RF Technology T500B Base station transmitter User Manual Manual T500
RF Technology Pty Ltd Base station transmitter Manual T500
User manual with circuit diagrams removed
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| Document ID | 327852 |
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| Document Description | User manual with circuit diagrams removed |
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| Date Submitted | 2003-05-26 00:00:00 |
| Date Available | 2003-06-18 00:00:00 |
| Creation Date | 2003-05-26 17:33:34 |
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| Document Lastmod | 2003-05-27 08:16:08 |
| Document Title | Manual T500 |
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| Document Author: | GL |
Eclipse Ser ies RF Technology rfinfo@rftechnology.com.au August, 1998 T350 / T500 Tr ansmitter Operation and Maintenance Manual This manual is produced by RF Technology Pty Ltd 10/8 Leighton Place, Hornsby NSW 2077 Australia Copyright © 1998 RF Technology CONTENTS CONTENTS Contents Oper ating Instr uctions 1.1 Fr ont Panel Contr ols and Indicator s 1.1.1 PTT 1.1.2 Line 1.1.3 PWR LED 1.1.4 TX LED 1.1.5 ALARM LED Tr ansmitter Inter nal J umper Options 2.1 JP2: EPROM type 2.2 JP3: Dc Loop PTT 2.3 JP4: Audio Input Source 2.4 JP6: Input Level Attenuation 2.5 JP7: Audio Response 2.6 JP8: Sub-audible Tone source 2.7 JP9/10/11: dc Loop Configuration Tr ansmitter I/O Connections 3.1 25 Pin Connector Channel and Tone Fr equency Pr ogr amming Cir cuit Descr iption 5.1 VCO Section 5.2 PLL Section 5.3 Power Amplifier 5.4 600W line Input 5.5 Direct Coupled Audio Input 5.6 Local Microphone Input 5.7 CTCSS and Tone Filter 5.8 Audio Signal Processing 5.9 PTT and DC Remote Control 5.10 Micro-processor Controller 5.11 Voltage Regulator 10 10 11 11 11 11 12 12 13 13 Field 6.1 6.2 6.3 6.4 6.5 6.6 6.7 6.8 13 14 14 14 15 15 16 16 16 Page 2 Alignment Pr ocedur e Standard Test Conditions VCO Alignment TCXO Calibration Modulation Balance Tone Deviation Deviation Line Input Level Output Power RF Technology T350/T500 CONTENTS CONTENTS Specifications 7.1 Over all Descr iption 7.1.1 Channel Capacity 7.1.2 CTCSS 7.1.3 Channel Programming 7.1.4 Channel Selection 7.1.5 Micro-processor 17 17 17 17 17 17 18 7.2 Physical Configur ation 18 7.3 Fr ont Panel Contr ols, Indicator s and Test Points 7.3.1 Controls 7.3.2 Indicators 7.3.3 Test Points 18 18 18 19 7.4 Electr ical Specifications 7.4.1 Power Requirements 7.4.2 Frequency Range and Channel Spacing 7.4.3 Frequency Synthesizer Step Size 7.4.4 Frequency Stability 7.4.5 Number of Channels 7.4.6 Antenna Impedance 7.4.7 Output Power 7.4.8 Transmit Duty Cycle 7.4.9 Spurious and Harmonics 7.4.10 Carrier and Modulation Attack Time 7.4.11 Modulation 7.4.12 Distortion 7.4.13 Residual Modulation and Noise 7.4.14 600W Line Input Sensitivity 7.4.15 HI-Z Input 7.4.16 Test Microphone Input 7.4.17 External Tone Input 7.4.18 External ALC Input 7.4.19 T/R Relay Driver 7.4.20 Channel Select Input / Output 7.4.21 DC Remote Keying 7.4.22 Programmable No-Tone Period 7.4.23 Firmware Timers 7.4.24 CTCSS 19 19 19 19 19 19 19 19 20 20 20 20 20 20 20 20 21 21 21 21 21 21 22 22 22 7.5 Connector s 7.5.1 Antenna Connector 7.5.2 Power and I/O Connector 7.5.3 Test Connector 22 22 24 24 RF Technology T350/T500 Page 3 CONTENTS CONTENTS Engineer ing Diagr ams A.1 Block Diagram A.2 Circuit Diagrams A.3 Component Overlay Diagrams 24 24 24 25 Par ts List 26 Page 4 RF Technology T350/T500 1 OPERATING INSTRUCTIONS WARNING Changes or modifications not expressly approved by RF Technology could void your authority to operate this equipment. Specifications may vary from those given in this document in accordance with requirements of local authorities. RF Technology equipment is subject to continual improvement and RF Technology reserves the right to change performance and specification without further notice. Oper ating Instr uctions 1.1 Fr ont Panel Contr ols and Indicator s 1.1.1 PTT A front-panel push-to-talk (PTT) button is provided to facilitate bench and field tests and adjustments. The button is a momentary action type. When keyed, audio from the line input is disabled so that a carrier with sub-tone is transmitted. The front-panel microphone input is not enabled in this mode, but it is enabled when the PTT line on that socket is pulled to ground. 