McMartin S.C.A. Hidden Subchannel Multiplex FM Receiver Model TR-E5

Description

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Collectible McMartin S.C.A. FM Receiver Model TR-E5
in excellent--
virtually unused
--working condition, encased in wood.
Locked tuned to 91.3 FM Frequency
Designed to receive
HIDDEN
subchannel broadcasts which cannot be heard on regular FM radios.
A hard-to-find collectible item.
(A Professional Radio Technician would be necessary if you wish to change the locked tuned frequency)
A switch located on back of receiver allows you to switch from regular FM to special FM subchannel broadcasts.
Here is what it is, and how it works:
The S.C.A. receivers (Subsidiary Communications Authorization multiplex receivers) are tuning devices capable of picking up and demodulating program content transmitted over subchannel radio frequencies by FM broadcasting stations.
S.C.A. receivers are
fundamentally different than normal household AM or FM receiving sets.
The concept of transmitting programmed material via subchannel radio frequencies was developed in 1948. It was discovered that subchannel or subcarrier radio frequencies could be effectively imposed on main channel broadcasts by radio stations. By use of this "piggyback" system the main channel programs are received by ordinary household radio sets and the subchannel programs are received by specially tuned S.C.A. sets.
S.C.A. receivers are usually purchased by FM radio stations since they are the only type of stations authorized to transmit subchannel frequencies. These receivers are distributed to the premises of subscribers wishing to tune in special interest programs of the nature described in the regulations, as follows:
"Transmission of programs which are of a broadcast nature, but which are of interest primarily to limited segments of the public wishing to subscribe thereto. Illustrative services include: background music; storecasting; detailed weather forecasting; special time signals; and other material of broadcast nature especially designed and intended for business, professional, educational, religious, trade, labor, agricultural or other groups engaged in any lawful activity. [2] Transmission of signals which are directly related to the operation of FM broadcast stations; for example: relaying of broadcast material to other FM and standard broadcast stations; remote cueing and order circuits * * *." 47 C.F.R. § 73.293, [Revised 1/1/68].
A frequent use of McMartin receivers has been what is termed "rebroadcasting." "Rebroadcasting" is the relaying of programmed material from one station to another; sometimes for broadcast use at a later time in the program day by the receiving station.
S.C.A. receivers have a fixed frequency, with the capability of receiving only programmed material transmitted on the subchannel to which they are lock-tuned.
A great collectible to own and use.