When did Superhets turn up in domestic homes?

[GMB]

This is just a history question.

I was wondering when superhet radios first appeared in the shops. I presume they started as a high-end product.

And by when did they become common, so everyone could buy them?

[Herald1360]

Around mid/late '20s, mid '30s. Somewhat ill defined either way.

[Paul_RK]

Yes: a few high-end models appeared in the mid '20s, but I'd go for 1933 as the first year in which typical domestic sets were superhets. TRF models after that were mostly only the simplest radios on the market, aside from Philips keeping to them for a couple more years and to some extent Cossor likewise.

Paul

[julie_m]

The Philips "Superinductance" sets were about as good as TRFs were going to get, at least until the Ferranti ZN414 came onto the scene some 40 years later, but even they proved to be an evolutionary dead end. The first commercially-available transistor set, the PAM 701, was a superhet; though there was no shortage of transistor TRF designs for home constructors to choose from.

[Radio Wrangler]

The first superhets on sale were definitely up-market radios, for example the Burndept Ethodyne. Their cost put them within the reach of only the rich. With valves costing several week's wages for the average family, a technique which doubled the number of valves needed was going to limit the market.

However, the changeover period from TRFs being dominant to superhets being dominant seems to have been quite short, especially considering the financial depression in that era.

David

[russell_w_b]

It must've been around the mid-1930s, as my father remembers certain people 'boasting', in much the same way their descendents do about today's technology: '...how many valves THEIR set had: how many has yours got?'

This was in 1930s Workington, an industrial town in the NW of England, and where unemployment was always waiting behind the door. But, as now, some people simply had to have the latest gadgets!

[Cobaltblue]

IMHO it was the introduction of multiple valves specifically designed for use in superhets that brought on the change.

Valves such as the AC/TP introduced in 1934.

Multiple valves reduced the cost to manufacture a Superhet that could now be achieved with 3 valves + Rectifier.

So My guess is that 1933/4 was the changeover to the cost effective Superhet.

Cheers

Mike T

[Radio Wrangler]

Having just mentioned the Ethodyne, I went looking for a photo of one. Google turned up a page on www.sciencemuseum.org with photos.

http://www.sciencemuseum.org.uk/onli...dex/smxg-35696

Unfortunately, the text begins "In 1917, Edward Howard Armstrong (180-1954) developed the first superheterodyne...."

Edward?

Wasn't he Edwin?

David

[richrussell]

Certainly by 1935 superhets were common in ordinary domestic receivers, and by 1939 they were getting quite sophisticated (given the types of valves available).

[turretslug]

Is it so that the BVA's frowning on multiple valves (i.e. Telefunken's triode-hexode) and levy on individual base count tended to hinder the adoption of the superhet in the UK relative to other countries?

[FERNSEH]

The earliest HMV and Marconi superhets employed an MS4B RF tetrode as the frequency changer.
Here's an example of an early thirties superhet:
http://www.radiomuseum.org/r/marconi...phone_262.html


Superhet receivers were made in the late twenties in small numbers.
Most of these receivers employed a very low IF, typically 50Kc/s.

DFWB.

[G6Tanuki]

Originally Posted by turretslug

Is it so that the BVA's frowning on multiple valves (i.e. Telefunken's triode-hexode) and levy on individual base count tended to hinder the adoption of the superhet in the UK relative to other countries?

The "Valve Tax" did indeed mitigate against any design that used more valves than were absolutely necessary: there was a definite motivation to squeeze every last decibel of gain out of every valve so you needed fewer of them.

This might possibly have been driven by the need for heater-power economy and discouraged superhets [remember that many parts of the UK didn't have mains electricity until the late-1930s: when you're paying for accumulators or dry-batteries for your heater power fewer valves is a good thing].

Even when superhets took over [because they were easier to drive - no need to twiddle several unganged tuning-knobs and a reaction-control] the cost of valves made the "short" superhet popular.

There were 2 essential options for the short-superhet: some did away with an IF-amp and fed the IF signal from the mixer direct to a detector; the other approach kept the IF amp stage but used a 'high slope' output valve driven direct from the detector (rather than the traditional triode-tetrode or triode-pentode output).
This is the explanation for valves like the EBL31 diode-output-pentode.

Achieving sensible AGC with some configurations was, let's say, 'interestingly unsatisfactory', moreso when you include the occasional design that "reflexed" an IF-amp to provide the first stage of audio gain as well.

The UK/Europe never embraced that US oddity for 'midget-superhets' which combined an audio-output valve and a half-wave power rectifier in the same bottle:

http://www.radiomuseum.org/tubes/tube_117l7m7gt.html

we sometimes used copper-oxide 'metal rectifiers' for the HT to save on a valve though - at one time a lot of UK radios described themselves as "4 valve plus rectifier" .

Also worthy of pondering regarding early superhets: The US were heavily into single-valve multigrid self-oscillating mixers ['autodyne' converters] whereas Europe went more for triode-pentodes/triode-hexodes which separated the oscillator and mixer duties: I wonder why??

[Radio Wrangler]

BVA Valve tax....

The invention of the transistor couldn't have happened to a finer bunch of people.

David

[G6Tanuki]

I always found it amusingly ironic that by the 1960s there were various valves being marked as "BVA Foreign" - a quiet acceptance that they were losing their hold on the market.

[this was about the same time as 'resale price maintenance' - the ability of a manufacturer to set and enforce a 'recommended resale price' and deny supplies to distributors who wanted to sell to customers below this - started to crumble.

At one time even the Co-Op's 'divvy' was seen as heresy by the major radio manufacturers - it was, after all, a discount!! The Co-Op's use of the brandname "Defiant" for their TVs and radios was a subtle challenge to the resale-price-maintenance mafia]

[Wendymott]

May I put in my "ten pennorth", slightly "off topic" but relevant "I Hope". I came across a website, americanradiohistory.com, which was noted on another thread now closed. What a mine of information. To answer Richrussels question, there is a section covering technical articles amongst them Wireless world and Practical Wireless, going back to the year dot. And his question and answer I was reading this PM. About 1930 ish, as TRF and Superhets were still being sold. But what struck me, reading a copy of Wireless world circa 1971, why there are no "except Elektor" magazines for us "techies" anymore. ADVERTS, or the revenue from adverts. If you look in any magazine of post war, the number of companies selling all sorts, valves, semi's, everything the enthusiasts wanted. Now Hardly anyone, no Colomore, Henrys radio, RSC, just to name 3, thus no income for the magazines that could not survive on subscriptions or sales solely, they relied on income from adverts.
"Just saying"...

[AC/HL]

Please keep on topic. The question posed in this thread is: When did Superhets turn up in domestic homes?

[Wendymott]

Sorry MOD

[wireful3]

I have been looking through Radio Radio and this supports mid 1930s as the time when superhets were generally available. The simplicity of use must have been a very strong market feature because TRF sets seemed to decline rapidly.

The multiple valves must have been a big factor. The artificial effect of price being affected by number of valves seems to have been important. I have little experience of bulk manufacturing at the time but wondered whether just using a separate local oscillator might have had a big effect on price.

It is amusing to think of the overlap period. I am sure there were people who considered valve count something of a prestige feature. They would be faced with the situation (probably not recognised) where what to them might been inferior set, could well be technically superior as well as being easier to use.

[Wendymott]

One useful book I have is...SETMAKERS, by Keith Geddes and Gordon Bussey. Both well respected names in the trade. The book covers Radio manufacture from the year dot. and TV from its conception to the mid eighties.

[AC/HL]

Required reading IMHO, if you want to speak authoritatively on many of the topics we cover.