[Collins] 4D32 question

[Dr. Gerald N. Johnson]

On Mon, 2007-08-06 at 17:22 -0400, jeremy-ca wrote:
> Johnson included instructions on converting to the 829B. I'd guess that it 
> was applicable to the 32V series also.
> 
> The 829B, 3E29, 5894 and 7854 are still fairly common so if 4D32's run out 
> again we always have a backup plan.
> 
> Carl
> KM1H
> 
I don't know that I've ever seen a 4D32. Does it have two tubes parallel
inside or just one? I see a 4D22 with the same specifications in my old
handbook but with a center tapped heater for 12 and 24 volts.

Anyway the 4D tubes have a rating of 50 watts plate dissipation while
the 829B has a 40 watt rating. I have boucoup 829B and plenty juniors as
832. And the bases aren't wildly different, though paralleling the tubes
in the 829 may need a little care of individual grid and plate parasitic
suppressors to keep them from oscillating.

Paralleling pieces of 5894 may not work well because it has internal
neutralization capacitors set up for push-pull operation and those would
add to the grid-plate capacitance when paralleled.
-- 
73, Jerry, K0CQ, Technical Advisor to the CRA
All content copyright Dr. Gerald N. Johnson, electrical engineer