Motorola Gp328 Gp338 Detailed 6804110j64 F Manual
Have a look at the manual Motorola Gp328 Gp338 Detailed 6804110j64 F Manual online for free. It’s possible to download the document as PDF or print. UserManuals.tech offer 249 Motorola manuals and user’s guides for free. Share the user manual or guide on Facebook, Twitter or Google+.
Troubleshooting charts6B-455V at pin 6 of D3701Is information frommP U409 correct?Is U3701 Pin18AT 4.54 VDC?Is U3701 Pin 47 AT = 13 VDCIs U3701 Pin 19 4.3 VDC in TX?StartVi s u a l check of the Board OK?Correct ProblemCheck 5V Regulator+5V at U3701 Pin’s 13 & 30?Is 16.8MHz Signal at U3701 Pin 19?Check Y3761, C3761, C3762, C3763, D3761 & R3761Are signals at Pin’s 14 & 15 of U3701?Check L3701, R3701Check Q260, Q261 & R260U3701 pin 2 at >3VinTxand -30 dBm?Are C3721, C3722,C3723, R3721, R3722, R3723 OK?Replace U3701If R3727, C3726 & C3727 are OK, then see VCO troubleshooting chartAre Waveforms at Pins 14 & 15 triangular?Do Pins 7,8 & 9 of U3701 toggle when channel is changed?Check programming lines between U409 and U3701 Pins 7,8 & 9Replace U3701Check uP U409 Troubleshooting ChartNO YES NO YES NO YES NO YESNO NO NO YES YESNOYES YESNO YES YES YES NONO NO NO YES NO YES YESCheck D3701, D3702, U3701, C3701 - C37073.3V at U3701 pins 5, 20, 34 & 36Check U3201, L3731Is 16.8MHz signal at U3701 pin 23?Replace U3701YES NO NO YES NO YESTroubleshooting Flow Chart for SynthesizerReplace U3701
6B-46Troubleshooting chartsSTARTNo LO?Tx Carrier?VCO OKCheck R3829TRB = 3.2V?Pin 10 >1V?L3831, L3832, L3833 O/ C?Change L3831, L3832Change U3801AUX 3 High?Check U3701 Pin 2 for 3.2VPin 19 =0VAUX 3 Low?Change U3801Vctrl0V or 13V?L3821, L3822, L3823 Open Circuit?Change U3801Change L3821, L3822, L3823,L243Change U3701Check for faulty parts or dry joints of L3812 C3806, R3806, R3802 & L3801A ANo No Ye s Ye s Ye s No NoYe sYe s Ye s No Ye sNoNoYe sYe sNo NoCheck R3811, L3811 for dry joint or faultyNoTroubleshooting Flow Chart for VCOYe s
6C-1Section 6C MODEL CHART AND TEST SPECIFICATIONS (450-527 MHZ)1.0 Model ChartGP Series, UHF Band 2, 450-527 MHzModel DescriptionAZH25SDC9AA2GP328 450-527 MHz 4W 4CHAZH25SDC9AA3 GP328 450-527 MHz 4WAZH25SDH9AA6GP338 450-527 MHz 4WItem DescriptionX PMUE1564_ GP328 Super Tanapa 450-527 MHz 4W 4CHXPMUE1477_GP328 Super Tanapa 450-527 MHz 4W X PMUE1478_ GP338 Super Tanapa 450-527 MHz 4WXPMUE1566_GP328 Tanapa 450-527 MHz 4W 4CH X PMUE1489_ GP328 Tanapa 450-527 MHz 4WXPMUE1490_GP338 Tanapa 450-527 MHz 4W X PMLE4172_ GP328 B/C Kit 450-527 MHz 4W 4CHXPMLE4118_GP328 B/C Kit 450-527 MHz 4W X PMLE4119_ GP338 B/C Kit 450-527 MHz 4WXPMLN4348_GP328 Front Housing Kit 4CH X PMLN4216_ GP328 Front Housing KitXPMLN4199_GP338 Front Housing Kit XXXNAE6483_ UHF16cmMonopole(Whip)antenna(403-520MHz)XXXPMAE4008_UHF 13 cm Monopole (Whip) antenna (470-530 MHz) XXXPMAE4006_ UHF9cmantenna(465-495MHz)XXXPMAE4007_UHF 9 cm antenna (490-527 MHz) X X 6804110J54 GP328 User ManualX6804110J55GP338 User Manual x = Indicates one of each is required.
