[Amps] AL1200, RTTY contesting, temps, duty cycles (not 100%)

[Bill, W6WRT]

ORIGINAL MESSAGE:

On Sun, 5 Jul 2009 09:03:15 +0800, "Jeff Blaine AC0C" <keepwalking188 at yahoo.com>
wrote:

>
>If I'm not missing my guess, I think you would only approach the tube plate 
>disipation limit at up to something like 1100 ma of plate current and 
>perhaps 100w drive.  Assuming the same overall efficiency, that would be 
>around 1200w out and a bit over 1KW of plate dis.  I'm assuming the B+ line 
>would drop slightly off the 2KV level.  The 3500z is a pretty tough beast - 
>if you can keep it's feet cool.

REPLY:

The 3-500Z cathode current limit is 400 Ma or 800 mA for two tubes. The 3-500Z
will work at 2 kV on the plate but it is happier with more. At 3 kV and 800 ma
you have 2400 watts DC input and with a decent tank circuit, should get 1500
watts out or very close to it. Also, at 3 kV on the plate, it can be run "zero
bias" which means you don't need a zener in the filament circuit.

73, Bill W6WRT