The Heathkit Virtual Museum

TX-1 "Apache" Ham Transmitter

150 watts phone, 180 watts CW & SSB
Covers 80 through 10 meter amateur bands
Provision for SSB adapter built-in
Rotating slide rule dial with vernier tuning
Adjustable low-level speech clipping
Time sequence keying--"spotting" push button

Famous for value ... "Apache" AMATEUR TRANSMITTER

Representing the entire transmitting complement of the amateur station, the "Apache" incorporates many fine features and modern styling to bring you all the extras required for effective and dependable communications.

The "Apache" operates with 150 watt phone input and 180 watt CW input on 80 through 10 meters and features chassis provision for plug-in connection of the Heathkit SB-10 SSB adapter. A specially-designed VFO provides minimum drift frequency control necessary for SSB transmission. The illuminated, rotating slide-tule VFO dial with full gear drive vernier tuning provides ample bandspread for accurate frequency settings. Each amateur band is spearately calibrated on the rotating slide-rule dial for maximum accuracy. Also featured in the "Apache" is adjustable low-leve speech clipping and a low distortion modulator stage employing two 6CA7/EL34 tubes in push-pull class AB operation. Time sequence keying is provided for "chirpless" break-in CW operation. A "spotting" push button allows tuning of the transmitter before switching on the final amplifier and also enables the operator to "zero beat" an incoming signal without placing the transmitter on-the-air. The final amplifier is extensively shielded for maximum TVI protection and is neutralized for high stability. Pi network output coupling provides smooth loading into antenna impedances of 50 to 72 ohms.

This inside rear view of the "Apache" shows the heavy-duty potted transformers used for long life and depandable performance. Note the extensive shielding of the final amplifier and fan forced-air cooling of the final tubes. A specially-designed VFO and many more features combine to bring you effective and dependable communications in addition to ease of assembly.

The Apache's modern styling, identical to the Heathkit Mohawk receiver RX-1, presents a smart appearance that any amateur would be proud to display in his station. Color styling is in the traditional Heathkit amateur radio colors of gray and gray-green. Front panel control knobs and escutcheons are of heavy die-cast metal which impart a rugged, handsome quality to its overall appearance. The precision mechanical controls operate smoothly with the positive action characteristic normally found only in the most expensive equipment. The formed one-piece cabinet has a convenient top hatch for easy access to tubes and crystal socket.

Specifications--Power input: 150 w PHONE, 180 w CW. Output impedance: 50-72 ohms (non-reactive). Output coupling: Pi Network (coaxial). Operation: Crystal-VFO, CW-SSB-PHONE (time sequence keying, SSB requires external adapter). Band coverage: 80, 40, 20, 15, 10. Audio output: 100 watts at 300-3000 cycle (Adjustable low-level speeh clipping; 500 ohm output available). Tube complement--power section: 2 selenium rectifiers, 5V4 low voltage rectifier, 2-5R4GY HV rectifier, OA2 voltage regulator, 2-OB2 voltage regulators. Audio section: 12AX7 speech amplifier, 12AU7 clipper amplifier, 6AL5 clipper, 12BY7 audio driver, 2-6CA7/EL34 modulator. RF section: 6AU6 VFO, 6CL6 crystal oscillator-buffer, 5763 driver, 2-6146 power amplifier, 6AQ5 clamp. Power requirements: 115 V AC, 50-60 cycles. Standby (AM, CW): 150 watts. Standby (SSB): 230 watts. CW: 420 watts (intermittent). Phone: 500 watt;" W x 11 5/8" H x 16" D.