1.1.2 Line The LINE trimpot is accessible by means of a small screwdriver from the front panel of the module. It is used to set the correct sensitivity of the line and direct audio inputs. It is factory preset to give 60% of rated deviation with an input of 0dBm (1mW on 600W equivalent to 775mV RMS or about 2.2V peak-to-peak) at 1kHz. The nominal 60% deviation level may be adjusted by measuring between pins 6 and 1 on the test socket, and adjusting the pot. By this means an input sensitivity from approximately -30dBm to +10dBm may be established. An internal jumper provides a coarse adjustment step of 20dB. Between the jumper and the trimpot, a wide range of input levels may be accommodated. RF Technology T350/T500 Page 5 1.1 Front Panel Controls and Indicators LED Flash Cadence 5 flashes, pause 4 flashes, pause 3 flashes, pause 2 flashes, pause 1 flash, pause LED ON continuously 1 OPERATING INSTRUCTIONS Fault Condition Synthesizer unlocked Tuning voltage out of range Low forward power High reverse (reflected) power Low dc supply voltage Transmitter timed out Table 1: Inter pr etations of LED flash cadence Indication Flashing, 8 per second Flashing, 4 per second Flashing, 2 per second Flashing, 1 per second Continuous Fault Condition Synthesizer unlocked Tuning voltage outside correct range Low forward power High reverse power dc supply voltage low or high Table 2: Inter pr etations of LED flash speed, for ear ly models 1.1.3 POWER LED The PWR LED shows that the dc supply is connected to the receiver. 1.1.4 TX LED The TX LED illuminates when the transmitter is keyed. It will not illuminate (and an Alarm cadence will be shown) if the synthesizer becomes unlocked, or the output amplifier supply is interrupted by the microprocessor. 1.1.5 ALARM LED The Alarm LED can indicate several fault conditions if they are detected by the self test program. The alarm indicator shows the highest priority fault present. Receivers using software issue 5 and higher use the cadence of the LED flash sequence to indicate the alarm condition. Refer to table 1. Receivers using software issue 4 and lower use the LED flash rate to indicate the alarm condition. Refer to table 2. Page 6 RF Technology T350/T500 2 TRANSMITTER INTERNAL JUMPER OPTIONS Tr ansmitter Inter nal J umper Options In the following subsections an asterisk (*) signifies the standard (Ex-Factory) configuration of a jumper. 2.1 J P2: EPROM Type Condition 27C256 27C64 Position 2-3 * 1-2 2.2 J P3: Dc Loop PTT This jumper enables or disables the keying of the PTT function by means of a dc signal passed down the 600W line input pair. When enabled, JP9-JP11 control how the dc signal is configured with respect to an internal opto-coupler. Condition dc loop connected (enabled) dc loop not connected (bypassed) 2.3 Position 1-2 * 2-3 J P4: Audio Input Sour ce Either the 600W or the high-Z balanced inputs may be selected. Condition 600W Input High-impedance Input 2.4 Position 2-3 * 1-2 J P6: Input Level Attenuation This jumper permits coarse input sensitivity to be set. Condition 0dB attenuation 20dB attenuation Position 1-2 * 2-3 RF Technology T350/T500 Page 7 2.5 JP7: Audio Response 2.5 J P7: Audio Response Condition 750 uSec. pre-emphasis Flat response 2.6 Position 1-2 * 2-3 J P8: Sub-audible Tone Sour ce Condition Internal CTCSS External input 2.7 4 CHANNEL AND TONE FREQUENCY PROGRAMMING Position 1-2, 4-5 * 2-3, 5-6 J P9/10/11: dc Loop Configur ation These settings are only relevant when the PTT signal is to be used across the same wires as the audio. Refer to setting of JP3. They control the levels and connection into the audio balanced line circuitry. Condition Current Loop Input 12Vdc Loop source 3.1 J P9 ON OFF J P10 OFF ON J P11 OFF * ON Tr ansmitter I/O Connections 25 Pin Connector The D-shell 25 pin connector is the main interface to the transmitter. The pin connections are described in table 3. Channel and Tone Fr equency Pr ogr amming Channel and tone frequency programming is most easily accomplished with RF Technology TecHelp software or the Service Monitor 2000 software. This software can be run