[Antennaware] Installing a Hy-Gain AV-18HT vertical - several questions, especially about radials

Shon Edwards sre.1966 at gmail.com
Thu Mar 4 11:19:46 PST 2010

Hello all, I'm getting a Hy-Gain AV-18HT and have several questions about
it, especially about a radial system.  I am very new to HF and so am quite
clueless, but would be grateful for any help possible.

How deep do the radials need to be underground?  Is 2 or 3" OK?

I wonder if it's necessary (as some say) to put down radials only at a
percentage of the wavelength of the lowest frequency you plan on working on,
or (as others say), do you need to put down radials at a percentage of the
wavelength of all frequencies you plan working on?  How many radials should
be put down for each band, if it is necessary to go this route?

Also, how long should these be? I have lately read Rudy Severn's article in
QST this last month, which was excellent, but it doesn't always answer all
my questions.  Also, his 7 articles on the Internet he refers to don't
readily answer all these questions, although very good articles, all of
them.  Is it .4 wavelength if I plan on doing 60 radials or .25?  .2?

I'm also wondering if I have a space problem, if I must absolutely, put out
my radials in a straight line, or if I can bend them, and go around things
in my yard at angles of around 70 degrees, if need be.  Will that have a
negative effect on my radiation pattern?  I have about a 90 degree section
of my antenna radial field, where I will need to be bending lots of radials
up to 70 degrees.  Unfortunately, this is the exact direction that I want to
focus on most for most of my communications, toward the east and northeast,

What is the best type of coax to use if I want to minimize losses the most
at 1-30 MHz?  It doesn't matter if it is expensive.  I'd just like to get as
many dB of gain as possible.

Also wondering how best to ground the antenna.  This might be for a person
who is familiar with this particular antenna.  Apparently, an SO-239 is
provided and connected to the antenna already.  I understand that the braid
of the coax needs to be soldered to the ground rods and that they should all
be connected together, but if I am connecting a PL-259 to an SO-239 on the
antenna, how would I do this?  Solder some part of the SO-239 to the ground?

Also, if I want to add 30 M and 60 M capability to this antenna, which is
53' high (so it should be possible, I would think), how do I do it?  I
probably wil not be too good here with the technical terminology, but I'll
do my best.

Does the size/type of the wire of the radials matter?  I've heard that it
does not, but I imagine that stranded wire, though more pliable and easy to
deal with, would deteriorate faster than solid wire.  Also, am thinking of
using #14 wire.  It seems to be the best I can get for the price at Home
Depot.  I've heard of people using chicken wire, but I want something more
permanent than this.  Also, I'm thinking if I use plastic-clad wire it will
last longer than bare wire.  That is, it would not rust or fall apart over
the years as fast as wire that is bare.

Also, any other things that I might need?  Like a balun or anything else
that I'm not thinking of.

Thank you and sorry I have so many questions.  As I say, I'm just getting
into this.  Thanks, Shon Edwards, sre.1966 at gmail.com.

Shon R. Edwards,
Amateur Call:  KO3U
Commercial radio licenses:
GROL:  PG00016801
GMDSS/O/M:  DB00000391
2nd class radiotelephone:  T2GB064388
Accredited VE:  W5YI, ARRL
ARRL Instructor
1039 N 2575 W
Layton, UT, 84041-7709
e-mail:  sre.1966 at gmail.com
phone:  (801) 444-3445
cell:  (801) 336-7635

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