PRIMARY SOURCE Archives |

Electromagnetic Spectrum

By Ron Hranac – Amateur radio operators still use wavelength to describe band allocations in the electromagnetic spectrum. For instance, the 80 meter ham band is 3.5 MHz to 4.0 MHz, the 40 meter ham band is 7.0 MHz to 7.3 MHz, the 20 meter ham band is 14.0 MHz to 14.35 MHz, and so on.

Loss

By Ron Hranac – There is some “it depends” in the answer. Where resistance is involved—such as the effective AC resistance in metallic conductors, etc.—the lost RF power is usually dissipated as heat.

Understanding and Managing Cable Modem Upstream Transmit Headroom

By Ron Hranac – Cable modem (CM) upstream transmit headroom is far more complicated than it seems, especially as the upstream radio frequency (RF) spectrum is expanded and more signals are added to that spectrum.

Modulation Error Ratio

By Ron Hranac – One of the most widely used metrics for characterizing the health of digital signals carried in cable networks is modulation error ratio (MER), or more specifically, receive modulation error ratio (RxMER).

Signal Leakage

By Ron Hranac – The metric of interest for leakage is its field strength in microvolts per meter (not just microvolts), which is typically measured with a dedicated signal leakage detector. The value of keeping the plant tight helps to avoid harmful interference to over-the-air users. An effective leakage monitoring and repair program also helps to reduce ingress problems, and ensures better network performance.

The Untapped Capacity of Coaxial Cable

By Ron Hranac – At some point in the future FTTH will be ubiquitous. I’ll defer to the finance folks to sort out when it makes sense dollar-wise to jump to all-fiber operation. In the meantime, HFC networks will be here for the foreseeable future.

Hammin’ it Up!

By Ron Hranac – RF technology is, without a doubt, the foundation of our HFC networks. Many of us learned and continue to learn about RF on the job, from SCTE, publications such as Broadband Library, NCTI courses, vendor and in-house training, and community colleges and universities. I’ll add amateur (“ham”) radio to the list.

Reflections on 50 Years in Cable

By Ron Hranac – As much fun as the technology part of our industry has been, the people I’ve known and worked with have without a doubt been the best part of the last 50 years.

Signal Level: The Powers That Be

By Ron Hranac – When we measure the level of an analog TV signal’s visual carrier, we are measuring its peak envelope power. For a legacy SC-QAM signal, we measure the entire haystack’s average power. And for orthogonal frequency division multiplexing (OFDM) signals, we also measure average power.

A Word Paints a Thousand Pictures

By Ron Hranac – It’s been said that the only constant in the cable industry is change, and that’s certainly true when it comes to technology and the terminology associated with that technology. Hopefully this introduction helps to clarify some of the often confusing terminology used by the cable industry.

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