Thread: Dish reflector
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Old April 21st 09, 01:28 AM posted to rec.radio.amateur.antenna
Jim Lux Jim Lux is offline
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First recorded activity by RadioBanter: Mar 2007
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Default Dish reflector

Art Unwin wrote:
I made a helical end fed antenna that is inside a cone shaped
reflector
The reflector is made from 1/2" mesh steel with an aluminum foil liner
and connected to the braid of the feed coax. No baluns are used, just
direct connections.
I was surprised to hear signals from the rear!
I thought that a dish reflector prevented such signals getting to the
receiver. So what can be wrong with the reflector or can signals get
reflected back from the frontal area? Antenna is at a 40 foot height
Any ideas as to what the fault could be?
Regards
Art
I have no experience with dishes thus the question Note, the helical
antenna does not protrude beyond the dish envelope.
Art


What's the relative size of "reflector" and helix? (i.e. is the
reflector in the near field of the helix, in which case, you could
easily have waves propagating along the surface of the reflector)