>
>
>-----Original Message-----
>From: Hans Goldschmidt <sm5ki@algonet.se>
>To: measures <measures@vcnet.com>; amps
><amps@contesting.com>
To: <amps@contesting.com>
>Date: 30 October 1999 17:50
>Subject: SV: SV: [AMPS] feedback sought: Ameritron AL-80
>
>
>
>Thanks!
>
>Yes, a string of short pulses and a pep output meter is the
>right method
>tuning up an amplifier. For a grounded grid linear, tune for
>maximum output
>and increase loading a bit beyond that and try to keep the
>manufactures
>recommended relationship beetween anode and grid current.
>The grid current
>is also a good indicator of proper loading.
>-------------------
>In all the Eimac data for g-g triodes I can recall, there is
>a statement that the grid
>current value is immaterial provided it is within the spec.
>maximum.
Close enough. For a g-g amp., when the grid current is too high, not
enough electrons reach the anode and power output decreases. When grid
current is too low, the anode potential swing is reduced and power output
decreases. Tune for max power out with max drive (provided you do not
exceed the emissive limit of the cathode) and you achieve a correct
tune-up.
>There isn't a recommended relationship, although
>there are 'typical' values. Clearly, you can use it as an
>indicator for any given tube once you have established how
>that tube behaves - in practice, are tubes sufficiently
>similar to aim for the typical values every time? I guess it
>will vary according to PSU regulation too?
Surely, Steve. Decreased anode volts means more grid current.
- Rich..., 805.386.3734, www.vcnet.com/measures.
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