Midland M Zero Manual

M Zero
40 CH AM MOBILE TRANSCEIVER |

M Zero Instruction Guide | 1
MAIN FUNCTIONS ................................................2
CONTROLS AND FUNCTIONS ..........................3
INSTALLATION........................................................5
REPLACING FUSE .................................................................................................. 6
CONNECTING THE MICROPHONE................................................................... 6
4:45&. ANTENNA...................................................................................
USING YOUR TRANSCEIVER...............................9
SELECTION OF BANDS .........................................................................10
QUICK SCROLL ...................................................................................................10
KEYPAD BEEP .......................................................................................................11
EMERGENCY CHANNEL MEMORY ................................................................11
EXTERNAL SPEAKER...........................................................................................11
PA FUNCTION.......................................................................................................11
TECHNICAL SPECIFICATIONS......................... 12

2 | M Zero Instruction Guide
MAIN FUNCTIONS
•Display4IPXTUIFDIBOOFMJOVTF
•RF GAIN: "djusts the 39 sensitivity. By turning the knob clockwise
the 39 sensitivity will increase#y turning counter-clockwise it will
be reduced (this is very helpfulXIFOTtrong signals BSFreceived);
•SQUELCH: &liminates the background noise in 39. 'PS best
sensitivitythe squelch should be adjusted UP the level when
background noise disappears;
•CH/EMG: 5his CVUUPOJNNFEJBUFMZswitchFT to the emergency
channel. The emergency channel can be set by the user.

M Zero Instruction Guide | 3
987 6
5
4321
CONTROLS AND FUNCTIONS
1. .*$ connector: Connect the microphone to this jack;
2. RF GAIN knob: Adjusts the receiver gain;
3. SQUELCH knob: Adjusts the squelch threshold;
4. ON/OFF-VOLUME selector: 5o switch on/off the radioBOEUPBEKVTU
the volume;
5. UP/DOWN controls: 1ush the buttons to select the desired channel;
 $)"//&- display: 5P show the channel in use;
 TX -&%: *MMVNJOBUFT when the PTT button on the microphone
JTQVTIFE;
8. CH-EMG: Channel in use /Emergency channel. 5PTXJUDIRVJDLMZ
between the emergency channel and the channel in use;
9. CB/PA TFMFDUPS: 5P use the radio asBOBVEJPBNQMJmFSJGTFUJO1"
QPTJUJPO(Bn optional FYUFOTJPOspeakerJTSFRVJSFE).

4 | M Zero Instruction Guide
=+*
7( ,?;
(5;
1213
10 11
 40Antenna connector: 5Pconnect B.)[antenna
 Power supply cable: *nsert the power cable with lighter plug into
the vehicle’s lighter TPDLFU*GIBSEXJSJOHSBEJPDVUPGGUIFMJHIUFS
QMVHBOEJOTUBMMBOJOMJOFGVTFIPMEFSXJUIB".1GVTF
 External speaker jack. 5P connect an external speaker*UXJMM
BVUPNBUJDBMMZNVUFUIFJOUFSOBMTQFBLFS
 PA jack: 5PDonnect an optional speaker to use radio as BOaudio
amplifier (the CB/PA selector must be in position PA)

M Zero Instruction Guide | 5
INSTALLATION
Safety and convenience are the primary considerationTfor mounting
any piece of mobile equipment. All controls must be readily available to
the operator without interfering with the safe operation of the vehicle.
Be sure all cables are clear of the brake, clutch and accelerator. Also,
thought must be given to the convenience and comfort of passengers.
Another extremely important requirement is the ease of installation and
removal for those occasions when you might want to remove the unit
for service and maintenance.
The most common mounting position for a transceiver is under the
dashboard directly over the drive shaft hump. Do not mount the
transceiver in the path of the heater or air conditioning stream. Take
your time and plan your installation carefully. When the best location
for mountingJTEFUFSNJOFE, use the mounting bracket as a template
to mark mounting holes. Take care that you do not drill into wiring,
trim or other accessories.
Washers
Washers
Washers
Washers
Screws
Screws
Screws
Bracket
Nuts
Nuts
Screws and
washers

6 | M Zero Instruction Guide
=+*
7( ,?;
(5;
/05& *G XJSJOH EJSFDUMZ UP WFIJDMF DJSDVJU DVU PGG UIF MJHIUFS QMVH BOE JOTUBMM BO
JOMJOFGVTFGPMEFSBOE".1GVTF
Mount in position with bolts, lock washers and nuts or self-
threading screws. 5IJT transceiver DBO CF JOTUBMMFE in any location
where 126V%$ ± 10% power is available. Insert the power cable with
lighter plug into the vehicle’s cigarette lighter cord. %POPUQPXFSPO
UIFSBEJPVOUJMUIFantenna systemIBTCFFODPOOFDUFE. The lead from
the antenna should be connected to the 40 antennaconnector. If
using an external speaker, connect it to the EXT-SPKR jack.
REPLACING FUSE
IfreplacJOH the DC Power Cord GVTF, use B 2A.1 type. Hold the
fuse holder and press on the inside, then rotate the holder.
CONNECTING THE MICROPHONE
Your transceiver has a 1*/ microphone connector. This ensures that
you won’t accidentally pull out or loosen the plug connection when
VTJOH the microphone.

