[Laser] Attempt on 200 km record in Australia.

[Chris L]

   Dear Group,

   Our Italian fiends are to be congratulated on their recent record - it
   seems  that the distances are being pushed upwards all over the world,
   and that DX activity is definitely on the rise.

   I'm  posting  this  on the off-chance that some Australian readers may
   like  to lend a hand with our forthcoming attempt to extend our 167 km
   record  in Australia, which was set in the island state of Tasmania on
   19 February.

   We've  been aware for some time that there's a line-of-sight path from
   'The  Camel's  Hump'  near  Mount  Macedon,  about 70 km North-West of
   Melbourne,  to  Mount  Buffalo  in the North-East of Victoria near the
   town of Myrtleford. The distance is just a little over 203 km. Camel's
   Hump  has  an  elevation of around 1000 metres, Mount Buffalo (at 'The
   Horn')  is closer to 2000 metres. Both summits involve a walk from the
   nearest car park, about 300 metres carrying bulky optical equipment.

   Because  of  Australia's relatively flat topography, with no mountains
   exceeding  2500  metres,  the  number  of  long line-of-sight paths in
   Australia  is rapidly running out! Have we any microwavers who know of
   any paths significantly exceeding 200 km in this country?

   Peter  Wolfenden  VK3KAU,  John  Nunan  VK3IC and  a  couple  of other
   amateurs  from  the Sunbury Amateur Radio Club have volunteered to set
   up  a station at 'Camel's Hump'. We have an offer of help from several
   Melbourne  Amateurs  to set up the Mount Buffalo end where I intend to
   be,  but  we need more help. An approach to the Twin Cities Radio Club
   in  Albury is currently being made. The time we're looking at for this
   attempt is  late (Australian) Autumn, hopefully a clear day after rain
   but with little wind would be ideal.

   We  have two new receivers with fresnels about 40 cm by 60 cm, working
   in  association  with  separate  Luxeon/fresnel transmitters having an
   aperture of 19 cm by 25 cm. At the moment I'm trying to fit the larger
   receivers  with  a  fine mechanical shifting arrangement operated by a
   cable  release,  which will alternately place a Luxeon and a PIN diode
   at  the  big  fresnel's  prime focus. That should obsolete the smaller
   transmitters.  To  keep  the size of the optical unit manageable we'll
   have  to sacrifice duplex operation, otherwise we won't be able to get
   the  optical  units into our cars easily, or to accurately direct them
   from  mountain  tops  in  a high wind. However, the quality of the new
   giant  fresnels  and  the  rock-bottom  noise  level  of  our receiver
   circuits (with several versions now comparatively tested on the 167 km
   path  in  Tasmania) should provide an even higher s/n than it did over
   the earlier path.

   If  anybody  in  Australia  - particularly in Victoria - would like to
   chip  in  with a pair of hands, some amateur radio backup or even just
   their presence, could they please contact:

   Chris Long on Melbourne tel: (03) 9890 8164 or via the above e-mail.

   The more people we have on those mountain tops, particularly at night,
   the safer the exercise will be.

   This  is  a  'long shot' but I'm hoping that a few Aussies are reading
   thses postings.

   With anticipation,

   Chris Long, Melbourne Australia.