Something is violating our specifications (typically over-current), causing the bias-tee to shut off. After a second or so, the bias tee will try to come back on. If the violation still exists, it will shut off again, and continue the cycle until the violation is removed. The clicking is the relay changing states.
The connector marked RF Out / Reflection is the only port that requires OSL calibration for Return Loss or / SWR measurements. Some Models like the S251C can make Insertion Gain or Insertion Loss measurements and the second port is included in an OSLIT (Open, Short, Load, Isolation, Through) calibration. Refer to the Users Guide for additional details.
Download your free update via the Internet. The software tools help menu has a direct link to the Anritsu Download site where this can be found. Or go directly to "http://www.us.anritsu.com/sitemastersoftware" Handheld Software Tools. Or call 1-800 ANRITSU and ask for Site Master Support.
There is not a a DX symbol, what you may bear seeing is the error message for Integrator Failure. It kind of looks like a "DX". If this is really what is happening then your Site Master may have been damaged by excessive RF or ESD being applied to the test port (most common cause). There could be other causes for this type of failure too. You should contact our Customer Service Department for more help.
If a battery is allowed to totally discharge, the smart-memory capability of the battery may be lost, resulting in incorrect battery capacity readings or loss of communication with the battery.
The NiMH battery will last longer and perform better if allowed to completely discharge before recharging. For maximum battery life, it is recommended that the NiMH battery be completely discharged and recharged once every three months.
If a flashing LOW BATT indicator is accompanied by an audio beep at the end of each trace, the battery has approximately one minute of useable time remaining.
Yes. If you are testing the line with the antenna attached, there is a good chance that the Site Master could be damaged by ESD. This happens because ESD gets onto the center conductor through the antenna's elements. It is safe to test with a load or short because there is no path for the ESD to get onto the center conductor.
An integrator failure is typically caused by excessive RF power to the input of the Sitemaster. Different Sitemaster models have different damage levels that they can tolerate and newer models have improved immunity to overpower conditions. See the appropriate user manual for the damage level for your particular unit. One common way this overpower condition can be caused is by a high powered interfering carrier when testing with the antenna attached at a co-locate site. If the power level of the interference is too high it could cause damage to the Site Master. To find out if damage has occurred, disconnect the Site Master from the coax under test and if the integrator failure still occurs then there may be damage to the unit. To prevent this type of situation, check the power level on the antenna first using a power meter or power monitor (Options 29 or 5) to see if any power is present on the antenna before sweeping it.
The FCC regulates how much output power of any given transmitter. Since this is a fixed quantity, the system designers are forced to squeeze out every bit of performance out of the entire system.
Basically, the maximum distance that can be measured in the DTF mode is controlled by 3 factors, 1) the data point resolution, 2) the frequency span or F2 minus F1 and 3) the propagation velocity entered for the coax under test. Since the propagation velocity cannot be changed, you must change either the frequency span or the data point resolution in order to go further. If using a 'B' or 'C' model, raising the data point resolution will almost double the distance. If you are using an 'A' or earlier model or cannot change the data point resolution then the frequency span will need to be smaller. Be sure to re-calibrate if the frequency span has to be changed.
This is a problem with the database operations. It is caused when more than 2 lines of information have been added into the Plot Description field even if the extra lines are blank. To fix this, select the Record then select Edit. Place the cursor at the end of the 2nd line of the Plot Description field. Left-click and hold down the mouse button and scroll down. The cursor will now be below the 2nd line. Press the Delete key on the keyboard to remove the extra lines. The cursor should now be at the end of the 2nd line. Either select another record or select Done. To prevent this from happening on the initial entry of Plot Descriptions, try to remember not to press the Enter key when done with the 2nd line entry.
It is normal for the display contrast to change with temperature. Use the contrast adjust to compensate.
