- The first thing a Tech 1 should do when he or she is required to gather TCM information is to locate the target list that is associated with the particular test they are supporting. This list will provided needed information for the TCM measurement.
- The Tech 1 should also have a target sheet that has space to write the needed TCM information. It is usually a good idea to have the target list under the target sheet on a clipboard. If TCMs have already been done by a previous shift that is working on the same test then it is good idea to put that sheet on the clipboard (if it is not already) and to look at the information that they have collected and compare it to the information that will be collected.
- When going into the field to collect a TCM measurement the Tech 1 will need his or her clip board with all the appropriate paperwork, a HHSA, a 15 foot with BNC male ends, 2 N-TYPE male to BNC female connectors, 1 BM-01 antenna, a ground plane for the BM-01 antenna, a tape measure, and a bucket. The equipment may change with time but the basic equipment names (clipboard, HHSA, cable, connectors, antenna, ground plane, and bucket) will stay the same.
- The Tech 1 should carry a black pen with them to fill out the needed information on the target sheets pertaining to the TCM trace. This information includes the technicians scheduled shift, system under test (SUT) abbreviation, target position, target identifier, date/time, test type, threat location, automation type, frequency, power level, TX height and polarization, RX height and polarization, TX to RX distance, test code, initials, target name, and TCM trace name. If writing error occurs just put a line through the mistake and continue, however if there is not enough room then start on a new line. Sometimes the job requires working at night so a head lamp or flashlight is also a useful tool.
- Once the target is in place and ready to have TCM information collected on it the Tech 1 (preferably 2 Tech 1s) will drive to the location of the threat with the appropriate equipment. On location make sure that the vehicle is not blocking the line of sight of the threat and that the vehicle is parked no closer than 10 m from the threat.
- If there is only 1 Tech 1 then the technician needs to walk to the TX side to collect the TX information. This includes name, serial number, height off of the ground, automation type, distance from RX, and antenna polarization (Vertical, Horizontal, 45 degrees etc…).
- Then the Tech 1 will walk back to the RX side and record more information including, serial number, height off the ground, and antenna polarization.
- Once this is done the Tech 1 will set up the ground plane and BM-01 at the same height as the RX (IE on the ground or on a bucket) and at the same distance that the TX is to the RX. Next connect the cable to the BM-01 and then extend the cable make sure there are no kinks or loops in the cable. The other end of the cable will be connected to the HHSA. If there were 2 Tech 1s then one would walk and gather the written information and the other would set up the ground plane, antenna, and HHSA in the appropriate spot near the RX.
- At this time the Tech 1 will request all vehicles and personnel to be clear of the RX and clear of TX to RX line of sight.
- Recall and Activate the TCM trace template that is saved on the HHSA. Locate the correct frequency from the target list or target sheet, call for the TX side to send continuously. Make sure you see the appropriate frequency spike while TX is sending. Once you see the appropriate spike select max hold under trace/trace mode and let it stay on max hold for at least 5 transmissions. Now select view under trace/trace mode, and then select save.
- The save menu will show up which requires a trace name. The basic save template will be saved as tcsh-sy-ps-tg-r where tc stands for test code (pr, md, or po), sh stands for shift (a, b, or c), sy stands for system under test (see SUT legend), ps stands for position (site target position), tg stands for target (see test plan or target sheet for target designator), and r for run.
Table 1 - Site Letter Designators
- Once the TCM trace is saved select save and write down the time/date and name of the trace on the target sheet. Select the trace that was just saved and then write down the frequency and power level of the spike.
- At this point the target sheet should be completely filled out for the TCM. Once the TCMs are complete and the Technicians have returned to base it is their job to show the site lead the TCM information for approval. Once the TCM information has been approved the Tech 1 can drop the data from the HHSA to the laptop.
- Connect the HHSA to the laptop via serial cable or USB cable. Open up the appropriate software for the HHSA on the laptop. If the HHSA used is a Rhode&Schwarz FSH3 or FSH6 the appropriate software is FSH View.
