RF Technology 1UTR800CN UHF BASE STATION User Manual R800 Manual
RF Technology Pty Ltd UHF BASE STATION R800 Manual
Users Manual
| Download: |  |
| Mirror Download [FCC.gov] | |
| Document ID | 1512886 |
| Application ID | CoHWoiPk0SO63PamZ6Q4TA== |
| Document Description | Users Manual |
| Short Term Confidential | No |
| Permanent Confidential | No |
| Supercede | No |
| Document Type | User Manual |
| Display Format | Adobe Acrobat PDF - pdf |
| Filesize | 14.73kB (184153 bits) |
| Date Submitted | 2011-07-29 00:00:00 |
| Date Available | 2011-07-29 00:00:00 |
| Creation Date | 2005-02-03 15:20:50 |
| Producing Software | Acrobat PDFWriter 5.0 for Windows NT |
| Document Lastmod | 2011-07-05 13:49:58 |
| Document Title | R800 Manual.doc |
| Document Creator | R800 Manual - Microsoft Word |
| Document Author: | GL |
Eclipse Ser ies RF Technology rfinfo@rftechnology.com.au September 2003 Revision 2 T800 Tr ansmitter Oper ation and Maintainance Manual This manual is produced by RF Technology Pty Ltd 10/8 Leighton Place, Hornsby NSW 2077 Australia Copyright © 1997, 1998, 2003 RF Technology CONTENTS CONTENTS 1. Operating Instructions 1.1 Front Panel controls and Indicators 1.1.1 PTT 1.1.2 Line 1.1.3 PWR LED 1.1.4 TX LED 1.1.5 ALARM LED 1.1.6 ALC LED 1.1.7 REF LED 1.1.8 TEST MIC 2. Transmitter Internal J umper Options 2.1 JP2: EPROM Type 2.2 JP3: Dc Loop PTT 2.3 JP4: Audio Input source 2.4 JP5: 600 ¿ Termination 2.5 JP6: Input Level Attenuation 2.6 JP7: Audio Frequency Response 2.7 JP8: Subaudible Tone Source 2.8 JP9, JP10, JP11 dc Loop PTT Input Configuration JP3 (1-2) 2.9 JP16: Direct Digital Input (Rev 4 or Higher) 2.10 JP17: Bypass Low Pass Filter (Rev 4 or Higher) 2.11 JP19: Alarm Output (Rev 4 or Higher) 2.12 JP22: Use Tone- as a Direct Digital Input (Rev 4 or Higher) 2.13 JP23: Connection of DMTX Board (Rev 4 or Higher) 3. Transmitter Internal J umper Options 3.1 25 Pin Connector 3.2 Rear Panel Connectors 10 11 4. Channel and Tone Frequency Programming 12 5. Circuit Description 5.1 VCO Section 5.2 PLL Section 5.3 Power Amplifier 5.4 Temperature Protection 5.5 600 ¿ Line Input 5.6 Direct coupled Audio Input 5.7 Local Microphone Input 5.8 CTCSS and Tone Filter 5.9 Audio Signal Processing 5.10 PTT and DC Remote Control 5.11 Microprocessor Controller 5.12 Voltage Regulator 13 13 13 14 14 14 14 15 15 15 16 16 17 6. Field Alignment Procedure 17 6.1 Standard Test Conditions 18 6.2 VCO Alignment 18 6.3 TCXO Calibration 18 6.4 Modulation Balance 19 ___________________________________________________________________________ RF Technology T800 Page 2 CONTENTS 6.5 6.6 6.7 6.8 CONTENTS Tone Deviation Deviation Line Input Level Output Power 19 20 20 20 Specifications 21 7.1 Overall Descr iption 7.1.1 Channel Capacity 7.1.2 CTCSS 7.1.3 Channel Programming 7.1.4 Channel Selection 7.1.5 Microprocessor 21 21 21 21 21 21 7.2 Physical Configuration 22 7.3 Front 7.3.1 7.3.2 7.3.3 22 22 22 22 7.4 Electrical 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 7.4.14 600¿ 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 7.5 Panel Controls, Indicators and Test Points Controls Indicators Test Points 22 22 23 23 23 23 23 23 23 23 23 23 24 24 24 24 24 24 24 24 24 25 25 25 25 Connectors 25 7.5.1 Antenna Connector 25 7.5.2 Power and I/O Connector 27 7.5.3 Test Connector 27 ___________________________________________________________________________ RF Technology T800 Page 3 CONTENTS Engineering Diagrams A1 Block Diagram A2 Circuit Diagram A3 Component Overlay Diagram Parts List CONTENTS ___________________________________________________________________________ RF Technology T800 Page 4 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 600Ω 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. 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. ___________________________________________________________________________ RF Technology T800 Page 5 1.1.5 Alarm LED 1.1.5 1 OPERATING INSTRUCTIONS 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. LED Flash Cadence 5 flashes, pause 4 flashes, pause 3 flashes, pause 2 flashes, pause 1 flash, pause LED ON continuously 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: Interpretations 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: Interpretations of LED flash speed, for ear ly models 1.1.6 ALC LED The ALC LED indicates that the transmitter output power is being controlled by an external amplifier through the external ALC input. 1.1.7 REF LED The REF LED indicates that the synthesizer frequency reference is locked to an external reference. 1.1.8 TEST MIC. The TEST MIC. DIN socket is provided for use with a standard mobile or handset 200 Ohm dynamic microphone. The external audio inputs are disabled when the TEST MIC’S PTT is on. ___________________________________________________________________________ RF Technology T800 Page 6 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 2.2 Position 2-3 * 1-2 J P3: 600 Ohm Line Dc Loop PTT Input By default, Eclipse exciters can be keyed up by pulling the PTT signal low, or by dc loop signalling on the audio pair. This jumper enables or disables this second method. Condition dc loop connected (enabled) dc loop not connected (bypassed) 2.3 Position 1-2 * 2-3 J P4: Audio Input Sour ce Selection Either the 600Ω or the high-Z balanced inputs may be selected. Condition 600Ω Input High-impedance Input Position 2-3 * 1-2 2.4 J P5: 600 ¿ Ter mination Normally the Line Input is terminated in 600 ¿ . The 600 ohm termination can be removed by choosing the alternate position. Condition 600¿ Termination No Termination Position 1-2* 2-3 ___________________________________________________________________________ RF Technology T800 Page 7 2.5 JP6: Input Level Attenuation 2.5 2 TRANSMITTER JUMPER OPTIONS J P6: Input Level Attenuation This jumper permits coarse input sensitivity to be set. In the default position, the unit expects a line level of 0dBm (nominal) at its Line Input. In the alternate position, levels of +20dBm(nominal) can be accepted. Condition 0dB attenuation 20dB attenuation 2.6 Position 1-2 * 2-3 J P7: Audio Fr equency Response Condition 750 uSec. Pre-emphasis Flat Response 2.7 J P8: Sub-audible Tone Source Condition Internal CTCSS External input 2.8 Position 1-2 * 2-3 Position 1-2, 4-5 * 2-3, 5-6 J P9/10/11: dc Loop Configur ation Dc loop current on the audio pair is normally sourced externally. The Eclipse exciters loop the current through an opto-isolator. When the current flows the exciter keys up. An alternative arrangement is possible. device can provide the dc loop. The exciters can source the current and an external These three jumpers select the appropriate mode. Condition Current Loop Input 12Vdc Loop source 2.9 J P9 ON OFF J P10 OFF ON J P11 OFF * ON J P16: Dir ect Digital