on an IBM compatible PC and provides a number of additional useful facilities. DOS and 32-bit versions are available. TecHelp allows setting of the adaptive noise squelch threshold, provides a simple means of calibrating the forward and reverse power detectors, setting the power alarm preset levels, and enabling transmitter hang time and timeout time limits. TecHelp can be supplied by your dealer, distributor or by contacting RF Technology directly. Page 8 RF Technology T350/T500 4 CHANNEL AND TONE FREQUENCY PROGRAMMING Function DC power Channel Select RS232 Data 600W Line Signal +12 Vdc 0 Vdc 10 20 40 80 In Out High Low 150W / Hybrid Direct PTT input T/R Relay driver output Sub-Audible Tone Input High-Z Audio Input [+] [-] [+] [-] External ALC input Pins 1, 14 13, 25 21 22 10 23 11 24 12 15 20 19 16 18 17 Specification +11.4 to 16 Vdc Ground BCD Coded 0 = Open Circuit or 0 Vdc 1 = +5 to +16 Vdc Test and Programming use 9600, 8 data 2 stop bits Transformer Isolated Balanced 0dBm Output Ground to key PTT Open collector,250mA/30V >10kW, AC coupled (1-250Hz) >10kW, AC coupled (10Hz-3kHz) <0.5V/1mA to obtain >30dB attenuation, O/C for maximum power Table 3: Pin connections and explanations for the main 25-pin, D connector . Cir cuit Descr iption The following descriptions should be read as an aid to understanding the block and schematic diagrams given in the appendix of this manual. 5.1 VCO Section The Voltage Controlled Oscillator uses a junction FET which oscillates at the required transmitter output frequency. A varactor diode is used by the PLL circuit to keep the oscillator on the desired frequency. Transistor Q20 is used as an active filter to reduce the noise on the oscillator supply voltage. The VCO is keyed ON by the microcontroller through Q10. It is keyed ON when any of the PTT inputs are active and OFF at all other times. RF Technology T350/T500 Page 9 5 CIRCUIT DESCRIPTION The VCO output is amplified and buffered by monolithic amplifiers MA2 and MA3 before being fed to the PLL IC U6. Amplifiers MA1, MA4 and MA5 increase the VCO output to approximately 4 mW to drive the power amplifier. MA1 is not switched on until the PLL has locked and had time to settle. This prevents any momentary off channel transmission when the transmitter is keyed. 5.2 PLL Section Temperature compensated crystal oscillator XO1 is the frequency reference source for the PLL Synthesizer. The frequency stability of XO1 is better than 1 ppm and it can be synchronized to an external reference for improved stability. External reference option board 11/9119 is required when using an external reference. XO1 is frequency modulated by the processed transmit audio signal from U7b. This extends the modulation capability down to a few Hz for sub-audible tones and digital squelch codes. A two point modulation scheme is used with the audio also being fed to the VCO to modulate the higher audio frequencies. The 12.8 MHz output of XO1 is amplified by Q22 to drive the reference input of the PLL synthesizer IC U6. This IC is a single chip synthesizer which includes a 1.1 GHz pre-scaler, programmable divider, reference divider and phase/frequency detector. The frequency data for U6 is supplied through serial data link by the microprocessor. The phase detector output signals of U6 are used to control two switched current sources. The output of the positive and negative sources (Q3 and Q6) produces the tuning voltage which is smoothed by the loop filter components to bias the VCO varactor diode D3. 5.3 Power Amplifier The 4 mW output from the main board connects to the power amplifier board through a short miniature 5W coaxial cable. Q2 on the power amplifier board increases the signal to approximately 200 mW. The bias current of Q2 is controlled by Q1 and the power leveling circuitry to adjust the drive to the output module U2. U2 increases the power to 10-30 watts (depending upon options) before it is fed to the directional coupler, low pass filter and output connector. The directional coupler detects the forward and reverse power components and provides proportional dc voltages which are amplified by U1a and U1b. The forward and reverse voltages from U1a and U1b are compared to the DC reference