Spectrum Lab grab of the band 501.2 - 501.4kHz
Received at GM4SLV, IP90gg, Clousta, Shetland
For a full band (501-505.5kHz) view click HERE
The equipment for the grabber is an AR7030 with 3.8kHz IF filter fed with a the signal from my 500kHz TX antenna.
A fixed level audio output is fed to a PC running Spectrum Lab (under Wine on a Ubuntu Linux PC) which captures the screen every 5 minutes. These captures are automatically uploaded to the web.
The page should refresh itself every 5 minutes.
The timestamps are now in UTC and are accurate, as the PC is locked to an NTP server.
GI4DPE has a QRPp Beacon at approx 501.318kHz, at the position of the blue marker, which this display has been set up specially to show.
The transmitter power generally in use at GI4DPE is 10mW
but occasionally the beacon may run at a transmitter power of 10W
Recent field strength measurements at 10W and 10mW indicate that the antenna efficiency is around 5%,
For 10mW TX power the ERP is approx.500uW
For 10W TX power the ERP is approx 0.5W
Amazing to see a signal from 682km / 424 miles at an ERP of 500uW
The 10mW signal has been copied by ear, as well as on the Spectrum Lab waterfall display!
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