[TenTec] Correction on the Grahn Antenna

[Rick - DJ0IP / NJ0IP]

James,

Mine was the older model, the GS3-SE, not the 5.

Today I had some sensational success.
An antenna project I have been working on for a while actually worked.

A German ham (he's on the Ten-Tec reflector or the Eagle reflector), DJ5IL,
has pattended a "Shortened End-Fed Dipole".
It turns out to be only about 65% of a half wavelength, so 20m is about 6.2m
long and 40m is about12.4m long.

By spiraling the radiator down the pole, I will be able to get the 40m
version completely onto one of our 12m fiberglass poles.

This is significant, because:
*	It needs NO RADIALS
*	Being a half wavelength long (electrically), it is completely ground
independent.  You won't have ground losses due to not enough radials.  
*	I can use it to replace my Vertical Dipole I was previously using
with this pole; this means I don't have to run a feed line off the middle,
so I don't have to counter guy it.  For portable, temporary use, I won't
need any guy ropes.  This makes it ideal for campgrounds where you can't
string a lot of wires.

I find the benefits for 40m really good.
For 20m you can already buy halfwave End-Fedz from Par-Electronics which fit
on one of our poles.
Of course this design enables you to use a much shorter, low profile stick
for the 20m version.
That means it will be great for HOA handicapped hams.
The downside is, it is and will always be a single band antenna.

It took me a few tries to get the transformer right.
I'm still not completely satisfied but it is good enough.
SWR is less than 1.5:1 across the entire 20m band.

It has been a productive day!

Of course we will not be able to sell these; Karl owns the patent, but hams
may build them their selves per personal use.

The next project is a (relatively) high efficiency 80m antenna built on our
12m pole, but it will need guy ropes.
Still, it will give people with a postage stamp sized yard the ability to
get on 80m with a decent signal.
This one was patented by a G station in the UK.  Looks promising.

The 40m version of this is really compact.
It will only need to be about 5m or 6m high and will have a wingspan of 3m.
Plenty of fun things to do!

73
Rick