Fisher RS 140 Service Manual

Page 1

SERVICE MANUAL

EFISHER
RS-1 40

DIGITAL SYNTHESIZER RECEIVER

The first name in high fidelity

Page 2

SPECIFICATIONS

POWER AMPLIFIER SECTION

Signal-toNoise Ratio

Minimum RMS sine wave power Mono 65 dB
per channel within stated bandwidth Stereo. 60 dB
at no more than stated distortion with Capture Ratio 1.5 dB
an 8 ohm load 40 Watts Alt. Channel Selectivity (:300 kHz) 60 dB
Power Bandwidth 10-30000 Hz Image Response Ratio 75 dB
Total Harmonic Distortion 0.09 /a Spurious Response Ratio 65 dB
|.M. Distortion .005 /o IF Rejection 90 dB
Speaker Damping 40 AM Suppression 50 dB
T.H.D. at 65 dBf
PREAMPLIFIER SECTION Mono 0.3 %
Frequency Response Stereo 04 a/u
Phono MM (RIAA) 10.8 dB Stereo Separation
Aux (20 Hz-20 kHz) :11) dB 1 kHz 40 dB
1901 SENSIIIVIIY and Impedance Sub-Carrier Product Rejection
Phono MM . 2.5 mVI47 k9 19/38 kHz 60 dB
Tape I50 VIN/47 k9 Audio Frequency Response
Aux 150 mV/47 k9 (20 HZ15kHz) :1 dB
Graphic Equalizer
50 Hz :10 dB MW SECTION
250 Hz :10 dB Usable SenSitivity 400 WM
1 kHz :10 d3 Signal-to-N0ise Ratio 40 dB
45 kHz :10 dB Image Response Ratio 45 dB
15 kHz 110 dB lF Rejection 50 dB
Low Filter (Below 60 Hz) -6 dBloct.
Hight Filter (Above 5 kHz) -6 dBloct. LW SECT'QN ,
Loudness Contour (100 H2110 kHz) + 7 dB/ + 3 dB same sens'I'V'IY . 120°"Vm
Hum and Noise (IHF A Weighted. Inputs snorted) $299 959 Ram 32::
Phono MM 75 dB e'ecmn
Tape 90 dB
Aux 90 dB GENERAL

FM TUNER SECTION
Usable Sensitivny

Power Requirements
Maximum Power Consumption
Dimensions (WxHxD)

220V AC 2 10%
185 Watts

Inches 15-3/4x4-3/4x1143/16
Mono (26dB S/N 40 kHz DEV.) 1.8 pV/162 dBI i'nm 400x120x300
Stereo (46GB S/N 40 kHz DEV.) 30 MV (40,8dBI) Weight

lbs. 15-1/4

kg 6.9

* Because its products are subject to continuous improvement, Fisher Corporation reserves the right to
modiiy product designs and specifications without notice and without incurring any obligation.

TO CHANGE THE VOLTAGE

This unit is capable of operation on 220V or 120V AC. 50 to 60HZ.
It has been preset at the factory for 220V AC operation by connecting a strip-wire into the position marked \1220V."
See VOL. SEL. P.C.B. WIRING DIAGRAM.
To change for 120V AC operation, cut off the strip-wire on the \/220V" position, insert a strip-wire into the \«12OV"
position, and solder it. After changing, replace the mains voltage indication of the rating plate with the 120V" label

supplied with the unit.

ALIGNMENT PROCEDURES
AM IF Sweep Generator, AM RF Signal Generator, VTVM, and Oscilloscope.
Place the controls and switches in the following positions nuless otherwise Instructed.

AM ALIGNMENT
INSTRUMENTS

NOTE FUNCTION-AN position
BALANCE-0 (center) Tape Monitor-OFF (SOURCE)
BASS-O (center) TREBLE-O (center)
MONO/FM mute, Loudness, High and Low Filters-OFF (outer) position Speakers-A position
where a pair of test speakers are connected.
Keep the input signal level as low as possible to avoid the AVG action.

Volume-0 (minimum)

AM IF ALIGNMENT

Generator Input Receiver, Dial

Test Equipment
Connection Signal setting

Step Connection

Adjustment

Sweep Generator to
1 TP 10 Thru a 0.02 mid
ceramic capacitor

Tune L13.L14,L16 for highest and
most symmetrical IF response.
See Figure 1.

Oscilloscope to
TP1 1

450 kHz 522 kHZ