Input (Rev 4 or Higher ) Some trunking controllers have digital encoding schemes which operate to very low frequencies. The elliptical filter, used as a 250Hz low pass filter in the tone section, can ___________________________________________________________________________ RF Technology T800 Page 8 2 TRANSMITTER INTERNAL JUMPER OPTIONS 2.10 JP17: Bypass Low Pass Filter cause excessive pulse edge distortion of the trunking controller’s digital signals. In such circumstances, JP16 allows a user to bypass the low and high pass filters in the tone input section. See also 2.12 - JP22: If direct tone input is selected, then JP22 should be removed (open) Condition Normal Tone Input Direct Tone Input Position 1-2* 2-3 2.10 J P17: Bypass Low Pass Filter (Rev 4 or higher ) Some trunking controllers have digital encoding schemes that require the low pass filter in the tone input section to be bypassed. JP17 allows this. Normally JP17 is open circuit. Placing a link across it will bypass the low pass filter. In conjunction with this change, it sometimes may be necessary, depending on the type of trunking controller used, to add a 100K resistor in the place reserved for R157. 2.11 J P19: Alar m Output (Rev 4 or higher ) The main audio transformer (T1), is connected to the Line IP1 and Line IP4 pins on P3. These two pins constitute the main audio input for the exciter. The centre taps of the audio transformer, though, are brought out on Line IP2, and Line IP3. These can be used as alternate audio pins for larger signals, or to directly access the dc loop sense circuitry. JP19 allows an alternate use for Line IP2 (pin 7 of P3). In the alternate position for JP19, the ALARM signal (the signal that drives the ALARM LED itself) is connected to pin 7 of P3. The ALARM signal when asserted is low active; when unasserted, it pulls high to +9.4V through an LED and a 680 ohm resistor. Condition P3, pin 7 connects to center tap of transformer T1 P3, pin 7 connects to ALARM signal Position 1-2* 2-3 2.12 J P22: Use Tone- as a Dir ect Digital Input (Rev 4 or higher ) JP22 is normally shunted with a jumper, which connects Tone- on P3 (pin 18), as the negative leg of the Tone input pair. Removing this jumper disconnects Tone- from this path and allows the use of the Tone- pin to be used as a direct digital input. See also 2.9 - JP16: If this jumper is removed, then JP16 should be in the alternative position (Direct Tone Input). 2.13 J P23: Connection of DMTX Boar d (Rev 4 or higher ) When a DMTX board is connected to an exciter, there is provision for digital or audio modulation of the reference osciallator and the VCO. The digital signal is input via the DB9 rear connector and the audio input signal is via the Line inputs on the standard DB25 rear panel connector. ___________________________________________________________________________ RF Technology T800 Page 9 3.1 25 Pin Connector 3 TRANSMITTER I/O CONNECTIONS Condition Position No DMTX board 1-2, 5-6* DMTX board connected 2-3, 4-5 In addition to the jumper changes, a wire link or zero ohm resistor must be connected in the place marked for R159. 3.1 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. Function DC power Channel Select RS232 Data 600Ω Line Signal +12 Vdc 0 Vdc 10 20 40 80 In Out High Low 150Ω / 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 >10kΩ, AC coupled (1-250Hz) >10kΩ, 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. ___________________________________________________________________________ RF Technology T800 Page 10 3 TRANSMITTER I/O CONNECTIONS 3.2 3.2 Rear Panel Connectors Rear Panel Connector s The exciter and receiver can be supplied with optional rear panel connectors that bring out the more important signals available on P1, the rear panel DB25 connector. Figures 1 and 2 show the rear panel connectors, and Table 4 shows the signals that are brought out to the spade connectors. The spade connectors (2.1x0.6x7mm) are captive/soldered at the labelled points. Fig 1 RX PCB Fig 2 TX PCB The Receiver and Transmitter modules plug into the back plane DB25/F connectors To configure: Solder wire connections between appropriate points. ___________________________________________________________________________ RF Technology T800 Page 11 4 CHANNEL and TONE FREQUENCY PROGRAMMING Receiver DB25/F RX PCB DESCRIPTION TX PCB Tr ansmitter DB25/F 1, 14 +12V +12V DC SUPPLY +12V 1, 14 TXD TX Data TXD 15 RXD RX Data RXD 15 COR+ Carrier Operate Sw+ PressToTalk input PTT 16 COR- Carrier Operate Sw- Tx/Rx output T/R 16 TONE Subtone output Hi Z audio input+ AUD+ 17 AUDIO Audio output Hi Z audio input- AUD- 17 AGND Audio Ground Ext tone input+ TONE+ 18 DISC Discriminator output Ext tone input- TONE- 18 LINE+ Line output+ Line input+ LINE+ 20 LINE- Line output- Line input- LINE- 20 EXT SQ Ext Squelch input Auto Level Control ALC 13, 25 GND Ground, 0V GND 13, 25 21 BCD 1 Channel select 1’s digit BCD 1 21 BCD 2 Channel select 1’s digit BCD 2 22 BCD 4 Channel select 1’s digit BCD 4 22 10 BCD 8 Channel select 1’s digit BCD 8 10 23 BCD 10 Channel select 10’s digit BCD 10 23 11 BCD 20 Channel select 10’s digit BCD 20 11 24 BCD 40 Channel select 10’s digit BCD 40 24 12 BCD 80 Channel select 10’s digit BCD 80 12 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. ___________________________________________________________________________ RF Technology T800 Page 12 5 CIRCUIT DESCRIPTION 5.1 VCO Section 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 bipolar junction FET Q19 which oscillates at the required transmitter output frequency. Varactor diodes D25 and D26 are used by the PLL circuit to keep the oscillator on the desired frequency. A second varactor diode D3 is used to frequency modulate the VCO. 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. 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 10 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 The frequency reference for the synthesiser is a crystal oscillator using transistors Q26 and Q27 and crystal Y3. The temperature stability is better than 5 ppm and it can be synchronised to an external reference for improved stability. External reference option board 11/9119 is required when using an external reference. A positive temperature coefficient thermistor, XH1, is used in versions intended for operation down to -30 degrees Celsius. The thermistor heats the crystal's case to maintain its temperature above -10 degrees thus extending the oscillator stability of 5 ppm down to -30 degrees ambient. Varactor diodes D27-30 are used to frequency modulate the oscillator. The processed transmit audio signal from U7b varies the diodes bias voltage to modulate the reference frequency. 