Heathkit SB-104 Transceiver

Completely solid-state from front end to RF output, with over 275 advanced solid-state devices, including 31 ICs, 75 transistors and 171 diodes. The result is a design that runs cooler, quieter, better, longer. The four finals are totally protected against high SWR and thermal runaway; operated properly, the SB-104 finals should never need replacement.

Totally broadbanded. The new 104 means instant QSY. You can go from CW on the low end of 80 to USB on the high end of 10 in seconds with perfect tune. Gone are the bothersome Preselector, Load and Tune controls. Just choose the band, dial in the operating frequency, select your mode and go!

True digital readout. The new SB-104 provides 6 digits of large, bright, easily read frequency information ... with resolution down to 100 Hz on all bands. And unlike other so-called digital readout systems that interpret just the VFO frequency, the SB-104 incorporates true digital frequency measurement circuitry that takes into account all three frequencies: VFO, HFO and BFO. There is no need whatever for a frequency calibrator in the SB-104 and there is none. Digital circuits eliminate the need to rely on inaccurate dial tracking and the questionable linearity of a VFO. With the SB-104 what you see is where you are always.

Performance-plus! The SB-104 is more than convenient to use it’s a pleasure. The transmitter delivers a solid 100 watts output in the high power position; for QRPers the output can be switched to one watt instantly with the front panel pushbutton. Harmonic and spurious radiation are low, third order distortion is 30 dB down or better at 100 W, and carrier and unwanted sideband suppression are rated at —55 dB.

SB-104 SPECIFICATIONS:

TRANSCEIVER SECTION - GENERAL OPERATION: Frequency Coverage: 3.5 MHz through 29.7 MHz amateur bands, 15 MHz WWV receive only. Frequency Stability: Less than 100 Hz/hr drift after 30-min. warmup; less than 100 Hz drift for ±10% change in primary voltage. Modes of Operation: Selectable upper or lower sideband (suppressed carrier) and CW. Readout Accuracy: Within ±200 Hz ±1 count Audio Frequency Response: 350 to 2450 Hz ±75 Hz (6 dB bandwidth). Dial Backlash: 50 Hz max. Phone Patch Impedance: 4 ohm output to speaker; high impedance output to transmitter. Power Requirements: 13.8 VDC nominal (max. 16 VDC) at: Receive- 2 amp. Transmit: low power: 3 amps.; high power: 20 amps.

TRANSMITTER: RF Power Output: High Power (50 ohm non-reactive lead). SSB: 100 watts PEP ±1 dB; CW: 100 watts ±1 dB. Low Power SSB: 1 watt PEP (minimum); CW: 1 watt (minimum). Output Impedance: 50 ohms, less than 2:1 SWR. Carrier Suppression and Unwanted Sideband Suppression: 55 dB down from 100 watt single-tone output at 1000 Hz reference. Harmonic Radiation: 45 dB below 100 watt output. Spurious Radiation: -50 dB within ±3 MHz of carrier; -60 dB farther than ±3 MHz from carrier, except -40 dB at 3.39 MHz on 80 meter band. Third Order Distortion: 30 dB down from two-tone output, reference at 100 watts PEP. Transmit/Receive Operation: SSB- PTT or VOX; CW: Keyed-tone VOX or manual. CW Side-Tone: Internally switched to speaker or headphones in CW mode. Approximately 700 Hz tone. Microphone Input: High impedance with a rating of -45 to -55 dB; approx. 25K ohms to match Heath desk-type microphone.

RECEIVER - Sensitivity Less than 1.0 microvolt for 10 dB signal-plus-noise-to-noise ratio for SSB operation Selectivity: 2.1 kHz minimum at 6 dB down, 5 kHz maximum at 60 dB down. (2:1 nominal shape factor). CW Selectivity: (with accessory CW filter) 400 Hz at 6 dB down; 2 kHz max at 60 dB down. Overall Gain: Less than 1 microvolt for 0.5 watt audio output Audio'Output: 2 5 watts into 4 ohms, 1.25 watts into 8 ohms, at less than 10% THD Low imoedance headphones (4-8 ohm). AGC: Less than 1 millisecond attack time; switch selectable 100Jisec. and 1 msec, release, and OFF. Intermodulation Distortion:65 dB min. Image Rejection: - 60 dB min, IF Rejection: —60 dB min. Internally Generated Spurious: Below 2 microvolt equivalent vantenna input, except at 3.65, 3.74, and 21.2 MHz.

MECHANICAL - Front Panel Controls/Switchess AGC - Off, Slow, Fast: AF Gain; Microphone Jack; Headphone Jack; Main Tuning; Mic/CW Level; Vox Gain; Vox Delay; Band Switch. Pushbuttons:/ALC (Meter); 13,8V (Meter); Relative Power (Meter); 100 Hz (Disable); Noise Blanker (On/Off); LSB (Mode); USB (Mode); CW (Mode); Tune; Hi/Lo (Powur Select); VOX (On/Off); PWR (On/Off). Rear Panel Controls/Sockets: Anti-Trip; Sidetone Level; Linear AmplifieriALClnpuf; Phope; Patch Input; Phone Patch Output; Key (CW) Input; Speaker (4 ohm) Output; Spare (2); Receiver Audio Input; VFO Input; VFO Output; IF Output; Driver Output; Ground Post; Power Plug; Accessory Socket (includes relay output); Antenna. Input; Receiver Antenna Input; Common/Separate Antenna Switch. Dimensions:  5,75"H x 14,5" W x 14" D. (Less knobs, feet and connectors).Weight: 20 lbs.