[Amps] 4 x GU-81 Grounded Grid Penthodes

Hsu hsu4qro at gmail.com
Tue Feb 28 17:33:28 PST 2012


4XGU-81 in GG  maybe need  300W driving power or more.
GU-81 seems not good in 15m or higher band.But I have no experience on it.
   73!Hsu


-----原始邮件----- 
From: Roger (K8RI)
Sent: Wednesday, February 29, 2012 7:50 AM
To: amps at contesting.com
Subject: Re: [Amps] 4 x GU-81 Grounded Grid Penthodes

On 2/28/2012 1:43 PM, Máximo EA1DDO_HK1H wrote:
> Hi all,
>
> Ok, so lets do that, 4 x GU81 grounded grid configuration.
> Anyone has a schematic to follow?
> What levels could be fine?
As  the suppressor grid is normally grounded and serves as a shield to
prevent secondary emission, how would this affect running the tube in
grounded grid...if at all?
I would think it would tend to lower the gain in GG, but that's just a
guess.

73

Roger (K8RI)
>
> Thank you
>
> 73, Maximo - EA1DDO
>
>
>
>
>> From: wlfuqu00 at uky.edu
>> To: ea1ddo at hotmail.com
>> Date: Mon, 27 Feb 2012 16:25:31 -0500
>> Subject: RE: [Amps] 833A/GU-48 x4 Amp support
>>
>> Maximo,
>>    Look at:
>>   2 x GU81 Grounded Grid; 
>> http://f5ssk.blogspot.com/2011/06/2-gu-81-grilles-la-masse.html
>> If you ground all the grids you don't need a bias supply.
>>
>>
>> 73
>> Bill wa4lav
>> ________________________________________
>
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> Amps mailing list
> Amps at contesting.com
> http://lists.contesting.com/mailman/listinfo/amps
>


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