Re: Any antenna gurus here?

Jerry N9AVY

Antennas may different due to location, that's a no-brainer. However they will vary from day to day, hour to hour, etc. depending on propagation to a specific area.
My own antenna will work great into Europe when the band is open, but not all of Europe. Sometimes I hear Eastern Europe well, but I can't hear Western Europe.  So, when I hear station in YO, HA, LZ, etc. I don't hear stations from F, G, PA, ON, etc.  But as the hours change the prop will shift from East to West. 

Measuring antenna performance could be done by measuring field strength rather than SWR.  My late Uncle Carl used to measure field strength and his antennas always seemed to do the job.  It's probably best if you have a remote location several hundred miles away to measure signal strength and have the opportunity to do this over a week's time.  Most of us don't have that luxury; so we have to make due with what we have. We just put up an antenna and hope it works.

I always wonder how manufacturers check antenna performance. It think a lot of them use some type of voodoo because most specs aren't what they seem, but then again it can all change from installation to installation as well the installation practices.

Guess it's all beyond me...

Jerry  N9AVY

From: "Robert Johnstone shopr3@... [070]" <070@...>
To: "070@..." <070@...>
Sent: Sunday, October 18, 2015 3:41 PM
Subject: Re: [070] Any antenna gurus here?

Needing and liking are two different things. I have worked all the lower states on under 24 watts without radials on a 5btv mounted 4 inches off the grass on a 3 Ft pipe driven into Grey Clay soil that I water occasionally in the summer.  I started adding copper wire radials and lost some of the near field contacts on all but 80M while gaining some increased DX stations.  Having worked Australia and NZ less than 30Watts without radials from KS I disagree with "have to have" and find TED perhaps exaggerating or at least painting with a broad Paint brush.  Finding a properly trimmed resonant antenna exponentially more efficient than any untuned to the location antenna. The recent Alpha Delta products purchased here are not what they once were.  Several have been cut up locally saving the center and ends to make nice dipoles as the traps are not doing as advertised. Their instructions now say you will have to adjust each segment.  His location is a unique situation and may take a unique solution.  Possibly something like the AD away from the Mt from the tree top and a fan dipole sloping at 45deg facing the MT.
My added $.02 AD0QO

From: "Jerry n9av! y@... [070]" <070@...>
To: "070@..." <070@...>
Sent: Sunday, October 18, 2015 2:08 PM
Subject: Re: [070] Any antenna gurus here?

The DX-EE  is a much better antenna than a G5RV.  I think the DX-EE can be installed in an inverted V configuration which will give somewhat of a vertical radiation pattern .  Ted is absolutely correct about verticals needing radials; the more the merrier. Unless , of course, you're sitting atop a pile of iron ore.

I have an Alpha-Delta DX-A  which is a dual sloper for 160/80/40m and requires a metallic center support (tower)  which is part of the antenna.  This probably wouldn;t work for you unless you can put up a 35 ft. self-supporting metal mast. Guess you might not get that one past YL.

Sound like you are pretty much limited to wire antennas. You can try a vertical, as I stated earlier, and see how well it performs or not.  Guess what I'm saying is you need to experiment.   (Or you can hypnotize YL to believe lots of aluminum up in air is a thing of beauty !  ha-ha !)

jerry  n9avy

From: "Ted pegduck56@... [070]" <070@...>
To: "070@..." <070@...>
Sent: Sunday, October 18, 2015 1:36 PM
Subject: Re: [070] Any antenna gurus here?

Hi Martin, I have up now, 2 identical Alpha Delta DX-EE as inverted V's. (1 roughly E-W and the other roughly N-S) I can get a match of about 1.5 max on bands 10-80 (incl WARC bands) (80 is admittedly not great, but installed  30 meter end fed wire that handles 80-160m). All these wires are low profile and wife and neighbors are happy. I believe that unless you have an extensive radial field (which takes a lot of room, too) a vertical is just radiating poorly in all directions. The verticals that claim you don't need radials are at best, misleading, if not lying. The problem with the GR5V is that it is a design for 20m. All other bands are simply a compromise with that antenna.
good luck with the project !!

3, Ted

On Sunday, October 18, 2015 11:27 AM, "Jerry n9avy@... [070]" <070@...> wrote:

Try vertical and see how it plays.  If it doesn't get over the mountain then back to drawing board.. .  or run 2000 ft of coax up the mountain !

Jerry n9avy

From: "Martin Tuip ajax@... [070]" <070@...>
To: 070@...
Sent: Sunday, October 18, 2015 1:11 PM
Subject: [070] Any antenna gurus here?

I hope I maybe can pick some brains in this group. At the moment I have a G5RV up in the trees on my property with the ends in about a 30 degree angle from each other due to the fact one end strung from the top of a tree on the bottom of a hill and the other from a tree on the top. Height is probably 60ft. I am really close to a mountain less than a mile away with nearly a vertical 2000ft risen (see my qrz page) and the back of my property has a steep hillside. The YL does not want towers so I am limited there. 

I am thinking to get a vertical antenna for a different radiation pattern but I think the low take off angle might not clear the hill and mountain. What are my options here?  

Build dedicated vertical arrays on the  hillside? 
Regular vertical ground mounted?
String vertical dipole from a tree?
Use a yagi on an angle to clear the mountain?
Anything else?


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