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Buddistick & Other Verticals

Some antenna advice please?..

I have a couple of portable verticals (Buddistick and Pac-12). I love the compact nature of these products. However tuning seems very picky and I don’t see how I can do it without taking my analyser which is bulky (my Mountaintopper has no SWR meter). Everytime I even move the counterpoise wire the SWR swings wildly from 1:1 SWR to potentally anything, therefore careful tuning at one location doesn’t seem to be able to be recreated at another!

Is this just the nature of verticals or is there a way I can make this setup less location dependant to be able to easily just put it up and go (once I have found the ideal setup in a single location using the analyser) or am I never going to achieve this?

I do have a ZM-2 tuner which is quite compact and I could use it. I guess I would just get the vertical to maximum noise then use the tuner? Though I would rather not use a tuner unless I have to.

I guess some of you are using verticals for SOTA so what do you do? Can I ever achieve my goal with this type of setup of simply plug and play or is dragging along an analyser of some kind of external SWR meter a must for this type of setup?

Thank you!

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Hi Olly,
I have seen that problem with the counterpoise/radials affecting an antenna with the QRP-Kits tri-bander antenna and in the end, I gave up and threw it away.

My “go-to antenna” has always been a linked dipole (SOTABeams Band Hopper) on a 6 or 10m high mast (depending upon how much weight I was willing to carry). This is rather bulky but there are no radials to worry about and it’s simply resonant without an ATU - always.

If you want to go with a compact vertical solution, my “Compact” antenna is a Komunica Power HF-PRO2 (the same antenna is available also from other suppliers (e.g. Diamond) at a higher price) and a modified photo tripod. Komunica also now produce a tripod as well if you don’t want to build yourself. The key point, I think, is to use 4 or 8 radial wires which ARE NOT resonant lengths - around 4 metres seems fine. Resonant radials/counterpoise - I think (guys before you flame me - this is my opinion and experience, not a scientific investigation) while improving the antenna, are critical on set-up while non-resonant lengths are more flexible. No tuner is needed for any of these set-ups.

73 Ed DD5LP.

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Using a rig with an SWR meter (IMO every rig should have one), you can adjust the SWR by wrapping the end of the radial wire(s) around a peg or pole and winding or unwinding to get minimum SWR.

I’ve always carried a tuner.
A vertical antenna is definitely the king of DX.

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Agreed, but it is a bit of a commoner for NVIS! :wink:

It is a pity that Sotabeams have discontinued the picotuner, it only weighs a few grams!

Hi Olly,

It is optimistic to use loaded short verticals for QRP work. This is explored extensively in the antenna handbooks by RSBG and ARRL. Mobile whips on cars are usually rated at about 10% efficiency compared with a full size antenna.

The shorter antenna length leads to a much reduced radiation resistance, and the use of a loading coil (whatever the brand) introduces losses which mean part of the power from your transmitter simply heats up the coil.

In addition, using a single radial for a quarter wave vertical is subject to the variations in ground conductivity and losses, So if you have the single radial lying on grass at one location, on ground the next, on rocks the next and elevated the next, that is four different antennas and the tuning of each configuration is definitely going to vary, as will the feed impedance. It may work well enough over a swamp, but over anything else it is a lottery.

As Ed has remarked, sometimes it is too frustrating when the antenna is giving inconsistent results. A consistent antenna is much more satisfying and is more predictable.

73 Andrew VK1DA/VK2UH

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I did try using loaded dipoles once or twice. Since then, if I’ve felt the need to use a vertical on a summit then it’s been a mono-band full-size quarter-wave vertical with elevated tuned radials (which isn’t all that far off being a vertically-mounted dipole). One for 20 metres is just about practical for SOTA if you have a long enough fishing pole. I have ones for 20,17,15,12 and 10 metres which I occasionally take out. The one for 12 metres was useful during the 12 metre challenge a few years back. Usually, though, I’ll just take a link dipole. It’s more versatile and easier for changes of band.

For operation on a single band e.g. 20, 17, 15, 12 or 10m - HF J-Poles are also worth a look, with the advantage that they have no radials to deal with as they use a quarter wave matching stub instead. Pack-up small and work well for DX - but don’t try using one in a forest topped summit or you will be disapointed as the trees asorb the RF! In a forest, you are better off with some sort of horizontal dipole (single band, linked or OCF).

