[AMPS] Alpha 374A

[2]

>
>Hi Rich,
>
>What's an "outout" control?
>
>The 1000MP has an output level control indeed.  But I never trust just
>turning down the output level to prevent overdrive of 8874's, they pop way
>too easily...which is why I leave the resistive pad installed in the 374A's.
>It provides sufficient attenuation to make overdrive impossible, but still
>allows the amp to run ~1500W PEP output, which is all it's supposed to do.
>
>On many rigs the RF out control is too close to other controls and could be
>easily bumped into the "gee, I wonder what vaporized the grids in my $400
>8874's?" position.
>
Autopsy shows that the 8874 grid is not damaged by overdrive.  The damage 
is to the cathode's  emissive coating - which flakes and shorts the grid. 
 /photo of flaked cathode in "Parasitics Revisited", Sept/Oct 1990 
*QST*./    

cheers, Steve
>
>> -----Original Message-----
>> From:	2 [SMTP:2@vc.net]
>> Sent:	Monday, December 03, 2001 10:08 AM
>> To:	Steve Katz; 'jbrown@luminet.net';  AMPS
>> Subject:	RE: [AMPS] Alpha 374A
>> 
>> >
>> >We use that combo among others at my contest station, K2XR (1000MP/374A)
>> and
>> >there's nothing to do to set it up except attach the coax from the rig to
>> >the amplifier...
>> >
>> >The 374A has untuned input and a large resistive swamping network at the
>> >input, I'd leave that in place for the 1000MP, to prevent overdrive.
>> 
>> Does the 1000MP lack an RF outout control?
>> 
>> -  R. L. Measures, 805.386.3734,AG6K, www.vcnet.com/measures.  
>> end
>
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>


-  R. L. Measures, 805.386.3734,AG6K, www.vcnet.com/measures.  
end


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