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