[AMRadio] Push-pull Triode HF PA layout question

ne1s ne1s at neandertech.com
Mon Feb 6 15:30:35 EST 2006

Hello all, 

I humbly request the experience-based advice of this esteemed group. 

I am working on a project, part of which involves completion of 1930s 
Push-pull trode PA deck for 80M - 10M. Notice I said "completion," not 
"construction." This deck already has the plate tank components, tube 
sockets, and neutralizing capacitors mounted on a beautifull black-wrinkle 
chassis & panel. The axis bisecting the holes for the tubes is parallel to 
the front panel, the plate tank air variable (split stator) is perpendicular 
to the front panel, and the plate tank coil (plug-in jack-bar style - 
actually I'll be using BC-610 coils, link-coupled to the antenna) is 
centered directly behind the plate tank capacitor, with its axis parallel to 
the front panel. What this deck lacks is a grid tank circuit, which I need 
to add. The tubes will be 812s or T-55s, and will be plate-modulated for 250 
 - 300W output. 

What is the worse sin: lack of physical symmetry, or proximity of the 
gazinta to the gizouta? It seems that I'll have to compromize one or the 
other in adding the grid tank circuit, based on the present layout. The grid 
tank will be link-coupled to the exciter. 

Thanks for your assistance, 


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