~
-
~
"
/
""
",
~
~
~
-----
A
co
me
prob
BY
NO
a
ab
GO
TI
JER interesting military antenna has
lo
ng in surplus.
RDON
ly be fl
arc actua lly g
si
nce
he is selling th
abb
ergasted to he
etting
ELIOT
The
m
WHITE
anuf
acturer will
ar
into the excess c
em
briskly to
Uncl
th
"
at
at
these
eg
or
e Sam,
y,
Surlot
Fig
. 2
f
.1.
-Ra
...1-
diation patterns for
...L
th
e MlA·2
/B
.
but at least one has gone the way
govern
me
nt good ies. This is the MLA-21B.
designed by Antenna Research Ass
Beltsville, M
Fig
rather
I is a
odd
the interesting
watt
and
b
conti
3-25
There is not a great deal of ga
ar
yl
an
d.
drawi
ng
of
the
ML
A-2
-looking loop device which has
ca
pa
bility of ha ndling a kilo-
nuously over the hi
gh-fr
equency
mHz.
in
of
oc
iates.
/B
in the
all
. a
N
ow
reader
any
cou
ti
ld be a starting point for
me
let me
wi
ll
soo
say
find a
that I d
1\1
LA-2 in a surplus s
oubt
the average
to
n, but the des ign of the antenna
some
very us
re
e-
ful amateur projects. From a commercial
standpoint,
(no
. 3,
588,905)
A
.R
.I.
of
but a
course
mateurs
has
a
pa
tent
might usc it
as a basis for their own experiments.
The the
transformer from a
or
y of the
l\ILA-2
50
oh m transmission line
is an im
peda
nce
MLA-2, except above 17
enn
t
co
tion, with a 4 mHz cover
perfectl y
patt
and it o
a has a beautiful elevati
vers b
ern
oth
uniform
is the typic al
tTe
high- angle
and
. (fig. 2) The
fi
gure
rs excellent directivity, with an in-
herent noise-figure impr
dipole. T he p
20
db.
attern
null is
mH
low-
age
eight
ove
ra
z,
on
that is alm
but
pattern that
ang
the an-
le radia-
os
horizont
of
a loop ,
ment ove r a
ted as sh
arp
al
as
t
to the nominal
of free s
pa
ce.
a feed loop placed within
T he signal is indu ctively
ar
m
y, which is the radiating
377
The
ohm radiati
input to
the
the
coupled
body.There
on
ant
pr
resistance
im
to
enn
ar
a is to
y loop.
the
pri-
is
no
direct connection between the primary
(o
ute
Tuning
plished by vary ing a moto
con
r)
loop, and
of
the
th
e feed loop .
prim
trolled vacuum varia
ar
y lo
r-dr
bl
e capac itor inserted
op
is
iven, re
acco
mo
m-
tely-
The
MLA·2'
s longest suit is its size, offer-
ing the performance of a half-wave antenna
with a devi
° 1502 Ston
ce
no longer than
ewall
54
inche s.
Rd.. Alexandria , Va.
22
302
,"
54 i
---
--
---1
"
•
"
in the t
from IOta 1,500 pic
Th
e lo
one-half inch
asse
mb
op
op
of the lo
itself is
dia
me
ly is a ru gg
op
of
co
ter tubing, and the
ed
device, c
ing up in 100 mile an h
The
feed lo
op
is m
.
The
ar
ad
ns
tru
our
atched
value is
s.
cted
ap
able
wind s.
to
of
thr
of
the
va
ried
ee and
whole
stand-
tran
s-
E"'''e
R
o'all
Anemb
s
10 -1
Vo
.~
&lO
c"um Vo.ioble
pf
' 0 '
I
Feed L
Co
Cond
OOJl
o-Cen
..etee
" .
84
Fig. l
• CO •
-Th
e MlA·2
January
/Bloop
,
1973
antenna.
Fig. 3
-Matching
system for the MlA·2 /
B.
Save
over
$9,000.00
on
this
AN/WRR
Orig
$10,000.001 One
radio receiving
Radio Co. in last decade. A
version
range
bands. Featuring
un
•
it
ile,
inal
super
: 2
rece
to
ives
32 MC. in 1 kc increments. 4
teletype and ISB. REQUI
-2
SSB
government
of
sets.
