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8875/8874/MLA2500 ?

Subject: 8875/8874/MLA2500 ?
From: Joe Subich" <subich@ramlink.net (Joe Subich)
On 2/9/96 you wrote: 

> MLA2500 owners, etc....
> Has anyone tried a 8874 in place of the 8875?

There is a major difference between the 8874 and 8875.  The '75 uses 
trasnverse cooling where the '74 uses axial cooling.  To change the 
tube would require major mechanical changes to pressurize the area 
under the chassis and build a chimney for each tube.  The chassis is 
quite open aproximately the front half in the RF side) and the bottom 
of the case have a great many vents.  

The mechanical changes necessary to convert the MLA-2500 to use 8874s 
would amount to almost a complete rework of the packaging ... and even 
then the electrical problems (driving impedence, grid metering, 
improper plate circuit Q on some bands) would remain. 

73, 

   ... Joe Subich, AD8I
       <subich@ramlink.net>

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