photo Gates BHF-10 MODEL BHF-10

A deluxe top commercial grade, high frequency, high level modulated 10 KW transmitter designed for 24-hour schedules in either telephone communication or high fidelity radio broadcasting. The BHF-10 transmittter is 100% tuned from the front over the entire 4 Mc. to 30 Mc. range. No coil changes are required. Counter type tuning dials provide accurate logging and return to any previously logged frequency in less than one minute. Even the output balun is continuously variable and the transmitter will feed either 600 ohm or 50 ohm transmission lines. The BHF-10 transmitter may also be used as a 15,000 watt high speed telegraph transmitter with adaption to optional frequency shift keying. One major international communications company uses the BHF-10 transmitter with a Kahn SSB adaptor.

DESIGN: Four cubicles bolt together to form the transmitter, which is totally self-contained with no external components and occupies a floor space of 100" wide and 41" deep. Solid state power supplies are used throughout. Ten crystal positions for .003% frequency accuracy excites five radio frequency stages including dual 4CX5000A power tubes in a single ended circuit.

RF SECTION: High level modulation with 3X2500F3 modulator tubes provides generous over-capacity. There are four audio stages.

If the transmitter is for telephone service only, the M-5263 communications limiter filter amplifier is suggested. RF harmonic reduction, because of the unique output balun, easily meets or exceeds both FCC and CCIR specifications. Unusual attention has been given to internal shielding and prevention of cabinet radiation. The maximum DC voltage is 5000. This design greatly enhances minimizing of insulation and corona problems.

CONTROL CIRCUITRY: Control circuitry is complete including under-voltage and overload relays, circuit breakers, air interlock switches, and door interlocks throughout. Recycling is automatic and provides positive protection for closely spaced carrier interruptions.

RUGGED COMPONENTS: Nothing has been spared to make this transmitter the finest. A glance at the rear view illustrates the very sizable blowers, coils with cast aluminum end supports, vacuum capacitors, large filter capacitors, excellent accessibility and workmanship. The BHF-10 is a transmitter with a totally new design and Gates is proud to recommended it for the most demanding service.

Power Output 10 KW. A-3
Frequency Range 4-30 Mc. continuous
RF Output Impedance 600 ohms balanced and 50 ohms unbalanced
Frequency Stability .003% or better
Carrier Shift 3% or less at 100% modulation
Audio Response ±1.5 db., 30-12,000 cycles
Audio Distortion 3% or less, 50-7500 cycles at 95% modulation
Noise 60 db. below 100% modulation
Audio Input Impedance 150/600 ohms at 0 dbm. for 100% modulation
A.C. Input 208/240 volts AC, 3 phase, 50/60 cycles. Power consumption approximately 19.9 KW carrier only. 22.7 KW at average progam modulation
Size 100" wide, 41" deep and 78" high
Weight and Cubage 5355 lbs. export packed. 430 cu. ft.
Finish Two-tone Gates gray, aluminium trim and black
Specifications may change without notice

Number Type Number Type Number Type
2 4CX5000A 2 3X2500F3 2 6BG6
4 5763 4 6528 3 GZ34
2 5R4G 1 6V4 1 OA2
1 6SN7 1 4-250A


ITU Country
ITU Country