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Re: [Amps] AL-80B transformer tap

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Subject: Re: [Amps] AL-80B transformer tap
From: "James M. Daly" <AD1L@AD1L.COM>
Date: Mon, 23 Jul 2007 04:56:45 -0400
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Thank you for your reply. Ok, so I am going to start with the 245VAC tap. I
will then search the list archives for the proper procedure for measuring
the filament voltage after that... remember complete newbie to tube amps
here (built a couple bricks in the past). 

James - AD1L

--- Gudguyham wrote:

> Hi James,  You are VERY fortunate to have such
> "nice" line  voltage.  But to 
> the point, the most important thing here is the
> filament  voltage.  You want 
> your filament voltage to be 5 volts.  Eimac will 
> tolerate 5.25 volts, but you 
> will get better tube life at 4.8 to 5 volts.   The
> thing to do is to actually 
> measure your filament voltage using the 245 tap  and
> see what it is.  If it's 
> high go to the 250 tap.  If it is spec,  you can
> stay with 245 tap.  The tube 
> must be in the socket when measuring  and measure
> right at the filament pins 
> of the tube socket.  As far as HV  goes, any tap is
> OK for that.  The lower the 
> tap, the higher your plate  voltage will be.  You
> won't notice a difference 
> of "on the air" signal but  you will get a tad bit
> more power out on a lower 
> tap.  The filament voltage  will dictate. 73 Lou

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