this is driving me nuts, so now i cant sleep

ok. im about to build a multi band fan dipole (75,40,20,17,15,12,10) longest leg is 60ft'ish. now where i live I dont have alot of options to string up something.. and I can not go very high in the air (feedpoint will be about 15ft) I have powerlines that run along the property to my west so i want to stay well away from them. 1 tree is not far enough out. which leaves 1 tree left. now I can run 1 leg to the tree then run the other leg over to a stink pipe then back over to the old antenna support then back to the feedpoint... which I want to stay away from since using that path one leg will be over the roof for most of the run.

but what if i ran both legs out to the tree the legs spaced by about a ft (see image black = house, green dot = tree, red line = power line, red dot = feed point, blue lines = antenna wire) what kind of radiation pattern would this have? would I have ok results with it or would i be better off using a dummy load?

While I couldn't pretend to be very technical about this I have had a few Fan Dipoles (and I haven't met one I didn't like) and I have learned a thing or 2 about them. We regularly used one of my extra fan poles for portable events as well as field day in different arrangements.

Center (Feed) Point at 15 feet? It will work reasonably well, but not even close to one that is installed higher. You can install the legs at right angles to the other, but you can not install them side by side as indicated by the blue lines in your drawing.

I wouldn't worry about those power lines too much, and with your limitations you might be better off to consider a vertical or even a loop.

I would suggest putting it up, and then hopping on the bands using PSK and having a few QSO's. In fact, leave it [The PSK software] up and running, with the rig on, reporting what it hears to PSKReporter.

In about 2 days per band, you'll see a decent radiation pattern map on pskreporter.info :)

Quote:

---

Originally Posted by KA9MOT

While I couldn't pretend to be very technical about this I have had a few Fan Dipoles (and I haven't met one I didn't like) and I have learned a thing or 2 about them. We regularly used one of my extra fan poles for portable events as well as field day in different arrangements.

Center (Feed) Point at 15 feet? It will work reasonably well, but not even close to one that is installed higher. You can install the legs at right angles to the other, but you can not install them side by side as indicated by the blue lines in your drawing.

I wouldn't worry about those power lines too much, and with your limitations you might be better off to consider a vertical or even a loop.

---

I had a chance for a butternut hf-9v with 160 resonator for $60.. but the 26ft tall stick got shot down real quick by the house owner.

my problem is, I get 1 pole (20ft no higher) everything else will have to be tied to a tree or something already on property. id love to tie to the trees to my east but they are not on property and well no way that guy would give me permission to tie anything off to it.

i have to keep it high enough where a truck can drive back there without pulling anything down. which leaves me 2 trees. 1 is to close the other is right distance (where blue is going) and the final 2 are IMO to close to power lines then I really want to mess with.

I can run 1 leg to the tree but it forces me having to take the other leg west tward the P-Lines to a stink pipe on the house then turning sharply back east to the wooden pole that supports my 2.4ghz wifi beam. and im not sure I can fit a 60ft leg in that short of space

Quote:

---

Originally Posted by KC2UGV

I would suggest putting it up, and then hopping on the bands using PSK and having a few QSO's. In fact, leave it [The PSK software] up and running, with the rig on, reporting what it hears to PSKReporter.

In about 2 days per band, you'll see a decent radiation pattern map on pskreporter.info :)

---

all I would be able to do is just RX. which would work (i think on reporting)

Steve said side by side wont work.. so I may be forced to have to run 1/2 of this over the back side of the roof. zig zaged everywhere... (that should be a interesting radiation pattern)

Here's what I can say now: your plan probably won't work well. With only a foot spacing, the antenna looks like a piece of ladder line even at ten meters.

I have to think about your typical layout a bit more, but here's what I'd keep in mind:

1. Any pattern is better than no pattern.
2. For a dipole, the highest currents are at the feed point, highest voltages at the ends; get the center as high as you can.
3. You can droop the ends, but not so low that kids can touch them by mistake.
4. Try to keep the angle between the wires to 90 degrees or greater at the feedpoint to prevent excessive cancellation.

Good luck and 73,

as for spaced layout this will be the best I can reasonably do

pink = rerouted leg from other pic. going to a wood mount attached to the stink pipe (its there from where I used to have the jpole) but suddenly at that point cutting back to the east to where my 2.4ghz beam is. just not sure the 60ft leg will be all used up by then in which then I will be out of options

'IBC, I'm afraid I don't know your "living conditions" well enough to help. What kind of building is it, and how long is it? Judging from your sketch, it looks like quite a long building; can you tie off each end near the peaks of the gables, and run the antenna along the ridge?

73,

Looks like an inverted-L antenna :) Should "work".

I must be missing something: Why are you not arranging the legs as such:

Code:

---


  |    \                    /
  |      \                /
  |          \            /
  |            \        /
  |              \      /
  |                \  /
  |                  V

---

The feed point being the V. The | being the power line, and the / and \ being the leg(s)? And, I wouldn't try to smoosh too many bands on there. Beyond 3, it looks really ugly.

I had a similar situation one time. What I ended up doing was making a dipole for 80, then using a staple gun, I fastened the elements to the edge of the fascia around the house in opposite directions. It ended up being an L in each direction if you can picture that. I used some 24AWG. You couldn't see it, and it worked reasonably well on most bands with an antenna tuner. It was all I had to work with and I was able to get on the air.