background image

The edge of the strip with the clips must

face toward the panel opening. Line up the

mounting strips on each side of the panel
cutout so the holes in the strips are in line

with the holes in the panel. (See Figure 8.)

Install the proper length flat head screws

through the front panel and into the center

hole of each strip. Drive the screws in so the

flat heads are flush with the panel. If neces-

sary, countersink the two center holes.

Carefully insert the tuner through the

front panel opening so it rests on the sup-

porting shelf. Insert the proper length round

head screws into the four holes in the mount-
ing flanges on each end of the tuner panel.

Drive the screws in through the panel and into

the threaded clips on the mounting strips.

Do not tighten these screws yet.

If the cabinet is fixed and will not be

moved about, it is not necessary to secure

the tuner chassis to the shelf. If the cabinet

is to be moved about, it is recommended

that the tuner chassis be secured to the

shelf in the following manner.

Tighten the four screws holding the tuner

to the front panel. The four 10-32 x ¾ inch

screws used in shipping the tuner are also
used to mount it to a shelf of ½ inch or

 5

/

8

inch thickness. Use the 10-32 x ½ inch

screws if the mounting shelf is

 3

/

8

 inch thick-

ness or less. Use the 10-32 x 1 inch screws if

the shelf is ¾ 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 cause electrical short-
ing in the tuner circuits.

Attach the two metal panel end caps

(packed with the tuner) on each end of the

tuner panel by sliding onto the pins. (See

Figure 9.) The end caps are held by spring

tension and can easily be removed if the

tuner is to be taken out of the cabinet.

PUSH ON

MOUNTING IN THE L66 CABINET

The Mclntosh L66 cabinet is supplied

with complete instructions and all necessary

hardware for installing the MR66 tuner. The

dimensions of the L66 cabinet are 16

9

/

16

inches wide by 6

11

/

16

 inches high including

mounting feet by 13¾ inches deep including

tuner front panel and control knobs.

CONNECTING

MONOPHONIC FM AND AM

Connect one end of a shielded cable sup-

plied with the tuner to either the STEREO-
MON 1 or 2 output jack on the back panel of

the MR66. Connect the other end of the

cable to a high-level auxiliary or tuner input of

a monophonic preamplifier. The MR66 has

sufficient output level to be connected

Figure 9. Fitting End Caps To Tuner Panel.

8

Figure 8. Securing The Mounting Strip To The Front Panel.

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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