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General Vintage Technology Discussions For general discussions about vintage radio and other vintage electronics etc. |
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3rd Apr 2018, 10:06 am | #21 |
Moderator
Join Date: Mar 2012
Location: Fife, Scotland, UK.
Posts: 22,800
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Re: How many radio signals in that box of space?
There might be a 2-for-1 deal on. Free time machine with every faster than light space ship sold!
Space and time seem to be two aspects of the same thing. Blue flashing beacon and doormat are dealer-fitted accessories and not included in the base price. David
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Can't afford the volcanic island yet, but the plans for my monorail and the goons' uniforms are done |
3rd Apr 2018, 10:41 am | #22 |
Hexode
Join Date: Jul 2010
Location: Royal Berkshire, UK.
Posts: 470
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Re: How many radio signals in that box of space?
I'm just bracing myself for the monumental update for my satnav from a map of Europe to starcharts ...
In all seriousness, it is deeply fascinating. The little radio sat on the table over there, been through a war, various family members, fashions/decades, other custodians, lofts, sheds, a recent resurrection & yet, able to pick out one station, amongst all the noise, the plethora of other waves, of which most of todays waves would never have been considered in the original drawing office! Mark |
3rd Apr 2018, 10:53 am | #23 |
Dekatron
Join Date: Aug 2003
Location: near Reading (and sometimes Torquay)
Posts: 3,086
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Re: How many radio signals in that box of space?
The thing that I have often contemplated is just how high one-off instantaneous additions of all the RF transmissions might reach.
We now know that water waves on the oceans, which generally show average behavior consistent with the local conditions, just occasionally exhibit a single huge wave briefly appearing at one location - and these events are now known to have sunk ships. So could the same happen in the world of electromagnetic waves? (OK, the big ocean wave effect may be due to non-linear effects). Having said that, unless you are very near a transmitter, what we usually see is a load of noise with man-made signals poking up through it trying to get enough s/n headroom to be usable. The noise has been there for ever so we must be adapted to it by now! |
3rd Apr 2018, 12:02 pm | #24 |
Rest in Peace
Join Date: Sep 2008
Location: Solihull, West Midlands, UK.
Posts: 4,872
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Re: How many radio signals in that box of space?
Yes, in theory EM could all add up. This is most likely when stations are equally spaced, so in Europe we will get a peak roughly 18000 times a second (9kHz spacing, positive and negative peaks). Frequency errors and deliberate offsets will modify this.
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3rd Apr 2018, 12:29 pm | #25 |
Dekatron
Join Date: May 2003
Location: Edinburgh, UK.
Posts: 3,273
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Re: How many radio signals in that box of space?
Listening to (some of) these signals on a crystal set makes it even more remarkable, especially when the set can drive a loudspeaker.
Peter |