Henry 3K Classic X MKII
3CX1200A7 Rugged, conservative POWER!

OK, I'll admit I just MAY be a little bit biased, but I really think my Henry 3K Classic X MKII is the best amplifier I have ever owned (and I've had quite a few including Alpha 78, Alpha 87A, Heath SB-220, SB200, HA-14, Yaesu FT2000B, Hallicrafters HT-45, homebrew 813's, homebrew 3-500Zs, and an early Henry 2K). Nothing puts out the power with <100 watts of drive as effortlessly as my 3K Classic X MKII. Even in the low voltage CW position it easily does the legal limit of 1500 watts output.
No "toy tubes", a real rugged 3CX1200A7. No "computer type" capacitors, you get a real transmitting type oil filled HV capacitor with a resonated filter choke. COMPARE the quality!
HENRY has no equal!
Can you operate RTTY (contesting too!) with your amp at the legal limit? Henry can!
Here's some pictures of my unit. They are all thumbnails so the page loads faster. Just click on any of them for a larger picture.
Radiodan now has a 3K Premier console (same as the 3K Classic X MKII but adds 160M and vacuum output relay for QSK)

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In the W7RF shack
Prowling for DX!
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Busy makin' power!
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The W7RF antenna farm
RADIODAN W7RF antennas
Open wire fed 170' invee @ 70'
Force12 C4XL @ 72'
M2 6M5 6M beam @ 76"
M2 440-11 yagi @ 77'
Force 12 30M dipole @ 80"
M2 2M12 2M beam @ 82"
VHf/UHF verticals @ 85'
Not up yet, Create CD78 80/75M rotatable dipole
MVC-008Fa.jpg (51492 bytes)
What, no HENRY?
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An easy 1500 watts while testing BIRD elements
All Henry HF amps are instant on, ready NOW!
RTTY contesting is the toughest mode and Henry does it easily!
Radiodan homepage:
RF Power page:
Ham Stuff page:
3k9.jpg (76310 bytes)
Rear view
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Blower, oil filled HV capacitor
Look at this construction!
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Step start relay (left)
Step start resistor (middle)
Some manufacturers won't give the schematics to their amplifier even after you buy it.
Why not?
Henry gives a complete manual WITH schematics.
3k3.jpg (58903 bytes)
Blower keeps the tube
MVC-004Fa.jpg (57208 bytes)
Bottom RF deck view showing clean construction

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Massive choke (left)
4400 volt transformer (rt)
I have not seen any currently produced Amplifiers for amateur radio that use a Choke input HV filter and oil filled capacitor but HENRY!
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The clean RF deck
Notice the lack of jammed in parts.
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Henry makes the roller inductor and plate choke in their LA facility
MVC-007Fa.jpg (74610 bytes)
Showing input circuit.
Yep, Henry makes all that too.
We make our own bandswitches, roller inductors, plate chokes, filament chokes, tube sockets, chimneys, coils, input matching networks, high voltage switches, all metal work and cabinetry.
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Complete view, bottom of RF deck
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RF deck showing tube and teflon chimney
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How we keep it all in sync
All this in a 1 year warranty and using the most rugged tubes in our designs.
Built HENRY tough!
Henry RF Power Makes it tough to look at anything else, eh? Henry HF pricing

Radiodan's 3K Premier (3CX1200A7) settings, (90-100 watts drive)

Frequency Tune Load Plate current Grid current Power output Notes
1830 +19 188 780 200 1700
1885 +7 194 780 210 1700
3515 139 +7 750 180 1700
3800 120 +8 760 200 1850
3870 117 +4 760 200 1850
3950 113 +4 760 200 1850
7020 73 162 720 220 1800
7185 72 104 750 230 1900
7250 71 104 750 230 1900
14020 49 119 750 260 2050
14210 50 133 780 210 2000
18125  35 124 800 200 1750 band sw on 15M
21020 26 120 780 280 2200
21300 25 135 780 260 2000
24925 18 126 840 200 1650 band sw on 10M
28020 13 130 830 210 2050
28400 12 70 820 230 1950
As you can see from grid current readings, the tube is NOT yet saturated and the power supply has plenty of reserve.
These reading were taken into a BIRD 50 ohm load. We recommend operating at the legal limit. The Henry has a SAFE operating margin even at full legal power in RTTY/PSK 31 or other continuous duty modes. These are MY readings, yours MAY vary. However, if you need a place to start, you may use these settings and start to tune your amp with 10-20 watts of drive to determine YOUR settings.

Henry Specs

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