Heathkit Single Banders

Discussion in '"Boat Anchor" & Classic Equipment' started by G3YRO, Jul 17, 2017.

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  1. G3YRO

    G3YRO Ham Member QRZ Page

    I've never seen much on here about Heathkit's single band SSB Transceivers, the HW-12, HW-22 and HW-32 . .

    Heathkit equipment was generally pretty rare over here, so although I was aware of these in my younger days, I have certainly never seen one in the flesh. (did see one in a movie once)

    The ones with the later-style knobs certainly looked prettier . . .


    But they seem a great idea, as many people operate mainly on one band - were they very popular?

    It's certainly MUCH simpler (and therefroe cheaper) to design a rig for just one band . . . I couldn't afford commercial gear back in those days, but built a valve single band SSB transceiver for 160m.

    However - that had a screened box for the VFO and the PA, with all the valves mounted on a metal chassis - having just looked at the details of these heathkit rigs, I'm amazed they just use a big PCB, and NO screening !

    But the basic idea seems good . . . . although if I had one of those transceivers I would have certainly have added a front-panel headphone jack, an IRT control and CW. (and why no PA Load control?!)

    Roger G3YRO
    Last edited: Jul 17, 2017
    AF6LJ likes this.
  2. AF6LJ

    AF6LJ Ham Member QRZ Page

    I have an HW-32 that is going to go on the air some day...
    Waiting for me to get around to it. :)
  3. N2EY

    N2EY Premium Subscriber QRZ Page

    To a certain extent.

    The "single banders" were the first SSB transceivers Heath made, and at the time (early 1960s) they were quite popular because they were incredibly inexpensive. A complete (well, without power supply and speaker) SSB transceiver for about $100 US! Incredible!

    There are actually two generations - the "early" ones (HW-12/22/32) and the "late" ones (HW-12A/22A/32A) Why they bothered to provide selectable sideband on the A models is a mystery; the tradition of LSB on 75 and 40, and USB on 20, was well established long before those rigs were thought about.

    The single-banders achieved their low low LOW price by eliminating ANYTHING that wasn't absolutely essential.

    The goal was a single-band SSB transceiver - so, no other modes were provided.

    Since they were SSB-only, they only cover the US 'phone subbands of the early 1960s - the HW-12 tunes 3.8 to 4.0 MHz, the HW-22 tunes 7.2 to 7.3 MHz, and the HW-32 tunes 14.2 to 14.35 MHz. (Which is a BIG reason you didn't see many on your side of the pond).

    Limiting the coverage meant that the low-level RF stage tuned circuits could be fix-tuned, saving lots of $$.

    The big PCB and no final cage reduced cost, so it was done that way. The dial is very simple - just an AM-BC style tuning capacitor with a big plastic circular dial. Tuning rate is fast - something like three and a half turns of the knob to cover the entire range. RIT/IRT cost money and wasn't common back then (none of the later SB-100/101/102 or HW-100/101 rigs had it.)

    The single-banders achieved reasonable stability by having the VFO at a low frequency (around 1.6 MHz) and the IF at 2.3 MHz. This gives 75 meters directly. For 40 and 20, the VFO signal is premixed with the signal from a crystal oscillator so that the resultant is the right frequency for those bands.

    Loading control? Cost money! Hams were/are fixated on low-SWR antennas anyway, so, why bother? Headphone jack? Who uses 'phones working 'phone? (Such was their reasoning).

    The crystal filter used in the IF is pretty basic. Four crystals IIRC, passband 2.1 kHz at 6 db, 6.0 kHz at 50 db (!). Unwanted-sideband suppression of -45 dB. A bit of a challenge in crowded bands!

    The matching power supplies for them are the HP-20 (AC) and HP-10 (DC). The later HP-23 and HP-13 can be used IF the low-B+ is set for 250 volts, rather than the 300 volts required by the SB series and later HW-100/101.

    The three models all shared most of the parts, reducing the cost through volume.

    The single-banders are a case study in design for a specific purpose and minimum cost.

    They were most popular for mobile use.