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 Q27 is amplified by Q28 and Q29 to drive the reference input of the PLL synthesiser IC U6. This IC is a single chip synthesiser which includes a 1.1 GHz prescaler, programmable divider, reference divider and phase/frequency detector. The frequency data for U6 is supplied via a serial data link by the microcontroller. ___________________________________________________________________________ RF Technology T800 Page 13 5.3 Power Amplifier 5 CIRCUIT DESCRIPTION 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, produce the tuning voltage which is smoothed by the loop filter components to bias the V.C.O. varactor diode D3. 5.3 Power Amplifier The 10 mW output from the main board connects to the power amplifier board through a short miniature 50Ω coaxial cable. Q2 on the power amplifier board increases the signal to approximately200mW. The bias of Q2 is controlled by Q1 and the power leveling circuitry to adjust the drive to the output module U2. U2 increases the power from the driver to 30 watts 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 power voltage from U1a and U1b are compared to the present DC reference voltage from RV1. The difference is amplified by U1c, Q3 and Q4. The resulting control voltage supplies Q2 through R10, R12 and completes the power levelling control loop. 5.4 Temper atur e Pr otection Thermistor RT1 on the power amplifier board is used to sense the case temperature of the output module U2. If the case temperature rises above 90 degrees C, the voltage across RT1 will increase and transistor Q5 will be turned on. This reduces the dc reference voltage to the power regulator which inturn reduces the outpower by 6-10dB. 5.5 600Ω Line Input The 600Ω balanced line input connects to line isolation transformer T1. T1 has two 150Ω primary windings which are normally connected in series for 600Ω 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 600Ω load through JP5 or left unterminated in high impedance applications. 5.6 Dir ect Coupled Audio Input A high impedance (10kΩ) 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. ___________________________________________________________________________ RF Technology T800 Page 14 5 CIRCUIT DESCRIPTION 5.7 5.7 Local Microphone Input 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 5.8 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. On Rev 4 or later revisions, the low pass filter can be by passed by inserting a jumper onto JP17. RV3, the tone deviation trimmer, is used to adjust the level of the tone 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. The subtone amplifier, filter and limiter can be bypassed on Rev 4 or later exciters by removing the link from JP22 and moving the link in JP16 to the alternate position. 5.9 Audio Signal Processing 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 750µs pre-emphasis) and C61, R55 (for flat response). JP7 selects the preemphasized 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. ___________________________________________________________________________ RF Technology T800 Page 15 5.10 PTT and DC Remote Control 5 CIRCUIT DESCRIPTION The composite audio from U7a is fed through the 3Khz low pass filter U7b. When the links on JP23 are in their default state, the filtered audio is coupled to the TCXO voltage tuning input and the modulation balance trimmer RV2. RV2, R99 and R98 attenuate the modulation signal before applying it to the VCO via varactor D3. When DMTX board option is required, Jumper JP23 allows the audio paths to be re-routed. The DMTX board provides for an external digital modulation input signal. When the two links on JP23 are positioned in the middle of the 6 pin header, the audio from the exciter is passed to the DMTX board via pin 5 of JP15, where the signal is conditioned and then returned from the DMTX board via pin 2 of JP15, and passed to the two modulation points. 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. 5.10 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. 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 of ISO1. Any low voltage current source capable of providing 2mA at 4V or switching circuit with less than 4.8k¿ 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. A DMTX board can also cause the exciter to key up. When TX (or TTL_TX) signal is received by the DMTX board, it pulls pin 6 of JP15 low, which in turn asserts the PTT_WIRE-OR signal, causing the microprocessor (U13) to key the exciter up. 5.11 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. ___________________________________________________________________________ RF Technology T800 Page 16 5 CIRCUIT DESCRIPTION 5.12 Voltage Regulator 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. If the processor detects that the PTT_WIRE_OR signal is asserted low, it will attempts to key the exciter up. If will first attempt to key the VCO through Q10, and if the LD pin goes high, it will switch the 9.2 Volt transmit line through Q14 and Q16. asserting Q16 has the effect of also asserting the yellow Tx LED (D12) on the front panel, enabling the local 25W power amplifier, and causing the T/R Relay output to be pulled low. D24 is 30 volt zener which protects Q25 from both excessive voltages or reverse voltages. Should there be a problem with either the tuning volts, or the battery voltage, the VCO locking, the forward power, or the reverse power, the microprocessor will assert the ALARM LED, through Q1. Depending on the setting of Jumper JP19, the ALARM signal can be brought out on pin 7 of P3. 5.12 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. Jumper JP18 is not normally fitted to the board, and is bridged with a 12mil track on the component side of the board. It is provided so that the 9.4V load can be isolated from the supply by the service department to aid in fault finding. Jumpers JP20 and JP21 are also not normally fitted on the board, and are usually bridged with a 12mil track on the component side. They allow U14 to be isolated from its input, or its output or both. 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. 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. ___________________________________________________________________________ RF Technology T800 Page 17 6.1 Standard Test Condition 6 FIELD ALIGNMENT PROCEDURE 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 600Ω impedance, 50-3000Hz frequency range, with level set to 387mV RMS. • Power supply set to 13.8Vdc, with a current capable of >5A. • RF 50Ω load, 30W rated, return loss <-20dB. • Jumpers set to factory default positions. Model T800A T800B T800C 6.2 Alignment Frequency Range 806-830 850-870 928-942 Align F 818MHz 860MHz 935MHz 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). ___________________________________________________________________________ RF Technology T800 Page 18 6 FIELD ALIGNMENT PROCEDURE 6.4 Modulation Balance 3. Key the PTT line. 4. Measure the carrier frequency at the output connector, and adjust XO1 until the correct carrier frequency is measured, ±50Hz. 6.4 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. Set JP4 for Hi-Z input 6. Key the transmitter on 7. Set the audio input to 150Hz, 0dBm.