[TenTec] OT: The problem with Fan Dipoles

[Rick - DJ0IP / NJ0IP]

FB Jim.  Good useful information.

But first, on the light side... which Illinois Governor were your referring
to?
As I recall the last 7 Governors are or were all in prison.  
You must mean the one who looks like Ringo Starr!   ;-)

You pointed out on VERY important point:  "height"

People would be surprised how well a simple dipole will work when it is
really high.
Unfortunately we have a legal limit of 33 ft. here in DL, unless you apply
for a building permit.
Of course many people cheat a bit and go 35 to 40 ft. high and just say it's
33 ft.

I think we need to distinguish between two types of situations here:

1) The guy who wants a great signal and is free to do just about anything he
wants - but can't yet afford a beam.

2) The guy who is highly restricted for whatever reason, and would like to
get on the air on as many bands as possible.  Of course he would like a
great signal, but having more bands is more important.

I have lived in both types of environments. No question which one I prefer! 
Unfortunately the choice to move into environment #2 is not always
voluntary. 

People get around the restrictions by: 
1) cheating (until they get caught) 
2) putting something up and down at night when nobody can see
3) working portable at some other location

For the last two, obviously you want something that goes up and down rapidly
and with ease.
That's the advantage of the single wire dipole over the fan dipole. 

If the wire is cut for 80m, I see not disadvantage over a fan dipole for 80,
advantages over the fan dipole for 40, but above that, the advantage goes to
the fan dipole (unless one of the tiny lobes happens to point towards your
favorite place to operate).

The good news is, we don't have to vote on which one is better.
We can choose which one works best for each situation. 
Important is to understand the advantages and disadvantages of both.

73 - Rick, DJ0IP
(Nr. Frankfurt am Main)

-----Original Message-----
From: TenTec [mailto:tentec-bounces at contesting.com] On Behalf Of Jim Brown
Sent: Tuesday, May 27, 2014 3:28 AM
To: tentec at contesting.com
Subject: Re: [TenTec] OT: The problem with Fan Dipoles

On 5/24/2014 2:33 AM, Rick - DJ0IP / NJ0IP wrote:
> The "Fan Dipole" is one of the worst antennas there is . . .  in the 
> eyes of the neighbors.
> Regardless of its technical characteristics, the neighbors think "it's 
> ugly and destroys the value of the neighborhood property."  That's 
> their biggest disadvantage.

That varies with your neighborhood, your neighbors, and how you build it.
They are certainly less ugly than a big Yagi or quad. And it's also possible
to build fan dipoles with reduced visibility by using smaller wire for the
shorter elements and smaller diameter spacers. Likewise, high impedance open
wire line can be done very well with a pair of enameled wires and small
spacers.

Somewhere on my website are photos of the hillbilly antenna farm on my
Chicago house. I never had a single complaint from anyone about it. Yes,
people did occasionally pause as they walked down the street and stare at
it, and our governor at the time (who is currently in prison for
bribery) used to jog by every week or two accompanied by bodyguards on
bicycles.

When I moved to CA in 2006, I sold that house to the couple who had been my
tenants for ten years or so. I took down the ham antennas, but two yagis,
one for TV and one for FM, were still there when I drove by last year.

My fan dipoles are up 120 ft, so I'm using #9 bare hard drawn copper for the
long element that has the stress on it, and #14 house wire for the shorter
elements. For an antenna that was lower, and thus didn't have to support as
much coax (I feed them with RG11), wire sizes could be reduced to #14 for
the long element, #18 for the shorter one(s). My high fans use 1/2-in PVC
conduit as spacers, but that lower dipole could easily be built with clear
plastic, or lexan dowels, or even wood dowels of much smaller diameter. If
the antenna isn't very high and run is fairly short, you can use smaller
diameter coax to reduce weight and visibility.

An important thing I learned working in theater and with architects is that
stuff that is pretty big looks a lot smaller when it's 50 ft up in the air.

Yes, a single wire dipole to work all bands is "easy," but easy doesn't
always get you through the pileups to work the rare DX, make contesting fun,
or let you be heard by your buddies on 75M. It takes "good" to do that.

73, Jim K9YC






_______________________________________________
TenTec mailing list
TenTec at contesting.com
http://lists.contesting.com/mailman/listinfo/tentec