[BC] RCA BTA 1R2

[WFIFeng@aol.com]

In a message dated 11/16/2005 7:56:56 PM Eastern Standard Time, 
kkty at netcommander.com writes:

> 
>  Mine's blue on blue... and after we let all of the smoke out of those
>  rectifier boards, a smart old ham did replace them with solid state 
critters
>  & never had any more problems with it.

They must have at least a couple dozen diodes on each board. I'm sure they 
could be replaced with a handful of new, HV diodes, instead. This box was 
removed from service as a still viable backup, so because it still works, I'm not 
going to "fix it".

>  Those 4-400's were one of the main reasons I justified buying the Nautel. I
>  was up to about a grand a year just for tubes. 

Wow! Since this unit will be a backup, I don't expect there to be much 
tube-changing going on, though.
When we had the old CCA, it used a pair of 4-1000a's for the modulators. We 
had to change 'em at least every year. At one point, we did a major overhaul, 
replacing them with a pair of 4CX3000's. That change kept us going for a couple 
years, with no sign of going soft. Then we got the Harris, and donated "Ol' 
Bessie" to Science... a college in NY State picked it up.

> And the rig's basically a
>  forced-air furnace with a transmitter attached. If I remember right, it's
>  rated about 35% efficiency, and that was when it was new.

Good gravy! I am guessing that that is Line-to-Antenna?

>  It was, however, usually a very reliable old transmitter, and it's still
>  online as a backup. Haven't had it on for almost 3 years, though, as the
>  Nautel never even burps.

Our Harris has been a cream puff, also. Still, it's never good to have 
*nothing* as a backup. We finally got rid of "Ol' Bessie" because it had developed 
an intermittent that I just couldn't nail down. It wasn't worth investing the 
time/money on it. It was "alive" as a backup for only two months before the 
failure became almost total. I guess just sitting idle day after day was too much 
for it. I was excercizing it monthly... on the 3'rd excercize cycle, she just 
couldn't make more than a couple hundred watts. That was it.

This old RCA has been their standby for some time. It's main power tranny 
fried when it was pressed into full-time service when their main conked out. 
Their main is going to become the backup when they get a shiny new Nautel. It was 
a nice deal, actually. This old RCA has that Ye Olde electronics smell to it. 
Hopefully, that's *not* from PCB residue. It is also only 1/2 the size of Ol' 
Bessie, so we still have plenty of room in the TX bldg.

Willie...