Buddistick-Style Portable Vertical
A Buddistick-style portable vertical is a coil-loaded, single-arm antenna that trades the second arm of a dipole for a counterpoise wire, packing down to a single telescoping whip and coil instead of a matching pair. Commercial versions run $150-250; this clone builds the same idea from off-the-shelf whip, magnet wire, and PVC stock, using the same loading-coil approach as the Buddipole-style dipole build. It's the go-to choice for operators working from a picnic table, summit, or park bench who want a mast-free, low-footprint vertical rather than two arms to guy out, and it rewards anyone who already understands loaded elements and wants to see how the same coil concept behaves against a counterpoise instead of a matching arm.
Why a vertical needs only one radiating arm
A vertical monopole works against an image of itself in the ground (or in a counterpoise standing in for the ground), so it only needs one physical arm where a dipole needs two. That's what makes this design so compact for portable work — one whip, one coil, and a wire counterpoise instead of a second matching element.
20m (14.175 MHz): 234 / 14.175 = 16.5 ft
Same loading coil, different job
The radiator arm on this build uses the identical coil design as the Buddipole-style dipole guide — a physically short whip still needs a series inductor to cancel its capacitive reactance and land on resonance. The only thing that changes is what's on the other side of the feedpoint: a counterpoise wire instead of a second loaded arm.
d, l in inches; n = turns — Wheeler's solenoid approximation, ±5% for practical d/l ratios
How many counterpoises do you actually need
A single elevated counterpoise is what makes this design portable, but it's a compromise against a full radial field:
- 1 elevated counterpoise: fastest setup, lowest efficiency of the options here, fine for casual portable contacts.
- 2-4 elevated counterpoises: noticeably better ground-return efficiency, still packs small, more wire and deployment time.
- Ground-mounted radial field: best performance of the three, but defeats the point of a quick-deploy portable vertical.
Why the feedpoint impedance runs low
A full-size quarter-wave vertical over good ground is already under 50 ohms at resonance, and a short, loaded radiator against a single counterpoise typically reads even lower — often in the 15-30 ohm range. That mismatch is usually mild enough to feed directly, but a small step-down matching transformer brings the SWR down further if your analyzer shows a stubborn 2:1 or worse at resonance.
same proportionality as the dipole build, but starting from a lower baseline once asymmetric
| Section | Length (inches) | Length (mm) | Notes |
|---|---|---|---|
| Fixed stub (feed to coil base) | 12 in | 305 mm | Non-adjustable, connects to the feedpoint bracket |
| Coil form (winding length) | 4 in | 102 mm | 96 turns max, #18 AWG enameled wire, 24 turns/in — same coil design as the Buddipole-style dipole |
| 40m radiator | 96 in | 2438 mm | 96 turns engaged (~79 µH); counterpoise ≈ 32.5 ft |
| 30m radiator | 96 in | 2438 mm | 72 turns engaged (~57 µH); counterpoise ≈ 23 ft |
| 20m radiator | 96 in | 2438 mm | 60 turns engaged (~46 µH); counterpoise ≈ 16.5 ft |
| 17m radiator | 96 in | 2438 mm | 48 turns engaged (~35 µH); counterpoise ≈ 13 ft |
| 15m radiator | 96 in | 2438 mm | 36 turns engaged (~25 µH); counterpoise ≈ 11 ft |
| 12m radiator | 96 in | 2438 mm | 16 turns engaged (~8 µH); counterpoise ≈ 9.5 ft |
| 10m radiator | 82 in | 2083 mm | 6 turns engaged (~2 µH); counterpoise ≈ 8 ft |
| 6m radiator | 40 in | 1016 mm | Coil bypassed (0 turns); counterpoise ≈ 4.5 ft |
Buddistick-Style Portable Vertical Dimension Calculator
Materials for Buddistick-Style Portable Vertical
Building the Buddistick-Style Portable Vertical
If you've already built the Buddipole-style dipole, the coil and whip assembly here is the same skill set — the new parts are the base bracket, the counterpoise, and tuning against a single ground reference instead of a matching arm.
Cut and prep the coil form
Cut one 4 in length of 1.25 in OD Schedule 40 PVC. Mark and drill tap holes at the turn counts you'll need (6, 16, 36, 48, 60, 72, 96 turns from the feed end), sized for the wire plus a tap lead.
Wind the loading coil
Anchor the wire end, then close-wind 96 turns of #18 AWG enameled magnet wire at roughly 24 turns per inch, keeping tension even. At each marked tap point, pull a loop through the drilled hole, scrape off the enamel, and solder on a tap lead before continuing.
Build the base feedpoint with a common-mode choke
Mount an SO-239 to the feedpoint bracket along with a separate binding post for the counterpoise wire. Wind 8-10 turns of your coax jumper on the FT240-43 toroid right at the feedpoint before it runs to your radio.
