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Multi Band HF / VHF / UHF base antennas

CHA-250HD (New version of the CHA-250B)

The Comet CHA-250HD is the revised CHA-250B.
The top section of aluminum has been replaced with a solid whip for greater flexibility and less strain on the lower sections in high winds.  A uniquely designed broadband vertical requiring NO GROUND RADIALS.

This is EXTREMELY easy to assemble, requires no tuning or adjustments and VSWR is under 1.6:1 continuously from 3.5MHz – 57MHz!

It is not a 1/4 wave vertical, but an end-fed long wire type antenna with a matching transformer in a vertical position.



TX 3.5 – 57MHz

RX 2.0 – 90MHz

VSWR: 1.6:1 or less

Max Power: 250W SSB 75W Digital modes/FT8, etc…

Impedance: 50 Ohm

Length: 23’5″

Weight: 7 lbs 1 oz

Connector: SO-239

Mast Size Required: 1″-2″ diameter

Max Wind Speed: 67MPH


If you have the space, budget and desire to erect a full size antenna system we suggest you do so… bigger is better…however…if you live in an antenna restricted area and must manage with antenna or space restrictions or you simply wish to operate incognito you will be forced to make significant antenna compromises. The CHA-250HD will make the most of these circumstances!

CHA-250HD Transformer Section

This is a the “magic” behind the CHA-250HD, the transformer matching section.

The transformer on the original CHA-250 had smooth sides.  The current version has a heat sink to dissipate heat created inside the transformer.

Yes, some of the RF that enters the power feeding section is turned into heat rather than transmitted as RF, but that is one of the compromises needed to create a broad-band, low SWR, multi-band HF antenna with minimal visual mpact.


5-Band, 1/2 wave rotatable dipole for 40/20/15/10/6 meters

This is the compact dipole used for HF communications on the set of the ABC Television show “Last Man Standing” with Tim Allen. The crowded space above the set required a compact multi-band dipole, and the CHV-5X was selected to solve the problem the minimal space presented.

Compact, lightweight, and easily assembled in either a horizontal, “V” shape or ground-plane configuration. Each band tunes independently of the others.

Comet engineers have specifically designed this antenna for those that desire a milti-band dipole that can be rotated if needed, but do not have a lot of room to install it.

If you have antenna restrictions, neighbors that tend to complain about antennas, simply want to operate without drawing attention…or you want a lightweight multi-band antenna to use in portable or emergency situations, the CHV-5X is a great choice.

Max power:
40/20M 150W SSB
15/10/6M 220W SSB

Horizontal length: 13 ft approx

Weight: 5 lbs 14 oz approx

Impedance: 50 Ohm

Connector: SO-239

Mounting mast req’d: 1″-2.5″

Typical 1.5:1 or less SWR bandwidth:
40M: 22kHz
20M: 36kHz
15M: 54kHz
10M: 140kHz
6M: 1.8MHz


As installed and used above the set of “Last Man Standing” starring Tim Allen