Shameless self-plug: Summer 2023 Broadband Library article

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Shameless self-plug: The Summer 2023 issue of Broadband Library is now available. My article in this issue is “The Untapped Capacity of Coaxial Cable,” which notes that coax has a much greater capacity than many people may think. Here’s a link to the article: The Untapped Capacity of Coaxial Cable -

Regards,
Ron Hranac

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Don’t forget todays coax is currently used for DBS/TVRO signals above 3 GHz and is the same cable as had been spec’d to 1 GHz.

At the coax manufacturer I worked for, when the coax is extruded it is typically swept to 3 GHz but only spec’d to 1 GHz unless the customer wants to pay more. We’d typically charge more for “DBS cable” even though it was exactly the same.

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Coaxial cable has been used in satellite receive installations going back to the 1970s. When the first C-band television receive only (TVRO) antennas were installed by the cable industry in the mid- to late-1970s, the feedhorns were equipped with low noise amplifiers (LNAs). The RF output of the LNA was the 3.7 GHz to 4.2 GHz C-band satellite downlink frequency. Installations often used Andrew 7/8-inch Heliax, a 50-ohms impedance low loss coaxial cable, between the LNA on the dish and the receiver(s) inside the headend. Later on the LNAs were replaced by low noise block converters (LNBs) and low noise converters (LNCs), which had an integrated LNA and a downconverter stage. LNBs and LNCs had a 75-ohms impedance output (usually an F connector), so lower cost CATV-type cables could be used between the dishes and headend. Probably the most common intermediate frequency (IF) output from LNBs and LNCs was 950 MHz to 1450 MHz, although I seem to recall one manufacturer had (for a while, anyway) an oddball IF output somewhere around the 770 MHz range. I remember connecting LNBs/LNCs to the headend using Series 11 coax for shorter runs, and .500 hardline or similar for longer runs. Some LNB/LNC IF outputs for Ka/Ku band downlinks covered the 950 MHz to 1950 MHz range, and others the 1100 MHz to 2150 MHz range (mostly Europe for the latter, if I remember correctly).