On Thursday, July 3, 2014 4:20:56 PM UTC-5, FBMboomer wrote:


By performance, I mean the readability of a received signal. The signal

to noise ratio.



What I was trying to explain also was that my 75 meter horizontal full

wave loop does not receive as well on 20, 15, and 10. Generally!

It should be OK. But the pattern is going to change for each band,
and having modeled that antenna, most of the higher bands don't really
have a low angle pattern. But good enough for general use I guess.
But then you also have to consider if any decoupling problems, and
local shack noise being piped up and back down to the radio.
Only the operator can judge what any issues might be.




When I operate on 20, 15, and 10, I use the pixel loop for receive. I

get a better signal to noise ration on these higher frequencies. I have

no idea why.

Like I say, could be any number of reasons, from antenna pattern, to
excess shack noise due to decoupling issues. etc..



40 meters is kind of a crap shoot. The 75 meter loop might work better

for receive or the magnetic loop. That is one of the reason I made an AB

switch.

Handy to have.. I have several.. I usually keep one of those small ones
in my trunk for portable use.




I do not know, but I can surmise that my receive on 75 would be better

on the magnetic loop if I was using a dipole for my antenna.


I don't know what you mean by this. It's not going to change if you
change the full size antenna.

I had a

dipole up at my lot a few years ago. The noise level in town was

horrendous. It was locking me out of using 75 meters. So I am now

comparing the pixel magnetic loop to a full size horizontal loop. This

may be kind of an unfair comparison. Most people probably would be

judging its improved performance over a dipole. I am currently unable to

make that kind of AB comparison. I took my dipole down in favour of the

full wave loop. The performance comparison between the dipole and loop

was profound. (meaning at least 10 db better S/N.

Normally there shouldn't be much difference between the dipole
and horizontal loop. I've run both, and I never did see that much
difference. If you had less local noise, it was probably sort of a fluke
thing where the pattern of the loop just happened to be what you wanted for
that direction and angle to the noise source.
The sky wave patterns are pretty close overall. In fact, I found them
so close in performance, I quit using the loops because they take more
wire, and more of a hassle to string up and keep in the air.
Also the dipole will give me max current at the apex, which on mine is
always the highest point of the antenna.


And yes, BC band performance is better than my 75 meter loop.

That is what I mainly use mine for. I have a couple of them. One
is a round circle 16 inch dia loop. The other is a diamond that is
48 inches on each side. It's PVC, and stands on the floor in a
rotatable stand.

My loops cost me very little..
This is the basic design I use for the PVC loops.
http://home.comcast.net/~nm5k/loop5.jpg