[Amps] ALPHA 77

Conrad G0RUZ g0ruz@btinternet.com
Mon, 5 Aug 2002 01:44:33 +0100


-----Original Message-----
From: amps-admin@contesting.com [mailto:amps-admin@contesting.com]On
Behalf Of 2
Sent: 05 August 2002 00:17
To: Phil Clements; dhearn@ix.netcom.com; Bob; AMPS
Subject: Re: [Amps] ALPHA 77




>> Why would one need to tune for grid-current ?  Minimal grid current does
>> not give a correct tune.  Maximal grid-current does not give a correct
>> tune.  A correct tune is max out with the drive needed to produce 1A of
>> anode current per 8877 -- which coincidentally results in c. 100mA
>> grid-current per grid, which could be seen on a 0-500 scale.  However,
>> there is no need to measure  grid-current on a cathode-driven amp.
>> Grid-driven, yes.
>
>When I tune an 8877 amp, I tune everything for maximum power out.
>I then tweak the PA loading cap slightly to give a needle-width decrease
>on the wattmeter. I need to see the grid current at this time to make sure
>it goes down and not up when making this adjustment. This slight reduction
>in suds makes a nice increase in clean. 

>>True, Phil, but the 8877 is so clean that there are no transceivers even 
>>in the same league.  

Ain't that the truth and ain't that a disgrace!

Conrad G0RUZ