[AMPS] input Q upgrade

[measures]

>
>nospam4me@juno.com wrote:
>> 
>> 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.
>
>It took me awhile to "see the light", but I think that I'm now on
>track!  Tnx!
>
>> 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 don't have any problems driving my SB-220 with my TS-930.  I'm hoping
>that will stay the same with the gg 4-400's.
>
€  When a G-G amplifier is driven with roughly 1w, the input Z is way 
different than normal.  However, when the driving power is around half of 
normal, the input Z is almost normal. 
 The TS-930 auto-tuner has the advantage of operating at half-power 
during tuning.  Later model transceivers have the disadvantage of 
auto-tuning with roughly 1w.   

cheers 
.

-  Rich..., 805.386.3734, www.vcnet.com/measures.  


--
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