80m dipole on 10m fishing pole - experiences?

Old Reflector
1

I have a 10m fibreglass fishing pole, and im going to knock up a dipole (inv V)for 80m using 7/0.2 speaker wire, and probably RG-58 as feeder (ive nothing thinner). My fish pole is normally guyed as a vertical using bungies from the 1m point (top of the outer case). This is pretty ok for a vertical. But im wondering about the loading with a dipole.

How do you chaps guy yours? Do you mount the dipole right at the top, or part way down at a more sturdy part of the pole? I want to put as little stress on it as possible whilst still getting the antenna elements out reasonably straight.

2

In reply to G7MRV:

10m poles are far too big and heavy for me. I have a 5m pole which seems to work FB. I’m only QRV for 60m/40m/30m using a dipole. I have the ability to run 80m but normally don’t bother. It’s possible the apex with a 5m pole is not really high enough for 80m.

The dipole sits about 30-40cm from the top, somewhere about 4.5m AGL. Feeder is RG-174 and the cable used is very thin stranded PVC covered hookup wire. I think the current wire in use came from splitting a roll of 6 core alarm cable. Lightness is what I’m aiming for. I’ve yet to have a wire element break in use though the connectors have come off twice. I guy the pole about 1m up, possibly higher. I have a triangular shaped piece of plastic as a yoke which fits over all but the bottom section of the pole with 3 lightweight lengths of 2 or 3mm nylon rope. I use standard cheap tent pegs.

The whole setup survives Scottish WX, the pole has done well over 200 activations. The joints are getting a little tired now so care is needed to twist them so it doesn’t fall down.

Andy
MM0FMF

3

In reply to G7MRV:

I find that 10m poles are too long and too heavy for regular hilltop use. I use a 7m pole and that’s as high as I find is easy to manage. I mount dipoles 1 metre below the top and use a single back guy (also 1m below the top).

73

Richard
G3CWI

4

In reply to G3CWI:
some interesting ideas, thanks. At the moment the only feeder ive got spare is RG-58, but if im going to forsake the top couple of sections of the pole, i can drop the feeder down the middle, just needs a hole in the bottom bung.

I’ll try a couple of ideas out in the garden first before dragging myself to my field site.

As for the 10m pole being too unweildy, i normally use a 5.4m racal clansman mast! The fish pole weighs nowt in comparison! :slight_smile:

5

In reply to G7MRV:

I use the same 7m pole as Richard & it handles RG58 no problem at all. If you start making holes in the pole I reckon you`ll compromise the pole more than the weight of the coax.

6

In reply to G7MRV:
I use 2 lots of coax with my SOTAbeams pole, one for my 40m dipole and one for my 2m dipole but I don’t use the top two sections. I just secure the coax and dipole centre piece to the pole with tape. It works fine. I also sometimes use two parts of a SOTA beam for each end of the dipole.

73 Nick

7

In reply to G7MRV:
I used to have a 7m pole until yesterday.
I now have a 6m pole, but I preferred it as it was to be honest.

I just use each leg of the di-pole (Plus rope) in a very wide V and the back leg is just a guy rope looped over the top of the pole.

Works for me, until the top falls off. :frowning:

8

In reply to G4OOE:

My dipole centre T’s are cast in plastic with a suspending loop at the top, the loop fits over the fishing pole about a metre below the top which is convenient! As it happens I do not use a dipole now, but a W3EDP, and a dipole end insulator has the same size hole as the T piece each end: one end of the insulator goes over the end of the pole, the wire threads through the other end. I find that the end of the pole is too flexible to feed the wire through the little wire loop provided at the end of the pole itself for the fishing line to run through.

73

Brian G8ADD

9

Minority voice:
10m pole of the sturdier DK9SQ-type, always unguyed as long as a support is available to which the pole could be tied at a height of one meter or a bit more (had no really bare QTH so far). Feedpoint a bit below the lowest end of the top section. Short 40m-doublet of 17m-length fed with light ribbon wire, fixed to the pole at the screw of a very small clamp with rubber inside. Bowing of the pole seems tolerable. I even think about buying a 12m-pole with 3,3 kg vs 1,5 of the actual one - but improving the antenna seems worth the sweat. At our mostly wooded summits here it would give also additional range to bring support lines higher in trees when hanging the dipole at branches.

For 80m I would prefer 10m wire up, then 10m horizontal plus radials as endfed quarterwave.
Best 73, Chris (DL8MBS)

10

Twin speaker wire can often be around 75 ohm if used as a balanced feeder. That’s what I use to feed my dipole with a small 1:1 balun at the rig. Works a treat with no ATU and no RF feedback problems which I occasionally suffered from when using co-ax.

