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I have two questions regarding tuning of vacuum tube linears.
I have a few questions about tuning a grounded-grid amplifier running in class
AB2.
The manufacturer of my ampl supplies representative values of grid current,
plate current, and power out as an approximate indicator of normal output. I
find that I can frequently obtain the suggested P.out and Ip with substantially
less grid current (sometimes 50% less). Is this an indication of improper
operation, or perhaps worse linearity? If so, why?
Second question. If I want to run my amplifier at reduced power (say 50% for
RTTY), regardless of tuning, it seems like the efficiency of the amplifier is
less then when operating at full power. By this I mean that the P.input -
P.out yields a *relatively* larger plate dissipation number at lower input
powers than at higher input power. I'm interested to know why, and the
practical application of this is to run RTTY within a safe anode dissipation
budget.
Thanks
Ed
N1TS
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<DIV><FONT face=Arial size=2>I have two questions regarding tuning of vacuum
tube linears. </FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>I have a few questions about tuning a
grounded-grid
amplifier running in class AB2.</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>The manufacturer of my ampl supplies
representative
values of grid current, plate current, and power out as an approximate
indicator
of normal output. I find that I can frequently obtain the suggested P.out
and Ip with substantially less grid current (sometimes 50% less). Is this
an indication of improper operation, or perhaps worse linearity? If so,
why?</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>Second question. If I want to run my
amplifier at reduced power (say 50% for RTTY), regardless of tuning, it
seems like the efficiency of the amplifier is less then when operating at full
power. By this I mean that the P.input - P.out yields a
*relatively* larger plate dissipation number at lower input powers than at
higher input power. I'm interested to know why, and the
practical application of this is to run RTTY within a safe anode dissipation
budget. </FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>Thanks</FONT></DIV>
<DIV><FONT face=Arial size=2>Ed</FONT></DIV>
<DIV><FONT face=Arial size=2>N1TS</FONT></DIV></BODY></HTML>
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