April 2012
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Back when transmitters used to look like something

Other than a humming box, that is.  RCA broadcast, prior to the period in the seventies just before they went out of business, made some good looking transmitters:

RCA BTA-10U AM transmitter

RCA BTA-10U AM transmitter

The Art Deco design was favored for a number of years, especially with the AM units:

RCA BTA-1AR transmitter, circa 1960

RCA BTA-1AR transmitter, circa 1960

Some of these RCA transmitters are still in service as backups.

GE made the BT-25A, which was a 50 KW transmitter in Syracuse, NY for a few years. These units were very similar to the RCA BTA-50 transmitters.

GE BT-25-A

GE BT-25-A looking from the control cabinet

Gates of Parker Gates, pre-Harris, also made some classic transmitters:

Gates BC1J transmitter

Gates BC1J AM transmitter

I remember the BC5P had a similar look, with more transmitter cabinets.

Bauer FB5000J AM transmitter

Bauer FB5000J AM transmitter

Fritz Bauer made a very solid AM transmitter.  Good looking, too.  We need more pictures of old transmitters and other hardware.

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13 comments to Back when transmitters used to look like something

  • I remember the RCA BTA-1R quite fondly as it was the backup at WMMM in Westport, CT. The main transmitter, a Harris MW-1 always reminded me of an overgrown refrigerator, looks wise.

    While both transmitters operated well there was nothing more frustrating with my high voltage “buddy” who accompanied me during transmitter maintenance would hit the crystal switches on the RCA to pop it into “Conelrad” mode. There was nothing more frustrating than having to open the box to manually reset the latching relay when he decided to play this little prank on me.

  • Bill McCarrey

    Some stations are still using them as mains. I have 1r3 as a main and a 1r1 for back up. Both make full power and mod!
    Like real radios, real transmitters glow in the dark.

  • Dewey Jacks

    Those classic radio broadcast transmitters sure look neat,…and it’s nice to know some are still in use! I like the looks of the RCA units,and though they’re not pictured,…a few of the old Collins and Continental units as well. Seen photos of those on another radio related site,…www.oldradio.com,I think! Another neat looking transmitter is the 50HG-2 Westinghouse transmitter
    featured on the Jim Hawkins Radio and Broadcast technology website for WOWO AM 1190!

  • Gary

    Off-topic: Sorry, Paul. I lost your e-mail and wanted to let you know I’ve transferred my domain for “Site 2241” on your blog roll to Namecheap. The URL is now just “www.site2241.net”.
    BTW, I loved your post on the Titanic!

  • BTA-1AR looks good enough to display in my living room.

    That’ll speed the divorce along, as well.

  • Paul Thurst

    @spine, beauty is in the eye of the beholder. I myself had to upgrade to wife 2.0 a few years back, the first version of the program was buggy.

  • David Van Barneveld

    Hi everyone. Iam based in Australia. I am seeking some information on a radio dation that has in use a Harris MW-50-C using 4CX-35000-C power tubes. I am truing to get hold of a set of photographs of the transmitter both inside and out, including power supply and R.F. units. Any help appreciated. David Van Barneveld VK4BGB davidbarneveld@bigpond.com

  • Paul Thurst

    David, I’ll check around and see, many of that model transmitter has been retired. I worked on a couple of MW-50A and B transmitters over the years. They have issues with the solid state damper diodes going bad. I believe those parts are no longer available.

  • […] Remember when aesthetic style was an important part of transmitter design? I do, and so does Paul Thurst, author of the Engineering Radio blog. […]

  • David Van Barneveld

    Thanks Paul. Any help appreciated. If you or anyone else here knows where I can get my hands on a 4CX35000C tube, please let me know. I want one for a display piece. Happy to pay shipping costs to Australia. 73’s. David………….davidbarneveld@bigpond.com

  • Paul Thurst

    David, I don’t know of anyplace where these tubes are just laying around, but I will keep my eyes open.

  • Thanks for posting the pictures.

    I am an old broadcaster seeking an RCA BTA 10u,

    Also seeking an “AmpliPhase” nameplate from the big 50kw Ampliphase transmitter from back in the day. If anybody knows anybody with recently decommission RCA transmitters that fall in the BTA era, please let me know, as I am working on a special project for a friend with cancer, and trying to build familiar surroundings as well as get his stories written down so a documentary and perhaps even a feature film about AM radio’s glory days can be told.

    Please reply to: jj@jjmccartney.com

  • Flavio Faria


    W#e need a copy of RCA RTA-20 Am transmitter manual

    Thank you for your cooperation

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