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Connect the two wires of the 300 ohm

lead-in from the external antenna to the
MR66 back panel FM ANT terminals.

75 OHM ANTENNA

FROM VHF TV

ANTENNA

An unbalanced 75 ohm FM antenna may

also be used with the MR66. Connect the
center lead of the coaxial lead-in cable to the

right hand FM ANT terminal. Connect the

shield of the coaxial cable to the ground
screw next to the right of this same FM ANT

terminal.

VHF-TV ANTENNA

A conventional VHF TV antenna of the

type also suitable for FM may be used with

the MR66. Connect the two leads from the
300 ohm TV antenna lead-in wire to the two

FM ANT terminals on the MR66 back panel.

Connect a length of 300 ohm flat lead-in wire

from the TO TV SET terminals on the MR66

back panel to the antenna terminals of the

TV set.

The MR66 MODE SELECTOR switch auto-

matically switches the VHF TV antenna to the
MR66 in any of the  " o n " positions. The

antenna is switched back to the TV set in the

POWER OFF position.

OPERATING INSTRUCTIONS

MONOPHONIC AM RECEPTION

Turn the MR66 MODE SELECTOR switch

to MON AM. Turn the FM FUNCTION switch
to FM OUT. Turn the AM FUNCTION switch

to any of the four bandwidth settings. It is

usually easiest to tune at the NARROW or
MEDIUM 1 position. After a warm up time of

approximately 30 seconds, turn the AM
tuning dial to the desired station. Depending

on the quality of the AM signal, select the

best possible bandwidth setting. (See the

section titled "AM FUNCTION SWITCH.":

The AM Signal Strength meter will indicate

the relative strength of the particular AM
station being received.

MONOPHONIC FM RECEPTION

Turn the MODE SELECTOR switch to

MON FM. Turn the AM FUNCTION switch to

AM OUT. Turn the FM FUNCTION switch to

MUTE IN. Set the AUTO FREQ CONTROL to

any position between MIN and MAX. (See the

section titled "AUTO FREQ CONTROL.")
After a warmup time of approximately 30
seconds, turn the FM tuning dial to the de-

sired station. The correct FM tuning point is

reached when the FM TUNING meter pointer
comes to rest anywhere in the center black

area of the meter scale. While tuning across
the dial you may notice movement of the

tuning meter, yet don't hear a station. This is

11

Figure 16. VHF TV Antenna Connections.

TO TV SET

Figure 15. Connection For 75 Ohm Coaxial Antenna.

Summary of Contents for MR66

Page 1: ...M Multiplex Remote Amplifiers Off The Air Tape Recording Antenna Connections OPERATING INSTRUCTIONS Monophonic AM Reception Monophonic FM Reception Stereophonic FM AM Reception Stereophonic FM Multiplex Reception ADJUSTMENTS Muting Threshold AM Signal Strength Indicator FM Tuning Meter AM and FM Output Levels Dial Panel Light GUARANTEE 1 1 3 5 6 8 8 9 9 9 9 9 11 11 11 12 12 12 12 12 13 13 14 14 MR...

Page 2: ......

Page 3: ...high rejection of spurious signals A newly developed Automatic Frequency Control AFC circuit greatly simplifies tuning As the tuning knob is moved the tuner re sponds as if there were no AFC action Approximately 3 seconds after the dial has come to rest on a particular station the AFC circuit gradually comes into operation The AFC action automatically brings the electrical tuning to the correct po...

Page 4: ... adjustment during tuning is there fore eliminated Two IF amplifiers are coupled through a low distortion detector into a two stage feed back amplifier The output is low impedance and approximately equal in level to the FM output Level controls on the rear panel allow you to exactly match the AM and FM output volume levels GENERAL A new type of mechanical tuning assembly gives the MR66 extremely s...

Page 5: ...ier 6BY8 2nd AM IF Amplifier 6BY8 AGC Amplifier 6U8 AM Audio Preamplifier 6BN4A FM RF Amplifier 6BN4A FM Oscillator 12AT7 FM Mixer 3 6AU6 FM IF Amplifiers 6BN8 FM Ultrasonic Muting 6AU6 1st FM Limiter 6CS6 2nd FM Limiter 12AU7 FM Meter and AGC Clamp 6U8 FM Audio Preamplifier 6BW4 High Voltage Rectifier 10mmu to both channels Dimensions Front Panel 155 8 inches by 51 8 inches Overall depth of chass...

Page 6: ...nimum noise and interference from other stations Medium 1 and Medium 2 Progressively wider frequency response for closer or more powerful local stations Broad Widest possible AM frequency response for high fideiity reception of powerful local sta tions The 10KC whistle filter is not operative at this switch setting MODE SELECTOR SWITCH Figure 3 Mode Selector Switch Power Off Turns off the MR66 AC ...

