[AMPS] G2DAF

[Rich Measures]

>
>Hi Chris
>
><SNIP> 
>> These were excellent designs and it seems a pity that this silent key's
>> reputation is being tarnished by this wretched amplifier. As a young boy I
>> was privileged to visit Dick in his shack and to see examples of his
>> workmanship which was first rate, both electrically and mechanically. 
>> 
>> Dick was instrumental in the growth of the use of SSB in this country and
>> around Europe because, in those days, commercial equipment which came
>> almost exclusively from the States was beyond the means of most regular
>> amateurs.
>> 
>> Just a few thoughts on a great guy.
>
>It shouldn't tarnish anyone's reputation because one circuit or 
>theory offered is a bust. No one understands everything about 
>everything.
>
€  amen, Tom.   However, unless G2DAF eventually admitted that the DAF 
amplifier was basically DAFt, he tarnished himself.  //  Another example 
is Maxwell's conjugate matching theorem.  If it were 100% true, 
amplifiers could be no more than 50% efficient.  .  

>For example, Collins had a spotless reputation of good designs, 
>yet they somehow came up with a goofy idea that lifting the grids 
>of a GG triode class AB2 PA with high reactance capacitors added 
>"negative" feedback.

€  To find out who's goofy, take a dipmeter and measure the 811A grid 
resonance in a Collins 30L-1 amplifier.  Short the grid to gnd capacitor 
by soldering a strip of copper foil from the grid terminal to ground.   
Remeasure the dip frequency.  If the dip frequency decreases with the 
short in place, Collins did not goof.  
-  later, Tom


Rich...

R. L. Measures, 805-386-3734, AG6K, www.vcnet.com/measures  


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