voltage from RV1. The difference is amplified by U1c, Q3 and Q4. Page 10 RF Technology T350/T500 5 CIRCUIT DESCRIPTION 5.3 Power Amplifier The resulting control voltage supplies Q2 through R10, R12 and completes the power leveling control loop. 5.4 600W Line Input The 600W balanced line input connects to line isolation transformer T1. T1 has two 150W primary windings which are normally connected in series for 600W lines. The dual primary windings can be used to provide DC loop PTT signaling or a 2/4 wire hybrid connection. All four leads are available at the rear panel system connector. The secondary of T1 can be terminated with an internal 600W load through JP5 or left un-terminated in high impedance applications. 5.5 Dir ect Coupled Audio Input A high impedance (10kW) direct AC coupled input is available at the system connector. The direct coupled input connects to U9a which is configured as a unity gain bridge amplifier. The bridge configuration allows audio signal inversion by interchanging the positive and negative inputs and minimizes ground loop problems. Both inputs should be connected, with one lead going to the source output pin and the other connected to the source audio ground. 5.6 Local Micr ophone Input The local microphone input is provided for use with a standard low impedance dynamic microphone. The microphone output is amplified by U9a before connecting to analogue switch U10a. U10b inverts the local microphone PTT input to switch U10a ON when the microphone PTT button is pressed. U10a is OFF at all other times. The local microphone audio has priority over the other inputs. Activation of the local microphone PTT input switches OFF the audio from the line or direct inputs through D16 and U10c. 5.7 CTCSS and Tone Filter The CTCSS encoder module H1, under control of the main microprocessor U13, can encode all 38 EIA tones and (on some models) additional commonly-used tones. The tone output of H1 connects to jumper JP8 which is used to select either H1 or an external tone source. The selected source is coupled to U9c which is a balanced input unity gain amplifier. The buffered tone from U9c is fed to 300 Hz low pass filter U7c. RV3, the tone deviation trimmer, is used to adjust the level of the tone RF Technology T350/T500 Page 11 5.8 Audio Signal Processing 5 CIRCUIT DESCRIPTION from U7c before it is combined with the voice audio signal in the summing amplifier U7a. Back to back diodes D4 and D5 limit the maximum tone signal amplitude to prevent excessive tone deviation when external tone sources are used. 5.8 Audio Signal Pr ocessing Jumper JP4 selects either the line or direct input source. The selected source is then connected to JP6. JP6 can be removed to provide 20 dB attenuation when the input level is above 10 dBm to expand the useful range of the line level trimmer RV4. The wiper of RV4 is coupled to the input of the input amplifier U9d. U9d provides a voltage gain of ten before connecting to the input of analogue switch U10c. The outputs of U10a and U10c are connected to the frequency response shaping networks C52, R133 (for 750ms pre-emphasis) and C61, R55 (for flat response). JP7 selects the pre-emphasized or flat response. The audio signal is further amplified 100 times by U7d. U7d also provides the symmetrical clipping required to limit the maximum deviation. The output level from U7d is adjusted by RV1, the deviation adjustment, before being combined with the tone audio signal in the summing amplifier U7a. The composite audio from U7a is fed through the 3Khz low pass filter U7b. The filtered audio is coupled to the TCXO voltage tuning input and the modulation balance trimmer RV2. RV2 adjusts level of the audio used to modulate the VCO. This primarily effects the deviation of audio frequencies above 500 Hz. RV2 is used to balance the high and low frequency deviation to obtain a flat frequency response relative to the desired characteristic. 