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Vintage Radio (domestic) Domestic vintage radio (wireless) receivers only. |
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21st Jul 2019, 4:29 am | #1 |
Pentode
Join Date: Jul 2011
Location: Mission Viejo, California, USA
Posts: 142
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MW Station Numbers (Wave Lengths)
How do you convert station numbers to frequency? I've got my Bush SAC-21 working nicely, but the MW dial shows numbers from 200 to 550.
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21st Jul 2019, 6:24 am | #2 |
Hexode
Join Date: Mar 2014
Location: Peacehaven, East Sussex, UK.
Posts: 278
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Re: MW Station Numbers
divide the station number ( which is the wavelength in metres) into 300 000 000 to get the frequency in MHz
for example, 200M wavelength is 1.5MHz Last edited by tony brady; 21st Jul 2019 at 6:26 am. Reason: additional info |
21st Jul 2019, 6:25 am | #3 |
Octode
Join Date: Feb 2018
Location: Southampton, Hampshire, UK.
Posts: 1,051
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Re: MW Station Numbers
Here's a photo of the dial of one of my sets which has both frequency and wavelength markings for MW and SW, hope it helps.
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21st Jul 2019, 8:58 am | #4 |
Dekatron
Join Date: Oct 2003
Location: Croydon, Surrey, UK.
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Re: MW Station Numbers
I always use 300,000 since that's the speed of light in metres per second (near enough). That will give the answer in Khz which might be easier. For instance LW Radio 2 was for many years on 1500 metres (200Khz). If 300,000 is divided by 1500 (metres) you get 200 (Khz). It actually works both ways since if you wanted to know what 200 Khz was in metres then just divide 300,000 by 200(Khz) and you get 1500 (metres).
Similarly if you wanted to know what 300 metres was in Khz then it's easy to see that 300,000 divided by 300(metres) will be 1000Khz (or 1 Mhz).
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21st Jul 2019, 9:37 am | #5 |
Dekatron
Join Date: Apr 2011
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Re: MW Station Numbers
MHz = 300/wavelength....wavelength = 300/MHz.
Lawrence. |
21st Jul 2019, 10:09 am | #6 |
Dekatron
Join Date: Nov 2003
Location: Fakenham, Norfolk, UK.
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Re: MW Station Numbers
Tuning dials with frequency calibration were unfamiliar in the UK until well into the 1960s, hence exhibits 1 and 2 here, midget American sets from 1938-40 provided with wavelength-marked dials - and long wave coverage - because they were for export to Britain. Exhibit 3 is more of a mystery, a 1935-6 radio by Pegasus of Leeds, presumably for the domestic market but with a dial marked in kilocycles (/second, of course) which must have been an obstacle to domestic sales.
Paul Last edited by Paul_RK; 21st Jul 2019 at 10:17 am. |
21st Jul 2019, 1:39 pm | #7 |
Moderator
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Location: Oxford, UK
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Re: MW Station Numbers
British broadcasters including the BBC were still describing transmitter frequencies in wavelengths in the late 70s, and Radio 1 was still using 275/285 metres in promotional material in 1984. Some commercial stations had names incorporating the wavelength until a decade ago.
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21st Jul 2019, 2:00 pm | #8 |
Dekatron
Join Date: Nov 2003
Location: Fakenham, Norfolk, UK.
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Re: MW Station Numbers
Yes, such acquaintance as most people in the UK had with frequency calibrations in the 1960s will have come by way of the increasing prevalence of receivers from the Far East. A few early Hong Kong-made pocket sets, for instance, had tuning knobs marked in metres if memory serves, but before 1970 frequency markings had become the order of the day. Also by around 1970 some UK-made portables had both frequency and wavelength markings on MW and LW.
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21st Jul 2019, 2:24 pm | #9 |
Dekatron
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Re: MW Station Numbers
The attached table of frequencies v wavelength might help.
