[Amps] 8650AS Grounded Grid

[Carl]

Any of the 4X150/250 family can be run cathode driven, but not grounded 
grid. The control grid is biased and grounded for RF. The benefit is less 
power wasted in a swamped grid resistor and the driving power adds to the 
output

See the Tokyo High Power HL-1K/A for an example, a nice compact well behaved 
amp that sometimes shows up real cheap.

http://bama.edebris.com/manuals/tokyohpl/hl1ka

Carl
KM1H



----- Original Message ----- 
From: "Roger (K8RI)" <k8ri at rogerhalstead.com>
To: <amps at contesting.com>
Sent: Monday, March 25, 2013 4:14 PM
Subject: Re: [Amps] 8650AS Grounded Grid


> On 3/25/2013 11:21 AM, Glen Zook wrote:
>> The 8560A is basically a 4CX250B with conduction cooling rather than air 
>> cooling.  Therefore, I would look at the various circuits for the 
>> 4CX250B.
>
> If you have the BeO2 block, it's easy to machine a solid anode block to 
> match for the GI-7B
>
> 73
>
> Roger  (K8RI)
>
>
>>
>> The Russian GI-7b and GI-7bT tubes work well in the SB-230.  However, 
>> they do require a fan or blower.
>>
>> Glen, K9STH
>>
>>
>> Website:  http://k9sth.com
>>
>>
>> ________________________________
>>   From: K4MT <k4mt at yahoo.com>
>> To: "Amps at contesting.com" <Amps at contesting.com>
>> Sent: Monday, March 25, 2013 2:03 AM
>> Subject: [Amps] 8650AS Grounded Grid
>>
>> I know some tetrodes have been successfully run in cathode fed grounded 
>> grid configuration. Is the 8560AS one that will run grounded grid without 
>> going through the trouble of creating screen supply?  I have been 
>> thinking about putting one in my SB-230 to keep the silent operation.
>> _______________________________________________
>> Amps mailing list
>> Amps at contesting.com
>> http://lists.contesting.com/mailman/listinfo/amps
>>
>
>
> _______________________________________________
> Amps mailing list
> Amps at contesting.com
> http://lists.contesting.com/mailman/listinfo/amps
>
>
> -----
> No virus found in this message.
> Checked by AVG - www.avg.com
> Version: 10.0.1430 / Virus Database: 2641/5703 - Release Date: 03/25/13
>