Re: Eclipse: A Call to Action

Graham
 

G0NBD  TX >>  RX GM4ZMK  Opera OP8  477 KHz  [dial]  Single carrier  + 1500 Hz ASK 

Shadow passed between stations ..

This was  one of those unexpected  results from the  eclipse 2015  , observed from the  UK , using  the Opera  single  pass multi detector , available  for 136  and 477 KHz 

using  477 KHz ,  the  land  path was ~ 250 miles,  constant ground  wave  @ -30 dB  s/n  in  2.4 KHz    average  over  8 minutes tx cycle.

At the  onset, signal  level fell  to  beyond the  system lower limit , the  next detection , at -40 dB , interpolation , would  indicate ~ -45 dN s/n

Indications  of  multiple  peaks before and  after the  event,.can also  be  observed .

What was observed

Turns out to be  QSB  caused by  SKY-Wave .......the  second  monitoring station , north  France , failed to run,  it would of  been  possible , that  a  peak , co-incident  with the  Dip  at  Liverpool should of  been  observed ,At my  range the  sky-wave , phase  , subtracted  from the  ground  wave

 I would offer the  system as  near  ideal for  this  type  of  experiment ,  being  single pass  and  good  sensitivity , all bands from  LW to uW are suitable

From the  aspect of  Data ''Validity'' each  recovered  s/n  is the  average  of the  TX time  line during a single pass ,  , data  may be  recovered  from the  application , running  on a web linked  pc , the  psk-map  and  http://ea3hmj.net/ea3hmj/spot/index.php 

73-Graham
G0NBD





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