[AMPS] Amp Tuning (was 3-500Z Grid Current Rating)

[Rich Measures]

>
>> I've found with my Henry that using the old "dip and load" technique
>always
>> leads to the best operating condx
>
>snip...
>
>> With modern gear there sometimes is a tendency to simply tune for max
>output without paying
>> close attention to the grid/plate.
>
>snip...
>
>Thanks, Dave. I'm glad somebody finally said this. I've seen a lot of posts
>here about tuning for max output, and I've never been able to reconcile that
>approach with the old "dip and load" technique I learned with my first tube
>transmitters back 15-16 years ago.
>
€  A Pi-network tank is Not the same animal as a parallel-resonant tank.  
A Pi-network is two L-networks in series.  L-networks are never resonant. 
 An enlightening dose of reality is to tune up a Pi-network tank 
amplifier at full suds, shut down, unplug from the electric mains, wait 
until the hv meter goes to zero, and measure the resonant frequency of 
the Pi-network tank circuit.  .  What!   The tank resonance is lower in 
freq. than the operating frequency?  No way!.  .  This must be a trick, 
right?
-  It is my opinion that for a Pi-network tank, dip and load is not the 
right road.  Better to start with heavy loading (minimal C-load) to 
reduce dissipation in the grid, apply max. drive, and tune for max. 
P-out. 
€  Grid-dissipation can not wax when P-max is going down the coax.    

-  cheers



Rich...

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


--
FAQ on WWW:               http://www.contesting.com/ampfaq.html
Submissions:              amps@contesting.com
Administrative requests:  amps-REQUEST@contesting.com
Problems:                 owner-amps@contesting.com
Search:                   http://www.contesting.com/km9p/search.htm