Sigtronics MRIM-2 - Manual (Page 5)

mOBIlE RADIO INTERFACE mODUlE
TROUBlESHOOTING GUIDE
First determine if the trouble occurs with the vehicle engine running.
vEHIClE ENGINE OFF:
1. Can’t hear radio in headset:
a) Make sure the headset is plugged all the way into the jack.
b) Turn up radio volume at the radio as normal.
c) Check the blue and gray wires going to the headset jack.
d) Check violet wire (SPEAKER HI and LO) connections from the Mobile
Radio Interface Module to the radio.
2. Can’t talk to dispatch (transmit) on radio through the headset:
a) Check for power and ground on the Mobile Radio Interface Module’s
red and green wires.
b) Check the connections between Mobile Radio Interface Module
and the radio. Both white wires (PTT HI and LO) and the Brown and
Black wires (MIC HI and LO).
c) Check the gray and white / orange wires going to the PTT / headset
jack.
d) Check the Mobile Radio Interface Module Radio Mic Transmit Level
adjustment.
vEHIClE ENGINE ON:
1. Electrical noise (alternator whine) in headsets when receiving on radio, or ...
Dispatch reports that they hear electrical noise (alternator whine) when
transmitting from vehicle through the headsets.
a) Check that the barrel of the headset jack is not physically touching
any metal on the vehicle
b) Check that the gray wire is not shorted to the vehicle chassis.
c) Check all six radio Interface wires between the Mobile Radio Interface
Module and the radio - MIC HI, MIC LO, PTT HI, PTT LO, SPEAKER HI,
and LO. Make sure that you have the correct pin numbers for the
radio you are hooking to. Make sure that MIC LO and SPEAKER LO
are not physically tied to the same pin on the radio; even if they are
tied together inside the radio.
d) If the wiring is OK, then noise is coming from radio:
i) Possible bad radio wiring, (Check radio power and ground
connections for loose or corroded connections) or ...
ii) Excessive noise is generated directly by the vehicle’s electrical /
charging system - most commonly known as alternator whine.
This is only present when the vehicle’s engine is running and
recognized by the fact that the pitch or frequency of the whine
changes directly with the change in engine rpm.
The preferred way to solve this type of problem is to have the vehicle’s
electrical / charging system serviced. The most common cause of this
type of noise is bad diodes in the vehicles alternator. Other possible
causes are: Bad vehicle voltage regulator; Bad alternator or battery
cable connections; Missing or bad engine or alternator grounding
straps.
If servicing the vehicle’s charging system is impractical, installing a
good alternator whine power line filter in-line with the radio power
wire(s) will usually accomplish the same thing. All radio power wires will
have to be filtered. Some radios have more than one wire that hooks to
vehicle power. Contact the radio manufacturer for a recommendation
on the best filter for the particular radio. NOTE: This solution should
not be considered a permanent fix. Vehicle charging system problems
of this type will eventually cause other equipment failure as well as
shorten the life of the vehicle’s batteries.
2. Dispatch says too much background noise or unclear or weak
transmissions.
a) Check to see if a radio hand mic on the vehicle is also active or “live”
when transmitting through the Mobile Radio Interface Module
headset. Check this while not wearing the headset and by talking
directly into the radio hand mic and pressing the Mobile Radio
Interface Module PTT switch. Do not press the PTT button on the
hand mic itself. If dispatch can hear you loud and clear, then the
background noise pick up is coming from this active hand mic. If
you have this type of hand mic, then it is best to contact the radio
manufacturer for instructions on a possible microphone modification
to fix the problem. Alternately, some radio manufacturers can supply
a compatible microphone that does not have this problem.
b) Adjust the Mobile Radio Interface Module Radio Mic Transmit Level. If
the mic level is set too low, you will get reports of weak transmissions.
If the mic level is too high, you will get reports of noisy or garbled
transmissions. See “Radio Mic Transmit Level Adjustment” on page 5.
mOBIlE RADIO INTERFACE mODUlE SpECIFICATIONS
Input Voltage: 11-16 VDC
Maximum Current: 0.03 Amps
Module Unit Size: 4 x 2.9 x 2 inches
Weight: 7 oz. (not including cable and hardware)
TwO YEAR wARRANTY
Every Sigtronics product has been carefully inspected before shipment. We
guarantee to correct any defect caused by faulty material or workmanship
free of charge to the user who originally purchased the product for a
period of two years from the original purchase date. Our obligation
assumed under this guarantee is limited to the replacing of any part or
parts which prove to our satisfaction, upon examination to have been
defective, and which have not been misused or carelessly handled. The
complete unit must be returned to our factory, transportation charges
prepaid. We reserve the right to decline responsibility where repairs
or replacements have been made or attempted by others. No other
guarantee, written or verbal, on our products is authorized by us.
Repairs required due to abuse, misuse, damage or normal service beyond
the warranty period will be subject to normal service charges.
To expedite factory service work, contact Sigtronics Service Department
and explain the problem. All correspondence relative to service work
should include model and serial number. Frequently problems can be
resolved by phone. The Sigtronics number is located below.
Sigtronics Installation Hot Line Number:
1-800-367-0977 ext. 8
M-F 8:00 am to 4:30 pm Pacific Time
www.sigtronics.com Sigtronics MRIM-2 page 5
8-5-2014 mrim_2.pdf
Sigtronics Corporation
178 East Arrow Highway
San Dimas, CA 91773
Phone: (909) 305-9399
E-mail: [email protected]
Web Site: www.sigtronics.com
igtronics
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