[BC] One kW. AM transmitters

[Dave Hultsman]

In a message dated 4/8/2010 5:40:09 PM Central Daylight Time, RichardBJohnson at comcast.net writes:
>In those days, most all 1 kW transmitters used 833-A tubes. Collins had just made a 500-watt transmitter that used 4-250A tubes and RCA was working on a BTA1-R, which was to use 4-400A tubes, but it was not available yet.
Not certain of the years but the post war Collins 20-T, 1kW was a two cabinet rig that used two 833-A's modulating two 833-A'a in the final RF Stage.  I don't know the year the Collins 20V came out but it was the first of three Collins 1 kW AM rigs using a pair of 4-400's modulating a pair of 4-400's in the final, as did the next model the 20V-2 and in the early '60's the new cabinet style 20V-3 with solid state rectifiers. The next Collins 1 kW. AM was the 820-D1 solid state, using only four tubes,  the 5-500A's in the modulator & RF PA stage.  
 
RCA prior to the BTA-1R used 833-A's in both the modulator and RF section of several different generations. The last RCA 1 kW. was a solid state version of the BTA-1R in a 19" cabinet with four each 4-400-A tubes.
 
I will try to find the date of the first 20-V from Collins.
 
Regards,
 
Dave Hultsman
on to Lost Wages