interests of the Marconi Company.  At its inception GE owned at least 80% of the stock in the new company with the Marconi owning the remainder.  The new RCA was initially a communications company, though broadcasting and the manufacturing of tubes and broadcast equipment soon over-shadowed the communications operations. According to George C. Oslin's book The Story of Telecommunications RCA's Radiomarine Corporation of America was formed in 1927.  

Radio Broadcasting Magazine - May 1928 states: RADIOMARINE CORPORATION ORGANIZED - The ship-to-shore marine radio communications of the Radio Corporation of America were transferred to a new subsidiary, the Radiomarine Corporation with which was combined the Independent Wireless Company. Charles J. Pannill, former president of the Independent, is now vice-president and general manager of Radiomarine and J. P. Duffy, for years superintendent of the New York division of RCA marine, has been appointed superintendent of operations.

RMCA was one of the prime providers  of marine communications equipment and services for more than 40 years. It appears that on the lakes both RMCA and Lorain Electronics gear were the most popular with Lorain having the top position.  On the rivers one ex-serviceman indicated that most of the AM gear that he serviced was RMCA brand.  However, some of the early AM gear was Western Electric and Dennis Widdows, who did service work for Lorain from a Chicago base, stated that in addition to working on the "lakers" he went down the Illinois River servicing boat gear - probably Lorain. 

The Great Lakes Cruise ships the SS South American, SS North American and the SS Alabama each had a RMCA ET-8031 system to support multichannel AM transmission and receiving. The system had 6 receivers, a motor-generator power supply, and a coil switching transmitter housed in a large cabinet. The system was operated from a control panel that could be located anywhere on the ship.  Tom Drake who served as radio op on these vessels provided these 3 images from the manual for this system.

Here's a link to the manual for the RMCA ET 8023 Radio-Telegraph Transmitter.

Here are three pages from a 1939-40 brochure promoting several RMCA  Radiotelephone units: 

 Page 1   Page 2   Page 3 (ET8020)

Don't have a photo of it, but here's a 1946 ad for the RMCA ET-8027 .

LA8AK's RMCA AR 8503 VLF receiver page is now only available via the Wayback Machine.

Here's a link to the manual for the RMCA AR 8506 receiver, and some service info. for it.

RCA ET-8037 AM Marine Radio Unit
RCA ET-8044 Marine Radio Unit
Above:  RMCA ET-8044 rig with a tunable receiver.  Likely intended more for pleasure boat use than for commercial service.
ET-8044 Ad # 1            
ET-8044 Ad # 2

Left: Alex Holden, VA3AEX supplied this photo of the RCA ET-8037.     It's a 6 channel unit rated at 30W (from a pair of 1624's modulated
by 1624s) and is a hefty 93 lbs. ET-8037 Advertisement

Shipboard receiver with 3 knobs and a center mounted speaker Bruce Spacer, WB8VCM provided the photo and information about his RMCA AR-8514 receiver shown at the left.

The introductory paragraph of the manual reads as follows:
Radiomarine model AR-8514 is a two channel, crystal controlled, radio receiver designed primarily for shipboard service in the 2000-3000 kc radiotelephone band.  This receiver may be used to maintain a radiotelephone watch on the safety-calling frequency 2182 kc, or on other frequencies in the band.
It appears that all radios were factory equipped with a 2182 kc crystal.  The radio operates from 115 VDC.  The RM-208 Rectifier (separately available) was used to power the radio from a 115 VAC source.  The receiver is a seven tube, single conversion super heterodyne with a 455 kc IF.  The drawings have 1952/1953 dates.

Front/top view of RMCA radio--direction-finding receiver
Photo of the front panel showing speaker grill and tuning contols
The RMCA AR 8510 is a 5 tube regenerative Rx,  covers
15-650 KHz in 4 bands and operates from 120 V DC.
Top View of 8510  

On the left is an AR-8712 direction finding receiver.  For more on RDF  see the Chum Bucket site's AR-8712 page and RDF page .

Photo of the front panel showing speaker grill and tuning contols
RMCA 10 tube Superhetrodyne RX Model 8506 - ca. 1940s.
Covered from 85KHz to 550KHz & 1.9 to 25 MHz
Larger Views: Front  Back  Top  Bottom

Doran Platt, K3HVG supplied this additional  AR-8506 photo.
 Photo of the front panel showing the cat's whisker crystal detector and the tuning dial
RMCA Backup/Emergency LF Xtal receiver - ca. 1944.
They worked since Morse code was actually a
modulated AM signal that was keyed on and off.

Here's an external link to another RMCA receiver, a superhet, the AR-8507

Here's a link to a photo of what appears to be a RMCA crystal controlled receiver.  Model number unknown.

Photo of the front panel showing speaker grill and tuning contols
Above is a RCMA Model 8059 1950s vintage 6 channel AM
unit which included a BC band receiver.

To the right is a somewhat later but still 1950s RCMA
8 channel rig.
Photo of the front panel showing speaker grill and tuning contols


A rig with two 19'" rack panel units in a cabinet. Speaker grill and handset on a hanger on the lower unit and meter on the upper one.
Here's an early version RCA AC powered SSB station  for use
 on larger craft. 
This 1951 ad  by RCMA shows one of their shipboard AM units as well as information on their communications services for the Mississippi River system.

Doran Platt, K3HVG supplied this instruction manual view of the 3U/4U series of shipboard rigs.  They were intended for high-seas operation & were far more complex than required for the rivers or lakes. 

The Maritime Radio Historical Society in San Francisco has done a wonderful job of restoring a RMCA 4U radio console as a part of recreating the radio room of a WW2 Liberty Ship at the San Francisco Maritime Museum.   In the first picture of the series note the rig on the floor in the foreground.  It is very similar to the ET-8012-HF AM rig shown in the 1951 RMCA ad above.  

Jerry Proc, VE3FAB has some pictures of a   RMCA 3U radio console on his web site which also has other marine radio gear images and information.

Photo of RMCA TRP-141 Emergency Transceiver
Ken Goodhue, WD6AOB, supplied the photo of the unit on the left.  According to ex-coastie, W8SU, these were used everywhere, light houses, surf boats, 40 foot motor boats for CG inter communications.  A carbon mike was used for AM, and power was from a 6V. battery via a dynamotor in the power supply, or by normal 115V AC.

The brass plate on the front panel has the following information on it: U.S. Coastguard Radio Transmitter Receiver Model TRP-141, Power output 5/10 Watts emission A3/A1, Frequency range 2000-9000KC. Serial No. 25.  Cont. TCG-37524. Date 12/30/47. Order No. CC 8657-C. Manufactured by Radio Marine Corporation of America, New York, New York

Bob Ballantine, W8SU, supplied this photo of the 1932 version of this type of unit.  Nomenclature unknown.

Patrick Jankowiak, KD5OEI has 21 detailed images of a RMCA Xmtr. manufactured for the Coast Guard in 1955 on his very interesting web site.

Here's a 1952 article with four photos of RMCA's equipment offerings at that years National Motor Boat Show. Thanks to Charles Eckard for this. 

Thanks to Bartley Cardon, KD1KG here's a nice image of the RMCA radio operator's console on the SS John W. Brown Liberty Ship. This gear was intended for high seas ships and is more elaborate than was used on the Great Lakes.

Needed: Much more information about RCMA.  I have so far been unable to contact anyone connected with this company.  Looking for photos of the 1950s RCA ET-8037 AM Radiotelephone unit and the RCA CRM-P22A Single Sideband unit (Is this the unit pictured immediately above?).  Help please.

Back to the Equipment Page