[Top] [All Lists]

Re: [Amps] SB-200 DATA

To: "Tom W8JI" <>, <>,<>
Subject: Re: [Amps] SB-200 DATA
From: "jeremy-ca" <>
Date: Tue, 17 Jul 2007 22:48:34 -0400
List-post: <>
The point that I have been proving for almost 40 years is that the SB-200 is 
an excellent candidate for 6M. Dollars per watt it is the best deal around 
and a preferred choice by many who do not want to install a 240VAC line into 
the shack. The 572B's work fine and last a long time which is really what 
its all about.

Since the output and efficiency is comparable with mid HF I doubt if 50 MHz 
is actually that close to the upper limit. I suspect that it is an 
arbitrarily set number.

There certainly is no magic to making sweep tubes work on 6M either. Ive 
converted several 2-3 tubeCB amps. There was an engineer at National that 
converted many NCX-3's to 6M also so the precedence was set over 40 years 
And dont forget the Drake TR-6 using 3 6JB6's; it worked very well and is 
still a sought after rig.


----- Original Message ----- 
From: "Tom W8JI" <>
To: <>; <>; <>
Sent: Tuesday, July 17, 2007 10:11 PM
Subject: Re: [Amps] SB-200 DATA

>I> In a message dated 7/17/2007 7:48:51 P.M. Eastern Daylight Time,
>> writes:
>> Converting the SB-200 to a 6M monobander is simple and straightforeward 
>> when
>> basic design principles are followed. Ive been doing those conversions 
>> since
>> the late 60's and it is completely stable and  repeatable. Power output 
>> and
>> efficiency is the same or better than a good  stock unit on say 20M.
>> Carl
>> Carl, Indeed, the word on the street is that the 572B is not good to 6
>> meters, but as you say if it is handled properly it can be made to be 
>> rather
>> stable and the power in the 700 watts range easily.  I haven't really 
>> seen  a
>> published article that really "gets it right" however. Lou
> I think you fellows are missing the point entirely. There is a BIG 
> difference between "I can make it work" and "it is a good choice".
> I can make a sweep tube work on six meters, but it doesn't mean it is a 
> good choice in tubes for six meters.
> Using a tube right at the upper limit frequency isn't the best idea, 
> unless you just have no other choice or are trying to prove a point.
> 73 Tom

Amps mailing list

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