Collins 20K AM Broadcast Transmitter

This 1KW AM transmitter was in service in Hot Springs, Arkansas at station KBHS. M.L. Young obtained it for his Hot Springs radio museum when the transmitter was taken out of service, and it lived in ML's museum for many years. The three phase powered heavy power supply iron and modulation transformer were discarded when it was placed in the museum as a static display. When ML's health forced him to close his museum his friend James, N5ARW, obtained the transmitter with the intention of restoring it. Here's a note he posted to the CCA mail reflector in August 2001.

I am the happy owner of a 20K transmitter. It is really great with motorized controls for most adjustments. As with most restoration projects, this one is missing a few things. From the cabinet, it is missing the left side panel and the lower rear panel section below the rear doors. It is also missing all the big iron, HV transformer and choke, modulation transformer and choke. It has spent many years of its life as a museum piece and so the heavy iron was not important. I would like to take a shot at getting it working again so please pass along any leads for parts.

It also came without any documentation so I am looking for that too (original or copies). There are some of you who are especially interested in broadcast transmitters and I would appreciate hearing from you an any advise you want offer.

Thanks & 73
James N5ARW in beautiful Hot Springs National Park, AR

James quickly determined that he could not get it into his basement (ceilings and door too low) so he traded it to me for a nice Drake TR-7 transceiver. Since then, it has lived in my shop, where I admire its stately Art Deco profile. I have not done anything with it except accumulate some 220V single phase candidate transformers with the idea when I retired it would be moved to the top of my project list.
Sadly, I must downsize and relocate before even starting this project. This is your opportunity to obtain and restore a classic Collins AM transmitter.

Price: $1,000


Cash, paypal, check, money order. Email w5or for additional info


Local pickup only in West Little Rock, AR. My QTH is a few miles off interstate I-430. You will need at a minumum a half-ton pickup to transport the transmitter. Weight with extras is about 1,400 pounds. Dimensions: 78 inches x 40 inches x 30 inches.


The transmitter is partially disassembled. In particular, the wiring harnesses are disconnected to allow removing the individual chassis modules for easier transport. Individual wires in the harness are tagged for easy reconnection. All tubes are packed separately. Original power supply components were discarded, as well as the modulation transformer. A replacement modulation transformer from a Gates BC-1T which used the same PA and modulator tubes is included. There are several plate transformers to choose from if you need them. The PA is a pair of 833s, and the modulator is also a pair of 833s. Two sheet metal panels are missing, as noted by James in his 2001 posting.