202BTA Autotune Transmitter
That's the baby! My recollection was that there was an engraving on one of the front panels to the effect that it was built for the Yacht Moana.
I think that the finals were behind the panel with the dialer. The bottom chassis contained a humongous power supply. There were wheels on the base, but moving it around, even a few inches, was a challenge.
I don't know the difference between the BA and BTA. I do know that the autotune mechanism was the forerunner of what they used in the WWII airborne ART-13. It was difficult to maintain the autotune and jams were frequent. Most of the time we used only 1 or 2 of the crystal channels. [10-7-07]
Notes from Steve Aug '56A, W3DEF
That sure looks like the one we had at W2DSC. In fact, we had both units. The transmitter was known as a Collins Autotune. It could be set on any one of 10 preset channels. Changing channels was accomplished by dialing up the channel number (1-10), using the telephone dial on either the transmitter or the speech amplifier unit which, I think, also served the yacht as an onboard telephone switchboard. The dial would set in motion a step-by-step switching system of the type then common in telephone central offices. With much clanking and whirring the transmitter would set itself to one of the 10 crystal controlled pre-tuned channels.
I think one of the meters indicated which channel was in operation. [10-7-07]
Notes from Merv MacMedan, N6NO
I remember using the Collins Autotune at W2DSC. I brought a crystal for my net "The Teen Agers' Net, TAN" to school, fired up the Collins on 3630 kHz CW and with the sun still up (around 6pm) I called my net and got check-ins from up and down the entire east coast. I was thrilled to get that kind of DX in daylight! (We used that dipole in the picture with me and Mel Cogen.) Tune-up was difficult, though. As I recall the channels were crystal controlled and pre-set with the output tuning capacitors and coils set with little motors that had cams and cam followers. Once it was set up, however, you could QSY to any frequency that had been pre-set in an instant using the telephone dial. I believe we decided to retire it mainly because it lacked a VFO, and modern radios of the time were sporting VFOs [10-13-07]
More about the Yacht Moana, aka USS Hilo
http://www.navsource.org/archives/12/09058.htm (with photos)