Antenna Simulator: Cut Lengths, Take-Off Angle and Radiation Patterns

G7RDX · antenna simulator 21.26 mλ
Cut lengths · take-off angle · patterns over real ground

Antenna Simulator

Cut it, hang it, and see what it actually does: the vertical lobe that sets your take-off angle, the horizontal lobe that says where it is pointing, and the dB you have towards the DX you care about. Height, ground quality, feedline and harmonic operation are all in the maths.

1 · Band and site

Everything below recomputes as you change these.

2 · Antenna

Sixteen models, all solved the same way.

3 · How you have put it up

 
Cut to 14.100 MHz

4 · The two lobes

Vertical lobe elevation cut through the main direction

Elevation pattern
this antennatake-off / target angle

Horizontal lobe azimuth cut at the take-off angle

Azimuth pattern
this antennaDX bearings

5 · The DX you are aiming at

Great-circle bearing, hop count and the angle the path needs — then what your antenna gives at exactly that angle and bearing.

6 · Height is the biggest lever

Radiated power against height and elevation angle, for this antenna on this ground.

Height map white line: take-off angle · orange: your target angle

0.05λ1.50λ
−25 dB → peakvertical axis 0–90°

Side view at this height

7 · Feeding it

Bandwidth, what the coax eats, and how much of your power actually leaves the wire.

SWR across the band

Feedline and losses what reaches the antenna

8 · Cut list

Start 2% long and trim to resonance.

9 · Every band at a glance

Same antenna, same height in wavelengths, every band.

10 · Questions people actually ask

Short answers, from the same maths this page runs on.

11 · Take it with you

Link, embed and API.

Share this exact antenna

The link carries every setting, so the page opens on what you are looking at now.

Embed it in a forum post

A drop-in iframe of this simulator, locked to your antenna, for club pages and forum signatures.

Roadmap
Call the API

The same solver behind a JSON endpoint, so your logger or shack dashboard can ask for a take-off angle.

Roadmap

Antenna Simulator Plus

PremiumGBP 10 / year

The free simulator answers “how long, how high, which way”. Plus answers “will this path work tonight”, using live propagation instead of a textbook hop model.

Model: sinusoidal current distribution, Fresnel ground reflection, induced-EMF impedances No feedline radiation, no nearby objects, flat ground G7RDX · built for people who put wire in the air