Fisher FM 80 Owners Manual

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THE

HSHR

FM TUNER

INSTALLATION AND
OPERATING INSTRUCTIONS

MODEL FM-80

. PRICE: $1.00

FISHER RADIO CORPORATION NEW YORK

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.
THE 77

CHER

GENERAL INFORMATION

THE FISHER FM Tuner, Model FM-SO, is one of the finest instruments
of its type ever produced in the laboratories of the Fisher Radio Corpora-
tion. The original specifications, which called for a tuner capable of meeting
exacting professional standards, have not only been met but in some
instances exceeded, It is one of the most compact high-quality FM tuners
ever produced, yet its circuitry is so advanced and some of its features so
new that it will out-perform any FM tuner now knOWn to us, including
several many times its size.

The circuit comprises a dual ttiode, rascodertype, tuned RF stage (for
maximum signal-to-noise ratio) and two IF stages, followed by two cascaded
limiters. The latter are combined with a Foster-Seeley Discriminator to
produce a genuine Armstrong System, universally recognized as the ulti-
mate in FM receivers. The continuously variable AUTOMATIC FREQUENCY
CONTROL (AFC,) located on the front panel, assures accurate tuning and
freedom from the annoyance of drift. The range of AFC lock-in can be
adjusted according to the needs of the particular and exact location of the
receiver, being continuously adjustable. The AFC feature can also be ten-
dered inoperative, if desired.

THE FISHER Model FM780 features two meters. The first is a signal
strength meter, which shows the relative intensity of the incoming signal.
The sensitivity of the receiver to the prevailing signal intensity can be
adjusted with the SENSITIVITY Control. The second meter is a centerrtflv
channel indicator that shows when the receiver has been accurately tuned
to the desired frequency.

The cathode-follower output assures low distortion as well as the ability
to use output leads of any desired length up to 200 feet. There are two
output receptacles, one for use with the main or monitoring amplifier
and one for use with any desired auxiliary equipment such as a tape, Wire
or disc recorder, a second amplifier, a commercial sound installation, or
multiple distribution amplifiers.

A carefully designed flywheel tuning mechanism, equipped with an antir
backlash gear, makes selection of stations extremely simple and smooth.
The edge-lighted glass slide-rule scale has large, casy-to-read numerals, as
well as a 0 to 100 Logging Scale for convenient spotting Of the stations
most frequently used. The front panel of the Model FM-SO is a handsome
brushed-brass fascia that adds distinction to any group of equipment.

INSTALLATION INSTRUCTIONS

THE FISHER Model FMr80 is supplied with the following:
1 ~- FM Folded Dipole, with plug attached. 1 * Shielded Cable.
4 -Mounting Screws and Flat Washers. 2 -Mounting Templates.

MECHANICAL INSTALLATION: THE FISHER Model FM-80 is constructed
with a completely self-contained front panel, housing the dial mechanism.
It can thus be placed on a shelf or it can be mounted in the conventional
mannner, behind a 92, to 34;" plywood panel. The necessary cut-out should
be made in accordance with TEMPLATE No. I. The mounting holes should
be drilled in accordance with TEMPLATE No. 2. To remove the front
panel:
1. Remove the control knobs by pulling forward. 2. Remove the two
5/3" nuts on the control shafts. The front panel will come free. When
reassembling the 3/3 nuts on the control shafts, have the smooth,
washer-faced surface toward the panel. Finally, press the knobs back
on the control shafts.

EROPER VENTILATION: In any of the installations described above, it is
imperative that adequate ventilation be provided. The tuner should never
be mounted in a totally enclosed cabinet of small dimensions. In cases where
a completely enclosed cabinet cannot be avoided, cut air slors at the rear
edge of the shelf on which the tuner rests, as well as at the top rear of
this compartment (either in the rear wall, or the shelf above.) This is
especially necessary where an amplifier or other heat-producing equipment
will be placed in the same compartment with the tuner.

ELECTRICAL INSTALLATION: ANTENNA REQUIREMENTS: The FM
antenna connection is made with a fourrprong plug (attached to the antenna
furnished.) A folded dipole is supplied and is generally adequate, except
in extreme fringe areas, or where there is a high noise level. The folded
dipole can be afiixed to the rear surface of the tuner compartment or placed
under an adjacent carpet. Check for the best positioning of the dipole,
for maximum signal, before laying it under the carpet. The lead-in portion
of the dipole antenna can be extended if necessary, by adding Mill-ohm,
twin-lead. Should an external FM antenna be desired, it will he found that
the FM antenna inputs have been designed to accommodate either a 300-
ohm balanced system or a 72-ohm unbalanced, coaxial system. Connections
for both types are shown on the antenna transformer shield.