(387mV) 8. Measure deviation and adjust RV4 (line Level) for a deviation of 5kHz (2.5kHz for narrow band transmitters). 9. Set the audio input to 1.5kHz, 0dBm. 10. Adjust RV2 (Mod. Bal.) for a deviation of 5kHz (2.5kHz for narrow band transmitters). 11. Repeat steps 6-9 until balance is achieved. 12. Key the transmitter off. 13. Return JP7 to its correct setting. 14. 6.5 Carry out the Deviation (section 6.6) and Tone Deviation (section 6.5) alignment procedures. 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 If sub-tone (CTCSS) coding is not to be used, adjust RV3 fully CCW. _________________________ The factory default is 500Hz for wide band (5kHz maximum deviation) and 250Hz for narrow band channels. ___________________________________________________________________________ RF Technology T800 Page 19 6.6 Deviation 6.6 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. 6 FIELD ALIGNMENT PROCEDURE 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 1. 2. Line Input Level Set the audio to 1kHz, 0dBm, on the line input, or use the actual signal to be transmitted. 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. 6.8 Key the transmitter off. 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. ___________________________________________________________________________ RF Technology T800 Page 20 7 SPECIFICATIONS 7.1 7.1 Overall Description 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 600Ω 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 channelsetting 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. 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. ___________________________________________________________________________ RF Technology T800 Page 21 7.2 Physical Configuration 7.2 7 SPECIFICATIONS 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) 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 ___________________________________________________________________________ RF Technology T800 Page 22 7 SPECIFICATIONS 7.4.2 Fr equency Range and Channel Spacing Frequency 806-830 MHz 850-870 MHz 928-942 MHz 7.4.3 7.4.2 Frequency Range and Channel Spacing 25 kHz T800A T800B T800C 12.5 kHz T800AN T800BN T800CN 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 50Ω 7.4.7 Output power Preset for 2-15 or 2-25W depending upon model 7.4.8 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 0.25µW 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 200µs< 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 ___________________________________________________________________________ RF Technology T800 Page 23 7.4.12 Distortion 7 SPECIFICATIONS 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 600Ω Line Input Sensitivity Adjustable from -30 to +10 dBm for rated deviation 7.4.15 HI-Z Input Impedance - 10KΩ Nominal, balanced input Input Level - 25mV to 1V RMS 7.4.16 Test Micr ophone Input 200Ω 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 ≅10kΩ, 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. ___________________________________________________________________________ RF Technology T800 Page 24 7 SPECIFICATIONS 7.4.21 7.4.21 DC Remote Keying 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 600Ω line or through a separate isolated pair. 7.4.22 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 No-Tone 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 Connector s 7.5.1 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 ___________________________________________________________________________ RF Technology T800 Page 25 7.4.22 Programmable No-Tone Period 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 7 SPECIFICATIONS EIA Number 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 Frequencies ___________________________________________________________________________ RF Technology T800 Page 26 7 SPECIFICATIONS 7.5.2 7.5.2 Power & I/O Connector 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 ___________________________________________________________________________ RF Technology T800 Page 27 Eclipse Series RF Technology rfinfo@rftechnology.com.au February 2005 Revision 2 R800 Receiver Operation and Maintainance Manual This Manual is produced by RF Technology Pty Ltd 10/8 Leighton Place, Hornsby NSW 2077 Australia Copyright © 2003 RF Technology CONTENTS CONTENTS Operating Instructions 1.1 Front Panel Controls and Indicators 1.1.1 Mon Volume 1.1.2 Mon. Sq 1.1.3 N. Sq 1.1.4 C. Sq 1.1.5 Line 1.1.6 PWR LED 1.1.7 SQ LED 1.1.8 Alarm Led Receiver Internal Jumper Options 2.1 JP1: 240Hz Notch Filter 2.2 JP2: Audio Response 2.3 JP3: Audio Filter In/Out 2.4 JP4: 600 Ohm Line dc Loop COS 2.5 JP6: COS Polarity 2.6 JP7, JP8, JP9 dc Loop COS Configuration (JP4 1-2) 2.7 JP7, JP8, JP9 Direct Output COS (JP4 2-3) 2.8 JP11: Eprom Type Receiver I/O Co nnections 3.1 25 Pin Connector Frequency Programming Circuit Description 5.1 RF Section 5.2 IF Section 5.3 VCO Section 5.4 P.L.L. Section 5.5 Audio Signal Processing 5.6 Noise filter, Amplifier and Detector 5.7 Subtone Filter and CTCSS 5.8 External Squelch 5.9 Microprocessor Controller 5.10 Carrier Operated Switch 5.11 Voltage Regulator 5.12 Tuning Voltage Supply 10 10 10 11 11 11 11 12 12 12 Alignment Procedure 6.1 Standard Input Signal 6.2 RF Alignment 6.3 IF Alignment 6.4 Line Level Adjustment 6.5 Reference Oscillator Calibration 13 13 13 14 14 14 7.1 Specifications General Description 7.1.1 Channel Capacity 15 15 15 ___________________________________________________________________________ RF Technology R800 Page 2 CONTENTS 7.1.2 7.1.3 7.1.4 7.1.5 CONTENTS CTCSS Channel Programming Channel Selection Microprocessor 15 15 15 15 7.2 Physical Configuration 16 7.3 Front Panel Controls, Indicators and Test Points 7.3.1 Controls 7.3.2 Indicators 7.3.3 Test Points 16 16 16 16 7.4 Electrical 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 Nominal Antenna Impedance 7.4.6 IF Frequencies 7.4.7 Sensitivity 7.4.8 Selectivity 7.4.9 Spurious and Image Rejection 7.4.10 Intermodulation 7.4.11 Modulation Acceptance BW 7.4.12 Noise Squelch 7.4.13 Carrier Level Squelch 7.4.14 Receiver Frequency Spread 7.4.15 Receiver Conducted Spurious Emissions 7.4.16 Audio Frequency Response 7.4.17 Audio Output Level 7.4.18 Audio Distortion 7.4.19 Channel Select Input/Output 7.4.20 Carrier Operated Switch Output 7.4.21 CTCSS 7.4.22 External Squelch Input 16 17 17 17 17 17 17 17 17 17 17 18 18 18 18 18 18 18 19 19 19 20 20 7.5 Connectors 7.5.1 Antenna Connector 7.5.2 Power & I/O Connector 7.5.3 Test Connector 20 20 20 20 Parts List ___________________________________________________________________________ RF Technology R800 Page 3 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. Operating Instructions 1.1 Front Panel Controls and Indicators 1.1.1 Mon Volume The Mon. Volume control is used to adjust the volume of the internal loudspeaker and any external speaker connected to the test socket. It does not effect the level of the 600 Ohm line or direct audio output. 