11

In reply to G7MRV:

I have been using this antenna for a while:

http://www.moosedata.com/g6wrw/hfdipole.pdf

The centre is only 5 metres agl. The only problem is absorption on 80 metres at this time of year.

Carolyn (G6WRW)

12

In reply to G6WRW:

It’s enlightening looking at the server statistics Carolyn. In the 3 days since you posted that link 222 people have downloaded the file.

Andy
MM0FMF

13

In reply to MM0FMF:

Carolyn says thanks for still hosting the file. She really needs to sort out some web space as she has a couple of other multiband antennas she uses to write up that could be of interest,

Helen
M0YHB

14

In reply to M0YHB:

You’re welcome to stick them on the big moose box (moosedata.com) as it has effectively infinite diskspace and infinite bandwidth.

Andy
MM0FMF

15

In reply to MM0FMF:

Hi Andy,

I have Carolyn’s design before, but it was still worth another look :wink:

A very good design & well contructed too!

Thanks Carolyn :slight_smile:

In reply to the original poster, 80m in summer, in the daytime is a bit of a challenge, even with 100 Watts.

On activations, I have mostly used a 7m telescopic fibreglass pole to support my 80/60/40 link dipole at about 6m, using three guy lines at the top of the bottom section of the pole about 1.1m above the ground, assisted by walking poles at each end of the dipole to keep the ends of each leg as far off the ground as possible. This arrangement works fine but I haven’t used 80m much recently as conditions have been so poor.

Since I have started dabbling with 160m, I use a different arrangement, which I actually find easier. I use what was originally an 11m carbon fibre pole with the centre of what is now a 160/80/60/40 link dipole supported in the centre at 9m AGL & fed with RG58 coax. I only use one back guy line to keep the antenna aloft after first pegging out each leg of the dipole & then raising the pole. As before, I still use fully exteded walking poles at each end of the antenna to keep the ends of the dipole as far off the ground as possible.

This is quite a strurdy arrangement, but if using a telescopic pole you may have to make allowance for the extra vertical force on the joints of the pole, which could lead them to collapse. The carbon fibre pole I use is of the slot together variety so any vertical force will only force each section together more, rather than force them into each other as with a telecopic pole.

I tried twice to get decent video of my 160/80/60/40 link dipole in use, & I think this video is the clearest, although my other video from two weeks earlier also gives you an idea of what I now use on HF/MF.

I now normally only use a Yaesu FT817ND, so with only 5 Watts available it is handy to have more than one band to use, hence in your position I would aim for having links to enable at least 40m operation, & if you can do, but haven’t done so yet, apply for a 5MHz NOV. The 60m band sits in a very useful part of the spectrum & is superb for low power portable operation in my opinion.

Good luck with 80m

Best 73,

Mark G0VOF

16

In reply to G0VOF:
After some quick weight vs. bend tests, i have to agree with many that the top couple of sections should be avoided as they are not nearly sturdy enough to handle it. Ive knocked together a simple 80m dipole which will loop over and be held by the third section down (7m). I will probably abandon the idea of running the RG58 down the inside of the pole, not so much for general integrity issues (the hole i mentioned would have been in the bottom ‘bung’ that closes the bottom of the tube, not the tube itself) but to avoid damaging the end of the section it exits from.

It would seem, for the cost of the wire, that a few different simple antennas should be carried, along with a small ATU and SWR meter to quickly match them. A simple method of avoiding the bulk of even a small QRP ATU is to have winders for the wire so the length can be quickly adjusted. My Clansman HF antenna system has this, but is more a field day mast system than a SOTA system!

As it stands, 80m is the only HF band i can use for SOTA. I dont have an all band rig - my portable kit is homebrew! I am in the process of applying for the 60m NoV, but then comes the task of building a suitable rig!

With any luck, by the end of this week i’ll have the dipole and the vertical built and tested, and will then take them out for a real field test, although whether i can get on a summit for that or just the local nature reserve i dont know yet

Martin G7MRV

17

In reply to MX0TSE:

well, ive had it up! (ooh err missus!)

I found a forgotton dipole center, so have used that. The first thing i discovered is that with the center at 8m, i need a bigger garden! some 42m is needed for the dipole, i expect no problem on a hilltop. The second thing i discovered is that ive cut the dipole too long, its resonant at 3MHz.

But, i mangaged to prove the guying system with the full pole up, and checked the distances needed to get the correct tension. I only had the mast collapse once, and telescope itself once!

Its a start