Amps
[Top] [All Lists]

[AMPS] Additional Tube Brand Questions

To: <amps@contesting.com>
Subject: [AMPS] Additional Tube Brand Questions
From: W8JI@contesting.com (Tom Rauch)
Date: Thu, 1 Feb 2001 17:49:29 -0500
Hi Stan,

> Not having (anywhere close to) the technical knowledge of some -
> However, it seems that the L-4B deck WAS comparatively overdesigned
> for what was the legal limit (about 600W output) when it was designed.

It was a bit better than the SB-220 in some aspects, but not in 
voltage rating of tank components. It also was not cooled better 
than the 220. While it had chimneys, the blower was MUCH too 
small for more than about 300 watts *dissipation per tube* in heavy 
duty cycle modes.   

> Compare the tank components to the SB-220 that has well over 3,000
> volts.  At any rate, with additional cooling, about 3,500V, and bias,
> I get 1500W out in a 48 hour contesting environment.  Of course I am
> eliminating the normal tuning errors by carefully tuning it up on a
> single band in mulit-multi environment (no fast band switching and
> tuning).  

A person can not and should always plan on having zero load or 
tuning defects. A "shut loading cap" on a band where it normally is 
about half open is a reasonable test for a compromise between too 
much overkill and too little margin for sensible operators.


73, Tom W8JI
w8ji@contesting.com

--
FAQ on WWW:               http://www.contesting.com/FAQ/amps
Submissions:              amps@contesting.com
Administrative requests:  amps-REQUEST@contesting.com
Problems:                 owner-amps@contesting.com


<Prev in Thread] Current Thread [Next in Thread>