5.9 PTT and DC Remote Contr ol Two main PTT inputs are provided. The first, a direct logic level input, is connected to pin 3 of the system connector. The transmitter can be keyed by applying a logic low or ground on pin 3. Pin 3 connects to the PTT logic and microprocessor through D10. DC current loop control can be used for remote PTT operation. The current loop can be configured by JP9, JP10 and JP11 for use with either a remote free switch or a remote switched source. Opto-isolator ISO1 is used to isolate the loop current signal from the transmitter PTT logic. The loop current passes through the input of ISO1 and the output of ISO1 connects to the PTT logic. Page 12 RF Technology T350/T500 5 CIRCUIT DESCRIPTION 5.10 Microprocessor Controller A bridge consisting of diodes D6, D8, D9 and D14 ensures correct operation regardless of the current polarity. Q17 limits the current and D7 limits the voltage input to ISO1. Any low voltage current source capable of providing 2 mA at 4 V or switching circuit with less than 4.8kW loop resistance can be used to switch the DC loop. The test PTT button on the front panel and the local microphone PTT button will also key the transmitter. Both of these also mute the line audio input. The microphone line also enables that audio input. 5.10 Micr opr ocessor Contr oller The microprocessor controller circuit uses a single-chip eight bit processor and several support chips. The processor U13 includes non-volatile EE memory for channel frequencies, tones, and other information. It also has an asynchronous serial port, a synchronous serial port and an eight bit analogue to digital converter. The program is stored in U5, a CMOS EPROM. U4 is an address latch for the low order address bits. U2 is used to read the channel select lines onto the data bus. U11 is an address decoder for U5 and U2. U3 is a supervisory chip which keeps the processor reset unless the +5 Volt supply is within operating limits. U1 translates the asynchronous serial port data to standard RS232 levels. The analogue to digital converter is used to measure the forward and reverse power, tuning voltage and dc supply voltage. The processor keys the VCO through Q10, switches the 9.2 Volt transmit line through Q14 and Q16, and the alarm LED D1 through Q1. 5.11 Voltage Regulator The dc input voltage is regulated down to 9.4 Vdc by a discrete regulator circuit. The series pass transistor Q23 is driven by error amplifiers Q8 and Q18. Q9 is used to start up the regulator and once the circuit turns on, it plays no further part in the operation. The +5 Volt supply for the logic circuits is provided by an integrated circuit regulator U14 which is run from the regulated 9.4 Volt supply. Field Alignment Pr ocedur e The procedures given below may be used to align the transmitter in the field. Normally, alignment is only required when changing operating frequencies, or after component replacement. RF Technology T350/T500 Page 13 6 FIELD ALIGNMENT PROCEDURE 6.1 Standard Test Condition The procedures below do not constitute an exhaustive test or a complete alignment of the module, but if successfully carried out are adequate in most circumstances. TCXO calibration may be periodically required owing to normal quartz crystal aging. A drift of 1ppm/year is to be expected. Each alignment phase assumes that the preceding phase has been successfully carried out, or at least that the module is already in properly aligned state with respect to preceding conditions. 6.1 Standar d Test Condition The following equipment and conditions are assumed unless stated otherwise: · AF signal generator with 600W impedance, 150-3000Hz frequency range, with level set to 387mV RMS. · Power supply set to 13.8Vdc, with a current capable of >5A. · RF 50W load, 30W rated, return loss <-20dB. · Jumpers set to factory default positions. 6.2 VCO Alignment 1. Select a channel at the center frequency (half way between the highest and lowest frequencies for the model in question). 2. Disconnect the Audio input (no signal input). 3. Key the PTT line. 4. Measure the voltage between pins 9 and 1 of the test socket (TUNE V), and adjust C99 to obtain 4.5±0.25V, while the TX LED is ON and the ALARM LED is OFF. 6.3 TCXO Calibr ation 1. Select a channel at the center frequency (half way between the highest and lowest frequencies for the model in question). 2. Disconnect the Audio input (no signal input). 3. Key the PTT line. Page 14 RF Technology T350/T500 6.4 Modulation Balance 4. 