- When FSH View is opened the first screen will appear with a com port connection window.
- Once the com port is selected the laptop is connected to the FSH3/6 and the program will appear blank.
- Now the Dataset Control needs to be selected to view and transfer files from the FSH3/6 to the laptop.
- The window on the left shows information that is stored on the FSH3/6. The window on the right shows information that is stored on the laptop.
- To transfer information from the FSH3/6 to the laptop a user must first select the RAW DATA folder in the correctly dated target trace folder THAT IS IN THE CORRECT TEST FOLDER! Once it has been verified that the right laptop window is displaying the proper RAW DATA folder the user can then click on or select the traces in the left FSH3/6 window and then click on the >> button to transfer the traces.
- Now that the traces have been transferred from the FSH3/6 to the laptop and verified that they all open properly from the laptop they can be removed from the FSH3/6. To remove the traces using the FSH View software involves opening up the Dataset Control, selecting the traces in the left FSH3/6 window, and then clicking on the red X in the upper left hand corner of the Dataset Control window. Deleting traces without using the FSH View software involves turning on the FSH3/6, pressing the SAVE button, and then using the wheel and DELETE soft button (F2), or the DELETE ALL soft button (F1). VERIFY THAT ALL OF THE NEEDED TRACES HAVE BEEN PROPERLY TRANSFERRED BEFORE DELETING!
- Turn the HHSA on. This is done by pressing the orange/yellow button in the lower left hand corner of the FSH3/6 HHSA. If it does not turn on the battery may not be charged. So find the standard AC wall plug, plug in the FSH 3/6, and then try to turn it on again.
- Once the unit is on make sure that the date/time is correct and that the preamp is turned on the HHSA. To do this press the setup button, the general soft key (F1); use the wheel to select DATE…, and then press ENTER or F1 to select date. The date for the FSH3/6 comes up in DD/MM/YYYY format NOT MM/DD/YYYY like most software applications so MAKE SURE YOU ENTER THE DATE CORRECTLY.
- To set the time follow the same steps required to set the date except when you get to the general menu use the wheel to select TIME…. The time format on the FSH3/6 is 24 hour.
- To turn the preamp on press the SETUP button and then press the HARDWARE SETUP soft button (F3). Use the wheel to select PREAMP…, press enter, use the wheel then to select on and then press enter again.
- To set the span to 8 MHz press the SPAN button and then use the numbered key pad to type 8, use the unit buttons to type MHz, and then press enter.
- To set the RBW and VBW to 30 KHz press the BW button, and then select MANUAL RES BW soft button (F1). Type in 30 using the numbered key pad, press the kHz unit button, and then press enter. Pressing the down arrow when the MANUAL RES BW soft button (F1) is selected will also change the RBW to 30 KHz. If the VBW/RBW ratio is set to 1 then changing the RBW to 30 KHz will automatically change the VBW to 30 KHz. If the VBW does not automatically change to 30 KHz then repeat the steps for changing the RBW but when you get to the BW soft buttons select MANUAL VIDEO BW.
- The sweep time should be set to auto. Press the SWEEP button and then make sure AUTO SWPTIME and CONT SWEEP are selected.
- To adjust the reference level to -30 dBm press the AMPT button, press REF LEVEL soft button (F1) and then using the numbered key pad type 30 and then press the –dBm unit button.
- If the trace that is sweeping across the screen does not appear to be a thin jagged line then select the TRACE button, press the DETECTOR soft button (F4), then use the wheel to select MAX PEAK and press enter.
- Turning the power on. The EME Trailer requires a 60 KW Generator that must be started upon arrival at the site. The voltage must be set for 120 VAC using the knob on the front panel and read using a voltmeter in the EME Trailer. The frequency should be set for 60 Hertz using the generator throttle and verified using the indicator on the front panel.
- Connect the outputs of the amplifiers to dummy loads to inhibit unintended transmissions
- Apply power only to the generators required for the EME scenario and make sure the RF output is turned off.
