Need advice for "rapid deployment antenna"

The “Four-Band ‘Tree’ Vertical” article is available from the ARRL here: http://www.arrl.org/files/file/protected/Group/Members/Technology/tis/info/pdf/9511071.pdf

That and other articles are linked from this page: http://www.arrl.org/hf-vertical

It is simple, with three parallel radiators cut for 10, 20, and 40 meters. The diagram shows the 40m vertical as an inverted-L.

For two bands, you could use window line for the stretch where the two elements are in parallel, then add on wire for the longer element. The 15/40 meter trick would still work to get three bands, of course.

If you have a wide-range tuner, a vertical for 20m is roughly 5/8 wave for 17m, which should work well.

For radials, two resonant radials work nearly as well as three and even one radial works pretty well. That gives a bit of directionality towards the single radial. Running one radial per band would be enough for many purposes.

K6WRU

[quote=“K6WRU, post:15, topic:9787”]even one radial works pretty well[/quote]By that stage you’re pretty much using a (more or less) vertical dipole :wink:

I went with the mono-band gp vertical antennas because they were an easy educational exercise to construct, they’re simple to put up and take down, and, so long as I carry more than one I have a fallback antenna if one gets broken. Of course, it’s usually the pole (or something else you’re only carrying one of) that fails…

I’ve found it’s worth looking for telescopic flag poles rather than telescopic fishing poles, as the fishing poles are often too flexible near the tip.

73, Rick M0LEP

Because of limited time it will be monoband only, 20m.
I can get help from 1-2 friends to set up the antenna.

Hi,
Here on the East coast of VK 40 m is the band of choice for a quick activation. Next most useful if further away from the Sydney-Canberra-Melbourn- Adelaide line is 20 m. However 30 m can fill in some holes in coverage. Only if conditions are very good is it worth worrying about higher bands over here. Our nearest dx is 2,500 km away but most is 12,000 to 18,000 km away via short path.

I use a 40/30/20 m croclink dipole (link dipole using crocodile clips) and support it and its thin coax from various telescopic fibre glass poles from 4 to 10 m long. I use a stake in the ground for the pole and two pegs for the ends although sometimes tree branches and rocks have been used instead. It takes 10 minutes to put up with most of the time spent unwinding the wire and feeder. Dropping the pole section by section allows for a fast band change. I’ve found that, up to the stage where the mast splits due to extreme wind, no guys are required. I do sometimes align the dipole so it is end on to the wind and the stake is also aligned for max strength. They are a small section of arc of a tube cut length ways, so not flat but not a quadrant in enclosed angle. I have a steel stake with rings and aluminium stakes with velcro ties. There are always three masts ready to go in the garage. The stakes mean I am independent of trig points supports etc. I carry a small 300 g hammer to drive the pegs into hard ground and a piece of wood to avoid damaging the top of the stake when bashing away with the little hammer.

Tuned doublets with 7.2 m per side or 14.4 m per side fed wit 300 ohm line and a balanced ATU will give all bands from 40 m to 6 m with QSY as fast as you can tune the ATU. Some of us use these over here.

I’ve also used a G5RV, OCFD, EFW and 1/4 W verticals. The croclink dipole is still my preference for ease of erection and efficiency on 3 bands. I prefer to use an ATU to be kind to the PA but have had a number of activations without the tuner and no smoke was seen.

73
Ron
VK3AFW

Situation is a bit different here in YO.
Most of my chasers are DL, EA, G/M which are fine for 20m. Not many chasers close by in YO, HA, LZ, so I will be better with 20m than 40m.
When I have time it will be nice to activate multiband and try some DX in USA or Australia, but this weekend time on summit will be limited, so I will just activate on 20m and hope to have time to work every chaser I can hear.

73,
Petronel
YO8SEP

Quick setup will be a linked dipole trimmed for 20m and with a few m of string on each end; no ATU.
One helper holds pole; peg one guy (only) downwind.
You hold pole, sending one helper with each end of the dipole to form a shallow V upwind and peg down ends of string.
Works fine Force 4 wind and below; needs 3 guys in stronger wind.

I use this setup with a 60/40/20 dipole; erecting single handed takes longer walking to-and-fro to the ends.

73,
Rod

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On the pole support front, I have taken to guying a walking pole to start with, using three guys with a running loop on one end, which tightens around the handle of the walking pole, and a fixed loop the other, which goes on the peg. Very quick to set up, even in strong wind. No knots to tie / untie with numb fingers. The fishing pole is then bungied to the walking pole. It is easily manageable for one person, and quick to raise and lower the fishing pole for antenna changes etc.

Adrian
G4AZS

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That’s an interesting idea Adrian.
Is it secure enough?
How long do you extend the walking pole?
Must give it a go next time i’m out.

72
Pete :gb:

With a bit of practice, it’s no problem to put up an inverted-V dipole single handed with no need to guy the pole independently and only one trip to each peg. I find I only need assistance if the wire gets tangled in heather, and I only need multiple trips if I get the pegging out wrong in the first place.

That being said, I did it wrong many times before working out how to do it right!

Martyn M1MAJ

It seems very secure compared to directly guying my 5m pole. In high wind I use two bungies, one at the top and one at the bottom - unless the ground provides a good register for the base of the pole.