73 Ed.

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Sell them and build clones. Or make some dipoles (end or centre fed).

You can make a clone of a Buddistick for pennies that has the massive advantage of not weighing lots. My clone for 30/20/17/15 weighs about 150gm, it’s just wire with a coil wound on some PVC waste pipe. The build instructions are on here if you want to try one.

It’s definitely a compromise on lower bands but is fine on 17/15m with acceptable performance on 20m. A bit vague on 30m because there is a lot of loading coil in use. I would never think of using it for 40/80m. It also works on 10/12m but the way I built mine, that involves swapping the top section. The only reasons I see to use it are that it is quick to deploy and an omni. It took a while to learn how it tunes up and it is dependant on the ground. Fairly predictable in Scotland and mainland Europe, but badly affected by thick layers of snow on the ground. Tuning is different on volcanic islands (Madeira, Canaries ) but again, once you have learnt how it tunes, it is repeatable.

Definitely needs some kind of SWR indication to confirm it is OK. Easy for me as I use the SWR display in an 817.

Would I buy/use a real Buddistick? No, far too heavy for SOTA and far too expensive when my clone cost under a few pounds to make. I think a link dipole is a better bet though.

I used it for all my 20/17/15m QSOs made between 6-nov-2011 to 3-jun-2018, 2609 QSOs (CW/SSB) over 147 distinct activations in GM, OE, DL, F, EA8, CT3, OK, PA, ON, LX, HB9. It worked FB when solar conditions were better on the lead in and lead out of the last solar maximum. Now conditions are much poorer I’ve been using a link dipole for 30/20/17 which definitely outperforms the Buddistick clone but it is much more directional.

For SWR, you can use an old CB meter which can be had for coppers. Or you can make up one of the many circuits that either use the brightness of an LED or number of LEDs to indicate the SWR. if you want something small to go with the mountain topper.

So my advice is sell the commercial antennas and get as much of your cash back as possible. Home brew a SWR meter/indicator, home brew a link dipole that covers the bands on the Mountaintopper. When you have experience of using the dipole, homebrew a link EFHW for the same bands and compare it. Leave making trapped dipoles/EFHW and Buddistick clone for now.

For the record, I’ve nearly always used a 5m pole and have the following antennas

For the 5m pole:

80m Inv-V dipole.
60/40/30 Inv-V link dipole. (LF bands work horse antenna)
30/20/17m Inv-V dipole.
40/30/20 trapped EFHW (commercial)
30/20/17/15/12/10m Buddistick clone
12m 1/4wave GP

For an 8m pole
0.64wave 10m vertical (2x 2m elevated radials, base loading coil)

I normally would not buy HF antennas, especially wire ones but the EFHW was on offer at the time.

Note there is no perfect antenna. They all have pros and cons for differing uses and environments. But HF antennas are so easy to build and play with, you can have loads of fun figuring out what you like and works best for you.

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Here’s the webpage to give you the dimensions for building a linked dipole Olly:

https://www.sotamaps.org/extras

Click on the “linked antenna designer” tab if it doesn’t open already on that page.

73 Ed.

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I attempted to basically make my own Buddistick from some design I found here. Even with an antenna analyzer I could not get it to properly tune on any of its 3 bands. I tried many iterations of counterpoises, raidals at different heights, radiator lengths, etc. and gave up in frustration.

In the mid 90’s (well before SOTA) I attempted to also use the “St.Louis Vertical”, a somwhat similar concept to the Buddistick. That antenna I could finally get to tune but wasn’t happy with its performance so I scrapped it as well.

My linked dipole, doublet and linked EFHW antennas are now my go-to HF antennas and I can’t see myself attempting another portable vertical as the wires seem to work very well for me…

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Verticals are great antennas … on the beach with a salt water take-off. On a rocky peak they suffer from ground losses, maximum current is right on the ground if it is a quarter wave vertical, needs either lots of radials, or four elevated radials, and half of the radiation left after the ground loss goes down hill, and lost to scatter. Popular because it is easy, but not recommended for SOTA peaks.

An inverted vee is a perfectly effective antenna if you have a way to suspend it. I tried to get one up on a rather flimsy portable pole above treeline, and abandoned the concept as only occasionally useful.

