rec.radio.amateur.antenna Google Group

Re: Cushcraft MA5B Noise floor?

2010-03-18T16:29:56Z

On Thu, 18 Mar 2010 16:01:13 -0000, "David" <bar...@blueyonder.co.uk>
wrote:
Hi David,
Possibly because your feed point is not choked enough.
73's
Richard Clark, KB7QHC

Re: Cushcraft MA5B Noise floor?

2010-03-18T16:01:13Z

The noise level does not change when I turn the beam 360 deg.
I have used the Cobwebb and the Cushcraft R5 in the same location and I do
not get the same noise. The noise is also present in the audio on stronger
signals.
Its the same noise you get on a weak station, where its combined in with the

Re: antenna type question

2010-03-18T13:38:26Z

Your welcome
Howard

Re: antenna type question

2010-03-18T13:36:17Z

That's it! Thanks howard.
- 73 de Mike N3LI -

Re: antenna type question

2010-03-18T13:26:01Z

I think it was called a Super Scanner
Howard

antenna type question

2010-03-18T13:20:56Z

Hey all,
There was a type of antenna that I remember from when I was a young'un,
but I cannot remember the type that it was.
It was a directional antenna, and had three vertical sections, I'm
assuming they were dipoles, but am not even sure of that. These
verticals were arranged in a Y pattern, and were apparently

Re: J pole question

2010-03-18T12:50:01Z

No argument there.
Yes, I'll note that my installation was not particularly sensitive to
proximity.
No, this is just a dipole hung vertically, mainly because it will be
used for repeater work.
Agreed, for me at least, putting an antenna in an attic is a last
resort. I came into this thread sideways, hence some of the confusion,

Re: Cushcraft MA5B Noise floor?

2010-03-18T09:28:32Z

"David" <bar...@blueyonder.co.uk> wrote in
If the noise is received equally from all directions, then the amount of
noise power received is proportional to the average gain of the antenna
system, which is essentially, the inverse of the efficiency of the
system.
Some noise sources are not very directional, eg galactic noise. Manmade

Cushcraft MA5B Noise floor?

2010-03-18T08:38:56Z

If you own or have used the Cushcraft MA5B in the past could you let me know
what the noise floor reading is/was and the rough height of your antenna?
I know that the noise floor will be different location to location but it
will give me some idea of what I should be looking at.
I have had mine up for a couple of years now and although the signals

Re: J pole question

2010-03-18T02:22:51Z

That is my choice for a vertical antenna hung from rafters.
I've got one in my attic. Quarter wave ground plane with
8 radials. Hung from the rafters with fishing line. I'm lucky
that my roof is fairly non conductive. All the ducts etc are
well below the antenna. I've never really like J poles for all

Re: J pole question

2010-03-17T22:59:03Z

Some people have more agressive killfiles than others. :-)
Geoff.

Re: Art's quiet mesh antenna

2010-03-17T22:45:09Z

oh wow, a twofer... art and fracky in the same thread!

Re: J pole question

2010-03-17T22:36:28Z

In article <Xns9D3F52C8A3A33nonenowh...@6 1.9.191.5>,
That would certainly be another workable alternative for this
situation. An SO-239, a few feet of 10-gauge solid wire, and a bit of
soldering, and you end up with a ground-plane antenna with a hanging
loop at the top, two or four ground radials drooping at around a

Re: J pole question

2010-03-17T22:25:44Z

"Geoffrey S. Mendelson" <g...@cable.mendelson.com> wrote in
...
I suspect you probably haven't read the thread. That was my original
suggestion with the addition of a balun and some detail on feedline
routing.
Owen

Re: J pole question

2010-03-17T21:34:06Z

I assumed when he said a vertical dipole, he meant exactly that. Two 19 inch
wires center fed. It's cheap, versatile, and does a lot better than your
average rubber ducky.
You mount it verticaly for FM, horizontaly for ssb/cw and at an angle for
satellite work.
Geoff.