1.1.2 Mon. SQ. The Mon. SQ. switch allows the normal squelch functions controlling the monitor output to be disabled. When the switch is in the Mon. SQ. position the audio at the monitor speaker is controlled by the noise detector. The CTCSS, carrier and external squelch functions are disabled. This can be useful when you are trying to trace the source of on-channel interference or when setting the noise squelch threshold. the audio from the 600Ω line and direct outputs is not effected by the switch position. 1.1.3 N.SQ The N.SQ trimpot is used to set the noise squelch sensitivity. Use the following procedure to set the noise squelch to maximum sensitivity. 1. Set the toggle switch to the Mon. Sq. position and set the Mon. Volume control to 9 o’clock. 2. Turn the N.SQ adjustment counter clockwise until the squelch opens and noise is heard from the speaker. Adjust the volume to a comfortable listening level. 3. In the absence of any on channel signal, turn the NSQ screw clockwise until the noise in the speaker is muted. Then turn the screw one additional turn in the clockwise direction. ___________________________________________________________________________ RF Technology R800 Page 4 1.1.4 C.SQ 1 OPERATING INSTRUCTIONS 1.1.4 C.SQ The C.SQ trimpot is used to set the carrier squelch sensitivity. Carrier squelch is useful at higher signal levels than noise squelch and can be used from 1-200µV input It is provided mainly for use in fixed link applications where a high minimum signal to noise ratio is required or where very fast squelch operation is required for data transmission. The carrier squelch will open and close in less than 2 mSec. In most base station applications the carrier squelch is disabled by turning the adjustment counter clockwise until the screw clicks. The carrier squelch may be set to a predetermined level with the Techelp/ Service Monitor 2000 Software or by using the following procedure. 1.1.5 1. First turn the adjustment fully counter-clockwise. Then set the noise squelch as above. 2. Connect a source of an on channel signal with the desired threshold level to the receiver’s RF input. 3. Turn the screw clockwise until the SQ LED goes OFF. Then turn the screw back until the LED just comes ON. LINE The LINE trimpot is used to set the line and direct audio output level. It is normally set to give 0dBm (775mV) to line with a standard input signal equal to 60% of maximum deviation at 1 KHz. The level can be measured between test socket pins 6 and 1 and set as desired. 1.1.6 PWR LED The PWR LED shows that the dc supply is connected to the receiver. 1.1.7 SQ LED The SQ LED comes on when the audio to the line and direct outputs is un-squelched. The LED and squelch function are controlled by noise, carrier and tone squelch circuits. 1.1.8 ALARM LED The ALARM LED can indicate the detection of several different fault conditions by the selftest circuits. The alarm indicator shows the highest priority fault present. In order of priority the alarms are. Indication Cadence Flashing 5 times, pause Flashing 4 times, pause Flashing 3 times, pause Fault Condition Synthesizer unlocked Tuning voltage outside limits Signal level below preset threshold (for fixed links) ___________________________________________________________________________ RF Technology R800 Page 5 2 RECEIVER JUMPER OPTIONS Flashing 1 time, pause LED ON continuously 2.1 JP1 -240Hz Notch Filter dc supply voltage low or high External squelch is active 2 Receiver Internal Jumper Options In the following subsections an asterisk (*) signifies the standard (Ex Factory) configuration of a jumper. 2.1 JP1 - 240 Hz Notch Filter Condition Notch filter In Notch Filter Out Position 1-2* 2-3 2.2 JP2 Audio Response Condition 750µSec de-emphasis Flat response Position 1-2* 2-3 2.3 JP3 Audio Filter In/Out Condition Hi-pass & Notch In Flat response to 3 KHz Position 2-3* 1-2 2.4 JP4 600 Ohm Line dc Loop COS Condition dc Loop Configured by JP7, JP8, JP9 dc Loop Not connected Position 1-2* 2-3 2.5 JP6 COS Polarity Condition Active on Signal Active on No Signal Position 1-2* 2-3 2.6 JP7, JP8, JP9 - dc Loop COS Configuration (JP4 1-2) Condition Source +12 Vdc Loop Free Switch Output JP7 2-3 1-2 JP8 ON ON JP9 2-3* 1-2 ___________________________________________________________________________ RF Technology R800 Page 6 2.7 Direct Output COS 2 RECEIVER INTERNAL JUMPER OPTIONS 2.7 JP7, JP8, JP9 Direct Output COS (JP4 2-3) Condition +12 Vdc Direct Output Free Switch Output 2.8 JP7 2-3 1-2 JP8 OFF OFF JP9 OFF OFF JP11 EPROM Type Condition 27C256 27C64 Position 2-3* 1-2 *= Standard Ex-Factory Configuration ___________________________________________________________________________ RF Technology R800 Page 7 3 RECEIVER CONNECTIONS 3.1.25 Pin Connector 3 Receiver I/O Connections 3.1 25 Pin Connector The D-shell 25 pin connector is the main interface to the receiver. The pin connections are described in table 3. Function DC Power Channel select RS232 Data 600 Ohm Line Signal +12Vdc 0 Vdc 10 20 40 80 In Out High Low 150 Ohm/Hybrid Access Discriminator Audio Direct Audio Output Audio Ground Sub-Audible Audio Output Carrier Operated Switch External Squelch Disc Audio Agnd Tone COS+ COSExt Sq Pins 1,14 13,25 21 22 10 23 11 24 12 15 20 19 18 17 16 Specification +11.4 to 16Vdc BCD Coded 0 = Open Circuit or 0 Vdc 1 = +5 to +16Vdc Test and Programming use 9600, 8 data 2 stop Transformer Isolated Balanced 0 dBm Output AC coupled, unsquelched Direct AC Coupled Audio Direct Audio Ground Unsquelched, 1-250 Hz Opto-coupled Transistor Switch (10mA) <1 Vdc to Squelch >2 Vdc or open ckt to unsquelch Table 3: Pin connections and explanations for the main, 25-pin D-shell Connector 4 Frequency Programming Channel and tone frequency programming is most easily accomplished with RF Technology TecHelp/ Service Monitor 2000 Software. This software can be run on any IBM compatible PC and provides a number of additional useful facilities. TecHelp/ Service Monitor 2000 allows setting of the adaptive noise squelch threshold, provides a simple means of calibrating the signal strength output and minimum signal alarm ___________________________________________________________________________ RF Technology R800 Page 8 5.1 RF Section 5 CIRCUIT DESCRIPTION TecHelp/ Service Monitor 2000 can be supplied by your dealer, distributor or by contacting RF Technology direct. 