Specifications for the KK5DR HB amplifier.

Specifications for my Home-Brew HF amplifier.

RF deck

Uses (2) EIMAC 3CX800A7's in a class AB2 grounded-grid, Pi-L output network. Output rated @ 1500 watts, no time limit, any mode. Tuned input network. Typical RF drive is 20 watts for 1Kw+ output.

Pressurized plenum, forced air-cooling of the tubes, approx. 40CFM "squirrel cage" blower.

Covers 160-10 meters including 17 & 12 meters (no 30 meter coverage). Blinking green LED band-switch position indicators.

0-100 graduated tuning dials.

Vacuum relay T/R system. Red/Green, T/R condition LED indicator.

Analog metering, with accuracy of 0.1%, LED indirectly lighted.

Grid over-current protected (grid-trip circuit), transmit lock-out, Red LED "trip" indicator. 100mA trip level.

ALC protected, exciter RF envelope derived.

Tube "warm-up" time delayed, transmit locked out. Red/Green LED, Warm-up/Ready condition indicator, 4 minute delay.

Passive plate over-current limiting.

14" deep, x 15"wide, x 6" tall, x 15Lbs.

All 1/8th" aluminum cabinet with aluminum angle stock re-enforcement.

Main power supply

Power supply weighs about 60Lbs., 14"T, x 14"W, x 14"D. Angle stock re-enforced, all aluminum cabinet.

Blower cooled, 65CFM muffin fan.

Peter Dahl Hypersil plate transformer rated at 1.1A CCS secondary output. 240Vac primary only.

Full-wave bridge rectifiers (K2AW "Silicon alley") 12kV @ 3A units, mounted on aluminum heat-sink.

66 µF @ 3.6 kV, & 4.2 kV surge rated, "computer-grade" capacitor filter bank, 220k ohm @ 2 watts, voltage equalizing/bleeder resistors across each cap.

Step-start time-delayed, 2 seconds.

Plate voltage = 2.49 kV. 75 V B+ drop under full current load.

Separate filament transformer with adjustable secondary voltage, passive current "in-rush" limiting.

24Vdc fully regulated control power supply, 1.1A max load.

Extensive EMI/RFI/EMC filtering.

This amplifier was designed & built by Matt Erickson, KK5DR.

Many circuits in it are completely unique, and proprietary to the builder.

Total build time; about 1 year, in stages.