6C-2Specifications2.0 SpecificationsGeneralTransmitter ReceiverAll specifications are subject to change without notice.UHFFrequency:450-527 MHz Channel Capacity: GP328 : 4/16 Channels GP338 : 128 ChannelsPower Supply:7.5 Volts±20% Dimensions with Standard High Capacity NiMH Battery: with Ultra High Capacity NiMH Bat- tery:137mm x 57.5mm x 37.5mm 137mm x 57.5mm x 40mmWeight: with Standard High Capacity NiMH Battery: with Ultra High Capacity NiMH Bat- tery:420 g 500 g Average Battery Life @ (5-5-90 Duty Cycle) Standard High Capacity NiMH Bat- tery: Ultra High Capac- ity NiMH Battery:Low Pow- er >11 hrs >14 hrsHigh Pow- er >8 hrs >11 hrsSealing:Passes rain testing per IP54 Shock: Meets MIL-STD-810- C,D & E and TIA/EIA 603Vibration:Meets MIL-STD-810- C,D & E and TIA/EIA 603 Dust: Meets MIL-STD-810- C,D & E and IP54Humidity:Meets MIL-STD-810- C,D & E and TIA/EIA 603 FCC ID AZ489FT4834UHFRF Output NiMH @ 7.5V:Low 1WHigh 4W Frequency 450-527 MHzChannel Spacing12.5/20/25 kHz Freq. Stability (-30°Cto+60°C)0.00025%Spurs/Harmonics:-36 dBm < 1 GHz -30 dBm > 1 GHz Audio Response: (from 6 dB/oct. Pre- Emphasis, 300 to 3000Hz)+1, -3 dBAudio Distortion: @ 1000 Hz, 60% Rated Max. Dev.
Transmitter6C-33.0 Transmitter3.1 General(Refer to Figure 6-1) The UHF transmitter contains five basic circuits: 1.power amplifier 2.antenna switch 3.harmonic filter 4.antenna matching network 5.power control integrated circuit (PCIC).3.1.1 Power AmplifierThe power amplifier consists of two devices: 1.9Z67 LDMOS driver IC (U101) and 2.PRF1507 LDMOS PA (Q110). The 9Z67 LDMOS driver IC contains a 2 stage amplification with a supply voltage of 7.3V. This RF power amplifier is capable of supplying an output power of 0.3W (pin 6 and 7) with an input signal of 2mW (3dBm) (pin16). The current drain would typically be 160mA while operating in the frequency range of 450-527MHz. The PRF1507 LDMOS PA is capable of supplying an output power of 7W with an input signal of 0.3W. The current drain would typically be 1300mA while operating in the frequency range of 450- 527MHz. The power output can be varied by changing the biasing voltage.Figure 6-1: Transmitter Block DiagramPCIC Antenna PA DriverVcontrolVcontrolFrom VCOJackPA - F i n a l StageAntenna Switch/ Harmonic Filter/ Matching Network
6C-4Transmitter3.1.2 Antenna SwitchThe antenna switch circuit consists of two PIN diodes (CR101 and CR102), a pi network (C107, L104 and C106), and two current limiting resistors (R101, R170). In the transmit mode, B+ at PCIC (U102) pin 23 will go low and turn on Q111 where a B+ bias is applied to the antenna switch circuit to bias the diodes on. The shunt diode (CR102) shorts out the receiver port, and the pi network, which operates as a quarter wave transmission line, transforms the low impedance of the shunt diode to a high impedance at the input of the harmonic filter. In the receive mode, the diodes are both off, and hence, there exists a low attenuation path between the antenna and receiver ports.3.1.3 Harmonic FilterThe harmonic filter consists of C104, L102, C103, L101 and C102. The design of the harmonic filter for UHF is that of a modified Zolotarev design. It has been optimized for efficiency of the power module. This type of filter has the advantage that it can give a greater attenuation in the stop-band for a given ripple level. The harmonic filter insertion loss is typically less than 1.2dB.3.1.4 Antenna Matching NetworkA matching network which is made up of L116 is used to match the antennas impedance to the harmonic filter. This will optimize the performance of the transmitter and receiver into an antenna.3.1.5 Power Control Integrated Circuit (PCIC)The transmitter uses the Power Control IC (PCIC), U102 to regulate the power output of the radio. The current to the final stage of the power module is supplied through R101, which provides a voltage proportional to the current drain. This voltage is then fedback to the Automatic Level Control (ALC) within the PCIC to regulate the output power of the transmitter. The PCIC has internal digital to analog converters (DACs) which provide the reference voltage of the control loop. The reference voltage level is programmable through the SPI line of the PCIC. There are resistors and integrators within the PCIC, and external capacitors (C133, C134 and C135) in controlling the transmitter rising and falling time. These are necessary in reducing the power splatter into adjacent channels. CR105 and its associated components are part of the temperature cut back circuitry. It senses the printed circuit board temperature around the transmitter circuits and output a DC voltage to the PCIC. If the DC voltage produced exceeds the set threshold in the PCIC, the transmitter output power will be reduced so as to reduce the transmitter temperature.
