[BC] RE: substitute driver tube for FM-2.5K ?

[Gary Glaenzer]

yes, this one does have the connector

I will keep that idea in mind

Thanks !

G


----- Original Message ----- 
From: "Tom Taggart" <tpt at eurekanet.com>
To: <broadcast at radiolists.net>
Sent: Tuesday, March 27, 2007 6:07 AM
Subject: [BC] RE: substitute driver tube for FM-2.5K ?


> The "H" and at least some of the "K"'s had a coaxial connection from the
IPA to the PA cavity.
>
> Get a good exciter with at least 30 watts of drive, pull the IPA out, and
feed the exciter directly into the PA.
>
> Works fine.
>
> Remember that Collins (later Continental) had a similar design 2.5 kw
transmitter which had no IPA.  Instead their exciter had 20 watts driving
the final.
>
> I have a 2.5 "H" that developed a short in the IPA socket.  Was blowing
the fuse on the 700 volt IPA plate supply (which also supplies screen
voltage to the final).  This happened on a weekend, of course.  At the time
I was using an MX-15 to get  1100 watts out (small Class A with a high
AHAAT).  To get something up and running I snipped & taped the plate
connection to the IPA & ran the MX directly into the PA.  Had to turn the
exciter's output down because the IPA was acting more like a buffer than an
amplifier.
>
> Now, of course, you need more drive than that to run the transmitter at
full power. The MX, at full bore, will only get you half power.  We
subsequently got a mod on this station to increase power to near equivalent
6 kw A, which required a TPO of 2450 watts. So the MX was replaced with an
802A, then a much newer BE FX-50.  About 25 watts gives me the required TPO.
> -- 
> _______________________________________________
>
> The BROADCAST [BC] list is sponsored by SystemsStore On-Line Sales
> Cable-Connectors-Blocks-Racks-Wire Management-Test Gear-Tools and More!
> www.SystemsStore.com       Tel: 407-656-3719    Sales at SystemsStore.com
>
>
>
>
> -- 
> No virus found in this incoming message.
> Checked by AVG Free Edition.
> Version: 7.5.446 / Virus Database: 268.18.18/734 - Release Date: 3/26/2007
2:31 PM
>
>