M Zero Instruction Guide | 7
ANTENNA SYSTEM
AO FGGJDJFOU mobile antenna system is not limited to the antenna. The
transmission DBCMF as well as the vehicle are important factors in the
total antenna system. Therefore, you must use the correct type of
DPBYJBM DBCMF and mount the antenna securely in a position that will
give you optimal results. Use coaxial cable with an impedance of 50
Ohms. We suggest type RG 58"U for lengths under m or RG "6 for
longer lengths. Generally speaking,keep the length of the DPBYJBM
DBCMF to a minimum. The above JOGPSNBUJPO is as important for
reception as for the transmission. If a mismatch exists between the
antenna and the receiver, the excellent sensitivity and signal-to-noise
radio of the receiver circuit will be defeated.
Suggestions
A few general rules should help you to install any mobile antenna pro-
perly.
• During operation, it must be vertical, and rigid enough to remain
vertical when the vehicle or boat is in motion.
• Mount it as far as possible from sources of noise (ignition system,
gauges, etc.) and keep the transmission DBCMF away from these
noisesources.
• An antenna mounted in a boat requires a good ground connection.
This can be either a metal hull or a ground made of tin-foil or copper
sheeting.
This ground should cover an area of at least 1 m2 or more. Be sure the
transceiver also has an adequate ground. There are many types of mobile
CB antennas: a full quarter-wave length whip, a centerloaded whip, top
loaded whip and the base loaded type are typical. A vertically polarized
whip antenna is best suited for mobile service. It is omnidirectional. If it’s
the loaded type, you will find it a physically shorter antenna. But, for gre-
ater efficiency the 2.5 m long, full quarter-wave whip is better. Antenna
length is directly related to efficiency.
Generally, the longer it is, the more efficient will be.
There are many possible antenna locations on a car.
Four of the most popular are shown and discussed on the following.
Roof Mount
In this position the antenna radiates equally in all directions. Since the

8 | M Zero Instruction Guide
normal 1/2 wavelength whip antenna is too long for roof mounting
on a vehicle, the antenna is shortened and loading coil is used to
provide the proper electrical length.
Front Cowl Mount
The radiation pattern is slightly greater in the direction of the rear
fender opposite the side on which the antenna is mounted. However,
the front position offers a number of advantages. The CB antenna can
be easily mounted.
Rear Deck Mount
The radiation pattern is stronger in the direction of the front fender
opposite the side on which the antenna is mounted. In this position you
can use a full quarter-wave antenna or a shorter loaded whip.
Bumper PS#SBDLFUMount
The antenna radiates in a pattern directly in front of and to the rear
of the vehicle, with maximum radiation directly away from the vehicle,
in a horizontal plane. Despite its fairly irregular pattern, a bumperPS
CVMMCBSmounted full-length whip antenna will normally give the
best results. Removing the antenna is simple and will leave no holes in
the car.

M Zero Instruction Guide | 9
USING YOUR TRANSCEIVER
Do not transmit without a suitable antenna or 50 Ohm load connected
to the antenna TPDLFU.
To receive:
 Make sure that the QPXFS plug is properly inserted into a12V
power socket.
 Make sure that the antenna and the microphone are attached.
 The emergency knob must be set to the CH position.
 Set the Squelch control to maximum counterclockwise position.
 Turn on the unit by rotating the VOLUME control clockwise.
 Turn the RF-GAIN knob totally clockwise.
 Set channel selector to the desired channel.
 Adjust VOLUME for a suitable listening level.
 Adjust Squelch to cut out annoying background noise when no
signal is being received.