After 700 activations, I have settled upon a resonant endfed halfwave wire deployed as an inverted-L on a very light weight (under 200 grams) 6 meter tall fishing pole. The end of the wire has essentially no current on it, very low ground loss, no need for any radials, no need for a feedline at all.

A simple tiny impedance matching device, and we are all set. I built that into a dental floss case, weighs 15 grams. The tinySWR indicator by DK3IT completes it.

73 Fred KT5X (aka WS0TA)

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Thanks for all the responses.

I like the vertical as if I’m on a bench it doesn’t look so huge just with ground radials. Feels like a smaller footprint! That’s why I am shying away from the dipole.

I guess it looks like it is never going to be that simple though!

I’ll see what difference it makes adding more radials but if not I’ll revert back to the EFHW and a pole of some kind!

Thanks again

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I use #28 teflon wire, essentially invisible, yet it has never broken. No end insulator for QRP, just tie nonstretch thread, braid fishing line, 40 pound test, for supporting the end. Pole is the cheapest available, the one I use collapses in 15 sections to just 18 inches in length. If a bush is handy, I lean it in a bush. If a tree is handy, I use the pole to drape the wire over a branch. If neither, I build a little cairn of rocks. Lean the pole away from the wind and toward the stretched out wire, and it won’t break even though very flimsy. I secure afishing pole type “tip-top” on top of the pole. Entire set up weighs half a KG, and sets up in three or four minutes. - fred

If hike is under an hour in length, no pack either, just pockets…

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This does look very neat.

Can you share details of your fishing pole and the match unit?

I have made the tinySWR but I don’t think I got the exact LED and it doesn’t work completely well. It’s still pretty good though. I also have made EFHW with a 49:1 transformer - is that the same as yours?

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I bought a Buddistick a few years ago.

It is a well engineered product but, as with all short verticals, it is very much a compromise as an antenna.

I also found it very fiddly to tune. Getting the exact tune spot with the clip on the coil is very fiddly. Adjusting the counterpoise is also part of the antenna tuning, and they suggest it is kept approx 30cm of the ground.

I found it altogether too fiddly for SOTA, so I sold it.

I now use a Sotabeams Bandspringer-Midi, and or link dipole.

73’s
David

2 Likes

This is the tuning unit in the photo. The capacitor is a film capacitor for an AM radio, has two sections, I use just the smaller section, set the trimmer high to reach 40M.

This is a broadband matching device like you 49:1 probably, only I think it is 81:1. All that does is change the length of the wire it will match by a few inches.

Here is a photo of the broad-band impedance matching transformer built into a dental floss case, weighs 12 grams, I prefer RCA jacks for this application.

to multiband, I have been making tiny traps since 2014. The traps weigh 2.5 grams. Search OSH PARK WS0TA for a circuit board on which to mount the SMD.

ones I have seen being sold commercially, maybe copies of my earliest ones, use too much capacitance, too little inductance, to work well. The trap really needs to produce an impedance over 1,000 ohms. Use as many turns on the core as you can fit, use fine wire #28 perhaps, then can get something like 40 turns with a 15 pF 500v NPO SMD, then the trap will actually work and wire tuning becomes easy. See < toroids dot info > for turns/capacitance/toroid and see what impedance (ohms) it produces.

My wire is 43 feet long. With three traps and the AA5TB style tunable impedance matcher, I get 15 (3 halfwaves), 17 (trapped), 20 (trapped), 30 (trapped), and 40 meters. With the KX2 ATU for a little help, I also get 12 (four halfwaves), and 60M (by replacing the EFHW tuner with a straight through connection and ten feet of counterpoise, it easily matches it.

The pole came from China found on eBay…

I used hot glue to mount a fishing tip-top on the skinniest first section. Then I used hot glue to secure it permanently inside the second section. The top section too flimsy on its own, but inside the second section, now the entire rest of it is quite sturdy.

  • fred
7 Likes

Yesterday, for the first time, I used a home made single band vertical for SOTA, for 20 m. I was very pleased by the easy set up, compared to my “long” wire I used before.

