Most amateur radio gear uses the so-called “UHF” connector (formally called PL-259 for the male side and SO-239 for the female side). The name is misleading because the connector is not designed for use at the frequencies we now call “UHF.” (What was considered “ultra-high” in World War II isn’t anymore.) It is not a 50Ω connector, and each connection made with one will suffer some signal loss, especially when used at UHF frequencies, such as 440 MHz (70 cm band). Nevertheless, because the connector is so common on amateur gear, if the site has few connections, such as a field site or a simple base station site, it makes sense to purchase coax with PL-259 (“UHF”) connectors. 

N-type connectors are 50Ω connectors.

• • The standard N connector (named after Paul Neill of Bell Labs) is about the same size as a UHF connector.

  • Type N connectors support frequencies up to 11 GHz with a maximum VSWR of 1.3 to 1.5. This frequency range makes Type N RF connectors suitable for low-loss coaxial applications, wireless networks, and high-frequency communication systems. 

  • Type N connectors are compatible with RG58, RG55, RG174, RG188, RG316, RG213, RG223, RG8, RG142, RG141, RG316, RG400, RG401, RG6, Belden 7807, Belden 7808, Belden 7805, Belden 8219, Belden 8240, Belden 9913, Belden 7810, WBC100, WBC195, WBC200, WBC240, WBC400, WBC600, WBC1005, CA-100, CA-200, CA-240, CA-400, CA-600, CA-195, CA-195R, CA-195RW, CA-400UF, CNT-100, CNT-195, CNT-400, TWS-900DB, TWS-195, TWS-400, and 195, 200, 240, 400, and 600-series cables. 

The BNC (“Bayonet Neill-Concelman”) is a smaller version of the N connector with a bayonet-style attachment. BNC connectors are quick and simple to attach, but they can wiggle somewhat and leak RF. BNC is commonly found on some older HTs.

The TNC (Threaded Neill-Concelman) is about the same size as the BNC, but is threaded, like a standard N connector, making it more secure than a BNC and less susceptible to leakage. The TNC connector is not common with amateur radio equipment but is often found on commercial radios and RF test gear.

• TNC connectors support 4 GHz, 6 GHz, and 11 GHz frequencies. The specific frequency capability depends on the connector model selected for your application. 

• TNC connectors work with coaxial cables including RG58, RG174, RG213, RG223, RG8, RG136, RG142, RG141, RG316, RG400, RG6, Belden series (7805, 7807, 7808, 8219, 8240, 9913, 7810, 78056), WBC series (WBC100, WBC195, WBC200, WBC240, WBC400, WBC600, WBC1005), CA series (CA-100, CA-200, CA-240, CA-400, CA-1004, CA-195, CA-195R, CA-195RW, CA-400UF), CNT series (CNT-195, CNT-400), TWS series (TWS-195, TWS-400), and 600-Series coaxial cables. 

Miniature versions of UHF connectors, Mini-UHF connectors are designed for applications where size, weight, and cost factors are critical. With a miniature 3/8-24 thread size, these connectors provide excellent RF performance for applications up to 2.5 GHz. 

The SMA (Subminiature version A) connectors are commonly found on HTs. SMA connectors are 50Ω connectors. The connector is small and not suitable for use with RG-8/LMR-400 or larger cables. 

• SMA connectors are offered in both standard and reverse polarity versions. While both maintain 50-ohm impedance and support frequencies up to 6 GHz, 11 GHz, and 12.4 GHz, reverse polarity configurations provide alternative connection options for specific applications. Both versions are available in male, female, plug, and jack configurations with maximum VSWR of 1.3 to 1.5. 

• SMA cable connectors are compatible with a wide range of coaxial cable types, including RG58, RG316, RG174, RG188, RG141, RG142, RG8, LMR-200, LMR-400, CA-100, CA-200, CA-240, CA-400, CA-195, CA-195R, CA-195RW, WBC100, WBC195, WBC200, WBC240, WBC400, 100-Series, 195-Series, 240-Series, 400-Series, CNT-195, TWS-195, Belden 7805, Belden 7807, Belden 7808, Belden 7810, Belden 8240, Belden 8219, and Belden 9913.