    73 de Jim, N2EY
    Last edited: Jul 17, 2017
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  4. G3YRO

    G3YRO Ham Member QRZ Page

    Not in those days ! Most people didn't even have an SWR Meter . . . you simply adjusted the Tune and Load controls into your antenna. (which was often just a longwire, straight into the rig)

    But I understand about the cost of things . . . a Load control and IRT is something I would have added if I had owned one, probably CW too.

    I had noticed when I looked them up before posting that they only covered the top end of the band . . . but it would have been very simple for people over here to re-tune the VFO so they covered 3.6 - 3.8 and 7.0 - 7.1 (that's all we had for 40m in those days).

    And back then I think many people might have been more interested in the 20m version anyway . . . it was very simple to build a 160m or 80m single-conversion rig (from 455 kHz) . . . but harder to get on 20m !

    $100 was about £36 back in the 1960s !

    Roger G3YRO
    Last edited: Jul 17, 2017
  5. K9STH

    K9STH Platinum Subscriber Volunteer Moderator Platinum Subscriber QRZ Page

    One thing about the "single banders" was that the "A" versions, with both sidebands, sold for $20.00 less than the earlier versions. The price for the original units was $119.95 and the later units sold for $99.95.

    It was very easy to add an external variable antenna loading control to any of the units. I did this with the HW-12A that I built my senior year in college.

    There were a couple of companies that made kits to convert any of the "single banders" for tri-band (75, 40, and 20-meter) operation.

    As for operation: In the late 1960s, well into the 1970s, there was still a lot of "normal" AM operation and not anywhere near the SSB operation of today. The receiver selectivity was "on par" with that of many of the separate receivers in use as well as with a number of the lower tier SSB transceivers.

    In 1966, Army MARS used frequencies of 4020 kHz and 4025 kHz for SSB operation. I discovered that it was possible to put a coat hanger wire through the cabinet perforations directly into the VFO coil and that would allow the HW-12A to tune to the 4020 kHz and 4025 kHz frequencies. Then, when the net was over, the wire could be pulled out of the VFO coil and the calibration would return for the 3800 kHz to 4000 kHz range.

    Glen, K9STH
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  6. AI0K

    AI0K Ham Member QRZ Page

    Maybe not in the U.K., but most of the hams I knew back in the 60's (including me) had an SWR meter. They were pretty cheap - even a poor high school student could afford one!
  7. G3YRO

    G3YRO Ham Member QRZ Page

    It wasn't about the cost . . . back then most people DIDN'T have antennas fed with coax, so what would be the point?

    Roger G3YRO
  8. N2EY

    N2EY Premium Subscriber QRZ Page

    On your side of the pond, probably.

    But, here in the USA, coax became the Holy Grail not too long after WW2. And with it, SWR meters, low-pass filters, and pi-networks.

    One big reason was TVI.

    The math might not work out so well, in terms of spurs.

    In any event they enjoyed some popularity - but then the SB-100 appeared. Although much more expensive, it was much more rig.

    73 de Jim, N2EY
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  9. N7ANN

    N7ANN QRZ Lifetime Member #181 Life Member Platinum Subscriber QRZ Page

    At one time I owned all three versions and loved them! The stark simplicity and loud clear audio just made them really fun to use. But at that time (1996 range) I seldom actually ran SSB. Certainly not enough to warrant the space they took up, so I sold them all off. I have to keep resisting the urge to buy the 20m version whenever a nice one comes along - you could actually make a pretty decent "go-kit" by stuffing an IC-7300 inside and have room left over for a small SWR meter and key/mic storage! :)

  10. N2EY

    N2EY Premium Subscriber QRZ Page

    One wonders how Heathkit was able to do that. Also, IIRC, the HW-12A sold for slightly less because it didn't have the premixer stage with its crystal.

    Of course. And, on 40 and 20 meters, a simple dipole or quarter-wave vertical, fed with 50 ohm coax and adjusted for minimum SWR in the middle of the 'phone subband, would usually work fine without any loading control.

    In QST for April, 1965, W3ZP showed how to add an SWR bridge to the HW-12, using the internal meter and a few inexpensive parts.

    73 de Jim, N2EY

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