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Re: [Amps] Is this tube anygood for a monoband 80meter GG amp

To: Carl <km1h@jeremy.mv.com>, Jeff Pederson <kd4lyh@yahoo.com>, "amps@contesting.com" <amps@contesting.com>
Subject: Re: [Amps] Is this tube anygood for a monoband 80meter GG amp
From: "Fuqua, Bill L" <wlfuqu00@uky.edu>
Date: Wed, 18 Dec 2013 00:55:24 +0000
List-post: <amps@contesting.com">mailto:amps@contesting.com>
  It is similar to a 3-1000H except for filament and the mu is 20 instead of 
24. 
You can run it in grounded grid, with sufficient grid bias and lots of drive. 
   There is nothing wrong with running a low mu tube in grounded grid as long 
as you 
have the drive capability for the output you want. An example is in one of the 
Bill Orr
Radio Handbooks where there is an example of a 304TL run in GG. It takes 200 
Watts 
drive for 800 Watts output. 
   I ran a pair of 250TH when I was young. I had scavenged a HT-4 for parts and
had lots of spare tubes. It has somewhat higher mu but it worked great. 
However, legal limit
then was 1kW average plate input power.  
   You could run it in grid driven neutralized if you like. A little more 
complex but is 
a classic design. If you want something really different, you can use an 
inductor (with DC block cap)
between plate and grid to resonate with grid plate capacitance. This was often 
used with single
ended triode single frequency AM broadcast transmitters. Hows that for being 
different.

73
Bill wa4lav

________________________________________
From: Amps [amps-bounces@contesting.com] on behalf of Carl [km1h@jeremy.mv.com]
Sent: Sunday, December 15, 2013 2:01 PM
To: Jeff Pederson; amps@contesting.com
Subject: Re: [Amps] Is this tube anygood  for a monoband 80meter GG amp

With a mu of only 20 it would be a poor choice for GG but it would make a
great AM Class C grid driven amp for one of the many 100W rigs.

I recently passed on 4 supposedly NOS ones.

Carl
KM1H


----- Original Message -----
From: "Jeff Pederson" <kd4lyh@yahoo.com>
To: <amps@contesting.com>
Sent: Saturday, December 14, 2013 9:04 AM
Subject: [Amps] Is this tube anygood for a monoband 80meter GG amp


>      Good Day,
>  Well its been awhile since I posted to this list but read the posts.  My
> weakness is how to determne if this tube is suitable for use as a ssb amp
> and does anyone have a tutorial or link on how to use the constant current
> characteristic tube charts? That -1000v grid in the specs makes me think
> it wont work or be practical but thats why Im asking.
>
> http://www.ok1rr.com/tubes/Thales/T1000-1.pdf
>
>
> Happy Holidays
>
> Jeff
> KD4LYH
> _______________________________________________
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> http://lists.contesting.com/mailman/listinfo/amps
>
>
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