[Amps] Re: GU-84b: Drive power required for full power output ?

[R.Measures]

>In einer eMail vom Do, 25. März 2004 18:21 MEZ schreibt 
>frank_goenninger at t-online.de (Frank Goenninger):
>
>>I initially intended to ask if about 1A of input current will be enough
>>to really get reasonable power output?
>>
>>This comes from a simple calc from Pout of the TRX, which is about 100W
>>producing about 1.4 A of current into 50 Ohms.
>>
>>Also, for this tube, what type of input circuit would you recommend when
>>trying to cover all bands up to 30MHz ?
>
>Hi Frank,
>
>Since this is a tetrode it will be run without grid current, 
>the driver does not need to deliver current, just voltage.
>Typically the grid is loaded with a 50 Ohm dummyload, into
>which drive voltage developes without tuned circuits.
>For the higher bands you probably have to compensate the high
>input capacity with a small coil in parallel.
>I guess you will need not more then 25W drive for full throttle.
>
•  My guess is that with a 50-ohm termination, somewhat more than 25w 
will be needed to drive the grid up to the 0v point.  The grid potential 
is typically -80vdc.   64w is needed to produce 80v-pk across 50-ohms.  

cheers, Peter