THE MclNTOSH MR 80 DIGITAL FM TUNER
Reading Time: 32 Minutes |
Price: $2.00 |
VARIOUS REGULATORY AGENCIES REQUIRE THAT WE BRING THE FOLLOWING INFORMATION TO YOUR ATTENTION. PLEASE READ IT CAREFULLY.
WARNING: TO PREVENT FIRE OR SHOCK
HAZARD, DO NOT EXPOSE THIS UNIT TO
RAIN OR MOISTURE.
The Mclntosh you have purchased is a Model MR 80. It has a serial number located on the rear panel of the chassis. Record that serial number here:
Serial Number
The model, serial number and purchase date are important to you for any future service. Record the purchase date here:
Purchase date
Upon application, Mclntosh Laboratory provides a Three-Year Service Contract. Your Mclntosh authorized service agency can expedite repairs when you provide the Service Contract with the instrument for repair. To assist, record your Service Contract number here:
Service Contract Number
Your MR 80 Digital FM Tuner can give you many years of satisfactory performance. If you
have any questions, please contact:
CUSTOMER SERVICE
Mclntosh Laboratory Inc.
2 Chambers Street
Binghamton, New York 13903-9990
Phone: 607-723-3512
Take Advantage of 3 years of Contract Service ...
Fill in the Application NOW.
Contents
SERVICE CONTRACT INFORMATION . . . 1 INSTALLATION ..2
HOW TO CONNECT AND
BACK PANEL INFORMATION...4 FRONT PANEL INFORMATION
AND USE OF CONTROLS. . .6 TOP PANEL INFORMATION
AND SECONDARY CONTROLS . . .8 PERFORMANCE LIMITS . . .9 PERFORMANCE CHARTS. -10 TECHNICAL DESCRIPTION. 14 BLOCK DIAGRAM..20
MclNTOSH THREE YEAR SERVICE CONTRACT
An application for A THREE YEAR SERVICE CONTRACT is included with this manual.
The terms of the contract are:
1. Mclntosh will provide all parts, materials and labor needed to return the measured performance of the instrument to the original performance limits. The SERVICE CONTRACT does not cover any shipping costs to and from the authorized service agency or the factory.
2.Any Mclntosh authorized service agency will repair Mclntosh instruments at normal service rates. To receive service under the terms of the SERVICE CONTRACT, the SERVICE CONTRACT CERTIFICATE must be presented when the instrument is taken to the service agency.
3.Always have service done by a Mclntosh authorized service agency. If the instrument is modified or damaged as a result of unauthorized repair, the SERVICE CONTRACTwill be cancelled. Damage by improper use or mishandling is not covered by the SERVICE CONTRACT.
4.The SERVICE CONTRACT is issued to you as the original purchaser. To protect you from misrepresentation, this
contract cannot be transferred to a second owner.
5.To receive the SERVICE CONTRACT, your purchase must be made from a Mclntosh franchised dealer.
6.Your completely filled in application for the SERVICE CONTRACT must be postmarked within 30 days of the date of purchase of the instrument.
7.To receive the SERVICE CONTRACT, all information on the application must be filled in. The SERVICE CONTRACT will be issued when the completely filled in application is received by Mclntosh Laboratory Incorporated in Binghamton, New York.
8.Units in operation outside the United States and Canada are not covered by the Mclntosh Factory Service Contract, irrespective of the place of purchase. Nor are units acquired outside the U.S.A. and Canada, the purchasers of which should consult with their dealer to ascertain what, if any, service contract or warranty may be available locally.
Copyright 1980 © by Mclntosh Laboratory Inc. |
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How to Connect and Back Panel Information
Refer to page 5.
AUDIO OUTPUTS
Use the FIXED OUTPUT jacks on the rear panel to feed program to a stereo control preamplifier or other equipment which has its own volume control. The front panel VOLUME control does not affect the loudness of the tuner at the FIXED OUTPUT jacks. The output level is a nominal 1 volt for 100% FM modulation.
Use the VARIABLE OUTPUT jacks to connect to equipment such as a power amplifier or a tape recorder where control of the volume at the tuner is desired. The output at the VARIABLE OUTPUT jacks is a nominal 2.5 volts for 100% FM modulation. There is no difference in the signal quality at either pair of output jacks.
