Technical Manual Operation, Maintenance, Installation Instructions and Illustrated Parts Breakdown HF/VHF/UHF DSP RECEIVER RX-400 TEN-TEC, INC. 1185 DOLLY PARTON PARKWAY SEVIERVILLE, TN 37862 Part Number 74416 Ten-Tec RX400 Manual Revision 0.
WARNING HIGH VOLTAGE is used in the operation of this equipment. DEATH ON CONTACT may result if personnel fail to observe safety precautions. Learn the areas containing high voltage within the equipment. Be careful not to contact high voltage connections when installing, operating or maintaining this equipment. Before working inside the equipment, turn power and ground points of high potential OFF before touching them.
Table of Contents Item Page 1. Introduction RF Signal Path HF Signal Path VHF/UHF Operation I.F. Output Control Interface Firmware Updates 4 4 5 5 5 5 5 2. General Information Front Panel Connections Rear Panel Connections Audio Connection 6 6 6 7 3.
RX400 DSP RECEIVER This manual provides operation and maintenance instructions for the RX-400 HF/VHF/UHF DSP Receiver. The manual was prepared in accordance with MIL-HDBK1221, “Department of Defense Handbook for Evaluation of Commercial Off-The-Shelf (COTS) Manuals." Introduction The RX-400 HF/VHF/UHF receiver couples a rugged wide-band RF front end to a highperformance Digital Signal Processing back end.
HF Operation: Signals entering the HF front-end will pass through a user-activated RF attenuator followed by 1 of 8 band-pass filters. Each filter is designed to eliminate potential interference from other undesired signals. The RF attenuator may be used to reduce interference from undesired signals that may overload the receiver hardware.
2. General Information Figure 3 Front Panel Connections Figure 4 - Rear Panel Connections Part Number 74416 Ten-Tec RX400 Manual Revision 0.
Figure 5 - Audio Connections Pin Description Note 1 2 3 Chassis Ground A/C Coupled Mono Audio Line B- 4 5 6 Line B center tap Line B+ Line A- 7 8 9 10 11 12 Line A center tap Line A+ Chassis Ground DC Coupled Mono Audio No Connection User Programmable Output #1 (not available when frequency extender attached) User Programmable Output #2 (not available when frequency extender attached) User Programmable Output #3 (not available when frequency extender attached) User Programmable Output #4 (not availa
3. General Theory of Operation OVERVIEW The Ten-Tec model RX400 is a narrowband DSP-based receiver with a wide-band IF output available at 21.4MHz. The superhetrodyne architecture is triple-conversion to the IF output for received frequencies of 88 MHz to 3GHz, and double conversion when tuned below 88 MHz. The IF output bandwidth is 6 MHz for tuned frequencies of 20 MHz to 3 GHz, and 2 MHz when tuned below 20 MHz receive frequency. Tuning step size is 10 kHz (1 kHz optional) at the 21.4 MHz IF output.
MECHANICAL CONFIGURATION Six modules located on the bottom chassis deck accomplish the analog frequency conversion functions. These interconnected modules are the FIRST, SECOND, and THIRD CONVERTERS and the FIRST, SECOND, and THIRD LOCAL OSCILLATORS. Signal interconnection between modules is by miniature semi-rigid coax.
cover 108 to 1650 MHz. The selected filter output is amplified by U2 and lowpass filtered by FIL4 en route to the RF1 terminal of Mid Band / High Band switch U6. Position 4 of U3 on the MID/HIGH BAND PRESELECTOR board routes the High Band antenna signals through one of two highpass/lowpass filter cascades selected by switches U7 and U8. Complimentary switch positions of U7/U8 are determined by logic line A4. This arrangement creates two half-octave subbands of 1650-2200 MHz and 2200-3000 MHz.
7.71 to 119.7 MHz in 10 kHz steps (1 kHz optional). Low Band receive frequencies use a 240 kHz segment of this range from 118.48 to 118.72 MHz to fill in the 250 kHz tuning steps produced by the divided-down first LO. The third LO injection signal is amplified by U4 and U15 and applied to the LO port of mixer MX1. The 159 MHz trap L11/C70 attenuates a potential image frequency band at the input to U4. The 21.
the synthesizer chip, completing the loop. U4 develops the Mid/High Band First LO output which splits between the module output at E1 and MODULO 16 divider U6/U7 to provide the Low Band First LO of 142-228 MHz. The 100 MHz master frequency reference signal is developed on the DSP board and is delivered through this module to the SECOND LOCAL OSCILLATOR module via emitter follower Q11.
Logic/DSP System The RX400 Logic/DSP assembly incorporates Digital down Conversion, Signal Processing, Control & Interface, Power and Master Clock Reference circuitry on a single circuit board. The Logic/DSP board controls all Preselector, RF Converter and Local Oscillator (LO) boards over ribbon cables. The RF/LO and Preselector boards are programmed by the DSP processor via the attached ribbon cables to achieve the correct RF tuning.
4. Maintenance & Troubleshooting RX-400 MAINTENANCE INSTRUCTIONS INTRODUCTION: To perform maintenance tasks, the technician shall identify faulty modules or subassemblies. The faulty module or subassembly shall be replaced with a known good one. CLEANING AND LUBRICATION: Front panel and control surfaces may be cleaned using a soft cloth dampened with a mild detergent solution. Never use caustic cleaners on knobs or panel surfaces. The RX400 has no lubrication points.
SPECIFICATION TEST SETUP TYP. MIN/MAX Sensitivity Attenuator OFF Connect a signal generator to the receiver USB mode RF Input. (Calibrate cable loss first.) 3 kHz bandwidth Connect an audio analyzer with SINAD measurement capability to the mono audio output. Low Band -114 dBm 15 dB max NF For each frequency in the following list, apply -114 dBm to the receiver input: SINAD 12 dB typ. 10 dBmin. 2.0, 2.6, 3.19, 3.2, 4.1, 4.99, 5.0, 6.5, 7.99, 8.0, 10.0, 11.99, 12.0, 16.5, 20.99, 21.0, 27.5, 33.99, 34.
SPECIFICATION TEST SETUP TYP. MIN/MAX For each frequency in the list below: Temporarily set generator #1 on frequency to supply a level of -110 dBm to the receiver input. Record the SINAD displayed on the audio analyzer as "reference". Move generator #1 to (frequency / 2) -9 kHz. Set generator #2 to (frequency / 2) +9 kHz. Set both generator amplitudes to produce -30 dBm each at the receiver input connector. Observe the SINAD of the second order distortion product on the audio analyzer.
Figure 7 – Air filter Replacement The air filter can be cleaned or replaced by removal of the fan shroud located on the front of the RX400. Part Number 74416 Ten-Tec RX400 Manual Revision 0.
5. Illustrations & Parts Lists Figure 8 - Location of Receiver Assemblies Part Number 74416 Ten-Tec RX400 Manual Revision 0.
Figure 9 - Location of Logic, Control & Power Assemblies Part Number 74416 Ten-Tec RX400 Manual Revision 0.
Figure 10 - Location of Preselector Assemblies Part Number 74416 Ten-Tec RX400 Manual Revision 0.
Circuit Boards, Materials and Placement Assembly 82011 1st LO Board Schematic Material List Parts Placement 82012 2nd LO board Schematic Material List Parts Placement 82013 3rd LO Board Schematic Material List Parts Placement 82010 3rd Converter Board Schematic Material List Parts Placement 82009 2nd Converter Board Schematic Material List Parts Placement 82008 1st Converter Board Schematic Material List Parts Placement 82014 Low-Band Preselector Schematic Material List Par
