[TenTec] Radial Research

Billy Cox aa4nu at ix.netcom.com
Sat May 19 04:52:07 PDT 2012


Good Morning Kris,

Actually I like simple, and so let's
take a look at your situation please.

It's it very easy to qualify what is
going on there with sound proved facts.

One ... most will gently tell you that
a WIDE bandwidth on 80/75 is a strong
clue that your ground losses are HIGH.

And that if you were to add more radials
the bandwidth will decrease while the
antenna is actually working better. 

Again, consider a dummy load and it's
low SWR, and how well does it "work" DX?

Each of us has to decide the plus and
minus of each tradeoff. You are happy
with yours, and that's FB for you.

There could be other factors that also
influence the performance. Like your 
site and local ground conductivity.

Two ... you are comparing a low physical
antenna, which will have a VERY high
angle of radiation and less effective
signal at the lower angles you need for
the longer distance for say DX with your
vertical that MAY have more effective
RF at the lower angle needed for the
path you need to snag that new country.

Especially if that DX country lies off
the end of the low dipole where there
could be a NULL. Guess which antenna is
going to appear to be better? 

The vertical, which even with it's likely
high ground losses, is still putting out
more RF than the NUll of the dipole.

So we can understand why the difference
in performance exists there for the two
different antennas. No mystery really.

Rather let's ponder what is going on, 
understand why, and what you might do 
to improve things? Or not do ...

Odds are if that JT1 shows up for a new 
zone on 80m there, you will be looking 
for every last dB to log him? hihi

BTW, the various ARRL Antenna Anthology
publications are a great shack resource!

KISS is great, when it works for what
each of us determine is needed.

73 de Billy, AA4NU

-----Original Message-----
>From: Kris Merschrod <Kris at merschrod.net>

>Rick's message on practicality is sound.
>
>My 80 meter vertical started out as a "Marconi" That is ground rod in the 
>ground directly under the 7/8"  X 63' Cable TV feeder line found in a 
>recycling yard about 1983 that I dagged up a spruce tree for support (I tied 
>it to the branches) and used a sheetmetal screw to attach the hot wire to 
>the shield.  It was an immediate improvement for DX over the 80 meter dipole 
>at 35'  (See the 1st Antenna Anthology "Wiring up the Old Spruce.")  Since 
>then I added a few (6) radials on the ground and have always fed it directly 
>with RG8.  Band width - pretty close to all of 75 and 80 meters.
>
>For sure (Well theoretically) if I added more radials the efficiency would 
>improve, but in the last 25 years that has not been high on the antenna 
>farming list of chores!
>
>Keep it simple!
>
>Kris KM2KM


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