VHF or UHF?

[kellys_eye]

I'm discussing details of an Imperial HIFI 2700 receiver and there are questions raised as to the pushbutton selector and radio scale that goes from 2 to 56.

The only details I have found regarding this set is over at Radio Museum (I'm not a member so can't access anything more detailed) where the basic specs show that the bands it covers are:

Broadcast
Longwave
Shortwave
plus FM or UHF

UHF Really? Does it really cover such bands? Or is this a misnomer due to the original German spec and it should mean VHF?

Can anyone shed light on this?

[Reelman]

The Germans divided up the VHF band II into “channels”. Their radios usually had the channels marked on the dial as well as the frequency. I am guessing that’s what 2 - 56 refers to....

Peter

[paulsherwin]

It appears to be VHF. I think the VHF/UHF thing is just the way the standard Radiomuseum categories work.

The Germans did use channel numbers for band II FM for a while, though dials are usually marked with both frequencies and channels.

[kellys_eye]

Thanks for the clarification.

[Graham G3ZVT]

Originally Posted by paulsherwin

It appears to be VHF. I think the VHF/UHF thing is just the way the standard Radiomuseum categories work.

Strange.
Anyone know why "Super in general" always follows the word superhet?

[Graham G3ZVT]

Originally Posted by kellys_eye

Does it really cover such bands? Or is this a misnomer due to the original German spec and it should mean VHF?

Can anyone shed light on this?

German sets often call the VHF/FM waveband "UKW", Ultra Kurzwelle, Ultra Short-wave.

[Herald1360]

Guess they missed out on SKW (Sehr Kurzwelle) for Very Short Waves.

Not that I've ever heard that here, either.

[Graham G3ZVT]

It seems their UHF is also UHF Ultrahochfrequenz, which means they jump from wavelength to frequency units if that's true.

[Hartley118]

Originally Posted by rambo1152

Anyone know why "Super in general" always follows the word superhet?

I've been puzzled by this eccentric language in Radiomuseum. It's quite distracting! I just wish that the volunteers there would get an English speaker to check out their colloquial English. The problem is that Super in English usually implies something rather exceptional, whereas the Radiomuseum phrase 'Super in general' only means an ordinary general superhet.

Nothing exceptional.

Martin

[M0FYA Andy]

When did the accepted use of the terms become standard in Britain? Certainly during the WW2 era, military systems which operated at what we now call VHF were referred to as UHF, for example radar operating at 200MHz, or the WS19 B set at 240MHz if I remember rightly.
Andy

[kalee20]

I've got a Philips Philetta radio, where the VHF/FM band is marked UKW (for ultra short waves). Short wave AM is KW. Medium wave is MW; long wave is LW so I guess the German happens to start with the same letters as the English!

I have seen on very old British sets LF for low-frequency; and MF for medium-frequency. So, sometime, we went from frequency to wavelength, and eventually (1980's?) back to frequency. I can well remember Radio 2 being announced as 1500m in the 1970's.

When did UHF become VHF... dunno! I guess it's similar to TV, when 405 line standard was introduced, it was High Definition; and 1080 line digital is also called High Definition. The terms 'High', 'Low', 'Long', 'Short', 'Ultra', 'Very', 'Super', 'Extra', are all relative after all...

[ms660]

The Hallicrafters S27 "battle of the beams" receiver was called a UHF receiver, I think it tuned up to 145MHz.

Lawrence.

[M0FYA Andy]

Yes, definitely UHF in those days.

Andy

[turretslug]

On a few pre-war sets, there was a 12-5m or thereabouts band referred to as "ultra short". Probably fairly quiet in most locations, unless you were in a 41.5MHz locale, was there much usage of 11m broadcasting then? I suppose it's all relative to what had come before, at some point someone (or some committee) with a tidy mind seems to have decided on spectrum delineation in decimal wavelength increments, hence the familiar 30-300MHz VHF, 300-3,000MHz UHF etc.- this demarcation would seem to have more application to abstract book-keeping than practical application to circuit techniques, propagation and so on.

[Dave Moll]

Originally Posted by kalee20

VHF/FM band is marked UKW (for ultra short waves). Short wave AM is KW. Medium wave is MW; long wave is LW so I guess the German happens to start with the same letters as the English!

UKW = Ultrakurzwelle (as stated earlier)
KW = Kurzwelle
MW = Mittelwelle
LW = Langwelle

... so yes, it's only "kurz" for "short" that differs in its initial letter from the English (with apologies if I haven't got quite the correct German endings).

[emeritus]

The PL259 connector that my catalogue says is only suitable for use up to about 200MHz due to its non-constant impedance characteristics, is sometimes still referred to by its original name of "UHF connector". Presumably when it was designed, this upper frequency was considered to be UHF.

According to the 1956 edition of the "ITT Reference Data for Radio Engineers", standardisation of frequency band designation seems to have been first agreed at the Atlantic City Radio Convention of 1947, although the CCIR later recommended that the use of such arbitrary names be discontinued. In my days with Plessey in the 1970's the 225-400 MHz band was referred to as the Military UHF band, although it spans the Atlantic City VHF and UHF bands.

I guess the terminology has changed as the art has developed. In my late father's 1933 edition of Scott-Taggart's "Manual of Modern Radio", what we would now call "Radio Frequency [RF], is called "High Frequency" [HF]. German still retains this pre-war usage, as the German word for "Radio Frequency" is "Hochfrequenz", literally, "High Frequency", often abbreviated as "HF". Before I retired my work often involved scrutinizing German technical documents or their English translations. Often the English translator was evidently not aware that HF = RF, which sometimes caused confusion.

[Al (astral highway)]

[QUOTE=Hartley118;991409]

Originally Posted by rambo1152

The problem is that Super in English usually implies something rather exceptional...

*Super-* is from Latin, where it just means 'above' or 'beyond'. Hence supernatural, for example, superabundant, super-heavyweight, etc.

Hence it isn't clear why it is used in the sense of a Superhet(erodyne), as the mixing of the two frequencies, one incoming and one locally generated, isn't clearly 'beyond' anything...

[TonyDuell]

I read somewhere that 'superhet' is an abreviation of 'supersonic heterodyne'. The 'supersonic' meaning that the intermediate frequency was higher than an audio frequency

[Al (astral highway)]

Originally Posted by TonyDuell

I read somewhere that 'superhet' is an abreviation of 'supersonic heterodyne'....

That would do it, Tony. Convincing enough!

[ms660]

I think you read correct.

Lawrence.