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1997-02-01
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73 lines
INSTRUCTIONS AND SHAREWARE INFORMATION FOR THE ARMA PROGRAMS
(Automatic Resonating Mobile Antenna)
This type of an antenna was designed to provide maximum radiation
efficiency from a moving vehicle, under adverse conditions, from
one end of a band of frequencies to the other.
The menu driven programs on this disk are useful in designing an
ARMA antenna for any band of frequencies.
The first program calculates the loading coil inductance for a
quarter wave vertical antenna over a flat ground plane. It varies
somewhat when the antenna is placed on a vehicle, but is a good
ball park value. The large Hi Q coils act as a capacity hat and
this reduces the calculated inductance significantly. For
example, when using a small value for D in the program, as 1 inch,
D being the thickness factor of the antenna, a 9.5 inch coil
on the 160 mtr. band may reduce the required inductance by 20 %,
and a 5.85 inch coil for the 40 mtr. band might reduce it
by 10 %. Another way is to change the value of D for different
coil sizes. Example: Use 2.4 inches for D using a 9.5 inch coil
on 160 mtrs., 2 inches for D using a 7.9 inch coil on 75 mtrs.
and 1.5 inches for D using a 5.85 inch coil on 40 mtrs.
The second program is self explanatory. It is used to design a
ultra high Q loading coil. It will also calculate the inductance
of a single layer rf coil when the diameter, length and number of
turns are known. Instructions on how to wind a high Q loading
coil,is explained in the Builders Guide Supplement,"THE BIRD
CATHER".
The third is a set of programs for close wound coils. One for
designing a coil and the other for determining the inductance of a
close wound coil.
The fourth group of programs is useful to determine the exact
velocity factor of the coax that you use for the delay line.
The last program is for calculating the impedance L matching
network and the proper length of coax between the antenna and the
phase angle detector to allow the system to have a symmetrical
frequency response. The inductive reactance of the L network can
be combined in the loading coil, so all that is necessary is a
capacitor to ground to match an impedance that is less than 52
ohms, as it is in all quarter wave vertical antennas. Revision A
of the ARMA Builders Guide illustrates an efficient method of
plug-in modular matching capacitors.
To register this shareware and receive complete documentation, the
BUILDERS GUIDE for the Automatic Resonating Mobile Antenna,
including REVISION A and "THE BIRD CATCHER" supplement, send
$20.00 to Wayne L. Jamison Rt.3 Box 2932 Trinity, Texas 75862
Print out Registration Form under REGISTER.TXT file.
This documentation has all of the necessary drawings and
schematics to build an all band (10-160 Mtr.) mobile antenna and a
High Q single band high efficiency mobile antenna with easy to
change coils.
This antenna is protected by U.S. patent # 4,803,493, however you
have my permission to build this antenna for your own use but not
to be used for a profit.