Assemble the radiator arm
Build the single arm as stub (12 in, connects to the feedpoint bracket) → coil form → telescoping whip, in that order. Solder or clamp solid connections at both ends of the coil — a loose joint here is the most common source of erratic SWR.
Wire and label the coil taps
Bring a tap lead out from each drilled point to an alligator clip or a wired rotary-switch position. Label each tap with its target band from the dimensions table.
Prepare the counterpoise wire
Cut 25 ft of stranded insulated wire and attach a ring or spade terminal to one end for the base binding post. Mark the wire at the lengths in the dimensions table so you can fold back excess for the shorter high-band settings without re-cutting it.
Mount to a tripod, mast, or ground stake
Attach the feedpoint bracket to your tripod or short mast via the 1/4-20 adapter or clamp, keeping the radiator vertical. Run the coax jumper to your choke and radio with enough slack to avoid strain on the feedpoint.
Deploy the counterpoise
Run the counterpoise wire out from the base binding post, laid on the ground, elevated on a low support, or staked — straight and clear of metal objects and the mast itself. Consistency in routing matters more than the exact path; whichever way you lay it out, use the same routing every time you retune.
Set the starting whip extension, coil tap, and counterpoise length
Using the dimensions table, extend the whip, clip the coil tap, and trim or fold back the counterpoise to the starting lengths for your target band.
Fine-tune resonance and check the feedpoint match
Sweep SWR and adjust whip extension first for a resonance dip, then counterpoise length if the dip won't center on frequency. If the resonant SWR sits above about 2:1 with resistance well under 50 ohms, that's the low-impedance behavior described earlier — add the 4:1 or 9:1 unun and re-sweep.
Break down and pack for the field
Collapse the whip, disconnect the tap clip, coil up the counterpoise wire, and fold the arm in at the feedpoint bracket. Keep the counterpoise wire separate from the coil in your pack so it doesn't crush the winding.
| Symptom | Most likely cause | Diagnosis | Fix |
|---|---|---|---|
| High SWR (3:1+) on every band, no tap helps | Bad feedpoint or choke connection | Check continuity from center pin through to the whip stub and counterpoise post | Re-solder feedpoint joints; check the choke winding for a short to the form |
| Resonant SWR sits at 2:1-3:1 even when the dip is on frequency | Low feedpoint impedance typical of a single-counterpoise short vertical | Check measured resistance at resonance against the 15-30 ohm range described earlier | Add a 4:1 or 9:1 unun at the feedpoint and re-sweep |
| SWR shifts noticeably when the counterpoise is moved or coiled | Counterpoise routing and length affect the tuned system | Compare a sweep with the counterpoise laid straight vs. coiled or draped over metal | Lay the counterpoise out straight and clear of metal, then re-tune |
| Resonant on the bench, high SWR once staked outdoors | Ground proximity, damp grass, or a metal tripod detuning the antenna | Compare a bench sweep to a sweep in the actual deployed position | Always do final tuning in the real setup, in the exact spot you'll operate from |
| Hot mic or RF feedback while transmitting | Insufficient common-mode choking | Check turn count and toroid material on the feedpoint choke | Add turns or a second choke in line before the coax reaches the radio |
| SWR spikes intermittently while operating | Dirty or loose telescoping whip section contacts | Wiggle each whip section under load while watching SWR | Clean contacts with contact cleaner and add slight tension to loose sections |
How long should the counterpoise actually be?
Start with the length in the dimensions table for your band (roughly a quarter-wavelength) and treat it as a tuning element along with the whip and coil tap — small length changes shift resonance, so adjust it the same way you'd trim a wire antenna.
Do I need a matching transformer (unun)?
Not always. Many configurations tune close enough to 50 ohms that direct coax feed gives an acceptable SWR. Add a 4:1 or 9:1 unun only if your analyzer shows a resonant SWR stuck above about 2:1.
Can I use more than one counterpoise?
Yes — running 2-4 elevated counterpoises on the same binding post typically improves efficiency over a single wire, at the cost of more setup time and wire to carry.
Is this the same coil as the Buddipole-style dipole guide?
Yes, same form, wire, and tap layout. If you've already wound one for that build, you already know exactly what this one takes.
Is it safe to operate this close to the whip?
Keep reasonable distance from the radiating element while transmitting, especially at higher power or for long transmissions, and check current RF exposure guidance for your specific power and band if you'll regularly be operating near it.
Can I ground-mount this instead of using a counterpoise?
Yes, driving a ground rod and bonding it to the base binding post works in place of a counterpoise wire, though actual ground conductivity at your operating spot will affect performance more than it does with an elevated counterpoise.