[GCARC] Comet CHA-250HD antenna comments

[kbfrank3 at verizon.net]

I agree with Tony K3TS.  The Fair Lawn ARC has one of these antennas on its roof (it is the only way we can do 80 meters) and it is not much better than a dummy load.
Its only virtue is that it does not use radials (but this also keeps it from working well).  
Instead, use an end-fed wire antenna, dipole (with or without traps) or a vertical with radials.
Karl W2KBF

-----Original Message-----
From: gcarc-bounces at mailman.qth.net <gcarc-bounces at mailman.qth.net> On Behalf Of Tony Starr
Sent: Wednesday, November 15, 2023 11:22 AM
To: Jeff One <djgrath1 at gmail.com>
Cc: gcarc at mailman.qth.net
Subject: Re: [GCARC] Comet CHA-250HD antenna comments

Jeff,

All that Charlie,  or anyone else considering this antenna, needs to know about it, is contained in this very honest paragraph on the DX Engineering website"

*This improved Comet CHA-250HD features a new solid whip replacing the top aluminum section for greater flexibility and less strain on the lower sections in high winds. The “magic” behind the CHA-250HD is the transformer matching section. The transformer on the original CHA-250B had smooth sides. This improved design features a heat sink to dissipate the heat created inside the transformer from the RF that enters the power feeding section rather than transmitted as RF. This is the compromise needed to create a broad-band, low SWR, multi-band HF antenna withinimal visual
impact.*

Basically, it comes down to this:  Antenna "matching transformers" should not feature heatsinks or cooling fins.  If they do, it is a dead giveaway that they are HIGHLY in-efficient.  Unless you have lots of power ( and money ) to waste, there are many other vertical antenna choices that you can make which will put more RF in the air, and keep more money in your pocket. My favorite choice, which I own, would be the Hustler 5BTV, but there are many others, all of which will perform better than the Comet
CHA-250 series.

Tony K3TS


On Wed, Nov 15, 2023 at 8:56 AM Jeff One <djgrath1 at gmail.com> wrote:

> All,
>
> Charlie Wahl, KC2STO is asking for some comments on purchasing a Comet 
> CHA-250HD HF antenna. Please respond directly to him at 856-656-6122.
>
> Thanks
>
> D. Jeffrey Garth
>