Radiomarine Corporation of America

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. It would be 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.

Here's a link to information on the RMCA AR 8503 VLF receiver.

Here's a link to the manual for the RMCA AR 8506 receiver.

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

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
Here's an external link to another RMCA AR-8510 receiver.

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 .

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.

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.

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. Mid-1960s?

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 similiar 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.

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

Needed: Much more information about RCMA. I have so far been unable to contact anyone connected with this company. Help please.

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