5 Circuit Description The following description should be read as an aid to understanding the block and schematic diagrams at the rear of this manual. 5.1 RF Section A two section helical filter FL1 is used to limit the R.F. bandwidth prior to the R.F. amplifier transistor Q1. The output impedance of FL1 is matched to the input of Q1 by C177, C178 and a microstrip line on the printed circuit board. Q1 is a very low noise device with good intermodulation performance. A four section filter consisting of FL2 and FL3 is used between Q1 and the mixer MX1. This filter provides additional image and spurious frequency rejection. MX1 is a high level double balanced diode ring mixer with excellent intermodulation performance. It has a conversion loss of approximately 7dB. The gain between the receiver input and the mixer input is approximately 10dB so that the total gain between the antenna input and the I.F. input is 3-4dB. Monolithic amplifiers MA1, MA2 and transistor Q5 amplify the VCO output to the necessary L.O. level for MX1 approximately +13dBm. The network C8, C9, L1-3 and R6 passes the 45MHz I.F. frequency to the I.F. amplifier and terminates the R.F. and L.O. frequency components. 5.2 I.F. Section The first I.F. amplifier uses two parallel connected JFET transistors Q2 and Q3 to obtain 810dB gain. The two transistors provide improved dynamic range and input matching over a single transistor. A two pole 45MHz crystal filter XF1 is used between the first and second I.F. amplifiers. The second I.F. amplifier Q4 provides additional gain of 6-10dB. A two pole crystal filter is used between Q4 and the 2nd oscillator mixer. These two crystal filters provide some adjacent channel rejection and all of the second I.F. image frequency rejection. U1 is a monolithic oscillator and mixer I.C. It converts the 45MHz I.F. signal down to 455KHz. The second oscillator frequency or 45.455MHz is controlled by crystal Y1. The 455KHz output of the second mixer is fed through the ceramic filter CF1 to the 2nd I.F. amplifier transistor Q27. Q27 provides an additional 15dB gain ahead of the limiter and discriminator I.C. U3. CF1 provides additional adjacent channel selectivity for 25KHz versions and all of the adjacent channe l selectivity for 12.5KHz versions. CF1 and termination resistors R15 and R24 are the only component differences between the 12.5 and 25KHz versions. ___________________________________________________________________________ RF Technology R800 Page 9 5 CIRUCIT DESCRIPTION 5.3.0 VCO Section The limiter/discriminator I.C. U3 further amplifies the signal and passes it through CF2. CF2 does not contribute to the adjacent channel rejection but is used to reduce the wide band noise input to the limiter section U3. The limiter section of U3 drives the quadrature detector discriminator. C31 and I.F. tuned circuit L10 comprise the discriminator phase shift network. U3 also has a received signal strength indicator output (RSSI). The RSSI voltage connects to the test socket for alignment use. The RSSI voltage is also used by the microprocessor for the adaptive noise squelch, carrier squelch and low signal alarm functions. Dual op-amp U2 is used to amplify and buffer the discriminator audio and RSSI outputs. 5.3 V.C.O Section The Voltage controlled Oscillator uses a bipolar junction transistor Q6 which oscillates at the required mixer injection frequency. A fixed tuned ceramic coaxial resonator CR1 is used to set the tuning range. Varactor diode D18 is used by the P.L.L. circuit to keep the oscillator locked on the desired frequency. Transistor Q7 is used as a filter to reduce the noise on the oscillator supply voltage. 5.4 P.L.L. Section The synthesizer frequency reference is supplied by a temperature compensated crystal oscillator (XO1). the frequency stability of the TCXO is better than 1ppm over the operating temperature range. The 12.8MHz output of XO1 is amplified by Q8 to drive the reference input of the P.L.L. synthesizer I.C. U4. This I.C. is a single chip synthesizer which includes a 1.1GHz pre-scaler, programmable divider, reference divider and phase/frequency detector. The frequency data is entered by a serial data link from the microprocessor. The phase detector output signals from U4 are used to control two switched current sources. The output of the positive and negative sources Q10 and Q15, produce the tuning voltage which is smoothed by the loop filter components to bias the V.C.O. varactor diode D18. 5.5 Audio Signal Processing A 4KHz low pass filter (U27b) is used to remove high frequency noise from the signal. A 300Hz high pass filter (Y26a,b) then removes the sub-audible tones. A 240Hz notch filter (U26c,d) is used to improve the rejection of tones above 200Hz. The high pass and notch filters can be bypassed by internal jumpers JP1 and JP3. The audio frequency response can be set for either a 750uS de-emphasis or flat characteristic by JP2. JP2 switches the feedback networks of amplifier U27c to achieve the desired response. After de-emphasis and filtering, the audio signal is applied to the inputs of two analog switches (U17a,b). These switches are controlled by the microcontroller and squelch or mute ___________________________________________________________________________ RF Technology R800 Page 10 5.6 Noise Filter, Amplifier and Detector 5 CIRCUIT DESCRIPTION the audio to the line and monitor output circuits. The monitor output can be set for noise squelch only operation by S1. The audio from U17a is adjusted by the volume control before connecting to the monitor output amplifier U5. U5 drives the internal speaker and can also supply 3-5 watts to an external loudspeaker. The audio from U17b is adjusted by RV3 before connecting to the line output I.C. (U22a,b). U22 is a dual amplifier connected in a bridge configuration to drive the 600 Ohm line output transformer T1. 5.6 Noise Filter, Amplifier and Detector The unfiltered audio from the discriminator is fed to trimpot RV4 which is used to set the noise squelch threshold. From RV4 the audio goes to the noise filter (U27a). This is a 10KHz high pass filter and is used to eliminate voice frequency components. The noise signal is then amplified by U27d and fed to the noise detector. The noise detector consists of D6, Q17 and U26c. D6 and Q17 are a charge pump detector and pull the input to U26c low as the noise increases. U26c has positive feedback and acts like a schmidt trigger. The output of U26c goes high when noise is detected. It connects to the microcontroller and to analog switch U17d. U17d varies the gain of the noise amplifier to provide approximately 2dB hysteressis. 