Navy's most modern
Bu
-heterodyne. Frequency
AM,
full
CW
carrier suppression ,
,
MCW
Receiver
cost.
ilt
by
National
tr
iple con-
, voice, tacsirn-
RES
over
NO
2mH
M
ODIFICATION
earlier R390
Complete, operational. Sp
able. Spare parts
Columbia
P.O.
z
Box
9266
8mHl
·g
. 73
! Greatly s
AlUR
as
60
Aloll
17mHl
up
R model. Good
ec
she
erior to
condo
e-
ava
il- •
$4
needed. Overbeuted and cer
Electronic
Ave., North Holl
25mH
ywood
z
CA
three and five fect
quires
91609
no
gro
Sales.
T
.I
12 1
und system.
31
nu
ed
875
above
·2970
5
...
$595
the su
V.s.w
&
.00
Inc.
764
·9030
rface,
.r. with a 50
and re-
1---=::;::::;:~
---J.
L - - -
f ig. 4
-R
ough v.s.w.r. figu
-+-
=-
- -
--I-
.2:::
range.
::=
res
=f"'
::=...
over the 2
-----=711.
- - -
·25
VS
l--
mHz
WA I
e
1.0
ohm line is 2: I
r
ou
gh V.S.W.r. figures over the
range, and Fig.
on
li
way.
but I have
and its p
wide
Th
I
have
of
is
t
ru
he
cos,
nge
design.
the U.S. a
not transmitted with the
seen
erf
orm
of
or
5 is
b
ett
the
it
in
ance was e
frequencies. directi
er
. Fig. 4 in
sche
bo
ac
tion with a receiver.
ma
ut
tic r
$3,0
xc
ellent ov
dica
2·25
cpr
00.
~
1I.A
tes the
escnt a-
by the
on
s and
mHz
-2
/B
er
.
a
mission li
si
de
diameter
I:
6. In
pears
cra
in
of the
the
to
ft
loop direction finder about eight inches
diameter.
loop was
of
The
twent
pri
y-
ne
of
be
of
mary loop has an average radius
tw
by bringing the
loop.
the
actual
more
The
feed
as per the ratio
loop to
1\1
LA-2
or
old
less a
~l
the
-26 World War II
coax
the
feed loop ap-
standard
the same general size.
o inches. but
it
is flattened. and
into
of
primary
one
air-
the
is
wave a
Math
s
ho
uld
for
cuits
and both arc from Texas Instruments.
two
Both arc fairly
specific details.
There
ng
's
we
chips
Nates
of
les. •
(fro m page 46)
course
would
arc
arc
two
ob
the S
tain applica ble
like
new
complex
to
me
7400
74143
da
ntio n this
series
and S 74 144.
integrated circuits
ta
mont
TIL
sheets
h
cir-
The
the resulting
(ce
10
nter
cen
The M LA
ter
of
of
rubing )
tubing).
L •
f.ed
shape
·2
needs
L.
Pr
and
Imo',
is
to
51
36
be
•
'HI
inches high
operated
inches
11
c
I 1
0'15
across
(center
between
00pf
containing
abilities. B
or
plas tic
decade
Small
of
S3
my readers a
Iarnp driver. \V
DIP
counte
qua
$5
.00
At this poin t
and
each.
a
decad
CD
packag
ntity price
for
quan
wr
e
counter
to
7
seg
r stage less only the rcadour.
tities
ite to 1'1
I would
very
it
es
me
h
you
fo
nt
decoder
one
have the
r these is in the area
of
fo
r
li
ke to wish all of
happy. healthy and
.
storage
and L
of
100. 'hey d r
additiona
these 24 pin
co
mple
l
cap-
ED
op
da
te
to
ta.
Fig.5-S
86
Loop Loop
chematic represen t
• CO •
January
at
ion of the MlA.2
, 19
73
/B
prospe
very best of
.
rous New Year. and of
DX
.
73. lrv.
cou
WA2
rse. the
NDM
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