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Lightweight Vertical Antennas


#42

There are of course other antenna options for the winter SOTA enthusiast


#43

Not too far removed from a mag-loop or buddipole even. Might be an option (possibly heavy) if there really is little space on the summit.

BTW, for those on the NASOTA Yahoo group, take a look at the post by Fred KT5X entitled ‘SOTA Antenna’. Sounds magical!

Colin


#44

What is magical?


#45

Practicality is another word for compromise and as such, there will be a penalty to pay.

Having operated almost exclusively vertical from summits, in my humble opinion, height above terrain is critical…

If it’s DX you wish to work, a vertical is your best friend.

73 Mike
2E0YYY


#46

I prefer using random vertical wire GP instead of linked dipoles as I find GP lighter and easier to carry, install, set-up and mainly because they are omnidirectional.

When I’m activating from a summit, I want my signal spreading all around, so I can expect chasers from anywhere.

My preferred one is this 7m telescopic fiberglass fishing rod from Decathlon with a 7m wire inside it up to the top

The bottom end of the wire connects through a faston connector to the RG58 center wire. The coax braid is connected with another faston and this white chocolate block for electrical connection to 4 wire radials which I may lay down on the ground or hold elevated on bushes and branches when available and possible. The length of these radials was nearly 5m each but one broke some weeks ago and it may be 3m now.

I have some few times used a home made magnetic loop antenna, but mine -shown in this picture held with a photograph tripode- is too big and heavy, so I’ve only used it some time ago in very easy access summits.

Another light and very fast to deploy vertical antenna is this one shown in the next pictures. It consist in a monoband mobile whip and wire radials on top a PVC tube…
Firstly I used it with 2 wire radials:

But I currently use it in my Saturday morning express activations with just one single wire radial sloping down and keeping the final end above the ground. There’s no difference in terms of stations logged in an activation or S/R signal reports.

I have mobile whips for 10, 15, 20, 40 and 80m but I have only used 10, 20 and 40m so far.
Before starting my hike, I choose the band I will activate and I just take one or two whips with me. The single wire radial has links in it so I can set it up for 10, 20 or 40m.

Of course dipoles do very well also, but I don’t think they do neither worse nor better than verticals. At the end of the day, most of us work all the chasers in the pile up and we don’t work anymore not because our antenna can’t reach further or copy weaker signals, but because there are not any more chasers calling us in the time we are QRV from the summits.

Best 73 de Guru


#47

Is the Pocket Pole shown made of Carbon(-Fiber)?
If yes, what is your experience regarding conductivity/affection of radiation pattern?


#48

73, Colin


#49

Tks!
What is the top section diameter/height for practical use, e.g. to carry a 20m POLYS-26 inverted-V/-L antenna wire without coax?


#50

I prefer dipoles or EFHW for the activations. More punch around EU. Take off/ location is key as Colin pointed out.

I used an elevated GP when I want to work DX - mainly at the beach.

At home I have moved from a vertical to a doublet as I have a lot of local noise from the city / nearby houses / VDSL.

73 Angel


#51

Hmm just what I was thinking.


#52

Interesting views on Verts and and DP’s.

I use a Vert and Inverted L both seem to work for me.

BUT have found and learnt recently a single counterpoise wire as in use from a end fed antenna am using using via the 9:1 Unun as mine be 1/4w length of 40m and took that single wire and divided it into four lengths still totaling the full 1/4w length. And send if off in four different directions is a lot more effective than a single CP wire on the vert 1/4w and the Inverted L 1/2w both 40m.

Yet on beach best C/P is prob the single wire straight into the water itself. Have seen many years ago and done it myself. Cars park themselves next to the waters edge throw in a wire attached to the car and the difference is unreal and await high tide 1 hour prior and afterwards the higher the tide the better.

Yet have also found out in open areas the Vert do work well as try to avoid wooded areas and the sap is not rising as yet.

End of day build what you feel happy using easiest for yourself or even buy, prefer building myself and experiment but most vital thing in the case of Sota is keeping it simple and lightweight.

Karl


#53

Is it a myth, or wood really affects the signal?

I did not notice any dramatic changes on wooded summits. I got no instruments or means to detect changes in antenna performance. Poor performance, when happens, could be attributed to poor propagation or simply unmatched antenna.

For my activations I am using a 1/4 wl linked vertical with two elevated linked radials, for 30 and 20, on 8 m fishing pole, along with a ZM4 tuner.

73 Fric YU1WC


#54

I suspect it is a myth, Fric, as using a tree to disguise a wire vertical is a common strategy where antennas are forbidden, and I have never found any problems. Interestingly, page 8-13 in the book “ARRL’s Wire Antenna Classics” describes a successful three band parallel vertical using a tree as a support, whilst page 8-12 describes measurements showing that trees have an effect on verticals. I suspect that both the species of tree and the season has an effect.

Brian


#55

I’ve probably just been unlucky (and the sample size is certainly too small to be useful).

Of my twenty HF activations, six involved eight or fewer contacts. Of those, four were using verticals, and two of those involved verticals in woodland (by which I mean not just a tree or three, but whole stands of trees all round). It was around the time of those two that I heard talk that woodland messed with verticals, and it certainly seemed to match my limited experience, so I’ve not bothered trying verticals in woodland since.


#56

It’s very easy to believe things such as verticals and trees. Of course there is some effect and it’s worse when the trees are very wet such a pine trees after heavy rain.

Here is my log from Knock of Crief from a while back:

And here is where I was located (red mark) in the trees:

A fairly typical set of results for my vertical with 2012’s solar levels. It was a dry day and had been dry for a while however.


#57

Hi Andy,
It seems you have an error in the time of the 1st QSO of the activation which log you posted, unless you spent a bit less tan 13 hours waiting to get your second QSO (very unlikely).

Hi all,
I have activated with my GP in the middle of some foresty summits with pretty tall tres around and I haven’t noticed any bad effect to the antenna performance, albeit the proper way to figure this out would have been having a GP and a dipole or endfed installed at the same time in the same summit and switch from one to the other to compare the real signal reports.

Best 73 de Guru


#58

I spotted that when I copied the data… I’ll fix it tonight when I get a chance.


#59

My experiences:

Vertical & GP - best for DX
Dipole - best for chasers

Vertical & GP - best for 20-17-15-12-10m bands
Dipole - best for 80-60-40-30m bands

YMMV


#60

Not as much as bricks and mortar Fric!

I only picked up on this lengthy thread last night…

To throw in my opinion from a home station point of view. Verticals have their uses and work very well in the clear on summits where they offer lower angle radiation that that of a dipole, this is generally not essential or even desirable for SOTA when using QRP. In the average suburban back garden they can be poor radiators due to nearby structures and they are only as effective as the ground system they are working against, unless elevated radials are used, which are not generally practicable to have in the average domestic garden. One advantage is a vertical can be fairly unobtrusive. Over a good ground they really do transmit extremely well, however on receive most of the time they pick up much more noise than a dipole. Whilst I do use verticals on the home station, on summits for HF QRP work (I’m not trying to work the world - just qualify the summit as quick as I can until the pile up dries up) my choice these days is always a link dipole for 3 bands for cheapness and consistency whatever the ground below it, and ease of erection using the methods previously mentioned in this thread.

73 Phil


#62

The vertical antenna used by Emil DL8JJ/P yesterday on his DM/TH marathon may complement the many theoretical considerations.

Emil could realize 7 first activations with a total of 207 QSO on 7 MHz (DX: K4WMS).

BTW, the DM/TH marathon distance was 904.7 km of car ride and about 40 km walk…