5.7 Subtone Filter and C.T.C.S.S. The discriminator aud io is fed through cascaded low pass filters U28a and U28b to filter out the voice frequency components. The filtered sub-tone audio is supplied to the C.T.C.S.S. hybrid and the rear panel system connector. The filtered output can be used for retransmission of C.T.C.S.S. or D.C.S. The C.T.C.S.S. decoder module is a microcontroller base hybrid module. Under control of the main microprocessor U15 it can decode all 38 E.I.A. tones and 12 additional commonly used tones. The decode bandwidth is set to 1% but may be changed to 2% by a jumper on the printed circuit board. 5.8 External Squelch The audio output can be muted through pin 8 of the receiver system connector P1. When pin 8 is pulled to less than 1 Volt above ground, the microcontroller U15 will mute the audio output. This facility can be used to mute the audio during transmission, as is required in single frequency systems, by simply connecting pin 8 of the receiver to the transmitter T/R relay driver output (pin 16 on Eclipse transmitters). ___________________________________________________________________________ RF Technology R800 Page 11 5 CIRCUIT DESCRIPTION 5.10 Carrier Operated Switch 5.9 Microprocessor Controller The microprocessor controller circuit uses an advanced eight bit processor and several support chips. The processor U15 includes EE memory for channel frequencies, tones and other information. It also has an asynchronous serial port, a synchronous serial port and an analog to digital convertor. The program is stored in U12, a CMOS EPROM. U13 is an address latch for the low order address bits. U11 is used to read the channel select lines onto the data bus. U7 is an address decoder for U11 and U12. U14 is a supervisory chip which keeps the processor reset unless the +5 Volt supply is within operating limits. U16 translates the asynchronous serial port data to standard RS232 levels. The analog to digital converter is used to measure the received signal strength, tuning voltage, dc supply voltage and the carrier squelch setting. 5.10 Carrier Operated Switch The carrier operated switch is an opto-coupled (IS01) output. Internal jumpers (JP4,7,8,9) can be connected to provide loop source, loop switch, free switch and various other configurations. The C.O.S. can be set to active (switch closed) on carrier or active in the absence of carrier. The generic term “Carrier Operated Switch” may be misleading in this case. If a sub-audible tone has been programmed for the channel current channel, the C.O.S. will be controlled by carrier and tone detection. 5.11 Voltage Regulator The dc input voltage is regulated down to 9.4Vdc by a discrete regulator circuit. The series pass transistor Q20 is driven by error amplifiers Q21 and Q22. Q23 is used to start up the regulator and once the circuit turns on it plays no further part in the operation. This circuit is short circuit and overload protected. It provides much better line isolation and lower dropout voltage than can be obtained with current integrated circuit regulators. 5.12 Tuning Voltage Supply U18 is an astable multivibrator. The output from pin 3 of U18 is a rectangular 8 volt waveform with a frequency of approximately 200KHz. This output is connected to a voltage tripler circuit consisting of C170-C173, D13 and D14 to produce +20Vdc. This is used by the frequency synthesizer to provide tuning voltages up to +18Vdc. 6 Alignment Procedure The following procedures may be used to align the receiver for optimum performance. Normally alignment should only be necessary after repairs on that part of the circuit. ___________________________________________________________________________ RF Technology R800 Page 12 6.1 Standard Input Signal 6 ALIGNMENT PROCEDURE TCXO calibration may be required periodically due to crystal aging. The aging should be less than 1ppm/year. 6.1 Standard Input Signal RF Signal Generator 50? output impedence Frequency range 806-950MHz FM modulation at 1KHz 1.5KHz peak for 12.5KHz channel spacing 3.0KHz peak for 25KHz channel spacing 6.2 RF Alignment Step Input Select alignment frequency channel Signal generator on centre frequency channel to J1. Modulation off. Measure dc Volts on TP3 (next to FL4) dc Volts on test socket pin 7 to pin 1 Adjust FL4 for maximum dc volts Generator level to read 2-3Vdc As above As above FL1,FL2,FL3 for maximum reading. Reduce generator output to keep below 3Vdc. ___________________________________________________________________________ RF Technology R800 Page 13 6.3 IF Alignment 6 ALIGNMENT PROCEDURE 6.3 IF Alignment Step Input Signal generator on centre frequency channel to J1. Modulation OFF. As above Set generator level to 10uV Set generator level to 1 millivolt. Modulation ON As Above As above Set generator level to approx 0.25uV Measure dc Volts on test socket pin 7 to pin Adjust Generator level to read 2-3Vdc. As above L5,L6,L7,L8 For max. Reduce generator output to keep below 3Vdc Frequency U3 pin 9 L9 to read 455KHz +/- 10Hz Audio level test Line level (RV3) to socket pin 6 to pin obtain approx. 1Vrms As Above L10 for maximum Audio level P1 pin RV1 for .5Vrms 18 to pin 5 SINAD on test Reduce generator socket pin 6 to pin level to obtain 12dB SINAD. Carefully adjust L5,L6,L7,L8 to obtain the best SINAD. Reduce the generator output to maintain 12dB SINAD. 6.4 Line Level Adjustment Step Input Signal generator on centre frequency channel to J1. Modulation ON. Level 1 millivolt Measure Audio level test socket pin 6 to pin Adjust RV3 for 775mV rms 6.5 Reference Oscillator Calibration Step Input None required Measure Frequency Junction of R69 and R26 on the top of the PCB. (L.O. input to the mixer) Calibration X01 for L.O. +/100Hz L.O. =Fc+45MHz ___________________________________________________________________________ RF Technology R800 Page 14 7 SPECIFICATIONS 7 Specifications 7.1 General Description The receiver is a high performance, frequency synthesized, narrow band FM unit which can be used in conjunction with transmitter and power supply modules as a base station or as a stand alone receiver. All necessary control and 600 Ohm 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 receivers used at a given site. 7.1.2 CTCSS The CTCSS tone or no tone can also be programmed for each channel. Each channel number can represent a unique RF and tone frequency combination. 7.1.3 Channel Programming The channelling information is stored in a non-volatile memory chip and can be programmed via the front panel test connector using a PC and RF Technology supplied TecHelp/ Service Monitor 2000 software. 7.1.4 Channel Selection Channel selection is by eight channel select lines. These are available through the rear panel connector. 