POWER REQUIREMENTS: THE FISHER Model FM-80 is designed to
operate on 105 to 125 volts, 50 to 60 cycles AC. It consumes approxi-
mately 50 watts.

CONNECTIONS TO ASSOCIATED EQUIPMENT: THE FISHER Model
FM-SO supplies sufficient audio output voltage to operate into any control
chassis and conventional amplifiers.

OPERATING INSTRUCTIONS

THE FISHER FM-SO controls were specifically designed to avoid duplica-
tion within a given sound system. For this reason, you will discover that
there is no selector switch, volume control, or any other device that would
exist on a well-designed control unit, such as THE FISHER Master Audio
Control, Series SO-C.

INITIAL SET-UP: Turn the OUTPUT LEVEL Control, located on the tear
apron of the chassis, fully counterclockwise, the minimum position. Turn
the ON Advance the SENSITIVITY Control to approximately the halfway posi-
tion. Tune in the desired station. The center of the channel will be shown
by the pointer of the TUNING Meter (the pointer resting on the center
of the horizontal bar between - and +.) The OUTPUT LEVEL Control
should be set as follows:

I, If the Model FM-SO output is connected to an instrument that has
an input level control, adjust the tuner's OUTPUT LEVEL Control
to maximum, fully clockwise.

2, If there is no input level control provided, set the OUTPUT LEVEL
Control to the point where it will not overload the associated equip-
ment, or to a point that matches the level of other equipment, such
as a record player, TV sound, etc. This will insure the same relative
listening level when switching from one to the other.

Tune the instrument to the strongest signal in your area. Adjust the SENSI-
TIVITY Control to the point where the SIGNAL Meter reads between 3
and 4. The signal level of all other stations reading at least 1 will give
full limiting. The SENSITIVITY Control should be advanced only in the
event that the signal reading is less than 1.

NOTE: During the tuning process, the meters cannot be damaged, even
by extreme deflections of the pointer.

SETTING OF AFC CONTROL: Turn the AFC Control to maximum, clock-
wise. In this position, it will be found that the station will automatically
lock in and remain correctly tuned when the dial pointer is moved in the
vicinity of the desired channel. Under ordinary conditions, the Model
FM-8O can be used with the AFC in the maximum position at all times.
When the pointer of the TUNING Meter rests on any portion of the hori-
zontal bar, the instrument is correctly tuned. The amount of dial pointer
travel over which the lockain feature operates for a given channel can be
adjusted by means of the AFC Control. In some locations, however, when
a weak station is separated from a strong station by only one or two chan
nels, the latter will tend to operate the control unit, and make it difficult
to bring in the weaker of the two stations. When this condition prevails,
turn the AFC Control counterclockwise to the degree necessary for normal
reception of the weaker station.

ADJUSTMENT OF METERS: After the instrument has been in operation for
ten or fifteen minutes, note the positions of the pointers on each meter.
The SIGNAL Meter pointer should be at 0 with the SENSITIVITY Con
trol «11720:! at minimum (1102 at absolute minimum;) the TUNING Meter
pointer should be at the center of the horizontal bar. If one or both of
these conditions does not occur, adjustments must be made as follows:

The adjustment point, marked TUNING METER ADJUSTMENT or
SIGNAL METER ADJUSTMENT will be found on the top surface of
the chassis, behind each meter. Insert a screw driver in the corresponding
slot, and turn the slot until the pointer on the SIGNAL Meter reads '10
[bkdiust the TUNING Meter pointer to fall on the center of the horizontal

at.

LOGGING SCALE: THE FISHER Model FMVSO dial glass carries a logging
scale consisting of linear divisions from 0 to 100, With this, location of
your favorite and frequently used stations is reduced to its simplest form.

COMPLETE HOME MUSIC SYSTEM

Careful selection of associated equipment for use with THE FISHER FM
Tuner, Model FM»80, will result in a perfectly matched, high fidelity home
music system. Those seeking the ultimate in associated equipment will find
it in THE FISHER Master Audio Control, Series 507C, THE FISHER
High Quality Amplifiers, Model SO-A or Model 70-A, and THE FISHER
Hi-Lo Filter System, Model SO-F. Complete specifications on request.