Description (AMM 34-31-02)

 

A- Two navigation units (VOR/ILS receivers) are installed in electronic equipment rack E3-4. The receivers employ 2-out-of-5 binary switching for frequency selection. These units process VOR, localizer and glide slope signals and provide output of ground station bearing course deviation, and warning flag valids for the RDDMI's, the DFCS, the EFIS, and the GPWS.

 

B. AIRPLANES WITHOUT MMR VHF NAV UNITS;

Collins 51RV Series Receiver

(1) Each receiver contains circuit boards and an interconnect unit. The circuit boards consists of VOR/LOC and glide slope receiver assemblies with associated instrumentation, digital instrumentation and self-test circuit board assemblies, an RMI driver and a power supply.

 

(2) The chassis provides the mounting surfaces for connectors, support for two swing-out mounting frames, and a center mounting board.

 

(3) The center mounting board consists of a removable printed circuit board that contains the power supply, audio amplifier, and RMI driver circuits.

 

4) The left swing-out mounting frame supports the VOR/LOC receiver board and the glide slope receiver board. Each board contains tuner, synthesizer, self-test, and injection oscillator circuits. The VOR/LOC receiver is on the outer board and the glide slope receiver is on the inner board.

 

(5) The right swing-out mounting frame supports board for interconnections and the remaining VOR/ILS circuits. The VOR/LOC instrumentation and 2 out of 5 circuits, and optional expanded VOR monitor, programmable bearing filter, and digital bearing output circuits are on the inner board. The glide slope instrumentation, digital instrumentation, and optional VOR/ILS self-test and expanded ILS monitor circuits are on the outer board.

 

C- AIRPLANES WITH MMR VHF NAV UNIT;

Collins MMR RECEIVERS

(1) Each unit contains circuit boards, chassis, power supply, ribbon cables, coax cables, and plug connections. The left and right sides can be removed.

 

(2) The enroute and approach navigation is acheived with the VOR, ILS, and GNSS functions.

 

(3) The front of the unit has indicators and a test switch.

 

(a) The LRU STATUS indicator is off except during self test. When the self test switch is pressed, LRU STATUS is red for two seconds, green for two seconds, then off. It is then either green or red, if the test passed or failed. LRU STATUS then goes off after 30 seconds.

 

b) The CONTROL FAIL indicator is off except during self test.

 

When the self test switch is pressed, CONTROL FAIL is red for four seconds, then off. It is then either off or red, if the test passed or failed. The lru STATUS turns off after 30 seconds in any case.

 

(c) The ANTENNA FAIL indicator is off except during self test.

When the self test switch is pressed, ANTENNA FAIL is red for four seconds, then off. It is then either off or red, if the test passed or failed. The ANTENNA FAIL turns off after 30 seconds in any case.

 

(d) The TEST switch starts the self test. It will not start a self test when flying.

 

D- King Radio KNR 6030 Receiver

(1) The VOR/ILS receivers are 1/2 ATR short size, weight 12.6 lbs (5.7 Kg). The front panel mounts a three position test switch, used to initiate self-test of the receiver, and a self-test lamp for test observations. The back plate mounts the main connector and an ATE connector. The ATE connector is located nearer the top and used strictly for bench maintenance.

 

(2) The VOR/ILS receiver is a solid state unit capable of providing all outputs necessary for VOR/ILS navigation. Inputs to the receiver consist of the VOR/LOC and GS if, magnetic heading, course selection, tuning signals, and a self-test signal.

(3) The VOR/ILS receiver contains seven electrical subsystems which perform distinct functions and are described below.

 

(a) The VHF receiver is a single conversion super heterodyne receiver which tunes to the VOR and LOC frequency band. It contains a LO synthesizer, RF amplifier, IF amplifier, AGC circuits and an AM detector.

 

(b) The UHF receiver is a double conversion super heterodyne receiver which tunes to the GS frequency band. It contains a LO synthesizer, RF amplifier, two-stage IF amplifier, and AGC circuits.

 

(c) The VOR processor is a microprocessor based system which samples the receiver VHF signal, magnetic heading, and converts them into digital data. It then computes all VOR outputs and constructs the necessary analog signals. The VOR processor monitors for proper received signals and circuit operation. Modules contained in the VOR processor are the digital phase detector, Omni bearing (OB) word generator, OB microprocessor input, and synchrony to digital converter, microprocessor, interface, and output cards.

 

(d) The ILS processor inputs are taken from the VHF and UHF receivers whenever an ILS frequency is selected. It constructs both GS and LOC deviation outputs and their associated flags.