[Elecraft] Driving a linear with only 15 watts?

[Charles Greene]

Darwin,

I have a linear that has about 1000 watts output when driven with 
approx. 60 watts in class AB2 for CW and a little more when operating 
class AB1 for SSB.  It's an old Hallicrafter HT33A with a PL172 
pentode amplifier tube.  I tried it using my K2/100 on PSK31 with 20 
watts average power from the K2/100.  The amp put out 400 watts ave 
power.  The IMD coming out of the amp was identical to the IMD of the 
K2/100 without the amp, indicating no more distortion was added by 
the amp.  I don't expect you to hunt for a HT33A, but the principles 
are the same.  The efficiency is lower because of the idling power, 
but since it is all coming out of the power line, who cares?

73,  Chas W1CG



At 11:13 AM 3/8/2006, Darwin, Keith wrote:
>Since a linear amp is supposed to be "linear", is there any reason that
>you have to run 65 to 100 watts into one?  What if you used a linear
>designed for 65 watt drive and only gave it 15 watts?  Does the spectral
>purity change?  Does the efficiency drop?  Does the linearity degrade?
>
>- Keith KD1E -
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