Note
In spite of the “SB” prefix, the SB-1000 is not a true Heath product. It is an Ameritron AL-80A amplifier repackaged in kit form by Heath—and no one was ever really fooled.
Still, the SB-1000 was reasonably attractive from both a buyer’s and a seller’s perspective since it could be sold for less than many pre-assembled amps on the market. Thus Heath was able to revive, albeit briefly, the dynamic that gave it its start. The assembly manual was supplied as a stack of three-hole punched paper for insertion into a three-ring binder.
The SB-1000 covers 160 through 15 meters, including the WARC bands, and with a tiny modification will cover 10 meters as well. The amplifier runs about 1000 watts PEP SSB output and about 850 watts CW. It uses a single 3-500Z in class AB2 grounded grid service. It will dissipate about 500 watts in continuous duty for about 30 minutes and requires about 85 watts of drive for full power output. Maximum permissible drive is 100 watts.
The power supply uses a 22 pound hypersil steel E-I core transformer running about 3000 volts no load and 2700 volts at a full load of 0.45 amps.
Unlike the SB-200 series of amps, the SB-1000 is not “instant on” and requires a 10 second warm-up.
10-METER OPERATION
Out of the box and as assembled, the frequency coverage is from 160 to 15 meters, including WARC bands. However, the SB-1000 will cover 10 meters as well. All the parts for 10 meter operation are included and are put in place during assembly, including an unlabeled position on the band switch. To enable 10 meter operation requires only the snipping of a black wire that exits the input-network enclosure and is attached to the ground lug secured to the plate tuning capacitor reduction-drive mounting screw. This wire shorts out the 10 meter coil (L6) in the input filter assembly. Note: Coil L6 should be peaked for 10-meter operation.
When operating on 10 meters be sure to turn the band switch past the 15 meter setting.
WARC BAND OPERATION
The 12, 17 and 30 meter WARC bands are not labeled on the front panel band switch. To operate the SB-1000 on these bands, set the band switch to the nearest band position. Note: For operation on 12 meters use the 10 meter band position (this requires the 10 meter modification previously described).
The SB-1000 features a variable ALC providing a negative-going ALC voltage from 0-20 volts.
True QSK operation is possible with the optional QSK board. This fully assembled board mounts directly above the power transformer. Installation the board requires some wiring, some rewiring, and the drilling of two holes in the chassis. Unless you can remove the unit from its cabinet, the best way to check for the presence of the QSK board is to look one of these new holes, and a rear panel screw that had to be added to mount the board. This screw is located just above and to the right of the SO-239 RF output connector.
There are two large illuminated panel meters. One is dedicated to grid current and the other will monitor plate current, plate voltage, ALC, and power output.
Front panel controls include plate tune, load, band, meter function, main power, and operate/standby.
The only rear panel control is the ALC output adjustment. Rear panel connections include SO-239 RF input and output connectors and RCA jacks for a T/R relay, ALC out, and –12 volts (also for a T/R relay). There is also a ground post.
Although the SB-1000 can be wired for either 120 or 240 VAC operation, only a 120 VAC line cord and plug were supplied. Refer to Figure 4. Changing to 240 VAC operation (preferred) requires replacing the plug and/or line cord, rewiring a barrier strip, and installing the correct fuses.
The SB-1000 was the last amp Heath ever sold. It is a reliable, well-designed product and should be considered by anyone in the market for a good amplifier. Toward the end, Heath blew out its remaining stock of SB-1000s with substantial discounts. Finished in two-tone gray with red dial pointers.
Warning: Lethal voltages present when operating.
References:
Review. QST. Feb 1988, p. 33.
Review. 73 Amateur Radio. Aug 1988, p. 15.
Comments on. QST. Jul 1988, p. 47.
Use on 10 meters. QST. Dec 1992, p. 81.
Band coverage: 160-15 meters (12-10 meters with modification)
Drive power required: 100 watts maximum, 85 watts typical
RF power output:
SSB: 1000 watts PEP
CW: 850 watts
Duty cycle:
SSB: continuous
CW: 50%
30 minutes key down at 500 watts
ALC: 0-20 volts, adjustable, negative-going
Third order distortion: –30 db or better
Keying: requires contact closure, or sink of +12 VDC @ 100 mA
Input impedance: 50Ω unbalanced
Output impedance: 50Ω unbalanced; SWR of 2:1 or less
Power requirements: 120/240 VAC, 50/60 Hz, 15/7.5 amps maximum
Fuses: two 15 amp for 120 VAC; two 10 amp for 240 VAC
Tube: (1) 3-500Z
Photos, general information and specifications from "Heathkit: A Guide to the Amateur Radio Products," by Chuck Penson, WA7ZZE. Used with permission.
