[Amps] Plasma Thermo HFS 3000D

[Phil Clements]

> 
> It's a 3 phase. I guess the HV tran would work on single phase ok using
> the
> two outer winding in parallel but would lose 30% or 40% of its power
> capability. Probably at that it would still handle 2500 watts input for
> quite a long time. Lots of times the other transformers ( include filament
> )in units like these have multiple taps for 207, 220 with + or - 10 taps
> on
> 0 terminal. I've had several of the 2000 & 2500 watt Henry plasma units
> running the 3cx3000 and one using a 3cx1200. Most noticeable about these
> units is that parts were swapped out with the other units and the
> potentially bad part hung back in place, sometimes barely connected.
> 
> Regards,
> Larry N5BIP
> http://lists.contesting.com/mailman/listinfo/amps

Larry, 

I have converted several 3 phase Henry 2000D's. I have one sitting right
here in the shack running on 160 meters as a single-band unit.

When you float the center secondary winding on the power transformer, put in
a large filter capacitor, step-start, and increase the bleeder resistance to
c. 200,000 ohms, and toss the filter choke away, you actually end up with a
few hundred volts more than you had with a stock 2000D. The 2 primary
windings are hooked in parallel, running on 240 volts instead of the "stock"
208 volts. I am getting 5200 volts out of mine with a 52 ufd filter cap. The
center diode block can be removed and kept as a spare. I learned this trick
with 3-phase transformers years ago after tossing several perfectly good
transformers in the dumpster!

(((73)))
Phil Clements, K5PC