RCA BTA-250L ; News Radio 1330 KNSS, Wichita, KS

RCA BTA-250L Rescue: News Radio 1330 KNSS, Wichita, KS

Some pictures of the transmitter site. KNSS was kind enough to let me remove their old standby transmitter which I will convert to amateur radio use. A 1947 model AM transmitter is a beautiful instrument, but this one had developed a problem that was not economical to repair in a business environment. The transmitter in question is an RCA BTA-250L. It was not the first transmitter at the station, as the station was first opened in the 1930's. I would like to have seen (and taken custody of) that old transmitter! I suspect it used type "813" vacuum tubes, since there were a few lying around and nothing for them to go in.

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A shot of both towers. The 5/8 wave square tower on the left is guyed. The 1/4 wave tower on the right is used to protect in that direction, and is self-supporting. Both towers date from the 1930's.

Just the 5/8 wave. The building (not shown, unfortunately) has an interesting history in that it was originally an old civil defense-rated (Conelrad) station and has a basement in which there was a diesel fuel tank and who know what else. The basement is filled in with sand these days. The generator remains, and is in another room.

The racks as of 5/11/2008 are on the left.
Front to back: audio rack, Harris 5KW AM, phasing cabinet, Harris 10KW FM backup.
On the right is the cabinet of the RCA BTA-250L I was given.

Audio gear. Top to bottom: STL (studio-transmitter link) unit, multiband audio processor (compressor/clipper), AM stereo monitor, AM stereo modulator. The C-Quam stereo system shown here is not used today. Pity, it is a much better system than the awful IBOC digital method.

Antenna phase monitor and remote controls.

Meter readings on the Harris 5KW AM transmitter. It's a real nice solid state rig. Note the efficiency. Also, note the classic frequency counter! Just for casual inspection..

The 10KW FM transmitter is kept for standby use and its antenna is atop the 5/8 wave AM tower. The main transmitter is at another site.

A control panel on the Harris FM unit. (disregard the mess, they are working in here)

A few images of the inside of the AM phasing cabinet ("Phasor"), as the back was off for some work. Yes, there is 5000 watts of RF right there!

5/8" heliax lines in the bottom of the phasor