[Moon] Reception of DL0SHF 24GHz 4.5W beacon on a 1.2m dish

Charles g3wdg at moon-net.eu
Mon Jul 26 17:24:36 CEST 2021

Hi All

A few weeks ago I did some tests with the DL0SHF 24GHz beacon running 
its 4.5W SSPA and Q65-60E.  A number of '2.4m' class stations had 
decoded the 'QRP' beacon without difficulty previously. The objective of 
this test was to see if it is possible to decode it with a smaller dish.

The tests took place in early July, certainly not the best time for 
24GHz with relatively high temperatures and relative humidity 
contributing to higher atmospheric loss. No results were obtained for 
the first two days, but on day 3 (7 July)  decodes were finally obtained 
from an average of 5 periods:

This corresponded with reasonably clear weather and calculated 
atmospheric attenuation of just over 1dB at each end.  Moon was at 
apogee and Doppler spread was 450Hz.

6 wave files from 7 July are available  here:


The decode above was obtained playing back all the files from the start, 
with Ftol=100 and RxFreq=800Hz, using the 'Fast' decode setting.

Using the 'Deep' decode setting decoding is possible with 4 periods, 
when playing from the start:

A decode from three periods can be obtained if playback is started from 
the second file in the set:

Further tests have not been possible to date, but it is hoped to try 
again to see if single period decodes are possible with a 1.2m dish, 
under condtions with closer moon,  lower spreading and lower atmospheric 


Charlie G3WDG

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