Receiver6C-54.0 Receiver4.1 Receiver Front-End(Refer toUHF Band 2 Receiver Front End Schematic Diagramon page 6C-16 andUHF Band 2 Transmitter Schematic Diagramon page 6C-20) The RF signal is received by the antenna and applied to a low-pass filter. For UHF, the filter consists of L101, L102, C102, C103, C104. The filtered RF signal is passed through the antenna switch. The antenna switch circuit consists of two PIN diodes(CR101 and CR102) and a pi network (C106, L104 and C107).The signal is then applied to a varactor tuned bandpass filter. The UHF bandpass filter comprises of L301, L302, C302, C303, C304, CR301 and CR302. The bandpass filter is tuned by applying a control voltage to the varactor diodes(CR301 and CR302) in the filter. The bandpass filter is electronically tuned by the DACRx from IC404 which is controlled by the microprocessor. Depending on the carrier frequency, the DACRx will supply the tuned voltage to the varactor diodes in the filter. Wideband operation of the filter is achieved by shifting the bandpass filter across the band. The output of the bandpass filter is coupled to the RF amplifier transistor Q301 via C307. After being amplified by the RF amplifier, the RF signal is further filtered by a second varactor tuned bandpass filter, consisting of L306, L307, C313, C317, CR304 and CR305. Both the pre and post-RF amplifier varactor tuned filters have similar responses. The 3 dB bandwidth of the filter is about 50 MHz. This enables the filters to be electronically controlled by using a single control voltage which is DACRx .Figure 6-2: UHF Receiver Block DiagramDemodulator SynthesizerCrystal Filter Mixer Va r a c t o r Tuned Filter RF Amp Va r a c t o r Tuned Filter Pin Diode Antenna Switch RF Jack Antenna AGC Control Voltage from ASFICFirst LO from FGU Recovered Audio Squelch RSSI IFIC SPI Bus 16.8 MHz Reference Clock Second LO VCO U301IF Amp
6C-6ReceiverThe output of the post-RF amplifier filter which is connected to the passive double balanced mixer consists of T301, T302 and CR306. Matching of the filter to the mixer is provided by C381. After mixing with the first LO signal from the voltage controlled oscillator (VCO) using low side injection, the RF signal is down-converted to the 45.1 MHz IF signal. The IF signal coming out of the mixer is transfered to the crystal filter (FL301) through a resistor pad and a diplexer (C322 and L310). Matching to the input of the crystal filter is provided by C324 and L311. The crystal filter provides the necessary selectivity and intermodulation protection.4.2 Receiver Back-End(Refer toUHF Band 2 Receiver Back End Schematic Diagramon page 6C-17) The output of crystal filter FL301 is matched to the input of IF amplifier transistor Q302 by components R352 and C325. Voltage supply to the IF amplifier is taken from the receive 5 volts (R5). The IF amplifer provides a gain of about 7dB. The amplified IF signal is then coupled into U301(pin 3) via C330, C338 and L330 which provides the matching for the IF amplifier and U301. The IF signal applied to pin 3 of U301 is amplified, down-converted, filtered, and demodulated, to produce the recovered audio at pin 27 of U301. This IF IC is electronically programmable, and the amount of filtering (which is dependent on the radio channel spacing) is controlled by the microprocessor. Additional filtering, once externally provided by the conventional ceramic filters, is replaced by internal filters in the IF module (U301). The IF IC uses a type of direct conversion process, whereby the externally generated second LO frequency is divided by two in U301 so that it is very close to the first IF frequency. The IF IC (U301) synthesizes the second LO and phase-locks the VCO to track the first IF frequency. The second LO is designed to oscillate at twice the first IF frequency because of the divide-by-two function in the IF IC. In the absence of an IF signal, the VCO will “search” for a frequency, or its frequency will vary close to twice the IF frequency. When an IF signal is received, the VCO will lock onto the IF signal. The second LO/VCO is a Colpitts oscillator built around transistor Q320. The VCO has a varactor diode, CR310, to adjust the VCO frequency. The control signal for the varactor is derived from a loop filter consisting of C362, C363, C364, R320 and R321. The IF IC (U301) also performs several other functions. It provides a received signal-strength indicator (RSSI) and a squelch output. The RSSI is a dc voltage monitored by the microprocessor, and used as a peak indicator during the bench tuning of the receiver front-end varactor filter. The RSSI voltage is also used to control the automatic gain control (AGC) circuit at the front-end. The demodulated signal on pin 27 of U301 is also used for squelch control. The signal is routed to U404 (ASFIC) where squelch signal shaping and detection takes place. The demodulated audio signal is also routed to U404 for processing before going to the audio amplifier for amplification.