10 | M Zero Instruction Guide
4et the Channel Selector to a channel where no signals are present or
wait until signals cease on your channel. Then, rotate the Squelch
control in a clockwise direction to the point where the background noise
just stops. Now, when a signal is present, you will hear it, but will not be
disturbed by noise on the channel between signals. When properly set,
the Squelch keeps the receiver “dead” until a signal comes in on that
channel. However, do not set the Squelch too high, or weak signals will
not be able to open the Squelch circuit. To receive very weak signals, it is
best to leave Squelch set to the minimum position by rotating the
control maximum counterclockwise. The Squelch circuit in your
transceiver is an advanced design. It uses an operational ampMJGJFS IC to
accomplish a hysteresis action. The result is that when you set the
Squelch for a precise signal level, if that signal level increases or
decreases in strength, the Squelch circuit will follow this change. With
conventional Squelch circuitT, often a signal which changes strength get
“chopped” by the Squelch circuit and aportion of the messageJTMPTU.
With a hysteresis Squelch, you get it all
5P5SBOTNJU
4FMFDUUIFEFTJSFEDIBOOFM
 Press the push-to talk button on the microphone and hold about
5-7 cm from your mouth and speak in a normal voice.
 To receive, release the push-to-talk button. Be sure the mic plug is
firmly connected to the jack.
NOTE: shouting into the mic will not increase your power or signal.
An internal circuit automatically sets the mic signal for
maximum modulation, so speakJOH loudly will give no advantage.
SELECTION OFBANDS
 Turn on the radio while keeping pressed the UP/DOWN controls
 With the UP / DOWN buttons select the desired band:
"V = "VTUSBMJB(40 C)AM - 26.9627.40)
O- =/FX;FBMBOE (40 CH AM - 26.
"4.BSJOF$)".
 Push PTT to exit the selection
QUICK SCROLL
To scroll the channels, keep the UP or DOWN controlsQSFTTFE for
seconds.

M Zero Instruction Guide | 11
KEYPAD BEEP
When this function is enabled, you will hear a beep tone everytime a
button is pressed.
To activate/deactivate the beep tone:
 keep the UP button QSFTTFEwhile turning on the radio;
 press UP or DOWN to enable/disable the beep;
 when the beep tone is enabled, the display will show ‘ON’ and
when it’s disabled, ‘OF’ will be displayed
 QSFTT115UPDPOGJSN
EMERGENCY CHANNEL MEMORY
The emergency channel set by default is channel 19GPS$#BOE
GPS.BSJOF5o change it, follow these steps:
 move the knob of the CH/EMG selector to EMG position;
 the current emergency channel blinks on the display;
 press the UP / DOWN controls for 5 seconds at the same time.
Thedisplay will stop blinking;
 with the UP/DOWN buttons select the new emergency channel;
 push again UP / DOWN for about 5 seconds;
 the display will blink again and will indicate the new emergency
channel memory.
EXTERNAL SPEAKER
Connect aOFYUFOTJPOspeaker Uo the EXT jack. When an external
speakerJTDPOOFDUFE to the radio, the internal speaker is automatically
disconnected.
PA FUNCTION
The PA function allows you to use the radio as an audio amplifier.
 Connect a speaker with a power of 3-10 Watt to the PA jack;
 move the CB/PA knob UP PA position;
 press the PTT button of the microphone and talk.

12 | M Zero Instruction Guide
TECHNICAL SPECIFICATIONS
RECEIVER
Frequency coverage..................."V"VTUSBMJB$)".
...................................................O-/FX;FBMBOE$)".
Sensitivity.....................................................better than 1.0 μV for 20 dB SINAD
Adjacent Channel Rejection...................... 60 dB at 10 kHz; 70 dB for 20 KHz
Intermediate Frequency ........................ 1st IF=10.695 MHz; 2nd IF=455 KHz
Audio 1ower..............................................................................2wattsmax
Frequency Response (6dB) .................................................................450-2500 Hz
Cross Modulation ..............................................................................45 dB or better
Squelch .................................................................. adjustable from 1.2 μV to 1mV
Duty cycle..............................................................................................................5/5/90
TRANSMITTER
Output Power ............................................................................................................4 W
Type of modulation .................................................................................................AM
Max modulation ..................................................................................................... 90%
Spurious Radiation............................................................................62 dB or better
Frequency Tolerance................................................................better than 0.002%
Antenna impedance.......................................................................................50 Ohm
Power supply ..................................................................................126 V
Max Current Drain.................................................................................................... 2A
Dimensions.......................................................................................110x45x140 mm
Weight ......................................................................................................................665 g
..............................................................."4.BSJOF$)".
Specifications are subject to change without notice.
NOTE: 8IFOUIF.BSJOFCBOEJTTFMFDUFEJUNVTUPOMZCFVTFE4IJQUP4IJQ
4IJQUP4IPSF PS 4IPSFUP4IJQ $MBTT -JDFOTF  QSPIJCJUT VTF PG
.BSJOF'SFRVFODJFTGPSMBOECBTFEDPNNVOJDBUJPOT

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