It will be be clearer when printed off. You can use the table to convert either way, so for example, to take an obvious example, at the top of the third pair of columns of figures, you'll see 300 next to 1,000. So if you wanted to know what 300 kHz is in Metres it's 1,000 M. Conversely, 300 Metres = 1,000 kHz (1 MHz). Sure, that wouldn't be hard to do using mental arithmetic, but it might be more of a faff to work out that 470kHz = 638.3 Metres. Hope that's useful.
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21st Jul 2019, 4:47 pm | #10 |
Dekatron
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Re: MW Station Numbers
Just thinking idly... When FM started, radios in the UK were marked in frequency for FM but in wavelength (usually) for the AM bands including shortwaves. If this had not been adopted imagine an FM band marked from 3.4 metres to 2.77 metres! The BBC would have had to announce Radio 2 as 3.4 - 3.3 (metres) FM instead of 88 to 91 FM!
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21st Jul 2019, 4:50 pm | #11 |
Pentode
Join Date: Jul 2011
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Re: MW Station Numbers
Thank all of you! I've got two more British radios to restore after the Bush SAC-21, and may find more of them here. A woman I bought one or two from told me that somebody quite a few years ago had been bringing cargo containers of radios and other things here to sell in "antique" shops.
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21st Jul 2019, 8:35 pm | #12 | |
Dekatron
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Re: MW Station Numbers
Quote:
When it moved to FM and obsoleted the old 210M medium-wave service it called itself "210 FM" or "Two-Ten FM" for the next decade! https://audioboom.com/posts/700547-radio-210-launch |
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22nd Jul 2019, 7:24 am | #13 |
Rest in Peace
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Re: MW Station Numbers
It was a dodgy thing to do to name your radio station after the wavelength as the frequencies allocated for broadcasting can be a bit fluid..
Some Pirate stations tried it, one was Radio 390 on 773kHz. Radio Caroline used the wavelength in their jingles, and as they changed frequency, for one reason or another, they always chose a number which rhymed with Caroline, like 199 or 259, which did not always correspond exactly to the actual wavelength but was close enough so people could find the station on their dial which would have been marked in metres. The actual wavelengths were 197.4m or 200.9m for Caroline N. & S. then later changed to 252.7m & 252.6m but 199 and 259 were close enough. Mike |
22nd Jul 2019, 8:39 am | #14 |
Heptode
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Re: MW Station Numbers
Luxembourg 208 (metres), though unlike the others maybe they didn't make a big deal of the wavelength in the branding? I can't remember. I don't remember Caroline or Radio North Sea making any deal over the wavelength in the 1960s.
Atlantic 252 (kilo Hertz) Limerick Live 95 (Mega Hertz) Last edited by Station X; 22nd Jul 2019 at 9:16 am. Reason: This forum is a Brexit free zone! |
22nd Jul 2019, 9:14 am | #15 |
Dekatron
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Re: MW Station Numbers
And well into the 21st Century on the HF bands. Of course, on HF the actual frequencies varied within the bands, so it made sense to do so.
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22nd Jul 2019, 2:15 pm | #16 |
Tetrode
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Re: MW Station Numbers
Luxembourg certainly did -with 'Fabulous 208'.
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22nd Jul 2019, 4:04 pm | #17 | |
Nonode
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Re: MW Station Numbers
Quote:
Martin
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22nd Jul 2019, 4:41 pm | #18 |
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Re: MW Station Numbers
Hi Michael, a nostalgic reminder of some of the Pirate station jingles, and illustrating their use of the wavelength to promote themselves. https://www.youtube.com/watch?v=Ts5EfWPy-ew
Mike Last edited by crackle; 22nd Jul 2019 at 4:47 pm. |
22nd Jul 2019, 4:45 pm | #19 |
Dekatron
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Re: MW Station Numbers
Wasn't there 'Television Sound' marked on the MF bands from the earlier experimental Baird TV days, or am I dreaming this?
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22nd Jul 2019, 4:56 pm | #20 |
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Re: MW Station Numbers
I think you're right, Russell. A now long departed relative of min had a large radio - I don't recall what make or model after some 65 years - which included 'Television Sound' on it's dial.
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