Amps
[Top] [All Lists]

Re: [Amps] cathode to ground in tetrode amp

To: amps@contesting.com
Subject: Re: [Amps] cathode to ground in tetrode amp
From: "Will Matney" <craxd1@verizon.net>
Reply-to: craxd1@verizon.net
Date: Tue, 31 Jan 2006 00:08:29 -0500
List-post: <mailto:amps@contesting.com>
Jim,

That's what it's for but it don't look to be the right value. The original dwg 
(black dwg) looks to be a 15K 20W. Others I've seen though use a little more 
resistance than that if I recall. About all screen circuits I've seen will have 
that because of being able to have + and - current at times. Because of this 
same thing, a shunt regulator is better than a series like the one in the black 
dwg. The design in the black dwg will work though as it has been built by 
another ham. Below is a link to an amp using a GU-43B and it uses a 27K 10 watt 
with a shunt regulator. There is also two 230 Vac varistors in series to ground 
off the screen (safety). The screen voltage runs about +350 on this amp and is 
a decent setup. One thing this ham does is to use a light bulb for the shunt 
regulators dropping resistor.

http://www.xs4all.nl/~pa0fri/Lineairs/Frinear1500/FRI1500eng.htm

Best,

Will





*********** REPLY SEPARATOR  ***********

On 1/30/06 at 9:27 PM Jim Tonne wrote:

>Subject: Re: [Amps] [BULK]Re: [BULK]Re: cathode to ground in tetrode amp
>
>The 22 uH and 1000 pF in the grid peaks at 1 MHz and rolls off at 12 dB
>per octave after that.
>
>Can anyone tell me why they put a 12K resistor from screen to ground?
>Its on the load side of the screen current meter.  Perhaps negative screen
>current sometimes?
>
>-JT
>
>
>_______________________________________________
>Amps mailing list
>Amps@contesting.com
>http://lists.contesting.com/mailman/listinfo/amps



_______________________________________________
Amps mailing list
Amps@contesting.com
http://lists.contesting.com/mailman/listinfo/amps

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