[BC] XERA Historical Question

[Xmitters@aol.com]

Hello:

I received an article reprint that described the various power increases that 
took place at XERA in Mexico. I have a question for the group regarding the 
configuration of the 180 kW high level plate modulated PA. The article 
describes the PA system as being made up of eight 232A triodes in parallel, modulated 
by four UV-862 Triodes in a push pull parallel modulator. Each pair of UV-862 
triodes are capable of 90 kW of audio, but each 232A triodes in the PA is only 
capable of 12 kW plate modulated, so eight of them would then give 96 kW 
which would be 84 kW short of the supposedly rated 180 kW PA. Any of you 
historians have any details about the 180 kW rig?

This same article also describes the 500 kW Doherty designed by James O. 
Weldon and that description appears to be complete.

Prior to going to 180 kW, XERA had a 50 kW Western electric 407A, low level 
plate modulated, conventional class B linear amplifier made up of six 232A 
triodes. Mr. Weldon added two more 232 triodes which increased the transmitter 
power to 65 kW. According to the article, these eight 232A triodes were rebiased 
for class C making a 180 kW PA which was then high level modulated. Eight 232A 
triodes are not capable of this much power, according to my tube data sheet.

I would have to rewrite the article to fill in all of the details I've left 
out regarding the various stages of the XERA upgrade project. BTW, this article 
was originally published by the Radio Club of America written by Durell M. 
Roth.

Anyone have some other details?

Thanks,

Jeff Glass