Hi Charlie,
Glad to see you going with the g-grid circuit. You'll find the 4-400
amplifier
slightly harder to drive vs the similar 3-400/3-500Z.
I have most of the input circuits for the common tubes, the trouble is
the
paperwork was done before solid state final exciters. The lower Q of the
older designs plays havoc with some exciters. I've seen a real
interesting
oscillator made from an early SS exciter final where one wasn't wanted.
I'm in process of rebuilding my personal SB-220 with all the current
fix's,
during last nights late night tune up into a termination, I measured the
factory SB-220 swr using my TS-940. The best obtained was about 1.6 to
1 sweeping the entire 80/40/20 meter bands. Although my 940 seems to
drive it fine, "your results may vary."
I hoped to avoid rebuilding the input for a higher Q, but it looks like
it
should be a "must include" for a new project.
Rich mentions the SB-220 input factory Q about 1.6 and suggests more.
I agree with that opinion. His web site probably has the information
you need. I can scan the 4-400 inputs I have (better than nothing) here
for the sonic server, but it'll have to wait until next week. I'm in the
middle of another server upgrade process.
________________________________________________________________
YOU'RE PAYING TOO MUCH FOR THE INTERNET!
Juno now offers FREE Internet Access!
Try it today - there's no risk! For your FREE software, visit:
http://dl.www.juno.com/get/tagj.
--
FAQ on WWW: http://www.contesting.com/ampsfaq.html
Submissions: amps@contesting.com
Administrative requests: amps-REQUEST@contesting.com
Problems: owner-amps@contesting.com
Search: http://www.contesting.com/km9p/search.htm
|