Both pairs of OUTPUT jacks may be used simultaneously. The output impedance at both outputs is very low so that long audio cables can be used without a loss of high frequencies due to cable capacity.
RF INPUTS — ANTENNA CONNECTIONS
Two of four different antenna systems can be used with your MR 80. 1) an outdoor FM antenna, 2) an all channel (UHF-VHF-FM) antenna, 3) a cable input from your local cable company, or 4) the indoor dipole supplied with the MR 80. A switch is provided on the top level set panel to select between two of the four systems mentioned.
Avoid locating this antenna next to other wires or metal objects. This antenna may not prove effective in houses having metal siding or metal clad insulation.
The cable signal from a local cable company or a second FM antenna with 75 ohms impedance may be connected to the coaxial cable jack.
REMOTE SCAN
The REMOTE SCAN CONTROL SIGNAL jack is to be connected to the cable push button assembly supplied with the MR 80 for remote tuning. Plug the cable into the CONTROL SIGNAL jack. Pressing the push button at the end of the cable causes the MR 80 to scan to the next station. The mode of scan can be selected by the STATION'S slide switch. In the PRESET position every time the push button is depressed the MR 80 will scan to the next preset station. In the ALL position depressing the button will cause the MR 80 to scan to the next station.
An outdoor antenna is recommended for optimum performance in all areas. In fringe areas, best results will be obtained with a highly directional FM antenna used in connection with a rotator. Rotate the antenna until the best reception is obtained. Connect a 300 ohm outdoor antenna to the 300W ANTENNA (red) terminals. Connect a 75 ohm antenna and/or 75 ohm cable system to the coaxial antenna jack.
A flexible folded dipole antenna supplied with your MR 80 may be used in urban or in high signal strength areas. The flexibility of the thin flat wire assembly permits it to be placed under a rug. tacked behind the stereo or placed in any other convenient location. In some cases it may be necessary to position the antenna for best signal reception. This should be done before it is permanently located.
If REMOTE tuning is not used, leave the jack free of any connection.
SCOPE
The vertical and horizontal scope jacks are provided to connect to a maximum performance indicator or an oscilloscope for indication of FM multipath and signal strength. Connect the vertical jack to the vertical input of the indicator and the horizontal jack to the horizontal input.
UNSWITCHED AC POWER OUTLET
This outlet may be used to power auxiliary equipment such as an antenna rotator or a maximum performance indicator. Power is available whenever the MR 80 is connected to a power source.
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FM CABLE
INPUT OR FM ANTENNA
2ND 75W ANTENNA
LEAD-IN
OPTIONAL
75W ANTENNA
LEAD-IN
REMOTE CONTROL
PUSH BUTTON
TO AC
POWER
SOURCE
PREAMPLIFIER
POWER AMPLIFIER
MAXIMUM PERFORMANCE
INDICATOR
OR
OSCILLOSCOPE
LEFT SPEAKER |
RIGHT SPEAKER |
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Front Panel Information and
Useof Controls
The MR 80 Tuner has the most flexible control system ever designed in a stereo FM tuner. Correct use of these controls will yield a higher level of performance than previously possible with conventional tuners.
VOLUME CONTROL AND AC POWER SWITCH
The VOLUME control has been precision tracked throughout the listening range (0 to - 65 dB) for accurate stereo balance.
It sets the output level of the VARIABLE OUTPUT jacks and the front panel HEADPHONE jack. The FIXED OUTPUT jacks are not affected by the position of the VOLUME control. The AC power switch is part of the VOLUME control. Turning the VOLUME control fully counterclockwise turns the AC power off.
TUNING CONTROLS AND FREQUENCY DISPLAY
Frequency Display
The Frequency Display indicates the received frequency to the nearest 100 kHz.
Tuning
There are four methods of tuning your MR 80. Automatic selection of the tuning method is provided by touch sensors associated with each of the tuning controls.
Manual Tuning
When power is applied to the MR 80, the circuitry automatically selects the manual or knob tuning control mode. Turning the tuning knob clockwise will increase the received frequency. Counterclockwise decreases the received frequency.