Page 7: ...ger station a lower AFC setting is usually necessary for best tuning FM FUNCTION SWITCH FM Out Turns off the FM section of the MR66 Mute In Turns on FM with the Mclntosh developed ultrasonic mute in operation Ultrasonic mut ing suppresses all noise between stations including noises heard tuning in and out of a station Weak or distant stations mixed with noise or interference are also suppressed Mu...

Page 8: ... operating regardless of the MODE SELECTOR switch setting The AM function switch and the FM function switch affect the signals at these output jacks Use these jacks to connect the tuner to remote amplifiers apart from the main sound system AM OUTPUT LEVEL CONTROL Adjusts the volume level of the AM output See section titled ADJUSTMENTS FM OUTPUT LEVEL CONTROL Adjusts the volume level of the FM out ...

Page 9: ...rrect alignment carefully position the cutout template on the front panel Scribe the rectangular cutout on the front panel and mark the positions of the six mounting holes Drill the six3 16 inch diameter mounting holes before cutting the panel opening Next cut the main panel opening It is important that the cutout be just within the heavy black lines on the template SHELF MOUNTING Locate the exact...

Page 10: ...lf is 3 8 inch thick ness or less Use the 10 32 x 1 inch screws if the shelf is inch or 7 8 inch thickness Secure the chassis with the proper length 10 32 screws by inserting them up through the holes in the shelf and into the threaded holes in the tuner chassis bottom Tighten the 10 32 screws after you have first tight ened the front panel screws IMPORTANT Use of the wrong length 10 32 screws may...

Page 11: ...ows Connect the MA6 Multiplex Adapter power plug to the FM multiplex power socket on the MR66 back panel Connect a 24 inch shielded cable supplied with the MA6 adapter from the adapter INPUT jack to the FM MULTI PLEX OUTPUT jack on the MR66 back panel Connect a 24 inch shielded cable from the LEFT OUTPUT jack on the MA6 adapter to the MULTIPLEX INPUT 1 on the MR66 back panel Connect a 24 inch shie...

Page 12: ...e dipole may be carefully tacked or taped into position IMPORTANT Keep the dipole away from large metal objects or surfaces since they may interfere with the effi ciency of the antenna FM OUTDOOR ANTENNA An outdoor FM antenna is always recom mended for best FM reception under all con ditions In fringe or outlying areas a highly directional FM antenna used in conjunction with a rotator will give th...

Page 13: ...ELECTOR switch to MON AM Turn the FM FUNCTION switch to FM OUT Turn the AM FUNCTION switch to any of the four bandwidth settings It is usually easiest to tune at the NARROW or MEDIUM 1 position After a warm up time of approximately 30 seconds turn the AM tuning dial to the desired station Depending on the quality of the AM signal select the best possible bandwidth setting See the section titled AM...

Page 14: ...NCTION switch to MUTE IN Set the AUTO FREQ CONTROL to any position between MIN and MAX Tune the FM dial to the station broadcasting FM Multiplex Stereo Satisfactory FM Multiplex Stereo reception requires approximately 10 times as much signal from the antenna com pared to equivalent FM monophonic recep tion Monophonic installations that were satisfactory with an indoor FM antenna may require an out...

Page 15: ...e black scale To adjust rotate the red FM MTR ADJ thumb wheel control under right dial panel end cap until the meter pointer rests in the center of the black scale Tuner Serial Nos 1N001 to 1N961 have a screwdriver adjust FM meter control near back of tuner chassis AM AND FM OUTPUT LEVELS Adjust each control until the MR66 AM and FM output volume levels are equal to each other They should also be ...

Page 16: ... is 607 GUARANTEE Mclntosh Laboratory Inc guarantees this equipment to per form as advertised We also guarantee the mechanical and electrical workmanship and components of this equipment to be free of defects for a period of 90 days from date of purchase This guarantee does not extend to components damaged by improper use nor does it extend to damage incurred during transportation to and from Mcln...

Page 17: ...AM STATION LOG STATION DIAL FREQ LOG SCALE LOCATION CITY STATE ANTENNA DIRECTION REMARKS MONO STEREO TIME DATE ...

Page 18: ...FM STATION LOG STATION DIAL FREQ LOG SCALE LOCATION CITY STATE ANTENNA DIRECTION REMARKS MONO STEREO TIME DATE ...

Page 19: ......

Page 20: ...LABORATORY INC 2 CHAMBERS STREET BINGHAMTON N Y Made in U S A Phone A r e a Code 607 723 5491 Printed in U S A 1M AA107 236 BE122003 ...

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