By Tom Williams — Active radar is a well known method to locate objects in the air and is based on sending a probing signal out and receiving reflections to determine distances and bearings to objects such as ships, aircraft, or UFOs. In military applications there is an undesirable side effect of a radar transmitter revealing itself to an enemy.
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By H. Mark Bowers — Broadband noise generators offer a viable alternative to the tracking generator approach. A fairly flat RF output response noise generator can be purchased for several hundred dollars and can be paired with most spectrum analyzers.
Read MoreBy Bernie Cadieux – With the advent of the latest DOCSIS versions, new technologies emerge and new ideas are founded on the newly available data: full band capture, pre-equalization coefficients, non intrusive measurements, and more.
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By H. Mark Bowers — Revisions to FCC Part 76 Rules were released in April of this year. Significant changes were included in this release, including the rewording of some test procedures and standards, QAM carrier limits for aeronautical frequency notification.
Read MoreBy H. Mark Bowers — Preparation for AC design calculations requires a diagram of all amplifiers (system actives) in a tree-branch configuration as was shown in Part One of this series
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By H. Mark Bowers — Many technicians struggle with AC design, particularly in the area of proper power supply placement and loading. AC design involves concepts and principles that we don’t use in every day system maintenance or operation.
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By H. Mark Bowers — I believe this exercise raises the issue of how one is to perform accurate field strength measurements at higher LTE frequencies, where there is a low-level leak from the HFC plant (especially QAM).
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By H. Mark Bowers – Newer leakage detection systems are now available that measure at dual frequencies. While {the} present FCC required leakage detection frequency range remains in the 108 MHz to 137 MHz aeronautical band, measurements at higher frequencies can be revealing and may eventually be required
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By H. Mark Bowers – In my last column we examined the importance of scalar testing, definitions of various terms, equipment required, and examined waveforms of actual insertion loss and isolation measurements using a spectrum analyzer and tracking generator.
Read MoreBy Tom Williams – One of the tough decisions facing line technicians is deciding if suspected line damage is severe enough to warrant taking cable service down to shoot the line with a time domain reflectometer (TDR). This decision is no longer necessary as it is now possible to measure a standing wave on a block of digital signals, and accurately range the distance to a fault on in-service plant using live digital traffic as test signals.
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