1. Title of the inventíon
Aircraft Communication TransceiverTestingTool.
2. Field of invention
It is an engineering concept adopted as for testing Aircraft Communication Transceivers prior to installation on aircraft
3. Use of invention
The Aircraft Communication Transceiver need to be tested on ground for satisfactory functionality prior to its installation on Aircraft, as fault diagnosis or detailed testing of the unit on the Aircraft requires complete test environment. This invention is a self sufficient tool which removes the dependency on other Aircraft units and accessories. The testing effort and time are substantially reduced by this tool.
4. Prior art
Traditional way of testing the Communication Transceiver involves other Aircraft units &accessories.
5. Draw backs of prior art
As traditional way of testing involves other Aircraft units , Cost involved is more and availability &working condition of the units is major concern. User should be aware or shall have complete knowledge of other Aircraft units. Also Test looms required for testing will be more. Additionally, testing effort& time is increased.
6. Comparison between prior art and present invention
The present invention facilitates fault diagnosis or system analysis up to module level which enhances spectrum of better working condition of the Communication Transceiver on Aircraft after installation. Also, Instead of Actual Aircraft units , simulated pages are developed which are easy to opérate and maintain. Traditional way of testing lacks the above facilities which further . increases cost, time and testing effort.
7. Aim of the invention
Invention helps ¡n carrying out Transmitter & Receiver checks in detail, Mil 1553 Bus Communication checks for Aircraft Communication Transceiver. Initiated Built ¡n test of the Transceiver unit can be carried out which provides health of the transceiver including module level failure.
8. Summary of the present invention
Invention consists of developed Hardware and Simulated software pages. Bus communication, Channel Number selection , Frequency , squelch functionality, guard mode, Audio checks, mike checks, press to talk checks, Rebroadcast checks, Tone Transmission checks of Communication Transceiver unit can be carried out. This testing tools helps in complete diagnosis of the unit upto module level. User can initiate Built in Test of the unit to know the health of the unit at any instant . oftime.
9. Brief description of drawings
Figure 1.0 shows the block diagram of the Test setup. Figures 2.0 to 6.0 shows pictures of Hardware developed indicating different options available. Figures 7.0 to 9.0 shows Pictures of Software Pages developed indicating available selections.
10. Statement of invention
The invention has been used for testing many transceivers successfully prior to the installation of the same on the aircraft thereby reducing the Aircraft time & effort substantially.
11. Detaiied description of invention
Invention can be used to test tactical, V/UHF Airborne Communication Transceivers which incorpórate Digital signal processing Technology. It is capable of providing Conventional/Secure communicationin VHF/UHF band for Aeronautical platform. Further the invention can be used to communicate with nearby ground stations with required frequencies using extemally connected antenna. The Software and Hardware for the testing tool have been conceptualized & developed in house.Unit is tested with the test set up as shown in figure 1.0
The Hardware developed ¡s shown ¡n figure 2.0. It is provided with switches for various controls & Banana sockets for monitoring signáis and feeding DC power supply. It is provided with a fuse for short Circuit protection. Radio can be tested from 118MHz to 400MHz frequency range. Features ofthe Hardware are given below
> Powering up of the Communication Transceiver Unit
> Provision for selecting the Remote Terminal address ofthe Unit
> Provision for monitoring Audio &¡ntroducing Mike signáis
> Provision for operating Press To Talk (PTT)
> ON/OFF control through which unit can be switched ON or OFF
> Provision for Tone Transmission
> Provision for Re broádcast mode
> Provision for Emergency Erase /Zero functioning
> Portable, Handheld and weighing not more than a Kg

Developed software pages are shown ¡n figures 3.0 to 4.0.Following features of Communication Transceiver can be tested with the developed simulated software test pages.
> Total of 100 preset channels can be simulated
> Provision for selecting squelch ON/OFF
> Provision for selecting four different Transmission modes(High/Low/Whisper /PTT inhibit) of Transceiver
> Provision for selecting Crypto or ECCM (Electronic Counter Counter Measure)functionalities
> Provision for selecting Guard & Guard precedence mode functionalities
> Provisi0n for selecting Rebroadcast functionality
> Provision for selecting Bearing functionality
> Provision for performing Initiated Built in Test of Transceiver

12. Drawings &Worked examples
The following functional checks performed to ascertain functionality of the Unit:
> Channel number selection : Máximum of 100 preset channels can be selected as shown ¡n Figure 3.0: software test page-1. Frequency corresponding to the channel number will be displayed. Also programming of individual channels with required frequency is possible. Figures 5.0 & 6.0 shows Transmit & Receive test results for respective frequencies selected.
> Bus Interface checks: Bus functionality can be observed in Figure 3.0: Software Test page -1. Status is indicated on right side of the Software test page
> Receiver (Rx) checks: Unit will be tuned to a particular frequency by selecting appropriate channel number in Figure 3.0: Software test page 1. Signal to Noise and distortion (SINAD) displayed in RF tester ascertains the Receiver performance of the unit. Rx test results obtained with RF tester is shown in Figure 6.0
> Guard mode checks: Very High Frequency and Ultra High frequency Guard checks was performed by selecting appropriate Very High Frequency / Ultra High frequency channel in Figure 3.0:Software test page 1 and enabling Guard mode.
> Squelch checks: Squelch operation ís carried out by selecting squelch functionality as shown in Figure 3.0: Software test page -1.
> Initiated Built in Test (IBIT): Built in test can be initiated by selecting test option in Figure 4.0: software test page 2. Test result pass /Fail will be indicated in the same page with PS for pass and FLforFail.
> Transmitter (TX) checks: High, Low ,Whisper transmitter options was tested by selecting appropriate Transmit mode as shown in figure 3.0:software test page 1. Typical Transmitter output observed on RF tester is shown in Figure 5.0
> Tone Transmission & Bearing tests: Tone Transmission can be initiated by the switch located on Hardware. Corresponding Audio tone frequency observed on RF tester is shown in Figure 5.0.
> Rebroadcast checks: Rebroadcast functionality of the unit can be checked by selecting rebroadcast frequency as shown in figure 4.0: software test page 2 & also Rebro switch on Hardware.

Further, status about the health of the unit can be obtained from Message status word information as shown ¡n figure 7.0. Following status can be obtained.
> Unit is in Transmitting or Receiving mode
> Main receiver or Guard receiver signal present
> Power On self test is in progress or completed
> Initiate Built in test is in progress or completed
> Squelch functionality
> Automatic gain control status
> Channel number
> Transmitter status
> Receiver status
> Antenna VSWR status
> Receiver sensitivity
> Power Supply module status
> Modulator module status
> Synthesizer module status

TitleLAircraft Communication Transceiver Testing Tool Claims

We claim that
1. This ¡nvention ¡s a self sufficient tool which removes the dependency on other Aircraft units and accessories.
2. Provisión tocarryout Communication Transceiver Receiver &Transmitterchecks.
3. Capable of monitoring & measuring demodulated audio from the Communication Transceiver under test and to carry out further measurements like Signal to noise and distortion ,depth of modulation levéis
4. Simulates a ground station to communicate with nearby Aircrafts as well as other nearbyground stations.
5. Provisión for interfacing the Aircraft Antenna & Audio Management Unit of Aircraft to simúlate Aircraft conditions.