[Amps] Grounded Grid (Screen) 4CX250B power gain

Carl km1h at jeremy.mv.com
Wed Jul 22 17:42:19 PDT 2009


Zero is an absolute value which really doesnt exist in the 4CX1000A. There 
is enough overhead to do what Gary mentioned.

Carl
KM1H


----- Original Message ----- 
From: "Roger" <sub1 at rogerhalstead.com>
To: "Gary Schafer" <garyschafer at comcast.net>
Cc: "'Carl'" <km1h at jeremy.mv.com>; <amps at contesting.com>
Sent: Wednesday, July 22, 2009 1:15 AM
Subject: Re: [Amps] Grounded Grid (Screen) 4CX250B power gain


>
>
> Gary Schafer wrote:
>>
>>> -----Original Message-----
>>> From: amps-bounces at contesting.com [mailto:amps-bounces at contesting.com] 
>>> On
>>> Behalf Of Roger
>>> Sent: Tuesday, July 21, 2009 5:40 PM
>>> To: Carl
>>> Cc: amps at contesting.com
>>> Subject: Re: [Amps] Grounded Grid (Screen) 4CX250B power gain
>>>
>>>
>>>
>>> Carl wrote:
>>>
>>>> Yes, if you mean cathode driven. It has less grid dissipation than a
>>>>
>>> 250.
>>>
>>>>
>>> Yah can't get much less than zero<:-))
>>>
>>> 73
>>>
>>> Roger (K8RI)
>>>
>>
>> The 4CX250 actually can be run in AB2 as it can stand a couple of watts 
>> of
>> grid dissipation. There are AB2 specs for that tube.
>> The 4CX1000 is only rated for AB1 operation. Zero grid current, however
>> Eimac says that a small amount of grid current is acceptable for 
>> overdrive
>> monitoring as in developing ALC from the grid current/voltage change.
>>
> That seems strange as the grid is rated at zero watts dissipation.
>
> 73
>
> Roger (K8RI)
>> 73
>> Gary K4FMX
>>
>>
>>
>> 



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