Multi Band HF / VHF / UHF base antennas
The Comet CHA-250B is a newly designed broadband vertical requiring NO GROUND RADIALS.
This antenna 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
Impedance: 50 Ohm
Weight: 7 lbs 1 oz
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-250B will make the most of these circumstances!
This is a the “magic” behind the CHA-250B, 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.
40/20M 150W SSB
15/10/6M 220W SSB
Horizontal length: 13 ft approx
Weight: 5 lbs 14 oz approx
Impedance: 50 Ohm
Mounting mast req’d: 1″-2.5″
Typical 1.5:1 or less SWR bandwidth:
Horizontal: 33 ft 10 inches
80/40/20/15/10/6/2M/70cm compact 8-band vertical base station antenna
8 bands and only about 8 feet tall
Each HF band + 6M has it’s own tuning stub. Adjust the SWR to the desired band segment, then use an antenna tuner to TX outside of the 2:1 or less band-width. 2M and 70cm bands are pre-set at the factory and there are no adjustments.
The ground radial system is unique…the radials are screwed into 2 collars. The collars can be rotated and fixed so all the radials are located to one side of the antenna….allowing it to be side-mounted on a tower, or next to a building wall for stealth operation.
Gain & Wave:
80-6M: 1/4 wave
146MHz: 1/2 wave 2.15dBi
446MHz: 5/8 wave x 2 5.5dBi
VSWR: 1.5:1 or less at resonant frequency
Max Power: HF: 200W SSB 6M -70cm 150W FM
Length: 8′ 6″ (approx)
Diameter: 8′ (max. approx)
Weight: 5 lbs 7 ozs
The HVU-8 was designed for those suffereing from antenna restrictions in mind.
Anticipating it may need to be installed hidden from view along the side of a building or home, rather than in the preferable location in free space, the ground radial system uses two rotating rings. The radials are screwed into the rings, and the rings can then be rotated so they all are on one side of the antenna rather than the preferred 360 degree spacing.
The SWR maybe negatively influenced by the spacing, but if you are in need of a multi-band HF antenna, that includes 6M 2M and 440MHz, and have little space or cooperation, you will need to make some compromises.