Art Unwin wrote:
On Apr 10, 9:50 am, "Dale Parfitt" wrote:
"Art Unwin" wrote in message

...

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
There is a lot of very important information missing here.
What frequency are we talking about and what is the dish diameter?
Do you have any idea as to what your edge taper is or sidelobes?

Dale W4OP

Dale
I thought that if the radiator was in the reflector envelope, that is
snip
These signals appear at all frequencies though I fail to see what the
impact of frequency is because of the reflector envelope or umbrella.

Dale

You will, of course, have noted that he hasn't given a couple of the
important items that you requested. Based upon some of his earlier
babblings, I suspect that this is a helical antenna of perhaps UHF
dimensions that he is attempting to use on 160 or 80.

tom
K0TAR