Tony Langdon, VK3JED
vk3jed at optushome.com.au
Mon Aug 7 12:17:13 EST 2006
At 12:00 PM 8/7/2006, Gustaf Bjorksten wrote:
>Antenna-based DF Ideas:
>* Omni-antenna dopplar array
Doppler systems perform poorly in reflective environments (urban
clutter being an example), they also lack sensitivity.
>* Loop antenna (i suspect this won't work effectively as a DF
>antenna at such high frequencies, but i need to explore this further ;)
A gridpack dish, Yagi or other high gain directional antenna will do
better. Most foxhunters use Yagis down to 144 MHz.
>* Directional antenna w/ search-pattern software controlled stepper
>motors (all directions) rotating head and signal meter or spectrum analyzer
Can be made to work. :)
>Secondary, bolt-to-directional-antenna DF Ideas:
>* GPS and AHRS (or if not an AHRS then digital compass and digital
>* Powerful laser technology?
>Or some combination from all the above.
>BTW, I have or am building equipment to try all the above with the
>exception of the laser stuff. My research is for a different
>application than is the situation proposed here, but there are many
>similarities in the problem space.
For a bunch of hobbyists, the easiest methods (non LOS) are the
GPS/map/compass and UHF CB directional antenna measurements. These
are cheap, provided a small percentage of us have the necessary gear
(GPS and UHF CB). I'm happy to help out when I can. :)
My experience is that simple, but effective methods are the ones that
will be utilised the most. :)
73 de VK3JED
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