[BC] BE 1 KW am transmitter SS

[Mark W. Croom]

Yes yes I just fixed this in another TX controller. It was an FM, but I'd 
just about bet the basic idea is the same.

It's a small multi-output switcher. It powers the controller logic, without 
which the tx appears dead.

It has three sections, like most switchers I've seen. The input section, the 
"oscillator" part in the middle, and the regulator section on the other end.

If it appears dead, you know the problem's got to be either the input or 
middle section. Generally, when a switcher quits switching, it's because 
some frequency-dependent electrolytic in the "switching" part is out of 
tolerance. Just watch out when you play with that thing "connected" because 
it does run on 240VAC input.

BE told me the symptom is that after shutdown the transmitter won't come up 
for half an hour or an hour, if at all. This happened to me a couple times 
before I got wise to what was going on. By the time I called BE about it I 
was at the "if at all" stage and was off the air. They were going to 
overnight me another supply, but I didn't want to wait until the next day to 
get it back on.

Sooo...I started swapping caps in the middle section, especially where it 
appeared there had been some heat accumulation, and that got it back to 
switching again.

Good thing, too, because we had a major snowstorm coming in that night 
(Wednesday two weeks back) so my part didn't show up until the next MONDAY. 
*sigh*

Mark
MN


----- Original Message ----- 
From: <Mglin at aol.com>
To: <broadcast at radiolists.net>
Sent: Thursday, March 15, 2007 10:34 AM
Subject: Re: [BC] BE 1 KW am transmitter SS


> Any of you had experience with the 1kw not coming back on after being shut
> down for an hour.  The 240 v  meter shows we have AC.  No other  lights 
> come on.
> BE says the small power supply has some bad caps and to replace the PS.  I
> ordered a new one but wonder if any of you have ever worked on the supply
> itself?
>
>
> Mike
>
>
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