Not usually. The cable used is very critical in making accurate, repeatable measurements. The cable must be 'phase stable'. Many are, including all that are sold with the Site Master. This type phase and loss of this type of cable does not change much as it is flexed and therefore produces consistent measurements when used with your Site Master.
The SiteMaster can be used immediately without any warm up time, however the temperature inside the box will rise quite fast in the first 5 minutes of operation and then much slower after that. If you don't want to wait, you can calibrate and make measurements immediately. However you may need to recalibrate as the box warms up, the SiteMaster will warn the operator if the temperature change requires another calibration.
Typical absolute measurement accuracy for tower mounted transmission lines is within 1 foot. Please see our application note "Distance to Fault" (page 12) for a more detailed explanation. This Application Note can be found on the SMIU Education page.
Cable loss is displayed in the SM as loss/ft or loss/m. In the catalogs it is displayed as loss/100 ft or loss/100 m.
A return loss measurement is like using a SWR meter, it is a quick pass/fail type of measurement. DTF is used to identify where a problem occurs, your knowledge of the installation will indicate the type of problem. For example, a large spike in the middle of a main feed line indicates a problem. In some areas of the USA, cables make excellent target practice and bullet holes are common. A large spike typically indicates an open or short of some type. Somewhere in the middle, a crushed cable, ignoring the antenna.
One thing, on long cable runs, you can use either VSWR or RL in DTF. For short cable runs, like jumpers, VSWR sometimes makes it easier to interpret the display.
All cables have loss. If there is too much total loss, then not enough signal is reflected back to the Site Master for a valid measurement. The noise floor of the Site Master is ~40 dB, so if there is more than 40 dB of loss in the run of cable the Site Master will have trouble.
Here's an example: A typical cable spec'd as follows: 3.9 db/100 ft @ 2000 MHz
Let's assume we have 500 ft of cable. The first question I ask is: "how much loss is there with 500 ft of cable?" 0.039 db/ft * 500 ft * 2 = 39 dB (The * 2 multiplier is due to the round trip nature of a S11 measurement i.e. down the cable and back).
If the noise floor of the Site Master is about 40 dB and there is 39 dB of loss in 500 ft of cable, I would expect to have measurement limitations with the Site Master. So, for this particular set of conditions we should disregard anything passed 500 ft.
So now we can answer the original question properly.
The code uses the c able loss value you enter to adjust the plotted DTF measurement. Let's use another quick example: if you have a 20 dB antenna 100 ft down a perfect cable you would expect to see that on a 20 dB spike in your DTF plot. Now if the cable is not really perfect and you do NOT account for the loss of 0.039 dB/ft the actual antenna will show as 27.8 dB (0.039 * 100 * 2 = 7.8 dB). If you entered 0.039 as the cable loss, the code will subtract (0.039 * 2) for every ft on the screen, giving you the actual antenna RL. That's grand until your loss approaches your noise floor. Once you have subtracted loss equivalent to your noise floor, the actual noise floor starts to creep up on DTF display.
Don't forget that while the noise floor is generally a fixed quantity (40-45 dB), the cable loss in a system varies greatly. So, the maximum distance you can see down a cable can vary greatly as well.
Incidentally, there are 2 ways to "see further down a cable": Reduce your loss or improve yo ur noise floor. They might try sweeping it at 1000 MHz where the loss is usually a bit lower there. The other thing they can do is use a true bench top VNA. It typically can get 50-60 dB dynamic range so you can handle more net loss. Another option would be to use a S251C in Insertion Loss mode. Insertion loss measures the loss from one end of the cable to the other (instead of doing a reflected measurement where you get hit with the cable loss 2x). While this would not permit DTF plots, but it would allow for an average cable loss value calculated.
Software Tools provides several methods of exporting a graph for use in other applications. The Copy and Paste method will work for all MS Windows compatible programs. In addition, the File, Export function can save your Graph in a Windows Meta File format .WMF or to Text. The text file contains the data behind the graph for import into any spreadsheet.