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. BCD switches inside the receiver can be used to pre-set any desired channel. These eliminate the need to externally select the channel. 7.1.5 Microprocessor A microporcessor is used to control the synthesizer and squelch functions and facilitate the channel frequency programming. With the standard software it also can provide some rudimentary fault monitoring and reporting. ___________________________________________________________________________ RF Technology R800 Page 15 7.2 Physical Configuration 7 SPECIFICATIONS 7.2 Physical Configuration The receiver is designed to fit in a 19 inch rack mounted frame. The installed height is 4RU (178mm) and the depth 350mm. The receiver is 63.5mm or two eclipse modules wide. 7.3 Front Panel Controls, Indicators and Test Points 7.3.1 Controls Mute Defeat Switch - toggle (Overrides CTCSS and carrier squelch at the monitor output). Monitor Speaker Volume - Knob Line Output Level - Screwdriver adjust multiturn pot Noise Sq. Setting - Screwdriver adjust multiturn pot Carrier Sq. Setting - Screwdriver adjust multiturn pot 7.3.2 Indicators Power On - Green LED Squelch Open - Yellow LED Fault Indicator - Flashing Red LED 7.3.3 Test Points Line Output Level - 6 + Gnd (pin 1) Receive Signal Strength - 7 + Gnd (pin 1) Tuning Voltage - 9 + Gnd (pin 1) Serial data (RS232) - 2/3 + Gnd (pin 1) 7.4 Electrical Specifications 7.4.1 Power Requirements Operating Voltage - 10.5 to 16Vdc Current Drain - 500mA Max Polarity - Negative Ground ___________________________________________________________________________ RF Technology R800 Page 16 7 SPECIFICATIONS 7.4.2 Frequency Range and Channel Spacing 7.4.2 Frequency Range and Channel Spacing Frequency 800-830MHz 850-870MHz 896-930MHz Model No. 25KHz R800A R800B R800C 12.5KHz R800AN R800BN R800CN 7.4.3 Frequency Synthesizer Step Size -10.0 or 12.5KHz 7.4.4 Frequency Stability +/- 1ppm, 0 to +60C, Standard 7.4.5 Nominal Antenna Impedance 50 Ohms 7.4.6 IF Frequencies 1st IF Frequency 45MHz 2nd IF Frequency 455KHz 7.4.7 Sensitivity 0.25uV (-119dBm) for 12dB SINAD 0.35uV (-116dBm) for 20dB Quieting 7.4.8 Selectivity 25KHz spacing - 80dB per EIA-603 12.5KHz spacing - 70dB per EIA-603 7.4.9 Spurious and Image Rejection 90dB 7.4.10 Intermodulation 80dB per RS204C ___________________________________________________________________________ RF Technology R800 Page 17 7.4.11 Modulation Acceptance BW 7 SPECIFICATIONS 7.4.11 Modulation Acceptance BW 25KHz spacing - 7.5KHz per EIA-603 12.5KHz spacing - 3.75KHz per EIA-603 7.4.12 Noise Squelch Adjustment Range 6-26dB SINAD, 25KHz Versions 6-18dB SINAD, 12.5KHz Versions Attack Time 20mSec. above 20dB Quieting Release Time 150mSec. at 20dB quieting decreasing to 20mSec. above 2uV present threshold Hysteresis Hysteresis is equal to approximately 2dB change in noise quieting. 7.4.13 Carrier Level Squelch Carrier level squelch can be used when it is necessary to set the opening point above 26dB SINAD as may be required in link applications. The minimum adjustment range is 1 to 200uV. 7.4.14 Receiver Frequency Spread Less than 1dB change in sensitivity over 10MHz 7.4.15 Receiver Conducted Spurious Emissions Less than -57dBm from 1 to 2900MHz 7.4.15.1 Audio Frequency Response 600 Ohm Line and Direct Output: +1/-3dB 300-3000Hz relative to either a flat response or 750uSec. de-emphasis with the high pass and notch filters bypassed. Sub Audio Output: +1/-3dB 67-250Hz 7.4.15.2 Audio Output Level 600 Ohm Line: Adjustable -10 to +10dBm Monitor Loudspeaker: 5watts with external speaker. 0.3watt with internal speaker. ___________________________________________________________________________ RF Technology R800 Page 18 7 SPECIFICATIONS 7.4.18 Audio Distortion Discriminator and Sub-Audio Level: Nominally equal to 1 volt peak at rated system deviation. 7.4.16 Audio Distortion With 750uSec. De-Emphasis: Less than 3% at 1KHz and 60% of rated system deviation. With Flat Response: Less than 5% at 1KHz and 60% of rated system deviation. 7.4.17 Channel Select Input/Output Coding: 8 Lines BCD coded 00-99 Logic Input Levels: 0=<0.4Volts 1=>3.5Volts Internal 10K pull down resistors selects Ch.00 when all inputs are O/C. 7.4.20 Carrier Operated Switch Output Floating Opto-Coupler Output: The carrier operated switch output is via an opto-coupler. Collector and emitter connections are available to allow connection for source or sink. The opto-coupler can be linked inside the receiver to be on when a carrier is detected or to be on in the absence of carrier. Connection to Remote Switch via 600? Line: Internal connections are provided so that the opto-coupler can be connected to the 600? line for use over a single pair. Current Source/Sink, Collector Voltage: Ic = 10mA Maximum Vc = 30Volts Maximum. ___________________________________________________________________________ RF Technology R800 Page 19 7.4.21 CTCSS 7 SPECIFICATIONS 7.4.21 CTCSS The CTCSS decoding is provided by a hybrid module. This provides programmable decoding of all 38 EIA and 12 other common tones. TONE SQUELCH FREQUENCIES Tone Fre q. EIA# Tone Freq. EIA# Tone Freq. EIA# No Tone 114.8 A6 179.9 B12 67.0 A1 118.8 B6 183.5 69.4 123.0 A7 186.2 A13 71.9 B1 127.3 B7 189.9 74.4 C1 131.8 A8 192.8 B13 77.0 A2 136.5 B8 196.6 79.7 C2 141.3 A9 199.5 82.5 B2 146.2 B9 203.5 A14 85.4 C3 151.4 A10 206.5 88.5 A3 156.7 B10 210.7 B14 91.5 C4 159.8 218.1 A15 94.8 B3 162.2 A11 225.7 B15 97.4 165.5 229.1 100.0 A4 167.9 B11 233.6 A16 103.5 B4 171.3 241.8 B16 107.2 A5 173.8 A12 250.3 A17 110.9 B5 177.3 254.1 7.4.22 External Squelch Input An external input is provided to squelch or mute the receiver audio output. This may be used in conjunction with an external decoder or to mute the receiver during transmissions. The External Squelch Input can be connected to the T/R Relay pin on Eclispe transmitters to mute the receiver during transmission. 7.5 Connectors 7.5.1 Antenna Connector Type N Female Mounted on the module rear panel 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. ___________________________________________________________________________ RF Technology R800 Page 20
Source Exif Data:
File Type : PDF File Type Extension : pdf MIME Type : application/pdf PDF Version : 1.6 Linearized : No Author : GL Create Date : 2005:02:03 15:20:50Z Modify Date : 2011:07:05 13:49:58+12:00 Has XFA : No XMP Toolkit : Adobe XMP Core 4.2.1-c043 52.372728, 2009/01/18-15:08:04 Producer : Acrobat PDFWriter 5.0 for Windows NT Metadata Date : 2011:07:05 13:49:58+12:00 Creator Tool : R800 Manual - Microsoft Word Format : application/pdf Title : R800 Manual.doc Creator : GL Document ID : uuid:c1b7f468-0bb4-4c82-8515-691c7514027d Instance ID : uuid:12bb8301-bcef-44c3-80ba-6e9e40419867 Page Count : 47EXIF Metadata provided by EXIF.tools