|View single post by Jan|
|Posted: Jun 4th, 2013 07:53 AM||
1500 kHz (1.5 MHz) is 200 metres. The formula:
freq in kHz = 300,000/wavelength in metres
Your AM/MW radio dial is marked 200m to 550m or 1500 kHz to 545 kHz.
I doubt there is anything special about 1500 kHz. I expect it's just a close 'guesstimate' to where Jurgenson thought was tuned. Why not 1400 kHz, or 1507 kHz? He didn't have a digital readout on his radio at the time.
Any recordings on AM/MW are likely to be dismissed as just conventional radio signals so I don't know why anyone tunes there EVP experiment there.
The frequency of 7.15 MHz (7150 kHz or 41.9 metres) is right in the middle of the 41m broadcast band and is also in the 40m amateur radio band. I'd be surprised if you didn't pick something up. To my trained ear the buzzing sounds like you have mains-borne interference and the voice an SSB amateur radio signal.
To make sure you don't pick up conventional signals you need to tune right away from anything that could carry voice traffic. At night anything above say 15 MHz (20 meters) is more likely to be clear of any transmissions.
Your valve radio tunes to 17m (17.6 MHz) and a little beyond. 17m is a broadcast band, but probably not that busy and clear at night. Try the left-hand edge of that on your dial.