[Mldxcc] Fan Dipole (was Re: Question about 40M inverted V dipoles)

[Emily Clarke]

OK - so this is interesting and really good stuff.

Oddly I looked at this when I built it and asked myself if there was a 
way to fan it with other elements.  I wasn't sure if I had to do 
anything wonky with coax like you do when you phase VHF/UHF antennas.  
 From what I can see this is not only worth doing but is rather easy to 
do.  So I think I should be able to add 20, 18 and 10.  I'll definitely 
have to play with a basic design and see.  I should be able to make 
light standoffs using popcycle sticks.

Thanks for the idea!

Emi



On 8/14/2014 11:20 AM, Alan Maenchen wrote:
> Emily,
>
> It sounds perfect!
> I have a similar antenna here: 40 meter inv Vee with apex at 45ft.
>
> The antenna works fine at 7 and 21 MHz. that's the fundamental, and 
> all odd harmonics.
> Even harmonics should give you a very high SWR (20 and 10 meters).
>
> Yes, your tuner will make the radio think the antenna works well on 
> 20, and you can make QSOs that way. However, your signal will be about 
> 10dB lower than if you had a 20 meter inv Vee at the same height. The 
> proof of that is my performance in the IARU contest last month. While 
> 40 and 15 worked well, I had far fewer contacts on 20 even though 
> everyone else thought 20 was the "money band".
>
> In fact, today's project is to add a 20 meter set of wires to the 40 
> and make it a "fan dipole".
>
> Aloha, Alan  AD6E  /  KH6RR
>
>
>
>
>
>
> On Thu, Aug 14, 2014 at 8:02 AM, Emily Clarke <n1did at comcast.net 
> <mailto:n1did at comcast.net>> wrote:
>
>     So at W1RH Bob's suggestion I decided to get my butt in gear and
>     built a 40M dipole.  It's an inverted V so it fits on my lot with
>     a center mast currently 27 feet up at the center - 10 feet up at
>     the ends.  It has a 1:1 balun that I had for a while from LG.
>
>     I tuned it to 7.1 MHz the logic being:
>
>     7.1 = 14.2 (x2) = 21.3(x3) = 28.4(x4)
>
>     So I used my antenna analyzer and trimmed it up to 1.1 to 1 at 7.1
>     and it dips to 1.2 at 21.6 (odd).  The antenna analyzer doesn't
>     show any dip at 14.xxx or 28.xxx.  This I don't understand.
>
>     However I get a perfect 1:1 match on the rig with it's tuner all
>     across all of those bands which I guess is somewhat expected.  It
>     also tunes flat at 17m and 12m.
>
>     Does this sound right/safe?
>
>     Emily
>
>
>
>
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