H.A.C Receivers

[jimmy55]

My introduction to radio in the early 60's was building a kit called an HAC ( Hear All Continents )I remember it was a modular kit to which I added a second stage at some later date, and used an old 90V battery. It had a great geared tuning dial and I used to receive a lot of signals on 80m and 160m with a long wire chucked out of my bedroom window.
Has anyone still got one of these I wonder? I am pretty sure it used to be advertised in the small ads in Practical Wireless at the time.

[Station X]

There's a webpage on HAC's here:-

http://www.wftw.nl/hac.html

[Junk Box Nick]

I still have my one valve 'DX' set which dates from the 1960s - I was still in short trousers and it was my main Christmas present. In addition to coil 4, which covered the 49m and 41m broadcast bands, etc., I had the extra coils which gave me topband and 80m and the the higher frequency short wave range. I never had much success with the higher frequency coil.

Later, possibly for my birthday, I was bought bought the add-on kit with the extra valve. It was another directly heated triode and used an interstage transformer but the arrangement required 120v so I had to have another battery in addition to the 90v HT. Performance was little better than with the single valve - I can still recall my disappointment - and when valve got broken and I reverted to the original arrangement.

The 'DX' kit came with just a U shaped chassis punched with three holes for main tuning, reaction and bandspread. Main tuning with a little knob was very tricky. I coveted the big reduction drive shown in the ads but these sets were costly for what they were and so faced with saving pocket money for months I settled for what I'd got. In the end I overcame the problem by mounting the main tuning capacitor above the chassis on a sheet of aluminium and with a little bit of crude metal work using a couple of large coffee tin lids bolted together, a spindle and bush salvaged from an old radio set, and some cord, I made my own reduction drive.

I heard my first amateurs on 160m and received my first QSL cards as an SWL for QSOs I heard on this band. A teacher at school had an RSGB call book so I was able to lift addresses.

In response to my QSL letters I received a lot of encouragement from local amateurs and I was invited around to see their shacks. I remember that the first amateur to reply with a QSL card had his shack in a verandah and two HRO receivers. Another had a KW Vespa and a huge vertical in the back garden with guys to every corner. He also had a colour TV - this was equally fascinating as it was the first time I saw TV in colour.

Going on such visits would be unthinkable today but nothing untoward ever happened to me and I was given lots of encouragement and bits and bobs to help me with the little projects I was making. I was able to make a tuning unit using a large ceramic coil former I had been given. One amateur, who worked in engineering, even fabricated a couple of brackets for me to help mount an aerial pole I had been given. Up until then, my wire was strung to a broom stale screwed to the back of the garden shed.

Inevitably, I used the parts from the HAC in other projects but then, some years on I rebuilt the one valve set as it originally was. Subsequently it gathered dust in my parents' loft to be rediscovered after they had both passed on though the headphones - which were a crude arrangement - had been lost. I have since acquired a pair of vintage BBC high impedence phones and, once I have strung up a suitable length of wire and strapped together a line of pound-shop PP3s, I hope to see the homely glow of the heaters and re-live the magic of early SWLing once more. Sadly, there is not so much to be heard on the broadcast bands but perhaps with a simple QRP Tx I could even enjoy some QSOs using it. I might finally achieve 'hearing all continents' though working them might be a tougher task!

[jimmy55]

Station X ....great to see that link, I remember those ads so well! I built the things methodically but somehow none of the theory ever sunk in!
Nick. Yes I also went on to add on to the original set and I think I even managed the geared tuning! A few sixth formers at my school had a 'shack' in the language laboratory ( a very sixties term!) and we all went on to collect QSL cards. The Chinese Embassy at the time were very generous and would send out the famous Little Red Book and reams of propaganda at the drop of a hat! ... now they would be the ones knocking out the modern day HAC.

[rmslt56]

There was one for sale at Harpenden today
Doug

[G6Tanuki]

As well as the "HAC" receivers I remember that in the 1960s there was a series of similar radios produced by a company in Worcester: these used a VP23/ARP12 pentode [Mazda octal base] and were considered one or two steps up from the HAC sets.

The place in Worcester also did super-regen VHF kit-radios.

[Junk Box Nick]

I am curious to know who/what brand that was.

I remember a pal of mine had a 'Raymart' (?) set. It was a similar construction to the HAC but had a more modern valve and a modular transistor amplifier. He was of the opinion that his set was superior to mine, but that was his opinion about most things.

[G6Tanuki]

From memory the company in Worcester was "Johnsons" and the short-wave radio was called something like the Globe-king.

Raymart were a well-known brand in the pre/post-WWII radio world - they were based at 48 Holloway Head, Birmingham and also traded as "Radiomart (G5NI) Ltd".

In later years they produced a well-respected range of grid-dip-oscillators and tunable absorption-wavemeters.

[jimmy55]

Any idea what they were asking at Harpenden Doug?

[rmslt56]

I think the asking price was £25.
Doug

[Herald1360]

Sharp intake of breath.......

Was that for a pristine boxed unused kit or a collection of bits you could haul out of any old battery set for a fiver or less?

[Junk Box Nick]

In real terms probably cheaper than the original kit!

[David G4EBT]

Originally Posted by Junk Box Nick

In real terms probably cheaper than the original kit!

