Whatever's this? Strange 'radio aerial'?

[Phil G4SPZ]

That would be great, thanks John. These things are proving to be a lot more common than I first thought, so all sightings will be welcome!

[HamishBoxer]

Just found my NOS "Anomast" in its original box hiding in the garage!

[AndiiT]

Hi,
I certainly recall seeing these type of "Aerials" on houses in the Teesside/East Cleveland area and am almost certain that I have seen one (or more) somewhere close by within the last six months.

I might have to peel my eyes for some "picture opportunities"

Regards

Andrew

[turretslug]

I do like the way that the ads posted by Synchrodyne talk about the "downlead"- presumably this downlead needed to be as long and high as possible and not screened Just goes to show that "patent medicine" is an age-old syndrome...

[Synchrodyne]

Originally Posted by Phil G4SPZ

Synchrodyne, many thanks - spot on. Have you any idea of the date of the catalogue?

Aerialite were masters of marketing hype when it came to claiming wondrous performance from very basic products, often dressed up as something special. We have a box of Aerialite copper aerial wire which claims to receive better and with less interference than any other wire.

Unfortunately I do not have the dates for those items previously posted. They are part of a bunch that looks to date from the 1930s, but I cannot be absolutely sure.

The attached Aerialite advertisement from Wireless World 195309 makes mention of, but does not picture the Anomast, so evidently it survived well into the post-WWII era.

As already said by others, snake oil is nothing new, and the Anomast certainly appears to fall into that category. Aerialite appeared to be playing both ends of the game, though, as it also offered technically legitimate products. As far as I know, it was an Aerialite staffer who wrote the part-chapter on radio receiving aerials (including a detailed treatment of antistatic systems) that appears in Radio and Television Engineers’ Reference Book, 3rd and 4th editions. The Anomast might have been a case where the sales and/or marketing staff simply overruled the engineering staff. (It seems to be axiomatic that marketers always want to claim more than the engineers can properly support, often with the justification that such claims are necessary for sales success. (But the extras were not in included in the design brief because that would have increased the cost.))

One may endeavour to impute some kind of rationale – other than pure deception - for the Anomast and like products on the basis of perceptions. Let’s say that non-technical customers who could not or would not install a long-wire or vertical whip aerial might not have readily accepted that a length of open wire simply taken up a wall to an insulated mounting say to just below the peak of a gable end was going to work very well. But put a “technical” looking device on the end and then it was perceived to be “real”. Electronic “go faster” stripes, if you like.

Cheers,

[Tractorfan]

Hi,
As a lad I saw that our neighbour had one of those aerials mounted just below the gutter. Our houses were built in 1953 and I probably started noticing these things in the very early sixties. I remember their big table top radiogram with its bakelite 78rpm deck, but don't know what make or model it was.
When I started exhibiting my radio collection at steam fairs, I was given an aerial like that as well as a 'Trapeze' type as shown in post no.6 only not so tall.
Cheers, Pete.

[newlite4]

This is what I saw back in the early seventies:

http://www.google.com/patents/US2732551

Looks like it was patented in 1956,
Neil

[Phil G4SPZ]

Hi Neil,

That's interesting, but relies on a different (and a lot more meaningful) principle. The patent appears to be aimed at the VHF and UHF part of the spectrum, and the spherical antenna is a form of shortened vertical dipole, centre-fed with coaxial cable. The Aerialite Anomast is, by contrast, a single end-fed wire with a wire cage at the top, designed to receive on the broadcast bands in the range 0.15-18MHz.

I did wonder whether any design details, such as drawings or calculations, might survive in Aerialite's archives, but it's most doubtful.

[newlite4]

Thanks for that Phil. So, it could have been an early VHF aerial for the then new FM radio service.
Neil

[Phil G4SPZ]

Sadly, the patent contains no drawings, but it talks throughout as if the antenna was designed primarily for transmitting purposes. With a bandwidth of just 4% at the operating frequency, this certainly would have received OK but it would not have been optimum for VHF. The other point is that the antenna described in the patent would largely produce vertically-polarised radiation; VHF-FM was originally transmitted in the UK using horizontal polarisation, and the signal loss approaches 20dB. So, for several reasons, it wouldn't have been a good VHF-FM receiving antenna here.

It was probably more aimed at military or commercial two-way radio, or even VHF or UHF TV. One of the earliest forms of "Status" mobile omni-directional TV receiving antennas for touring caravans had several wire loops, followed by a pre-amplifier. But we digress... sorry, Mods!