I use the walking pole at normal walking length, probably about 1 metre.

Imgur

Imgur

Especially convenient in circumstances like this, where holding and guying a pole could be awkward. I could have chosen an easier spot within the AZ, but this was a VHF activation, where relative height can be very useful.

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I think, if you are going to use only 14mhz, a mono band dipole, inv. vee, rg174 coaxial, 6-9m pole, and 2 more guys to help rod to stand will do.
If you are going to make it on several bands, I like the linked dipole, but you must spend times gettng up and down the pole for every band change.
I’m using now a norcal doublet, less weight, no need to move the antenna once set up, and with a 4:1 balun usable from 7 to 28 mhz. I only need about 7-10 mins to set it up, and then, forget it!
But you know, on antennas, you can find as many oppinions as hams… :wink:
73 de Mikel

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My dipole is cut for 80m, and has links for 60m 40m 20m and 10m Unless there is a particularly perverse dip in the ground, I find I can reach as far as the 40m links without dropping the antenna. I am well below average height. I just grab the wire where I can reach it, and walk along pulling it down until I get to the link. The pole bends a bit but that’s fine.

To change the 20m or 10m links I do need to drop the antenna. I used to think this was a pain until I decided to try the “just do it” method. Pick up the pole at the bottom and move it towards the back guy peg, letting it fall gently. 5 seconds at most. Change the links. Reverse the process, picking up the pole at the base and flipping it back into the air, simultaneously walking it forward to plant it back on the ground where it was before. 10 seconds at most. No need to unpeg anything - if it stayed up before it will stay up afterwards as you haven’t changed the geometry.

If you have an assistant available, as I often do, you don’t even need to take the wire all the way to the ground. Just drop it enough that the assistant can reach the links, holding the pole at a suitable angle. Then just flip it back into position.

Martyn M1MAJ

Actually, I’ve done the same process -last weekend i.e.- and sometimes, f.i. when more than one are operating on the summit, IMO it’s better to work with sintonized antennas to minimize interferences, I admit. But while you (me) are making all that dance (always supposing you are on a summit wide enough, and without breathe or trees around to make it more difficult), with the norcal you simply push the band change, and ready. Even more when it is raining or snowing and all is wet. You have not to go out from your shelter to do all it…
And for the record, I really like the linked dipoles, but now we are talking about speed and ease :wink:
73 de Mikel

@EA2CW: But norcal doublet need an ATU and I don’t have one.
@EA2IF: Thank you for the info, brought one from Decathlon today.
@G4AZS: Nice idea to use the walking stick to secure the fishpole. I looked at you Flicker stream, nice photos.

Ok, Petronel, great!
I’m sure you’ll like it as it’s very helpful.
Even if you get to a very rocky summit, as long as there are some loosen rocks, you can try to quickly build a small cairn and hold the steel support in place for you to put the fishing pole vertical in it.
Cheers, Guru

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I was just out today testing a few antennas. My idea was for quick winter set up, or locations with treeless summits and the possibility of crowds. My first thought was a helical wind on the squid pole for 20 meters, but guying and supporting was more trouble than the EFHW. I went about as simple as one can get, 1 MFJ-1840T (40m) and 1 1820T (20m) telescopic whip, with 1/4 wave (on 40m) length of wire for counterpoise. 40m was FB, and I just touched it up with the tuner on 20 m. 12 QSO’s and even G4OBK DX on 20 (He was 579, I was 549). As simple as it gets, definitely not an EFHW or Norcal Doublet but it got the job done. Chasers have told me that 599 sigs are no challenge, they like digging out the weak ones :slight_smile: I started using these antennas with the FT-817 and no tuner, SWR was adjusted by shortening or lengthening the counterpoise. Here is a photo of the set up today. The 40m is on the rig, and the 20m is folded down laying against the bag.

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Well, at last that would be the fastest and easiest solution, just a small telescopic antenna tied to the rear of the FT-817 with a L SO213 adapter…
I’ve used it sometimes, achieving qsos with VK and NA (see EA2CW: "La Vida" (Life) EA1/CT-098, an odd activation. ). No need of poles, guys, or anything else (well, a pair of full size radials will help for sure…) but I prefer, once there up at the summit, to use bigger and not too much complicated antennas. (I really thing that size matters!)
:wink:

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Hello,
I use sometimes on thin summit this Short Whip Antenna SPX-100 with 2 radials.
It works good enought, and it is a “rapid deployement antenna”.
Photo on summit here: https://picasaweb.google.com/GEOF6HBI/FAM118CaireDeLAgnel#5794822173003620498
Gerald

Today I’ve made a linked dipole antenna for 20m/40m only using some 0.22mm wire and 8m of RG174. Choke balun or Guanella balun using 2x5 turns of RG174.

Was able to cut the wires to 1.4:1 SWR. Probably could do better but was cold and dark already :smile:. Didn’t had time to do some tests, but will do that tomorrow from a SOTA. Will have my GP Vertical with me as backup.

73,
Petronel

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I also favor the “one-legged” GP
I use another Decathlon pole support:

lighter, cheaper, and fits inside my backpack (and then holds my pens and pencil, and some plastic pegs;-)
in use , it looks like this:

(I seem to have better results if I keep the radial above ground, rather than laying on the ground)

73
Luc