I read in sci.electronics.design that Reg Edwards
wrote (in .
com) about 'Say what you mean.', on Sat, 26 Feb 2005:

The best I could do is ask what is the S22 of a 6J5. One thing for
certain, it is not mentioned in manufacturer's data sheets. Yet ARRL
simple PA design
rules manage very well without it.

You wouldn't expect to use scattering parameters for a 6J5. But change
that to 7194 and the question is not so facetious. (;-)
--
Regards, John Woodgate, OOO - Own Opinions Only.
The good news is that nothing is compulsory.
The bad news is that everything is prohibited.
http://www.jmwa.demon.co.uk Also see http://www.isce.org.uk