DYNACO FM-5 User Manual

Lead-ln
Wire
There
are three
basic
criteria
in selecting
the
appropriate
lead-in:
impedance
matching
(to
avoid
unneces-sary
signal
loss),
signal loss
characteristic
(expressed
in db/10o
feet).
and
shielding,
or intrinsic
resistance
to interference.
There are
two
impedances
of FM
systems:
72
(or
7i)
ohms,
and 300 ohms.
The
FM-5
provides
for direct
con-
nection
of either.
The majority
of antennae
are
designed
for
300
ohm
systems,
but matching
transfornlers,
or
baluns,
may
be used
to
convert from
one antenna
impedance
to
the other lead,in
impedance
with minimum
signal loss.
There are
several types
of
300
ohm lead-in,
but only
one
72
ohm in
comnron
use-coaxial
shielded
RG-S9U.
F'or
extrenrely long
runs,
RG-llU
is a lower
loss equivalent.
R(;
59tI
is
used
in many
apartment house
distribution
systems
and cable
TV systems
for it has
relatively
low
signal loss
and
good
life expectancy
and very
good
shicld-
ing.
It is fairly
expensive
and somewhat
bulky,
and the
instirllation
of
t:onnectors is
a
nuisance,
but it
is still
pre-
ferred
b,v nlan\:
inskrllers
where interfcrencc,
such
as from
rnotor
vehicles, is
a
problem.
'I'hr
lnost
lropular
300 ohnr lead-in
is the ll:rt
"ribbon"
twinlead.
It is
the least
exJrensive,
has
fairly low signal
loss
(
at
least
wlren
it
is new
),
and low
bulk, so it
can be
nrn
(
tlrough with
adverse
effect on signal
)
under
carpets
and
along walls with
minimum
unsightliness.
Since
it
has no
shielcling,
inskrllers
try to
avoid
horiz.ontal
runs
as much
as
possible,
skr.y
away from nretal
surfaces like
gutters
and
downspouts,
nnd twist
it
atnut once ear:h foot
to reduce
inlerrft:rence
pickup.
T'winlead
is more strbject
than nrost
to
the effects
of weather,
and it should be replaced
aftcr
about
3
years
in most
localitres.
In fringe
areas
where maximum
signal
transmission
is
irnportant,
a
special
open wire
300 ohm twinlead
uses
plastic
spacers to
supyrort
the two
conductors
with
a
mini-
mum
of loss. It,
too, has
no shielding
capability,
and is
affected
by the elernents.
Weather resistance
has
been
irnprovcd
with
sorne types
of
oval
twinlead,
both
hollow
and
foam-filled,
at
the
expense
of considererble
bulk
and
increased
cost-
The
most
recent
variation
is shielded
300 ohm
cable.
It
is
the
most
expensive,
with
rnoderate
signal
loss,
and
is
the
bulkiest
of
all. It
is weil
shielded
and
has
good
life
expectancy,
so
it is
preferred
by
manv
installers
in
urban
areas.
The
right
choice
of antenna
and lead-in
can take
maxi-
mum
advantage
of the
FM-5's superior
performance.
The
antenna
system
is
a
substantiallv
greater
factor
than
any
tuner
design
characteristic
in achieving
good
reception
of
weak
signals.
The
Dynatuner's
frorrl.
end
has such
low
noise
that
it is
doubtful if
any fr,rrm
of ltorlster
or antenna
ampiifier
can
provide
a signal
with
ari.u listcnilble
improve-
ment
over
that
directl-y
from
the
anteluri.r.
The
critical listener
nray
werll
spend
as
much
for the
antenna
system
as for the
FM-5,
but such
a
combination
will
accornplish
far
more
than
:r rurlitnenlery
atrtenna
at-
tached
to
tuners
several
times
the