6.4 6 FIELD ALIGNMENT PROCEDURE Measure the carrier frequency at the output connector, and adjust XO1 until the correct carrier frequency is measured, ±50Hz. Modulation Balance 1. Set RV3 fully counter clockwise (CCW) (sub-tone off). 2. Set RV1 fully clockwise (CW) (maximum deviation) 3. Set RV2 mid-position 4. Set JP7 for flat response 5. Key the transmitter on 6. Set the audio input to 150Hz, 0dBm. 7. Measure deviation and adjust RV4 (line Level) for a deviation of 5kHz (2.5kHz for narrow band transmitters). 8. Set the audio input to 1.5kHz, 0dBm. 9. Adjust RV2 (Mod. Bal.) for a deviation of 5kHz (2.5kHz for narrow band transmitters). 10. Repeat steps 6-9 until balance is achieved. 11. Key the transmitter off. 12. Return JP7 to its correct setting. 13. Carry out the Deviation (section 6.6) and Tone Deviation (section 6.5) alignment procedures. 6.5 Tone Deviation 1. Remove the audio input. 2. Key the transmitter on. 3. Adjust RV3 for the desired deviation in the range 0-1kHz.1 (CTCSS) coding is not to be used, adjust RV3 fully CCW. If sub-tone ____________________ The factory default is 500Hz for wide band (5kHz maximum deviation) and 250Hz for narrow band channels. RF Technology T350/T500 Page 15 6 FIELD ALIGNMENT PROCEDURE 6.6 6.6 Deviation Deviation 1. Set RV4 (Line Level) fully clockwise (CW). 2. Set the audio to 1kHz, 0dBm, on the line input. 3. Key the transmitter on.. 4. Adjust RV1 (Set Max. Deviation) for a deviation of 5kHz (2.5kHz for narrow band transmitters). 5. Key the transmitter off. 6. Carry out the Line Input Level alignment procedure (section 6.7) 6.7 Line Input Level 1. Set the audio to 1kHz, 0dBm, on the line input, or use the actual signal to be transmitted. 2. Key the transmitter on. 3. Adjust RV4 (line level) for 60% of system deviation (3kHz or 1.5kHz for narrow band systems). 4. If the test signal is varying, RV4 may be adjusted to produce a level of 234mV RMS or 660mVp-p at the audio voltage test connector pin 6 to pin 1. 5. Key the transmitter off. 6.8 Output Power 1. No audio input is required 2. Key the transmitter on. 3. Adjust RV1 on the power amplifier PCB for the desired power level at the output connector. 2 4. Key the transmitter off. ____________________ Be sure to set the power below the rated maximum for the model of transmitter. If in doubt, allow 1.5dB cable and connector losses, and assume that the maximum rated power is 15W. This means no more than 10W at the end of a 1m length of test cable. This pessimistic procedure is safe on all models manufactured at the time of writing. Page 16 RF Technology T350/T500 7 SPECIFICATIONS 7.1 SPECIFICATIONS Over all Descr iption The transmitter is a frequency synthesized, narrow band FM unit, normally used to drive a 50 watt amplifier. It can also be used alone in lower power applications. Various models allow 2-25W of output power to be set across a number of UHF frequency bands. All necessary control and 600W line interface circuitry is included. 7.1.1 Channel Capacity Although most applications are single channel, it can be programmed for up to 100 channels, numbered 0 - 99. This is to provide the capability of programming all channels into all of the transmitters used at a given site. Where this facility is used in conjunction with channel-setting in the rack, exciter modules may be “hot-jockeyed” or used interchangeably. This can be convenient in maintenance situations. 7.1.2 CTCSS Full EIA sub-tone capability is built into the modules. The CTCSS tone can be programmed for each channel. This means that each channel number can represent a unique RF and tone frequency combination. 7.1.3 Channel Pr ogr amming The channel information is stored in non-volatile memory and can be programmed via the front panel test connector using a PC and RF Technology software. 7.1.4 Channel Selection Channel selection is by eight channel select lines. These are available through the rear panel connector. Internal presetting is also possible. The default (open-circuit) state is to select channel 00. A BCD active high code applied to the lines selects the required channel. This can be supplied by pre-wiring the rack connector so that each rack position is dedicated to a fixed channel. Alternatively, thumb-wheel switch panels are available. RF Technology T350/T500 Page 17 7 SPECIFICATIONS 7.1.5 Microprocessor 7.1.5. Micr opr ocessor A microprocessor is used to control the synthesizer, tone squelch, PTT function and facilitate channel frequency programming. With the standard software, RF Technology modules also provide fault monitoring and reporting. 