[Refugee]

I have seen one of those "globe" aerials used for an analogue mobile phone.
It was on the roof of a small van that I used as a "run about" for a couple of years in the late 1990s.
The thing was about 2 inches across and had the remains of a chopped coax on the inside of the roof. I left it there as a plug for the hole in the roof.

[Phil G4SPZ]

I've just discovered that a friend of mine lives next door to a house fitted with one of these Anomast aerials, but despite his having been in the radio and TV trade all his working life, he didn't know what it was either.

[Scottart]

I've one of these collecting dust in the w/shop - looks like it's never been outside though :

https://www.vintage-radio.net/forum/...ad.php?t=43942

Stephen

[G6Tanuki]

I note there's a pic of such an "Aerial-topper" on Bill Wright's excellent "Ancient Aerials" page:

http://www.wrightsaerials.tv/aerialp...ient/065.shtml

[G8HQP Dave]

Originally Posted by Synchrodyne

One may endeavour to impute some kind of rationale – other than pure deception - for the Anomast and like products on the basis of perceptions. Let’s say that non-technical customers who could not or would not install a long-wire or vertical whip aerial might not have readily accepted that a length of open wire simply taken up a wall to an insulated mounting say to just below the peak of a gable end was going to work very well. But put a “technical” looking device on the end and then it was perceived to be “real”. Electronic “go faster” stripes, if you like.

Such devices do improve reception, very slightly! A capacitive hat on the end of a short antenna will increase the received signal by lowering the effective source impedance. In transmitting terms, the antenna current distribution changes from a triangle to a trapezoid, so the average current is a slightly higher proportion of the feedpoint current.

If 'wire+gizmo' gives you X mV signal, and 'wire alone' gives you 0.999 x X mV then claims of improved reception are true!

[Phil G4SPZ]

Originally Posted by G8HQP Dave

If 'wire+gizmo' gives you X mV signal, and 'wire alone' gives you 0.999 x X mV then claims of improved reception are true!

Whether the "gizmo" actually forms a capacity hat is perhaps debatable, Dave, particularly at such low frequencies and where the antenna length is such a small fraction of a wavelength, operating over a wide frequency range into an unspecified receiver input impedance. I think that in the 1930s it would have been extremely difficult, given the test equipment then available, for the manufacturer to demonstrate any meaningful increase in received signal strength over a straight vertical wire of the same length in a practical installation.

So even if they claimed an improvement based on theoretical considerations, they probably couldn't have provided the measured evidence to back it up...!

Don't forget, we are talking about a manufacturer who claimed special performance from his own brand of copper wire. I'm inclined to think that the marketing hype was just that, although judging from the sheer number of these gizmos that appear to have been sold, and have lasted around 80 years, there's no doubting the build quality, and the hype clearly translated into good sales to presumably satisfied customers!

[Radio Wrangler]

That patent above is in the name of John D Kraus. VERY famous for his text book on electromagnetics, used in a lot of universities.

The spherical cage described is of the order of a quarter of a wavelength in diameter. The 'anomast' would certainly be prominent if made on that scale for the frequency range it was sold for.

Also the spherical antenna patent is assigned to the Battelle Corporation, a large US military contractor and research contractor. So it's a serious item for VHF and upwards.

The proliferation of these anomast things shows the power of advertising, and the proportion of the population who haven't a clue about aerials.

David

[Phil G4SPZ]

Originally Posted by G6Tanuki

I note there's a pic of such an "Aerial-topper" on Bill Wright's excellent "Ancient Aerials" page...

And I note that Bill draws the same conclusion about sales hype!

[G8HQP Dave]

Originally Posted by Phil G4SPZ

Whether the "gizmo" actually forms a capacity hat is perhaps debatable, Dave, particularly at such low frequencies and where the antenna length is such a small fraction of a wavelength, operating over a wide frequency range into an unspecified receiver input impedance. I think that in the 1930s it would have been extremely difficult, given the test equipment then available, for the manufacturer to demonstrate any meaningful increase in received signal strength over a straight vertical wire of the same length in a practical installation.

It is precisely under the conditions of antenna length being a small fraction of a wavelength where a capacity hat (however small) is helpful. Not very helpful, mind you. Perhaps unmeasurably so, but theoretically helpful. It slightly lowers the impedance of the antenna, so slightly increases the delivered signal into any typical (lower) receiver input impedance.

Claims about special copper wire still abound, of course, but we mustn't go there!

[matthewhouse]

Originally Posted by Heatercathodeshort

I've seen a couple of the 'hedgehog' type within the last 3 years. I'll divert to Bramley when I next go to Guildford and see if one of them is still there. John.

There are loads of those hedgehogs in Devon, I've never seen the other styles fitted to houses around here though.