Excellent Chinese High Frequency Electron Oscillator Tube 3CX1500A7 for High Frequency Machine

FU959F is a metal ceramic structure of the oxide cathode, forced air-cooled, high amplification factor oftransistor, Rated anode dissipation power is 1500W, the GRID power dissipation rating is 25W, themaximum operating frequency is 250MHz, mainly used in the cathode incentive AB2 and Class Bamplifier, and cathode excitation anode modulated class C amplifier, with the U.S. Eimac production ofthe 3CX1500A7 type tube used interchangeably.

The Eimac 3CX1500A7/8877 is a rugged ceramic and metal power triode designed for use as a cathode driven Class AB2 or Class B amplifier in audio or rf applications including the VHF band,or as a cathode driven anode modulated Class C rf amplifier. As a linear amplifier, high power gain may be obtained with excellent intermodu-lation distortion characteristics.Low grid interception and high amplification fac-tor combine to make the 3CX1500A7/8877 drive power requirements exceptionally low for a tube of this power capacity.

MOUNTING – The 3CX1500A7/8877 may be mounted in

any position.

SOCKETING - The grid of the 3CX1500A7/8877 terminates in

the cylindrical grid ring about the base of the tube. This may

be contacted by multiple clips or flexible finger stock. Connec-

tions to the heater and cathode are made via the 7-pin base.

The Eimac SK-2210 socket is recommended for all rf amplifier

applications.

STORAGE – If a tube is to be stored as a spare it should be

kept in its original shipping carton, with the original packing

material, to minimize the possibility of handling damage. Be-

fore storage a new tube should be operated in the equipment

for 100 to 200 hours to establish that it has not been damaged

and operates properly. If the tube is still in storage 6 months

later it should be operated in the equipment for 100 to 200

hours to make sure there has been no degradation. If opera-

tion is satisfactory the tube can again be stored with great as-

surance of being a known-good spare.

COOLING - The maximum temperature limit for external tube

surfaces and the anode core is 250°C. Tube life is prolonged

if these areas are maintained at lower temperatures. For full

1500 watts anode dissipation 35.0 cfm of air is required at

a back pressure of 0.41” H2 O hold tube temperature below

225°C with 50°C ambient temperature at sea level. At frequen-

cies higher than 30 MHz, or at high altitudes, the air quantity

must be increased. The data shown is based on airflow in the

base-to-anode direction.