[BC] McMartin 50Kw

[Mark W. Croom]

----- Original Message ----- 
From: "Mail Radiolanes Account" <mail at radiolanes.com>
To: "Broadcasters' Mailing List" <broadcast at radiolists.net>
Sent: Thursday, June 08, 2006 10:52 PM
Subject: Re: [BC] McMartin 50Kw


> The McMartin 8000 was much better than the B-910 and never had a heat
> problem with the one I have, the B-910 is another story.
> Charlie told me some great stories about the 50kw box. The waning years at
> the Omaha factory were not good ones. But the 50kw plate modulated tx is 
> fun
> to hear about.
>
> Lane Lindstrom
>

The B-910 was my first FM exciter experience--the one that convinced me to 
avoid twiddling with the PA circuitry without having a spectrum analyzer 
handy. I recall replacing the output transistor in one of those things, and 
tuning it up for nice meter readings, then cranking up the power output 
control. What a mess--the thing got to about 7 watts then before hitting 8 
watts it went wildly spurious. Power output on the Bird went up fairly 
steadily, and ended up beyond output specs--I wasn't all that experienced 
but something didn't seem right. I called my friend Mark Persons and he 
rented me his IFR communications analyzer for a day.

Didn't take long to see what was going on. Ugly.

At least we could run the IPA with 7 watts of drive.

Mark
MN