Heathkit · Receiver · 1966–1970
Heathkit SB-301
The SB-301 is Heath's improved SB-300, a ham-bands-only receiver for SSB, AM, CW and RTTY from 80 to 10 m. Rigpix dates it 1966 to 1970, and 73 Magazine reviewed it in June 1967. Over the SB-300 it added an RTTY position, a WWV band at 15 MHz, an automatic noise limiter, and a front-panel switch for the plug-in 6 m and 2 m converters. It pairs with the SB-401 transmitter for transceive. The reviewer took about 24 hours to build it and didn't find a single operating difficulty. He credited the design and Heath's manual. It has its own AC supply, so it runs on its own. Collectors look for the optional AM and CW filters, the converters and, best of all, a matching SB-401.
SB-301SB-300 (the earlier version it replaced)
Spec at a glance
- Maker
- Heathkit
- Type
- Receiver
- Launched
- 1966
- Made
- 1966–1970
- Covers
- 80 to 10 m ham bands (3.5 to 30 MHz), WWV 15 MHz; 6 m and 2 m with converters
- Modes
- SSB, AM, CW, RTTY
- Receiver
- Better than 0.3 µV for 10 dB S+N/N; 2.1 kHz SSB crystal filter
- Tubes
- 6BZ6 RF, 6AU6 mixers, 6BA6 IFs, 6AS11 detector/BFO, 6HF8 audio
- Power supply
- Built-in AC supply, transformer and silicon diodes
- Weight
- About 17 lb (7.7 kg)
- Also listed as
- SB301, SB 301, Heath SB-301
Bench check
Receive, tubes and supply
- Receiver
- 73 Magazine quotes better than 0.3 µV for 10 dB signal-plus-noise to noise on all bands, with 2.1 kHz SSB selectivity. Ask whether it hears signals on every band from 80 to 10 m, plus WWV at 15 MHz. On a tube receiver, weak receive everywhere means checking tubes and alignment first.
- Tubes and circuit
- It's a tube receiver, with a 6BZ6 RF stage, 6AU6 mixers, 6BA6 IF amplifiers, a 6AS11 Compactron for the product detector and BFO, and a 6HF8 for audio. Ask for a photo of the top of the chassis with every tube in place. Empty sockets or mismatched types mark a set that's been robbed for parts.
- Power supply
- The power supply is built in, a transformer with silicon diodes, so it plugs straight into the wall. It doesn't need an HP-23; that supply is for Heath's transceivers and transmitters. Ask for a photo of the line cord and whether the supply has been serviced.
- Dial and display
- Tuning is a preassembled LMO (linear master oscillator) on an analog dial, with a 100 kHz crystal calibrator. 73's reviewer found drift unnoticeable from a cold start and readout within a fraction of a kilohertz. Ask for a photo of the dial lit and whether it tunes smoothly.
- Filters and options
- The 2.1 kHz SSB filter is standard. The AM (3.75 kHz) and CW (400 Hz) crystal filters were extra-cost options, and without them AM is received by exalted carrier and CW through the SSB filter. Ask for a photo of the filter area inside to count what's fitted.
Should come with it
- The optional AM and CW crystal filters
- The SB-401 transmitter, if you want the matching transceive pair
- The plug-in 6 m and 2 m converters for the rear apron
- The Heath manual
Check the listing photos against this list, and ask the seller about anything you can’t see. A missing piece should come off the price.
What to check
Heath told 73 Magazine in 1967 that 90% of the trouble in its kits traced to poor soldering, and every SB-301 was assembled by its first owner. Without the optional filters, the AM and CW positions fall back on the SSB filter, so a listing that says it works in all modes tells you nothing about filters.
- 01Every band: Ask the seller to tune in signals on 80, 40, 20, 15 and 10 m. Every band should bring in stations or band noise.
- 02Calibrator and WWV: Ask whether the 100 kHz calibrator and WWV at 15 MHz come through. A clean calibrator signal on each band is a good sign.
- 03Tubes: Ask for a photo of the chassis top with every tube in its socket. All sockets filled with the right types is what you want.
- 04Dial: Ask for a photo of the dial lit and whether it tunes smoothly. It should land on the calibrator marks.
- 05Crystal filters: Ask for a photo inside the filter area. The AM and CW filters are options, so count how many are fitted.
- 06Power: Check the line cord in the photos and ask whether it's been serviced. It has its own supply and needs nothing else.
- 07Build quality: Ask for close photos under the chassis. Neat, shiny solder joints suggest a careful builder.
- 08Manual: Look for the Heath manual in the listing. Its voltage charts and alignment steps are how you'll keep it running.
- 09Model number: Check it reads SB-301, not SB-300. The 301 has an RTTY mode position and a WWV band position.
New to used rigs? How to check a used ham radio covers receive, the tubes and the dial, and buying vintage tube gear covers old capacitors, tubes and first power-up.
Find one on eBay
We haven’t been through this model’s listings yet. Search eBay and run every listing through the checklist above. Ask whether it hears signals on every band, for a photo of the dial lit up, and whether the old capacitors have been replaced. Pass on any seller who won’t answer.
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