7.2 Physical Configur ation The transmitter is designed to fit in a 19 inch rack mounted sub-frame. The installed height is 4 RU (178 mm) and the depth is 350 mm. The transmitter is 63.5 mm or two Eclipse modules wide. 7.3 Fr ont Panel Contr ols, Indicator s, and Test Points 7.3.1 Contr ols Transmitter Key - Momentary Contact Push Button Line Input Level - screwdriver adjust multi-turn pot 7.3.2 Indicator s Power ON - Green LED Tx Indicator - Yellow LED Fault Indicator - Flashing Red LED External ALC - Green LED External Reference - Green LED 7.3.3 Test Points Line Input – Pin 6 + Ground (pin 1) Forward Power – Pin 8 + Ground (pin 1) Reverse Power – Pin 4 + Ground (pin 1) Tuning Voltage – Pin 9 + Ground (pin 1) Serial Data (RS-232) – Pins 2 / 3 + Ground (pin 1) Page 18 RF Technology T350/T500 7 SPECIFICATIONS 7.4 Electrical Specifications 7.4 7.4.1 Electr ical Specifications Power Requir ements Operating Voltage - 10.5 to 16 Vdc with output power reduced below 12 Vdc Current Drain - 5A Maximum, typically 0.25A Standby Polarity - Negative Ground 7.4.2 Fr equency Range and Channel Spacing Fr equency 330-365 MHz 360-380 MHz 375-400 MHz 403-420 MHz 430-450 MHz 450-520 MHz 7.4.3 25 kHz T350C T350A T350B T500A T500D T500B 12.5 kHz T350CN T350AN T350BN T500AN T500DN T500BN Fr equency Synthesizer Step Size Step size is 10 / 12.5kHz or 5 / 6.25kHz, fixed, depending upon model 7.4.4 Fr equency Stability ±1 ppm over 0 to +60 C, standard ±1ppm over -20 to +60 C, optional 7.4.5 Number of Channels 100, numbered 00 - 99 7.4.6 Antenna Impedance 50W 7.4.7 Output power Preset for 2-15 or 2-25W depending upon model RF Technology T350/T500 Page 19 7 SPECIFICATIONS 7.4.8 7.4.8 Transmit Duty Cycle Tr ansmit Duty Cycle 100% to 40C, de-rating to zero at 60C. 100% to 5000ft altitude, de-rating to zero at 15,000ft. 7.4.9 Spur ious and Har monics Less than 0.25mW 7.4.10 Car r ier and Modulation Attack Time Less than 20ms. Certain models have RF envelope attack and decay times controlled in the range 200ms< tr/f <2ms according to regulatory requirements. 7.4.11 Modulation Type - Two point direct FM with optional pre-emphasis Frequency Response - ±1 dB of the selected characteristic from 300 - 3000 Hz Maximum Deviation - Maximum deviation preset to 2.5 or 5 kHz 7.4.12 Distor tion Modulation distortion is less than 3% at 1 kHz and 60% of rated system deviation. 7.4.13 Residual Modulation and Noise The residual modulation and noise in the range 300 - 3000 Hz is typically less than 50dB referenced to rated system deviation. 7.4.14 600W Line Input Sensitivity Adjustable from -30 to +10 dBm for rated deviation 7.4.15 HI-Z Input Impedance - 10KW Nominal, balanced input Input Level - 25mV to 1V RMS Page 20 RF Technology T350/T500 7.4.16 Test Microphone Input 7 SPECIFICATIONS 7.4.16 Test Micr ophone Input 200W dynamic, with PTT 7.4.17 Exter nal Tone Input Compatible with R500 tone output 7.4.18 Exter nal ALC Input Output will be reduced 20dB by pulling the input down to below 1V. (Typically more than 40dB attenuation is available.) The input impedance is @10kW, internally pulled up to rail. The external ALC input can be connected to the power control circuit in Eclipse external power amplifiers. 7.4.19 T/R Relay Dr iver An open collector transistor output is provided to operate an antenna change over relay or solid state switch. The transistor can sink up to 250mA. 7.4.20 Channel Select Input / Output Coding - 8 lines, BCD coded 00 - 99 Logic Input Levels - Low for <1.5V, High for >3.5V Internal 10K pull down resistors select channel 00 when all inputs are O/C. 7.4.21 DC Remote Keying An opto-coupler input is provided to enable dc loop keying over balanced lines or local connections. The circuit can be connected to operate through the 600W line or through a separate isolated pair. RF Technology T350/T500 Page 21 7 SPECIFICATIONS 7.4.22 7.4.22 