[Milsurplus] re Curtis A-12 Aircraft

[Mike Morrow]

>The BC-AA-191 did not have an internal antenna relay and 
>some other internal parts that the BC-191-a  had. It was quite
>similar to the GE RT-76 which is described in ith IEE proceedings
>of about 1932.

Mike Hanz's web site has that article.  See below.

The BC-AA-191 most obviously lacks the antenna tuning networks
and antenna switch relay that are on the right side of the later
BC-191-* units.  The major components are:

BC-AA-191  Transmitter
BC-AA-192  Remote control box
BC-AA-193  Antenna tuning unit, 400 to 800 kc, aircraft trailing wire
BC-AA-194  Antenna tuning unit, above 800 kc, aircraft or fixed station
BC-AA-196  Antenna switching unit (mounts on top of antenna tuning unit)
BC-AA-204  Antenna tuning unit, 1500 to 4500 kc, vehicle whip
BD-AA-67   Dynamotor (unverified)
TM-AA-160  System junction box
TU-AA-3    Transmitter tuning unit,   400 to   800 kc
TU-AA-4    Transmitter tuning unit,   800 to  1500 kc
TU-AA-5    Transmitter tuning unit,  1500 to  3000 kc
TU-AA-6    Transmitter tuning unit,  3000 to  4500 kc
TU-AA-7    Transmitter tuning unit,  4500 to  6200 kc
TU-AA-8    Transmitter tuning unit,  6200 to  7700 kc
TU-AA-9    Transmitter tuning unit,  7700 to 10000 kc
TU-AA-10   Transmitter tuning unit, 10000 to 12500 kc

Mike Hanz's web site has a wealth of information on this equipment.

(1) IRE August 1932 article on the commercial version, RT-76-A:
http://aafradio.org/docs/GE_RT-76-A.pdf

(2) Pictures and discussion of the transmitter:
http://aafradio.org/garajmahal/BC-AA-191.htm
Includes picture of receiver switching relay function change
switch that lists receivers BC-AA-179 and BC-189 (position 1)
and BC-AB-199, BC-AD-199, and BC-AD-219 (position 2).

(3) The BC-224-A (said to have also used with the BC-AA-191), and the
BC-189 are shown here:  http://aafradio.org/flightdeck/1935/1935.html
(Didn't the BC-224-A first appear in 1937?)

Great and fascinating stuff, Mike!  You'll soon be wanting to expand to
RDFs of the pre-WWII era, such as the BC-310 (SCR-242) from 1937.

Mike / KK5F