Terry,
I think you have errors in your text. You keep saying 6990 and 6950. Don't
you mean a frequency near 10.1 MHz?
If you want to get the frequency to rise, just remove the capacity hats and
than lengthen or shorten the end tips for resonance. According to my
modeling of same, the antenna with the original 40-2CD loading coils
(approx. 11.5 microhenries), capacity hats removed and end tips set for a
total overall length of about 35 feet 4 inches should resonate close to
10.1 MHz. Remember that this is a shortened beam so the impedance may be
lower than 50 Ohms but should be well below 2:1 VSWR. Let me know if this
works. It should be pretty easy to do.
73,
Joe, W1JR
At 01:07 AM 9/23/99 -0400, N6CW@aol.com wrote:
>
>This is a followup on my previous email concerning using the CC D40 on 30
>meters. After trying a bunch of different element lengths I ended up just
>pulling the end elements out of the loading coils ( keeping the capacity
>hats)on the element). Checked it with MFJ -259 and it came in at 6.990 Mhz. I
>figured that was close enough for it being only 6 feet off the ground. I next
>installed it on the tower about 3 feet below my CC X7 and parallel to the
>boom. Cranked it up to about 35 feet and started working DX. 5 new countries
>tonight. The antenna shows a good pattern, about what you would expect from a
>dipole and the icom 706 loads into it without the tuner, although it is
>resonant at 6950 or so and starts dropping power at about 10125. Thats good
>enough for me. There is no way to shorten the element after the coils so that
>is what I am stuck with.
>
>On top of that I have no more RFI in the shack that my previous inverted V
>was famous for. And I should be able to drop the tower down, stick in the end
>elements and be ready to go on 40 meters for those pesky contests.
>
>So after one day of use I think it was an easy and sucessful modification. As
>someone said "keep it simple". I am looking forward to getting my strength
>back after cranking the tower up to 35 feet to get the antenna at 60 feet.
>Guess the next project is a electric motor to crank it up.
>
>Terry/N6CW
>
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