Meteorcomm 54530001 REMOTE EMERGENCY DEVICE User Manual MANUAL

Meteorcomm LLC REMOTE EMERGENCY DEVICE MANUAL

MANUAL

FCC TYPE ACCEPTANCE DOCUMENTATIONFOR THEMCC-54530001 REMOTE EMERGENCY DEVICE (RED)December 15, 1998METEOR COMMUNICATIONS CORPORATION8631 South 212th StreetKent, WA. 98031Tel: 253-872-2521 Fax: 253-872-7662© 1998 by Meteor Communications Corporationall rights reserved
2TABLE OF CONTENTSINTRODUCTION 3DESCRIPTION 3SPECIFICATIONS 3OPERATION 4THEORY OF OPERATION 5Block Diagram 5Power Switch and Battery Status Indicator 65 Volt Regulator 6Microcontroller 6Differential Data Encoder 6Data Filter 6Transmit Crystal Oscillator 6Phase Modulator 6RF Power Amplifier 7Harmonic Filter 7Loop Antenna 7TEST PROCEDURE 8APPENDIX A 10DrawingsAPPENDIX B 14Test Results FormAPPENDIX C 15Final Assembly PicturesAPPENDIX D 16Printed Circuit Assembly PicturesAPPENDIX E 17FCC Identification Label Source Control Drawing
3INTRODUCTIONThe Meteor Communications Corporation (MCC) Remote Emergency Device (RED) is alow power, RF transmitter, designed for use with the MCC-545A RF Modem. The unitwas developed as a personal emergency-signaling device that provides short-rangeconnectivity between the user and a nearby 545A.DESCRIPTIONThe RED is a battery operated, handheld device with a minimum operational range of1,500 feet. In an emergency, the operator presses the red button on the unit to transmit analert message. There is also a test button and battery indicator to periodically determinethe functional status of the unit. When not in use, the unit can be clipped to the user's belt.SPECIFICATIONSTransmitterFrequency Range 36-50MHzFrequency Stability +/- 20ppm (-30 to +60 o C)Transmit Power 250mW (at 9VDC)Rated Emission 16KOG1WWNSpurious and Harmonic Emissions -37dBcModulation BPSKData Rate 4k bpsTransmit Data Sequence Duration 300msAntenna Gain -36 dBdPower RequirementsVoltage 9VDCTransmit Current 250mABattery Life (Alkaline)Continuous Transmit 2 hoursStandby 5 yearsDimensions 4.0"L x 2.4"W x 1.4"HWeight 5 ounces
4OPERATIONBatteryThe RED requires a 9-volt alkaline battery to operate. It is installed through an accesspanel on the back of the unit. A light on the front of the unit provides a visual indicationof the battery's status whenever the test button is pressed. It will light as long as thebattery voltage is greater than 8VDC.Message TransmissionThe RED will transmit two types of messages to the 545A, alert or test. Both messagesare automatically sent 10 times with each button push for redundancy. In the event of anemergency, press the large, red button on the front of the unit to send an alert message.To test unit functionality, press the small, black button on the side of the unit to send atest message. To ensure message transmission, the buttons must be held down at least100ms. When the button is released, the unit will complete its transmission cycle andthen power down. If the button is held down, the unit will transmit message sequencescontinuously.RangeThe operational range of the RED is affected by its distance from the receiver, the type ofterrain in between, and the noise floor at the receiver. The RED is specified at 1,500 feetover level terrain, with a noise floor off 0.1uV at the 545A. Any deviation from theseconditions will produce variations in the operational range of the unit accordingly.
5THEORY OF OPERATIONThe MCC RED is a low-power (250mW) radio transmitter designed for one-way datacommunications in the low VHF band (36-50 MHz). Information is transmitted in BinaryPhase Shift Key (BPSK) form, using a monolithic quadrature modulator. See Appendix Afor assembly and schematic drawings.Block Diagram LOOPAN TENN ATR ANSMITCRYSTALOSCI LLATOR PHASEMODU LATO R RF POWERAMPLIFIER HARMONIC FILTERPROGRAMMING I /ODATA FILTER4. 096MH ZCRYSTALDIFFERENTIALDATA ENCODERMICROCONTROLLER9 VOLTS 5 VOLTSVOLTAGEREGULATOR9 VOLT BATTERY POW ER SWITCHBATTERY STATUSINDICATOR ALERTSWITCHTE STSWITCH
6Power Switch and Battery Status IndicatorWhenever switch SW1 or S2 is pressed, components Q1, Q2, CR1, R2, R3, R5, and R6switch battery power to all the circuits, except for the final power amplifier stage, whichis always connected. The circuits include the 5-volt regulator, and the first and secondstages of the power amplifier circuit. Whenever S2 is pressed, power is also routed to thelight emitting diode CR2, through components CR3, and R24 as a visual indication of thebattery status. The indicator will not light when the battery voltage is below 8 volts.5 Volt RegulatorA linear voltage regulator (U1) provides 5 volts to the microcontroller, differential dataencoder, data filter, crystal oscillator, and modulator circuits.MicrocontrollerAn 8-bit, CMOS microcontroller (U3) is used to generate the binary data sequence fortransmission. It outputs the appropriate sequence whenever switch SW1 or S2 is pressed.A 4.096MHz crystal (Y2) along with capacitors C15 and C16 determine the operatingfrequency of the device. The microcontroller also stores the application