>Hi all on the list:
>
>I have now tried to find (for several days) a design that builds a
>power supply for about 3.5kV and 2A.
>I'm looking for a regulated power supply design where output voltage
>does not drop more than 1% on load.
** The positive-floating V regulator circuit shown at:
http://www.somis.org/D.a.08.GIF
regulates to better than +/- 0.1%. I have used this circuit to regulate
6000V.. Since an FET pass element is utilized, many tens of amperes of
output current are possible by paralleling FETs and adding heatsinks. .
> I will be using a 3-phase 400V
>mains line.
>
>The objective is to have a "standard" power supply for various amps
>I have in the pipeline - starting with a GU-84b based grounded-cathode
>project. Next, I want to build one with a 4CX3500A (boy, what a piece of
>electronic device, wow).
>
** 4cx3500A tubes manufactured by Eimac/CPI reportedly have had
problems with the screen's ceramic insulator.
-- If you build a Class AB1 amplifier around any tetrode, to prevent a
runaway condition of reverse screen current, bleed a constant 25 - 30 mA
from the screen supply.
- Example at:
http://www.somis.org/D.a.05.GIF
-- Free advice for SSB-mode AB1:
1. Do not skimp on anode and screen V unless you are a QRP fan. If I
was going to build an amplifier with a 4cx3500A, I would start with a
least 6000V under load on the anode and 1200V on the screen . Otherwise,
you might not be able to utilize the full emissive capability.
2. Neutralize (see http://www.somis.org/D.a.05.GIF).
3. Under no circumstances tune the grid with a capacitor.
4. Except for >100MHz, consider using the 8171/4cx10,000D. It does not
require a noisy high-pressure blower; it costs less, it can make more P;
a low IMD version is available; plus it also has handles.
5. For any tetrode, to prevent a potentially fatal, runaway condition of
reverse screen current, bleed a constant 25 - 30 mA from the screen
supply.
>So, all the "surrounding" modules should be as much adjustable as
>possible...
>
cheers, Frank
have fun
_______________________________________________
Amps mailing list
Amps@contesting.com
http://lists.contesting.com/mailman/listinfo/amps
|
