On 6/23/2010 6:01 AM, Jim Thomson wrote:
> Date: Tue, 22 Jun 2010 12:54:46 -0700
> From: "Dino Darling"<dino@kx6d.com>
> Subject: Re: [TowerTalk] Have we been wasting our money?
>
>
> Roger, stop stirring the pot! That CB antenna works perfect for what it
> was designed for. The design was stolen from a guy named Kale who
> builds the "Penetrator 10K" antenna. I know you are not so naive to
> think that there isn't a huge outlaw CB market.
>
> ## anybody notice that the center loading coils in a cushcraft 402CD
> [and probably the new version XM-240] have puny coils , wound with really
> small
> ga magnet wire ?? Those coils have aprx 8.5 ohms RF resistance each !
> The Un loaded Q of those coils is a joke.
>
> ## feed point Z = rad resistance + series losses. 32 + 8.5 + 8.5 = 49
> ohms.
> Sure, you end up with a low swr.. and that's about it. The ant is very
> effective
> however. They shoulda used way bigger coils.. and also big capacity hats
> [f-12 calls em
> T-bars] .. then you end up with a more eff ant. IMO, capacity hats are the
> closest thing to
> a free lunch you can get. F-12 opted for center loading on their sigma
> series loaded yagi's
> on 80 + 40m.... and used 3/8" OD AL tubing...[ and big T bars] Big
> diff between puny small ga
> magnet wire [close wound to make the UN loaded Q even worse].. and 3/8"
> tubing coils.
>
Which brings up the question: which is better, the old WARC-7 with
linear loading, or the new ones using what they call the Sigma series 30
for the two 30 meter elements. It drops the required spacing from 16'
to a minimun of 4'. And that begs the question, can the old WARC-7 be
converted to the New WARC-7?
73
Roger (K8RI)
> ## and folks are bashing 11m ops for using 3/4" wide bar stock for a coil..
> and corrona balls ?
>
> later... Jim VE7RF
>
>
>
>
> Dino - KX6D
> _______________________________________________
>
>
>
> _______________________________________________
> TowerTalk mailing list
> TowerTalk@contesting.com
> http://lists.contesting.com/mailman/listinfo/towertalk
>
>
_______________________________________________
_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk
|