I got the design from Peter @OE5AUL. Its an endfed 5.05 m long wire with a loading coil at 1.73 m from the top. So it is like an half wave dipole, fed at the bottom at the high impedance end. This type of antenna does not need any radials. Simulation with NEC showed, that degradation by the coil losses is small. At the feed point, there is a 2:18 turns transformer for getting near 50 ohms.

I did the tuning of the antenna by changing the distance of the windings of the loading coil, and used a nanovna for this (I’m totally happy with it for this purpose). I don’t know, if it is sufficient to tune the coil once and have it fixed for ever. During my activation, I used a LED-SWR-indicator to confirm, that SWR kept low.

From my activation, my impressions of this antenna were really good. Nevertheless, there is one point, I’m not sure if this is good: The atmospheric noise which I heard in my RX, seemed to be lower than what I was used to hear when using my “long” wire antenna (while on SOTA, without man made noise). This can indicate losses. At home, I measured the transformer with a VNWA (not nanovna), left open at the antenna side, and it shows a self resonance at 7 MHz (below 14 MHz, where I used it!) with a resistance of 160 Ohms (real part, no imaginary part). Maybe (I don’t know) this means, that the transformer induces significant losses.

Next time, I’ll compare the atmospheric noise in the RX of this set up to the transformer replaced by a tuner (@kx0r tuner).

73, Axel

UPDATE: I measured the losses of the transformer. Result: No measurable losses.
How I measured it:
I connected a load to the antenna side, such that the input impedance was real 50 Ohms.
Load impedance: GND – 150R – 10uH – 18uH – 1K – 1.8K – 1.8K – 1.8K --o
I fed 1 W to the input and measured the voltage across the input and the 150R.
Than measured the actual impedances of the components (with a VNWA) and calculated the power in the resistors. => Output power equals input power within measurement accuracy.

73
Axel, DF1ET

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Fred, can you give us a little more information to help find telescoping poles like yours? I looked on e-pay and I don’t see anything that looks like yours. The 6 meter telescoping poles I found are all around 72cm (or 28 inches) long.

I want to replace my current pole, a telescoping 20 foot fishing pole I bought at Bass Pro. It’s worked fine for three years, but it is too heavy. Also, its collapsed length of 28 inches makes it pain in the neck here in the heavily forested Southern Appalachian mountains, as it sticks up from the pack and gets caught in every overhanging tree branch! And on the rare occasions when I have gone by air travel, it has to be shipped as its own piece of luggage in a plastic tube which inevitably draws the attention of TSA.

Also, what type of battery are you using and what duration of activation time do you get with it?

I echo the endorsement of the end-fed wire with one end supported by a pole. That’s what I use with my Elecraft KX1. A 43 foot length seems to load up easily on 40, 30, and 20m in the CW band, using the internal tuner.

73, Scott

I have only had the opportunity to examine a Buddistick system (not a PAC-12). While I thought it was beautifully designed and engineered, my personal thinking is that I wouldn’t want to lug it up a hill. I think I read somewhere that a survey of SOTA Activators revealed the EFHW to be the most popular antenna type. Not surprising, as the advantages incude:

  1. No heavy, bulky, potentially lossy feedline is required.
  2. As a resonant antenna, in full HW form, it is very efficient.
  3. No counterpoise or radial wires are required (at least in my experience when used for QRP).
  4. It can be erected vertical, horizontal, inverted-L or inverted-V, depending on what polarisation or angle of radiation is required (or as location permits).
  5. There is nothing to go wrong - it is a single section of wire.
  6. It can be made multi-band by adding a few traps or links.
  7. When it’s wound up, it’s small and light.
  8. Easy to homebrew. The only tools required is a tape measure and wire cutters :slightly_smiling_face:.

The disadvantages include:

  1. Some form of impedance match is required - though for QRP this can be lightweight, simple and inexpensive or easy to make.

  2. A VSWR indicator and some means of fine tuning is advisable (e.g. by varying capacitance/inductance in matching device or folding back some of the EFHW wire). However, as already commented, a simple lightweight minimum SWR indicator is all that’s required.

  3. If you want multiband, unless you opt for traps, you will have to add/remove links to change band.

If you want a vertical to attach to a bench and don’t want raised radials, why not consider a EFHW vertical? If you don’t want to use something as big as a 10m pole for, say, a 20m EFHW, consider adding a loading coil as already commented?

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