14th Nov 2017, 11:19 pm | #1 |
Octode
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VHF or UHF?
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? |
14th Nov 2017, 11:32 pm | #2 |
Octode
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Re: VHF or UHF?
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 |
14th Nov 2017, 11:34 pm | #3 |
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Re: VHF or UHF?
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. |
15th Nov 2017, 12:02 am | #4 |
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Re: VHF or UHF?
Thanks for the clarification.
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15th Nov 2017, 12:03 am | #5 | |
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Re: VHF or UHF?
Quote:
Anyone know why "Super in general" always follows the word superhet?
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15th Nov 2017, 12:06 am | #6 |
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Re: VHF or UHF?
German sets often call the VHF/FM waveband "UKW", Ultra Kurzwelle, Ultra Short-wave.
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15th Nov 2017, 12:23 am | #7 |
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Re: VHF or UHF?
Guess they missed out on SKW (Sehr Kurzwelle) for Very Short Waves.
Not that I've ever heard that here, either.
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15th Nov 2017, 12:50 am | #8 |
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Re: VHF or UHF?
It seems their UHF is also UHF Ultrahochfrequenz, which means they jump from wavelength to frequency units if that's true.
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15th Nov 2017, 1:53 am | #9 | |
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Re: VHF or UHF?
Quote:
Nothing exceptional. Martin
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15th Nov 2017, 10:05 am | #10 |
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Re: VHF or UHF?
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 |
15th Nov 2017, 10:38 am | #11 |
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Re: VHF or UHF?
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... |
15th Nov 2017, 10:44 am | #12 |
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Re: VHF or UHF?
The Hallicrafters S27 "battle of the beams" receiver was called a UHF receiver, I think it tuned up to 145MHz.
Lawrence. |
15th Nov 2017, 10:55 am | #13 |
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Re: VHF or UHF?
Yes, definitely UHF in those days.
Andy |
15th Nov 2017, 10:57 am | #14 |
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Re: VHF or UHF?
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.
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15th Nov 2017, 11:02 am | #15 | |
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Re: VHF or UHF?
Quote:
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).
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15th Nov 2017, 9:23 pm | #16 |
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Re: VHF or UHF?
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. |
15th Nov 2017, 9:40 pm | #17 | |
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Re: VHF or UHF?
[QUOTE=Hartley118;991409]
Quote:
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...
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15th Nov 2017, 9:46 pm | #18 |
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Re: VHF or UHF?
I read somewhere that 'superhet' is an abreviation of 'supersonic heterodyne'. The 'supersonic' meaning that the intermediate frequency was higher than an audio frequency
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15th Nov 2017, 9:50 pm | #19 |
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Re: VHF or UHF?
That would do it, Tony. Convincing enough!
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Al |
15th Nov 2017, 9:50 pm | #20 |
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Re: VHF or UHF?
I think you read correct.
Lawrence. |