code and useridentification information in internal flash and E2PROM memory respectively.Differential Data EncoderA CMOS J-K flip-flop (U6A) is used to differentially encode the binary date prior toentering the data filter.Data FilterAn Op-Amp (U5A) based circuit is used to filter the encoded binary data. CapacitorsC10, and C13, and resistors R9, R10, and R11 form a second order, low-pass filter with acut-off frequency of 2 kHz. Resistor R21 reduces the amount of crossover distortion fromU5. R15 scales the input to the filter from 0-5VDC to 0-3.2VDC.Transmit Crystal OscillatorA temperature compensated crystal oscillator (Y1) is used to generate the transmittercarrier signal. A trimmer capacitor located on the oscillator allows for fine frequencyadjustment of approximately +/- 200Hz. The oscillator's frequency stability is better than+/- 20ppm over a temperature range of –30o C to +60o C.Phase ModulatorA monolithic quadrature modulator (U4) is used to generate the BPSK modulated carriersignal. The output of the data filter is directly connected to the in-phase (I) input of themodulator and through C36 to the quadrature (Q) input. This configuration prevents zerocrossings of the phase-modulated carrier. This, together with the data filter, maintains thetransmitter modulation sidebands within the limits of the FCC requirement.
7RF Power AmplifierA three-stage, solid-state amplifier provides about 33dB of total gain. The first stage isimplemented with a monolithic amplifier (U2). It provides about 17dB of gain. The 50-ohm amplifier input is matched to the modulator output with components C8, C24 andL3. The second stage is also implemented with a monolithic amplifier (U11). It providesabout 4dB of gain.The final stage is implemented with transistor Q3. It provides about 12dB of gain. Theoutput is series tuned with inductor L7 and trimmer capacitor C33. Because the stageoperates class C, the battery voltage is directly connected to it. Only a small amount ofcurrent drain (< 50nA) is incurred, which is due to leakage through Q3.Harmonic FilterA third order, low-pass filter attenuates the harmonics of the transmitter center frequencyto a level that meets FCC requirements. At a 250mW output, the harmonics must be 37dB below the unmodulated carrier. Capacitors C34 and C35 and inductor L8 form thisfilter. The cut-off frequency is set to obtain about 20 dB of attenuation at twice thetransmitter center frequency.Loop AntennaA printed circuit board loop antenna is used to radiate the RF signal from within the REDenclosure. Capacitor C1 on the board is used to tune the antenna.
8TEST PROCEDUREEquipment List100 MHz Oscilloscope and probe with RF short ground100 MHz Frequency counter9VDC, 500mA Power supplyDigital Multimeter (DMM)Equipment Set UpFREQUENCYCOUNTEROSCILLOSCOPE14 GAUGE, ENAMELED, SOLID WIRE. PLACEDADJAC ENT TO TH E PC B LOOP AN TENN A.(SEE DETAIL BELOW)COAXPOW ER SUPPLY mAUUTDETAILSC OPE PROBE WI TH RF SHORT GROUN DWIRECOAX54530302 PC B PC B LOOP AN TENN A
9Record the following measurements on the test results form located in Appendix BTransmit Crystal Oscillator FrequencyWhile pressing SW1 of the UUT, measure the oscillator frequency using a scope probe(with an RF short ground) at pin 2 of Y1. The frequency should measure within +/- 10Hzof the transmit frequency. If it doesn't, then adjust trimmer C2 on the oscillator.Radiated VoltageAdjust trimmer potentiometer R23 fully clockwise. While pressing SW1 of the UUT,adjust trimmer capacitors C33 (on main PCA) and C1 (on antenna PCA) for maximumpeak to peak voltage on the oscilloscope. The peak to peak voltage should be greater than1.5Vpp.Transmit CurrentWhile pressing SW1 of the UUT, record the transmit current indicated on the DMM. Itshould be less than 250mA.Leakage CurrentWith the UUT off, record the leakage current indicated on the DMM. It should be lessthan 1uA.Disconnect the UUT from the 9VDC power supply.Attach the UUT enclosure cover and install a 9-volt battery.Battery Status IndicatorPush the small, black test button on the UUT. Verify that the LED lights brightly.
10APPENDIX ADrawings
11
12
13
14APPENDIX BTest Results FormTransmit Crystal Oscillator Frequency ___________MHz, +/- 10Hz ________HzRadiated Voltage >1.5Vpp ________VppTransmit Current <250mA ________mALeakage Current <1uA ________uABattery Status Indicator ________OK
15APPENDIX CFinal Assembly PicturesFIGURE 5 FrontFIGURE 6 Bottom
16APPENDIX DPrinted Circuit Assembly PicturesFIGURE 1 Transmitter top FIGURE 2 Transmitter bottomFIGURE 3 Antenna top FIGURE 4 Antenna bottom
17APPENDIX E Source Control DrawingFCC ID: BIB54530001MCC MODEL: R.E.D.PART NO: 54530001- 0.8” CONTRACT NO:FREQ: MHz S/N: 1.9”Label Material: Silver Matte Mylar #7222Clear Matte Imprintable Mylar Overlay #PM-200-CM/TProcess: Hot StampThickness: 4mils totalColor: Black LetteringActions: Laminate Diecut Strip WasteApproval: Phil StewartRevision A - Initial Release005-201-0058 FCC Type Acceptance Label for the MCC Model R.E.D.

Navigation menu