[Amps] Advice

[Carl]

I believe that goes way back to the "if one is good then 2 must be better 
phrase"

Since a single ended 100TH, for example, couldnt make a KW on CW then using 
a pair solved the problem. It actually goes mack to the original discovery 
of PP or parallel tubes sometime in the 20's or earlier.

Its also a lot easier to run a pair of 8877's then stepping up to 3 kW +  Pd 
tube such as the 3CX3000A7 which is a drive and filament power hog. The tube 
of choice then is the YC-156 which has its own issues.

And for the cost involved 3 or 4 813's can make some serious RF. I use 4 in 
one of my AM amps.

Carl
KM1H


----- Original Message ----- 
From: "Bill, W6WRT" <dezrat1242 at yahoo.com>
To: "Roger" <sub1 at rogerhalstead.com>
Cc: "Carl" <km1h at jeremy.mv.com>; <amps at contesting.com>
Sent: Thursday, December 03, 2009 4:21 PM
Subject: Re: [Amps] Advice


ORIGINAL MESSAGE:

On Wed, 02 Dec 2009 22:13:02 -0500, Roger <sub1 at rogerhalstead.com> wrote:

>Tubes should always be used as a pair,
>except for 813's and 572's and then you use 4 of them.

REPLY:

First time I've ever heard "tubes should be used as a pair". I have heard 
the
opposite: "If you need more power, don't use two tubes, get a bigger tube".

Care to elaborate?

73, Bill W6WRT