This is my new project an 80 -10 meter band
switchable HF amp using a 4-1000A. I will be adding to this page as I proceed
with the project. So check back often.
cost :(about $200.00) check prices at Thomas
J. Bruckner here on the web.
Life : estimates of about 30 years at plate voltages of 5KV running 1.5kw.
Look here for
feedback from homebrews about this tube. |
4CX-10000 will work in the circuit with little modifications.
Start with a good
transformer. This tube really likes about 7200v on the plate, but
the output there would be about 3500 - 4000 watts. The up side to the
higher voltage would be lower drive for legal limit output. I went with
a 5KV transformer at 1 amp, because of price to output to drive requirements.
This voltage should yield a good 1.5KW output with 100 watts of drive. You
will also need a filament transformer of 7.5 volts @ 21 amps, these can be
purchased at Peter W. Dahl Co.
The basic diagram for the
high voltage supply is shown below:
||The 4-1000A / 8166 is intended for use as
an amplifier, oscillator, or modulator and is capable of efficient
operation well into the VHF range.
Cooling of the tube is accomplished by radiation from the plate and by
circulation of forced-air through the base and around the envelope.
Cooling can be simplified through the use of a SK-510 Air-System
Socket and its accompanying glass chimney.
|Plate Dissipation (Max.)
|Screen Dissipation (Max.)
|Grid Dissipation (Max.)
|Frequency for Max. Ratings (CW)
||Radiation & Forced Air
|Capacitances (Gnd. Cath.
|Amplification Factor (g1-g2)
|Recommended Air-System Socket
|Recommended Air Chimney
|Recommended Heat Dissipating
|Maximum Seal Temperature
|Maximum Envelope Temperature
||9.63 in; 244.60 mm
||5.25 in; 133.30 mm
||1.5 lb; 0.68 kg
||Vertical, base up or down
I am staring with a diagram
form "Radio Handbook -- twenty-first edition, by William I. Orr, W6SAI.
This amplifier is a grounded
grid configuration. This makes this tube a little harder to drive, but
the more plate voltage the lower driving wattage needed with output remaining
constant. With the voltage of 5KV, and 125 watts of drive,
should make the output of this tube over 1.5KW. If you need to drive
this tube with lower wattage you may want to use grid drive, see
Richard Measures page for details on how to set up grid drive for a tube.
Below you will find the parts I used in my 4-1000 amp. I use the vacuum
variables captors, because of the higher voltage used on the plates