Programmable No-Tone Period Pr ogr ammable No-Tone Per iod A No-Tone period can be appended to the end of each transmission to aid in eliminating squelch tail noise which may be heard in mobiles with slow turn off decoders. The NoTone period can be set from 0--5 seconds in 0.1 second increments. The No Tone period operates in addition to the reverse phase burst at the end of each transmission.3 7.4.23 Fir mwar e Timer s The controller firmware includes some programmable timer functions. Repeater Hang Time - A short delay or ``Hang Time'' can be programmed to be added to the end of transmissions. This is usually used in talk through repeater applications to prevent the repeater from dropping out between mobile transmissions. The Hang Time can be individually set on each channel for 0 - 15 seconds. Time Out Timer - A time-out or transmission time limit can be programmed to automatically turn the transmitter off. The time limit can be set from 0-254 minutes in increments of one minute. The timer is automatically reset when the PTT input is released. 7.4.24 CTCSS CTCSS tones can be provided by an internal encoder or by an external source connected to the external tone input. The internal CTCSS encoding is provided by a subassembly PCB module. This provides programmable encoding of all EIA tones. Some models encode certain extra tones. Tone frequencies are given in table 4. 7.5 7.5.1 Connector s Antenna Connector Type N Female Mounted on the module rear panel The reverse phase burst is usually sufficient to eliminate squelch tail noise in higher-quality mobiles Page 22 RF Technology T350/T500 7 SPECIFICATIONS Fr equency No Tone 67.0 69.4 71.9 74.4 77.0 79.7 82.5 85.4 88.5 91.5 94.8 97.4 100.0 103.5 107.2 110.9 114.8 118.8 123.0 127.3 131.8 136.5 141.3 146.2 151.4 156.7 159.8 162.2 165.5 167.9 171.3 173.8 177.3 179.9 183.5 186.2 189.9 192.8 196.6 199.5 203.5 206.5 210.7 218.1 225.7 229.1 233.6 241.8 250.3 254.1 EIA Number RF Technology T350/T500 A1 B1 C1 A2 C2 B2 C3 A3 C4 B3 A4 B4 A5 B5 A6 B6 A7 B7 A8 B8 A9 B9 A10 B10 A11 B11 A12 B12 A13 B13 A14 B14 A15 B15 A16 B16 A17 Table 4: Tone Squelch Fr equencies Page 23 A ENGINEERING DIAGRAMS 7.5.2 Power & I/O Connector 25-pin “D” Male Mounted on the rear panel 7.5.3 Test Connector 9-pin “D” Female mounted on the front panel Engineer ing Diagr ams Most Eclipse transmitter modules contain two PCBs, a motherboard with the control and signal generation circuitry (the exciter board), and an RF Power Amplifier board. Certain models are equipped with optional functions on piggyback PCBs atop the exciter motherboard. The exciter PCB typically has a few components whose values vary from model to model depending upon operating frequency and local regulatory constraints. The RF PA PCB varies from model to model but to a greater extent. At least two different PCB layouts, and numerous variations, exist. This manual presents the circuits and parts lists for two representative variants. When ordering spare parts be sure to specify the model exactly, in case the part you require is different in value from that specified in this manual. Older models (predating this manual) may not be covered by this manual. However, advances are evolutionary, and the information in this manual will be sufficient in most cases to permit understanding and servicing of all models, past and present. Versions of more detailed circuit schematics, printed on A3 paper, may be inserted or bound with this manual towards the end. It is sometimes easier to work with these foldout diagrams because of their larger format. In case the inserts / fold-outs are missing or damaged, the reader is advised that information in the figures included with the text should be identical. A.1 Block Diagr am Figure 1 shows the block signal flow diagram. A.2 Cir cuit Diagr ams Figure 2 shows the detailed circuit diagram with component numbers and values for the main (exciter) PCB. Figure 3 shows the detailed circuit diagram with component numbers and values for the higher-power PA variation. Figure 4 shows the detailed circuit diagram with component numbers and values for the lower-power PA variation. Page 24 RF Technology T350/T500
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