Comet GP-3
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| Frequency | 144-148 / 440-450 MHz |
| Gain | 4.5 (2m) / 7.2 (70cm) dBi (manufacturer figures; 5/8-wave on 2 m, 3x 5/8-wave in phase on 70 cm) |
| TX power | 200 W (200 W SSB / 100 W FM) |
| Modes | FM, SSB, CW, digital |
| Connector | SO-239 |
| feedpoint | SO-239 at the base |
Estimated (unverified): introduction year (1990s-2000s, long-running model)
The sensible middle of every dual-band base lineup, which is why the manufacturer calls it their best seller: six feet of sealed fiberglass that adds a real decibel and a half over the compact class without the height, wind load, or price of the flagship sticks. No radials, nothing to tune, 200 watts SSB of headroom, and a decades-long owner track record of surviving weather.
It is the middle child: the compact GP-1 is cheaper and stealthier, and the taller GP-6/GP-9 class adds another decibel or two for those with the mast to carry it. Ham-bands only, FM rating is half the SSB figure, and the phased elements inside the radome are not user-serviceable.
The default answer to 'which dual-band base antenna?' - enough gain to feel, not enough length to fight. Buy smaller only for stealth, bigger only with a serious mast.
Ask a room of hams for a dual-band base antenna recommendation and the GP-3 is the name that keeps surfacing, Comet's own catalog copy calls it their best-selling dual-band base antenna, and the recipe explains why. Under five feet eleven of sealed fiberglass sits a 5/8-wave two-meter radiator over three 5/8-wave seventy-centimeter sections phased together: 4.5 and 7.2 dBi, real and audible gain over the compact class, without the height and wind load of the flagship sticks. No radials; clamp it to anything from 1.25 to 2.5 inches and connect the coax to the SO-239.
The numbers sit deliberately in the middle. Below it, the GP-1 gives up a decibel and a half to save twenty inches and a few dollars, the balcony antenna. Above it, taller collinears buy more gain at the price of a serious mast, more visible profile, and a flatter pattern that can work against you in hilly country. The GP-3's direct class rival is the Diamond X50A (virtually identical gain, length, and price) while the Diamond X200A sits a full size class up (6.0/8.0 dBi at over eight feet), rivaling Comet's own taller sticks instead. Within its class the promises are interchangeable: 200 watts SSB, SWR under 1.5:1 across the ham segments, fiberglass that ignores weather.
The 'base/repeater' label in Comet's copy is earned: the small profile and phased-collinear pattern are exactly what low-budget repeater sites want, and plenty of GP-3s spend their lives on club towers doing that job. For home stations it is the default for a reason, the antenna you buy when you want to think about radios instead of antennas.