I think when Phil says float the secondary of the center coil, he means don't
connect the center coils primary to the line, and don't use the secondary of
that coil
either. The two outer coils are what one would use for single phase ran in
parallel.
I e-mailed Larry about this earlier, but for any other readers, I wanted to
clear up
how it's done. You'll loose 1/3 the power rating this way, but for the input
power
this amp is rated for, it sure wouldn't be a problem. This amp is also rated
for a
100% duty cycle when used for RF heating. It's built like a tank. Phil brought
up
a good point I forgot though, I'd raise the capacitance on the filter cap for
the B+,
and do away with the choke. That will jump up the B+ voltage some though. You
may have to set the bias so the tube is running where it should be. The
oscillator / driver can be taken out or left in unconnected. An antenna realy
with
the RF jack for the transceiver will have to be added. If using it as a monoband
amp, you may not have to do much to the tank to convert it.
Best,
Will
*********** REPLY SEPARATOR ***********
On 7/31/06 at 2:06 PM Phil Clements wrote:
>>
>> 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
>
>
>
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