Note: When the MR 80 is operated but is not connected to any other device (preamp, power amp, antenna, test equipment, etc.), there is a chance the frequency display will blank out when tuning with the main tuning knob. This is normal and can easily be corrected by reversing the 120V AC line plug or by connecting the MR 80 to any other equipment.
Auto Scan
AUTO SCAN is provided by two touch pads immediately to the left of the tuning knob. These two touch pads start the tuner searching for a new station. The small arrow will light next to the pad touched and indicate the direction of scanning. It will scan in the direction chosen until it stops at a station or reaches the end of the band. At the band end the tuner will reverse its scan direction.
Preset 1, 2, 3 & 4
These touch pads located to the left of the frequency display select one of the four preset stations. Just touch to operate. A small rectangle will light above the pad indicating which preset has been selected.
Remote SCAN
Remote SCAN of either the presets or all stations is provided for as described under back panel information.
INDICATOR LIGHTS
Three indicator lights are provided immediately to the left of the preset touch pads. The uppermost STEREO indicates when a stereo broadcast is being received. The second, LOCK, indicates when the tuner is locked to the station. The lock circuit in the MR 80 is unique in that tuned frequency is locked to the station, not to an internal standard as in the case of many digital tuners. This allows the MR 80 to be tuned to any frequency within the FM band and lock on that frequency. Other digital tuners can only lock on specific channel assignments. This lock circuit is so powerful that it must be disabled in order to tune the tuner. You will notice that the moment that you touch any one of the tuning controls the lock light extinguishes and only comes on when the station is properly tuned. Once lock has been established it will remain on even if the station being received should drift up to 2 megacycles either side of the center of the carrier. Thus, perfect tuning is always assured. The third indicator light, FILTER, indicates when the stereo noise filter is in operation. The indicator lights are in three different colors: red for STEREO, amber for LOCK, and green for FILTER.
SELECTIVITY SWITCH
Two degrees of IF selectivity are selectable by the SELECTIVITY switch. The NARROW or normal position provides adequate selectivity for stereo reception even under severe receiving conditions. Five linear phase piezoelectric IF filters provide low distortion reception with this high degree of selectivity. Setting the SELECTIVITY switch to SUPER NARROW adds an additional 4-pole 4-zero quartz crystal filter to the five previously mentioned filters. Use the SUPER NARROW position to receive stations from distant cities which are on channels adjacent to local stations. There may be useable signals which were never heard before with ordinary FM tuners.
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SIGNAL COLUMN
A column of LED lamps respond to the signal strength of the station being received. The stronger the signal the higher the column reaches. There is a control on the tuner top panel to adjust the column height for full scale when receiving the strongest signal in your listening area.
FILTER SWITCH AND FUNCTION INDICATOR
The MR 80 FILTER switch provides automatic stereo noise reduction on weak stereo stations. With the switch in the AUTO position the filter will be on only when the station is broadcasting a stereo pilot tone and the signal strength is below 100 microvolts. With the switch in the IN position the filter is connected at all times. The filter has no affect on mono stations. The filter function indicator light glows green when the filter is on.
MODE SWITCH
A two position MODE switch is provided so that you may select either automatic stereo or mono reception. In the STEREO position the tuner automatically switches from mono to stereo mode when a pre-determined signal to noise ratio has
been reached. In the MONO position all stations will be received monophonically but the STEREO indicator will light if the station is broadcasting in stereo.
HEADPHONE JACK
A HEADPHONE jack is provided to drive low impedance dynamic headphones from an internal power amplfier.
SCAN CONTROL
The SCAN control adjusts the speed at which the tuner searches for the next station, when using the AUTO SCAN mode of tuning. If the dial is crowded with stations use a slow scan speed. If there are few stations fast scanning can be used.
MUTING CONTROL
MUTING suppresses the background noise and hiss normally heard between stations. Turning the control counterclockwise to the OUT position disables the muting circuits. Turning the control clockwise increases the signal level required to unmute. This control also adjusts the sensitivity of the AUTO SCAN tuning circuits and the number of stations you will receive when using this tuning mode.
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