GU74B, Power Tetrode (equivalent of 4CX800)

Tube, GU74B, Equivalent to 4CX800A, Ceramic Power Tetrode.

800 Watts Max Plate Dissipation.

NEW OLD STOCK

Tested for vacuum (ionization current or gas test), internal shorts, or open circuit filament, output power.

We can supply matched pairs on special request.

Pair price is 620Eur

Svetlana GU74B (4CX800A) high-performance ceramic/metal tetrode with a plate dissipation rating of 800 watts. The performance characteristics of the GU74B (4CX800A) allow its use as a high gain grid-driven RF amplifier or as used in grounded grid service.

These tubes are direct replacements for use in some of the best-built RF power amplifiers, including Alpha 99, 91B, 8100; ACOM 1000, 1006, 1010, and 2000A and Command Technologies, and several other manufacturers. These tubes may also be used to make great homebrew amplifiers.

With 1,200 watts input when used as linear power amplifier, the 4CX800A will conservatively produce 750 watts PEP SSB, and 750 watts Key-Down CW. When used in a modern amplifier with auto-tuning and vacuum tube protection circuits, they may produce much more power and exhibit very long life.

These tubes are NOS (New old stock) and may requier reconditioning (gettering) before use.

Good article on preparing surplus tubes for use: 

"Using Surplus Tubes" by ND2X