Alignment of (Narrow Band) DATA and WSPR frequency’s on the 500 KHz band.
The original wspr frequency 502.4 was defined as the working frequency to utilise the ‘clean’ area just under the 504 harmonic, whilst avoiding the various beacons running across the 501/504 band at the time. However, time has moved on and there are now numerous ‘dial setting’s’ in use both sides of the Atlantic.
Due to an apparent increase in the side band noise from the 504 signal , possibly by enhanced propagation , the ROS MF (100 hz b/w) working frequency is to be re defined as 500 USB dial set giving a centre carrier frequency of 501.500
Due to Ae bandwidth and perhaps alignment with other band’s, I would suggest the original WSPR 502.4K is replaced with the lower frequency of 495.9K , thus restoring the System’s coverage and facilitating changes of mode etc within a narrow bandwidth.
I don’t see this detracting from the monitoring of spot frequency beacons over 505Khz , but more appropriate to transmitting stations , which by the nature of the antenna arrays are not able comfortably to qsy from top to bottom of the band without re-tuning, not always a simple option.
Comments or suggestions please ?.
Graham
G0NBD