|View single post by Jan|
|Posted: Jun 5th, 2013 04:16 AM||
|If you use 1485 kHz you will get voices - and music - because it's exactly the frequency for numerous Classic Gold stations and BBC local stations all over the UK!
But I think Sparks is on the right track. (I wish I was there at Jurgenson's experiments to hear what he heard.)
You can tune between stations on MW, but you'll just get splatter(from the stations' sidebands). You may be able to interpret this as direct voice communication, but is that what it really is? Or is it just splatter from radio stations?
Assuming your old radio is working properly (and a radio that age will probably need most of the wax paper capacitors replacing, along with one or two resistors, a valve perhaps and some re-aligning) then you should get more noise if you add an aerial. Just push the stripped end of 10, 15 metres, or more of wire into the aerial socket. To minimise noise from domestic appliances, get the wire outside, high as possible.
Then just tune to somewhere where there are no stations. The shorter wavelengths particularly, at night, will have fewer stations.
You can check the sensitivity of any radio very easily and is particularly effective on SW;
1) connect the aerial.
2) tune to where there are NO signals.
3) pull out the aerial.
4) if the noise goes down the radio has sufficient sensitivity for the frequency to which it is tuned.
This works because the noise you are receiving is atmospheric/cosmic radio noise. (Though in practice, if you live in an urban environment this will be mostly man-made noise from domestic electronics, low-energy lighting, computers, etc.)
If the radio is sensitive enough to pick up cosmic noise, that's sufficient because any AUDIBLE radio signals have to be above that noise. Making a radio mere sensitive won't improve things, because if a signal is below the natural (or man-made) noise, it is still below the noise, no matter how sensitive the radio is.
Unfortunately, the higher in frequency you go, the less sensitive old radios tend to be and the less cosmic/atmospheric natural noise there is. To get the noise you want you'll have to try this test on different spots on the dial.
And even that's a bit of an over simplification, but more than enough techno babble I'm sure!