cost of thc
Fi\,I-5.
OPERATION
OUTSIDE
THE
UNITED
STATES
CONNECTIONS
FOR
240 VOLT
AC
LINE
I'he
power
transformer
supplierd
in
tlie
I.NI-S
may
be
connected
for
a 24O volt
A(l lint-'as
nell
as ior
the
standard
720
volt
AC line,
which
is how
the
lransfornrer
is wired
unless
this
manual
is
stampecl
"240
volt".
'l.he
transformer
has
dual
primary
windings-
'I'hey
are
conntcterl
in
parallel
for
120
volts,
and in
series
for
240
volts.
'l.hc
notes
to
steps 93
and
94 of
the wiring
instructions,
arrd
tire diagram
on the
pictorial
insert
dctail
the
240 volt
conrrcctions.
The
14o
ampere
t
100
ma
)
slo-blo
fuse's*upg[jgd
with
120
volt
wiring
should
be
replace<i
rvith
a,,i,,
anrlrele
(ti2
ma)
slo-blo
fuse
when the
turrer
is
wired f
or
240 ua*u-se.
The
F'M-5
is designed
for
use with
either
50 Hz or
60
Hz
current.
Variations
of line
voltage
up to 10.1,
fronr
nominal
value
will not
affect
performance-
I'he
standard
75
yrsec
I,'M
de-emphasis
time
constant
used
in
the
Unil.ed
States is
used in nrany
other
countries
as
well.
If
-your
location
us€sr ttre
altcrnal.ive
iit)
lrsec
de-em-
phasis (common
in
Europe),
capacitors
C-64
and
C-65
on
the PC-26
board
should
each
be
chansed
to .fi)56
mfd.
ASSEMBTY
INSTRUCTIONS
Assembly
of the
FM-5 is
exceptionally
sinrple
when
compared
to
other
kits.
The
preassembled
etched
circuit
boards have
saved
you
much
of the
work, and
the
assembly
that
remains
is
arranged
in
an open,
uncluttered
layout
that makes
wiring
quick
and
easy.
The construction
lime
will be
only a few
hours,
but it is
best to
work
slowl,y
and
carefully
rather
than
worry about
the
time.
Construction
will
be
greatly
simplified if
you
have
some-
one help
you
by reading
the
steps aloud,
selecting
the
required
parts,
and
preparing
the
necessary
wire
lengths
as
you proceed.
When
you
unpack
your
kit,
check
ofi the
components
agairut
the
parts
list
at
the
back of
the
manual.
you
can
r4entify
unfamiliar parts
by matching
them
to
the
pictorial
diagram
or
photograph.
-,
Have
the
proper
tools
at
hand
before starting
assembly.
You
will
need
a
pencil-t5pe
soldering iron
of
J0- to 60-watt
rating
with
a small
tip,
long nosed
pliers,
diagonal
cutting
8
pliers,
a medium-sized
screwdriver,
and
6A/4O rosin
core
sokler not larger
than
Ytc"
diameter.
You
will also find
a
damp
sponge or
cloth
helpful
lo wipcr
the
ti1;
uf the
iron
clean
periodically.
An
inexpensive
wire
stripping
tool
is
helpful,
but some
people
prefer
a single-cdged
razor
blade
for
removing
the insulation.
A
good
solder
connection
does not require
a lrtrge amount
of
solder around
the
joint.
A
well-made
connection looks
smooth
and
shiny
because
the solder
flouts
into
the
joint
when
both
parts
are hot
enough.
There
are
four
steps to
making
a
gond
solder cor-rnection:
l. Make
a
good
mechanical
connection.
2.
Heat
both
parts
r..'ith
the
tip of
the
iron
rzt the
junction.
3. Apply
solder
to the
junction
untii
it
melts and
flows.
4.
Allow
the
connection
to
cool
undisturbed.
ALL
SOLDERING
MUST
BII
DOI{E
WI'TH
A
GOOD
GRADE
OF
ROSIN
CORE
SOI,DER.

DYNACO FM-5 Specifications

General

Brand	DYNACO
Model	FM-5
Category	Tuner
Language	English