As to prices at the time, and as they would be today when adjusted for inflation, it's interesting to look at the info at the link that Graham provided. In particular, the 1983 invoice for a total of £30, made up of £15.00 for the basic one-valver, plus an additional £7.50 for two coils and bandspread tuning capacitor, then an additional £7.40 for something which is obscured on the invoice.

To put that into perspective, when adjusted for inflation, £30 in 1983 equates to £90 today. Strewth!

http://safalra.com/other/historical-...ce-conversion/

I've just looked at a Nov 1977 copy of PW, in which the HAC one-valver was advertised at £10.50. On the next page is a range of transistorised kits by another company, which - for example - included a Multi-band AM superhet receiver covering the LW, MW, Trawler Band, plus three short-wave bands. It used seven transistors, two diodes, push-pull output stage, 5" x 3" elliptical speaker, ferrite rod antenna, and an attractive cabinet with carrying handle. The price of that kit was £9.99.

I'm nonplussed as to why some punters considered a one-valve kit, costing more money, needing headphones, LT and HT batteries was a better buy than that 7 transistor kit, or any one of the many kits that abounded in the post-war years from the late 40s to the late 70s. As a schoolboy in the mid 50s, I was an avid reader of Hobbies Weekly on my paper round, which - by the time I posted it through the door of the intended recipient - had been well thumbed by me. It often had FG Rayer circuits in for one and two-valvers, as of course did radio magazines such as PW.

I built many simple valve receivers back then, as did school chums, at pocket money prices, and would never have given a thought to HAC kits at a time when my maximum outlay on a valve at a time when the country was awash with millions of them, would have been 1/6d - about 7 pence in 'new money'..

It's one of life's mysteries as to how HAC were able to stay in business from at least 1938 until the early 1980s.

Presumably the 'Heard All Continents' tag had a special allure to it, despite it being such a basic 'minimalist' bog standard one-valver?

That's not of course to say that it wasn't a nice little set, and given its longevity, it must have satisfied countless constructions happy to fork out for a kit.

[jimmy55]

As a 15 year old in 1970 a glowing glass tube and a pair of headphones had a certain allure. Once I'd saved up for that geared tuner then I'd really arrived. I saved the transistors for my Phillips Electronic Engineers set with its pegboard and springs!

[Herald1360]

Originally Posted by David G4EBT

I've just looked at a Nov 1977 copy of PW, in which the HAC one-valver was advertised at £10.50. On the next page is a range of transistorised kits by another company, which - for example - included a Multi-band AM superhet receiver covering the LW, MW, Trawler Band, plus three short-wave bands. It used seven transistors, two diodes, push-pull output stage, 5" x 3" elliptical speaker, ferrite rod antenna, and an attractive cabinet with carrying handle. The price of that kit was £9.99.

Are you sure it was a superhet- it sounds rather like the dodgy old Roamer Seven with its "air spaced ganged tuning capacitor". That was a straight set. One of the earliest instructions in the kit was to parallel together the two sections of said capacitor

[David G4EBT]

Yes, it was indeed the 'Roamer 7' and from what you say, it didn't enjoy a good reputation.

I assumed that with it having 7 transistors, a push-pull output stage and six wavebands that was a standard superhet design, I was clearly mistaken. The only kit radio I bought back in the late 50s to take Youth Hostelling was one that used two acorn valves, which gobbled LT batteries at a rate of knots, with their 150mA 6.3V heaters, provided by four 'U2' cells as they were called back then. A very lively little receiver and I think the kit cost £1.50 - about half a week's wages at the time, as an impecunious apprentice. I guess they used acorn valves not because of their suitability, but because there were as many ex WD acorn valves on the surplus market as there are acorns in Sherwood Forest, and hence, they were so cheap, as well as being good little valves, but not really suited to battery operation.

At least the HAC set had the merit of simplicity - hardly anything in it to go wrong!

Happy days!

[Junk Box Nick]

Originally Posted by David G4EBT

It's one of life's mysteries as to how HAC were able to stay in business from at least 1938 until the early 1980s.
Presumably the 'Heard All Continents' tag had a special allure to it, despite it being such a basic 'minimalist' bog standard one-valver?
That's not of course to say that it wasn't a nice little set, and given its longevity, it must have satisfied countless constructions happy to fork out for a kit.

The HAC was a kit and as such was 'guaranteed' to work. When you'd battled on the kitchen table with simple designs, that sometimes had basic errors in the published circuit*, or you couldn't get all the 'correct' parts, what you were buying was success.

When you are a kid in short trousers and know little better it's easy to pursuade dad, who knows even less than you, that this would be a good Christmas present.

I had a Philips Electronic Engineer kit which had a far more complex receiver design than the HAC. There were instructions in the handbook for winding your own coil for the short wave 'trawler' band. The result was silence which is hardly surprising given what I now know. Using hook-up wire wound around a ferrite rod was hardly going to result in a high Q coil and the set had no reaction/regeneration to improve the sensitivity. And I didn't have the knowledge or the components to cobble up my own arrangement.

Once the admittedly minimalist HAC was assembled it worked. I heard stations from foreign parts and radio amateurs.

They were seemingly overpriced kits but I guess I got my (or rather my father's) money's worth from the many hours of enjoyment I got from the set.


*See other threads on this forum.