- Apply power to the amplifiers and allow 1 hour warm-up time prior to use to ensure stabilization. If the AR amplifier is required apply power and adjust to a percentage previously established for the testing session (21% in ALC mode is close to the power of the 25 Watt Empower amps).
- At the EME trailer, turn on the laptop (laptop usage is only required if a signal generator control program is required) and Spectrum Analyzer (SA).
- Setting up the Spectrum Analyzer
- Press power on button
- Press “File” button
- Press the “Load” soft key
- Spectrum Analyzer: Using the up and down arrow buttons or the Jog wheel highlight the EME State File named “EME”. The settings for the EME State File are:
- Press the “Load Now” soft key
- Aligning the Spectrum Analyzer
- Press “System” button
- Press the “Alignment” soft key
- Press the “Alignment Now” soft key
- Press the “All” soft key; after self-alignment is complete continue.
- For EME level verification a technician level 1 or higher will use a portable SA with a broadband antenna for the appropriate frequency range of the EME. The SA settings used for EME receive signal levels (RSLs) are as follows:
- The benign bucket course at the center and each end of the course.
- The tactical emplacements course at the designated at the city center reference point.
- Or other predetermined site locations to measure EME levels.
- EME Laptop (If the EME setup requires signal generator controller software): Left click the HT Basic Icon to run the application and press “P” to pause on Condition 1. (If all generators do not turn on, the software will stop running before Condition 1. The software reads the generators sequentially and a list of the recognized generators, up to the stop point, will display aiding in troubleshooting. The last generator displayed is the generator that did not respond and is at fault)
- After EME software starts, enter a timing number established before test for example “3” for three seconds.
- When it is time to measure EME levels make sure that the amplifiers outputs are connected to the transmitting antenna via a low loss cable. Then a technician level 1 or higher will measure each signal in the EME script for each condition.
- To adjust the output power of each signal generator for the level required for the test (-60, -65, -70, -75, and -80 have all been used in the past) plus or minus 3dBm as measured at the reference points:
- On the Signal Generator press LOCAL
- Press LEVEL
- Press UP and DOWN to set output level or use the jog wheel. Make sure the step rate is set to MEDIUM so that a 1 unit turn of the jog wheel will equal 1 dBm of power adjustment.
- A technician 2 or higher will assist a technician 1 with recording the Signal Generators levels. To adjust the EME Script levels follow these steps:
- On the EME computer’s Desktop: double click on the RSDATA Shortcut Icon
- Look at the contents of the RSDATA folder and chose the correct Script scheduled for use that day.
- Edit the levels for each generator. After “Condition 1” is completed press “C” then “ENTER”
- When Condition 2 is displayed press “P” to pause at “Condition 2” and repeat (This order of level collection and setting is only an example of the process. In reality all levels may be established prior to editing the script).
- After EME levels are set Press “C” and “ENTER” to start the script.
- Turn off the amps and move the cables from the antennas to the dummy loads until EME is required.
- When EME is required, turn off the amps and move the cables from dummy loads to the antennas. Reapply power to the amps.
- Every two hours the EME is in operation verify and record EME status.
- Connect the SA to the WEST test Jack on the RF Patch panel.
- Then using the Spectrum Analyzer:
- Press the “View/Trace” button
- Press the “CLEAR WRITE” Soft key
- Press the “VIEW” Soft key
- Press the “Marker” button
- Press the “Peak Search” button
- At each Peak record the frequency and level in dBm. To get to the next peak press the “Next Peak” Soft key. Record all signals including intermod components above -35 dBm
- This procedure must be performed every two hours that EME is in operation (Be advised you are reading half of a condition to read the other half you must connect the SA input to the East test jack)
- Please describe, in your own words, the proper equipment and steps required for conducting TCM measurements (Please use a separate piece of paper if the space below is not sufficient).
- Please describe, in your own words, the proper steps required for basic EME start up and EME RSL level readings (Please use a separate piece of paper if the space below is not sufficient).