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General Vintage Technology Discussions For general discussions about vintage radio and other vintage electronics etc. |
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24th Jul 2017, 7:58 pm | #21 |
Rest in Peace
Join Date: Mar 2006
Location: N.W. Oxfordshire(Chipping Norton)
Posts: 7,306
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Re: Long wave and medium wave units confusion
American (or American market) AM radios often had the dial marked 54-60......up to 16. As Graham (Station X) noted, this was simply a short way of stating 540 - 600....up to 1600kHz -in other words the standard MW Band. Regarding Channel Numbers on VHF radios, it used to be the case that German sets had Channel (Kanal) Nos. on their dials.
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24th Jul 2017, 8:15 pm | #22 | |
Retired Dormant Member
Join Date: Dec 2007
Location: Shropshire, UK.
Posts: 3,051
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Re: Long wave and medium wave units confusion
Quote:
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24th Jul 2017, 8:39 pm | #23 |
Dekatron
Join Date: Jan 2012
Location: Brentwood, Essex, UK.
Posts: 5,339
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Re: Long wave and medium wave units confusion
All the scales on my late father's HMV 1120 (circa 1949 I think) are marked in metres only.
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24th Jul 2017, 9:14 pm | #24 |
Hexode
Join Date: Jan 2012
Location: Weymouth, Dorset, UK.
Posts: 422
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Re: Long wave and medium wave units confusion
Yes I remember Radio Luxembourg's earth link program after midnight, presented by Tony Prince announcing, THIS IS LUXEMBOURG ON 208 METRES 1440 KHz and 6090 KHz 49.26 metres. Oh and sometimes a mention of 1.3 million watts on 208! Also anyone else remember Radio Moscow was using wavelengths right to the end both for short and medium wave especially in winter when they where on 194 201 214 and 227 metres
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24th Jul 2017, 9:38 pm | #25 | |
Dekatron
Join Date: Apr 2012
Location: Wiltshire, UK.
Posts: 13,998
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Re: Long wave and medium wave units confusion
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Frequency-measurement was more-generally done with a "Heterodyne frequency meter" - basically a variable-frequency oscillator whose calibration could be checked against a crystal-oscillator contained within the instrument. The frequency-to-be-measured was then matched against a couple of harmonics of the variable oscillator [which by way of the xtal oscillator now had reliably calibrated 100KHz points on its dial]. BC221 and "Wavemeter Class D" being the WWII-military implementations. There were also 'fluorescent crystal' wavemeters: in these a Quartz crystal was precision-ground to the required frequency and then sealed in a glass envelope which also contained a small amount of a suitable gas [neon being the usual one]. When the RF-to-be-measured was coupled to the crystal's electrodes, if it was at the same frequency as the crystal was cut-to, the crystal vibrated and significantly-high voltages appeared across it, enough to ionise the gas and cause a nice orange glow. The brighter the glow the closer your applied-signal's frequency was to the calibration-frequency of the crystal. |
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25th Jul 2017, 12:50 am | #26 | ||
Nonode
Join Date: Jan 2009
Location: Papamoa Beach, Bay of Plenty, New Zealand
Posts: 2,944
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Re: Long wave and medium wave units confusion
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That extension was long-anticipated. For example, the Carver TX11a tuner that I bought in 1986 covered the extended band. Very long-range anticipation was shown by the Bush EU24 export model of 1951, whose MW band coverage was 524 to 1750 kHz (marked in kc/s). Actually, I suspect that that was done to provide continuous coverage; SW ran from 1.75 to 30 MHz in five bands. Quote:
Here in NZ we used the European UHF TV channel numbers. But an earlier proposal (extant in 1973) had the UHF channels numbered from 10 upwards, at a time when there were but 9 VHF channels. Two more, NZ10 and NZ11, were added later, so it was just as well that the original UHF numbering scheme was abandoned. Cheers, |
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25th Jul 2017, 9:01 pm | #27 |
Octode
Join Date: Jun 2011
Location: West Midlands, UK.
Posts: 1,571
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Re: Long wave and medium wave units confusion
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29th Jul 2017, 6:40 pm | #28 |
Octode
Join Date: Jun 2011
Location: West Midlands, UK.
Posts: 1,571
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Re: Long wave and medium wave units confusion
Just found this - Radio Times schedule for Christmas day 1943.
Details for Home Service in wavelength and frequency for medium wave and 49 metre band can just be made out on this scan. I guess the 49m transmission was for the benefit of those in the forces that might be close to a receiver - or clandestine listening in Europe*. *I doubt the latter would have a copy of the Radio Times! |
29th Jul 2017, 9:58 pm | #29 |
Dekatron
Join Date: Jan 2012
Location: Brentwood, Essex, UK.
Posts: 5,339
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Re: Long wave and medium wave units confusion
Interesting that Disney's "Snow White and the Seven Dwarves" is referred to as a "fantasy" rather than a cartoon.
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