On Jul 27, 8:40*am, "Andy" wrote:
The beam is pointed in there
direction. The noise and signal increases every time when switching to the
beam.

http://www.hobby.pwp.blueyonder.co.uk/ma5b/ma5b5.mp3

http://www.hobby.pwp.blueyonder.co.uk/ma5b/ma5b6.mp3

I think your antenna system itself is probably normal for the
most part. I do hear some "whine" though on a couple of
them. Not sure what that is, could be puter/monitor related..
How is yours mounted? Flat horizontal? I had to look up a picture
to see what they are, and the one in the picture seemed to be
tilted. ? Maybe that was just to show up better in the picture..
As far as the static in the last one , it sounded like power line
noise for the most part. Either the antenna has a strong lobe
towards that noise source, or you have some noise around you
that is being piped up the shield. But almost sounded more
like it was received by the antenna to me. You should be
able to vary the level of the static, and maybe even find a
null of sorts if you turn the antenna. If not, I would look at a
possible ingress problem, and the noise coming from your
shack or house.
I checked the feed, and they seem to use a matching device,
feeding two elements. I assume they are probably feeding 10m
with a separate DE, or something along those lines.
I doubt this matching device deals with decoupling the feedline.
So the first thing I would do is make a choke out of coax.
You can use the feedline you have now, and just roll a
choke at the antenna end. 8 turns using a 6 inch diameter
coil. You can use tie wraps, tape, etc to secure the windings.
That should take care of most any ingress/common mode
problems, if you have any. At the least, should put a pretty
good dent anyway. If the noise is still strong with the choke,
it's probably normally received line noise, fence, etc in the
area. And other than turning the antenna, not much you
can do about that.
That you seem to have a normal match on all bands seems
to indicate to me that your elements, matching device, and
coax are all probably ok.
I strongly recommend adding the choke though, just to nip
the possibilities of noise ingress in the bud. Just one less
thing to worry about, and just that much less RF you will
have on your coax when transmitting.