POTA Antenna — VDA Flagpole & 11.5ft Whip | Greyline

Parks on the Air — Field Operations — SOTA

The Park Doesn’t Owe You a Tree.

Most portable antennas need something: a tree, a mast, a radial field, dry ground. The Greyline VDA needs none of it. Balanced dipole physics means the lower element is already in the air — your counterpoise goes up with you, not into the ground. Concrete, granite, beach sand, or snow: the feedpoint doesn’t know the difference.

And if your favorite parks enjoy your go-bag, the 11.5’ DX Whip with a short Greyline VDA pole and a 4:1 balun (optional) handles the job in 2-10 pounds or less.

Why It Works in the Field

Three Reasons Operators Switch

Setup

3 Minutes, On the Air

Sections slip together, pick your base type, feedline connects at the bottom. No wires to string, no radials to lay, no tree required. The setup time is real — not marketing.

Physics

Balanced Circuit in the Air

The VDA’s elevated feedpoint at roughly 20% of radiator height decouples the antenna from near-field ground loss. You’re not fighting lossy soil — the counterpoise is already off the ground.

Noise

Smallest Possible Footprint

2” OD ground contact. Move the base to the quietest spot in the park — away from parking lot wiring, picnic shelters, or whatever the RF environment offers. Place it in the quiet zone.

Radiation pattern comparison: Greyline VDA 20-28ft vs R9 and AV680 legacy verticals — gain and takeoff angle

Modeled radiation patterns: Greyline 20’ and 28’ VDA vs. R9 and AV680. Lower takeoff angle = more signal toward the horizon.

The Ultralight Option

The 11.5’ DX Whip — Solo or Pole-Mounted

A lot of POTA operators already carry a short fiberglass or carbon pole and a 4:1 current balun for their EFHW wire. That same kit runs the 11.5’ DX Whip — and the whip works vertical 'up, up and away' which is where you want to be for DX.

Mount it on a 12’ Greyline VDA 'pole' and you have a complete portable HF antenna covering 10 through 40 meters. Add a small auto-tuner and the range extends. The whole package fits in a 3-4' tube. No wire cutting, no height math, no tree required.

Pair with a 4:1 current balun for best results. Most EFHW operators already own one — this is the same connection on your existing hardware.

Solo (Spike Mount)

Drive the spike into soft ground. Full 11.5’ vertical. Immediate 10–20M coverage, ATU extends lower.

Pole-Mounted

Slip onto any 7–10’ fiberglass or 8' Greyline VDA base, ground mount - mast. Elevated feedpoint. Works on hard surfaces where spiking isn’t possible.

“Set up my 16’ flagpole at a park on a concrete pad. No radials. Worked Australia and Japan from the East Coast on 20W. This is a game changer for rapid deployment.”

— Mark K., POTA Activator

Head to Head

How the VDA Stacks Up

Most portable operators choose between a wire antenna (EFHW with a 9:1 or 4:1 balun) and a vertical. Both are valid. Here’s the honest comparison:

The Challenge Greyline VDA EFHW Wire + Balun Mag-Loop
Tree or Mast Required? No — self-supporting Needs pole or tree at height Self-supporting
Ground / Radials? None required Counterpoise wire helpful None required
Full-Size Efficiency Yes — full aperture Yes (when elevated) No — narrow bandwidth, high loss
Band Changes ATU or adjustable whip Link removal or tuner Full retune every band
Hard Surface Deploy? Yes — base tripod or pole mount Needs anchor for mast Yes
Noise Footprint 2” — place anywhere Wire spans are fixed Small — but picks up local noise

Honest note on the EFHW: A wire with a good 4:1 or 9:1 balun and a 20’ mast is a capable antenna. Many great operators use one. The VDA wins on deployment independence — specifically when there’s no tree, no soft ground, or when you’re on concrete or rock. If those constraints exist in your parks, the VDA is the answer.

Which Model for the Field?

Match the Antenna to the Activation

Model Wind Rating Best POTA Fit
11.5’ DX Whip N/A (pole-mounted) Go-bag activations, hard surfaces, bicycle portable, SOTA. Pairs with any mast and a 4:1 balun.
12’ DXV 155 MPH flag-down High-wind parks, coastal, vehicle-portable, exposed ridgelines. Most compact self-supporting option.
16’ DXV 115 MPH flag-down Standard parks, picnic area setups, day trips. Strong on 20M and above, solid 40M.
20’ DXV 90 MPH flag-down Base camp activations, truck or trailer transport, operators who want full low-band aperture in the field.
24’ DXV 70 MPH flag-down Established park stations, drive-up sites, extended operations where max aperture is worth the carry.

Ready for Your Next Activation?

Choose your model below, or call the shop if you want to talk through the right configuration for your operating style. Every antenna ships with full setup documentation and personal support from the team that builds them.

435-200-4902 — Sun Valley, Idaho

Ham Radio is fun again. Pass it on… 73, The Greyline Performance Team