Receiver6C-74.3 Automatic Gain Control Circuit(Refer toUHF Band 2 Receiver Front End Schematic Diagramon page 6C-16) The front end automatic gain control circuit is to provide automatic gain reduction of the front end RF amplifier via feedback. This action is necessary to prevent overloading of backend circuits. This is achieved by drawing some of the output power from the RF amplifier’s output. At high radio frequencies, capacitor C331 provides the low impedance path to ground for this purpose. CR308 is a PIN diode used for switching the path on or off. A certain amount of forward biasing current is needed to turn the PIN diode on. Transistors Q315 provides this current where upon saturation, current will flow via R347, PIN diode, collector and emitter of Q315 and R319 before going to ground. Q315 is an NPN transistor used for switching here. Maximum current flowing through the PIN is mainly limited by the resistor R319. Radio signal strength indicator, RSSI, a voltage signal, is used to drive Q315 to saturation hence turning it on. RSSI is produced by U301 and is proportional to the gain of the RF amplifier and the input RF signal power to the radio. Resistor network at the input to the base of Q315 is scaled to turn on Q315, hence activating the AGC, at certain RSSI levels. In order to turn on Q315, the voltage across the transistor’s base to ground must be greater or equal to the voltage across R319, plus the base-emitter voltage (Vbe) present at Q315. The resistor network with thermistor RT300 is capable of providing temperature compensation to the AGC circuit, as RSSI generated by U301 is lower at cold temperatures compared to normal operation at room temperature. Resistor R300 and capacitor C397 form an R-C network used to dampen any transient instability while the AGC is turning on.
6C-8Frequency Generation Circuitry5.0 Frequency Generation CircuitryThe Frequency Generation Circuitry is composed of two main ICs, the Fractional-N synthesizer (U201), and the VCO/Buffer IC (U241). Designed in conjunction to maximize compatibility, the two ICs provide many of the functions that normally would require additional circuitry. The synthesizer block diagram illustrates the interconnect and support circuitry used in the region. Refer to the relevant schematics for the reference designators. The synthesizer is powered by regulated 5V and 3.3V which come from U247 and U248 respectively. The synthesizer in turn generates a superfiltered 4.5V which powers U241. In addition to the VCO, the synthesizer must interface with the logic and ASFIC circuitry. Programming for the synthesizer is accomplished through the data , clock and chip select lines from the microprocessor. A 3.3V dc signal from synthesizer lock detect line indicates to the microprocessor that the synthesizer is locked. Transmit modulation from the ASFIC is supplied to pin10 of U201. Internally the audio is digitized by the Fractional-N and applied to the loop divider to provide the low-port modulation. The audio runs through an internal attenuator for modulation balancing purposes before going out to the VCO.Figure 6-3: Frequency Generation Unit Block DiagramVol tag e MultiplierSynthesizer U201Dual Tran- sistorLoop FilterVCOBIC U241Low Pass FilterMatching NetworkAttenuatorTo Mixer To PA DriverVCPVmult1Aux3 Aux4 MOD Out Modulating Signal Vmult2Rx VCO Circuit Tx VCO CircuitTRB 16.8 MHz Ref. Osc.Rx Out Tx Out