Connectors and coaxial cable: what fits, and how much signal the cable costs

Connectors

TE Connectivity RF Coaxial Connectors Quick Reference Guide.^[1] IEC 61169-4 covers 7/16 to 7.5 GHz.^[2]

• 4.3-10 is aimed at outdoor cellular sites: TE cites "better PIM performance for use in many rugged outdoor applications" and IP68 moisture protection.^[1]
• SMA vs RP-SMA: same threads, swapped center contacts. "With an RP-SMA connector, the plug housing has a female/socket center conductor and the jack housing has a male/pin center conductor." (Linx/TE)^[3] Gender names are not standardized, so check the center pin in a photo, not the part name.^[3]
• Why odd connectors on unlicensed gear: US Part 15 devices must use only their approved antenna, so "the use of a standard antenna jack or electrical connector is prohibited" unless the device is professionally installed.^[4]
• ComAnt antennas come with N-, TNC- or 7/16-female connectors (depending on the model); add the connector to the part number when you order: -N, -TNC, -BNC, -SMA or -7/16. (ComAnt catalog, product list)^[5]

Cable loss

All radio cable here is 50 Ω;^{[6, 7, 8]} 75 Ω is for TV and CATV.^[1] Loss grows with frequency and with length. Manufacturers' figures, per 100 ft:

Belden publishes no 150 or 450 MHz points, so the nearest published frequencies are shown rather than estimates.^{[6, 7]}

What that means: on a 100 ft run at 900 MHz, RG-58 loses 21.1 dB,^[6] which is more than 99% of the power; RG-213 loses 7.6 dB;^[7] 7/8 in HELIAX about 1.1 dB.^[8] A 10 dBi antenna cannot make up for the wrong cable. Tell us the run length and the frequency and we will quote the cable with the antenna.

Lightning protection and grounding

CompleTech's LP lightning protectors are quarter-wave shorting stubs: insertion loss under 0.1 dB, surge current over 20 kA (8/20 μs), VSWR under 1.2, in versions from 70–90 MHz to 2300–2500 MHz with N, TNC or UHF connectors. CompleTech lists them as "maintenance free", with "no fuse like components" and "no non-linear (semiconductor) components". (ComAnt catalog, p. 73)^[5] ComAnt antennas themselves have a DC-shorted feed point. (ComAnt catalog, p. 1)^[5]

For grounding, CompleTech's GS grounding strip joins a Ø 17–48 mm pole or cable to 16 or 25 mm² grounding cable, and the GC cable is compatible with the GS, LP and LR parts. (ComAnt catalog, pp. 70–71)^[5] Follow your local electrical code for the ground itself.