RG178 cable

Cable

RG178

BNC MALE

End A

BNC MALE

$2.00

SO239 UHF Female

End B

SO239 UHF Female

$3.00

50 Ohm DC – 300 MHz

RG178 — BNC MALE to SO239 UHF Female

Custom RG178 cable assembly with BNC MALE and SO239 UHF Female connectors. Every cable is hand-assembled, tested, and ships free.

Length Price
1 ft $14.98
6 ft $17.48
25 ft $26.98
Need a different length? Use the Cable Builder

Specs Summary

CableRG178
Diameter1.75MM
Impedance50 Ohm
FrequencyDC – 300 MHz
Velocity Factor69%
BNC MALE InterfaceBNC bayonet (MIL-STD-348)
SO239 UHF Female InterfaceUHF threaded (PL-259 / SO-239)

About This Assembly

RG178 Cable

RG-178 is an extremely thin 50-ohm coaxial cable measuring just 1.75mm in diameter, designed for space-constrained RF assemblies. Its PTFE dielectric and silver-plated conductors deliver reliable performance from DC up to several GHz. Commonly used for internal wiring in test equipment, medical devices, and cellular module pigtails.

BNC Connector

BNC (Bayonet Neill–Concelman) is a quick-connect RF connector featuring a bayonet locking mechanism for fast mating and unmating, rated from DC to 4 GHz. Its ease of use makes it standard in test and measurement equipment, video distribution, two-way radio accessories, and laboratory bench setups where cables are frequently connected and disconnected.

UHF Connector

The UHF connector (also known as PL-259 male / SO-239 female) is a large, low-cost RF connector designed in the 1930s for HF and VHF frequencies. Despite its name, its practical usable range is below 300 MHz due to its non-constant impedance design. It remains extremely popular in amateur radio (HF through VHF), CB radio, and marine radio applications.

Common Applications

This BNC and UHF cable assembly is well suited for ultra-compact internal wiring in test equipment and small wireless modules. The combination of reliable BNC and UHF connectors and custom-cut cable length makes it a practical choice for both field installations and bench setups. Every assembly is hand-terminated, continuity tested, and ships free within the USA.

RG178 Signal Loss

Approximate attenuation at common RF frequencies.

Frequency Loss / 100 ft Loss / ft
100 MHz 7.5 dB 0.075 dB
450 MHz 16.5 dB 0.165 dB
900 MHz 24 dB 0.24 dB
1.8 GHz 35 dB 0.35 dB
2.4 GHz 42 dB 0.42 dB
5.8 GHz 70 dB 0.7 dB

Frequently Asked Questions

What is RG178 coaxial cable used for?

RG-178 is an extremely thin 50-ohm coaxial cable measuring just 1.75mm in diameter, designed for space-constrained RF assemblies. Its PTFE dielectric and silver-plated conductors deliver reliable performance from DC up to several GHz. Commonly used for internal wiring in test equipment, medical devices, and cellular module pigtails.

What is the signal loss of RG178?

At 1800 MHz, RG178 has approximately 35 dB of loss per 100 ft (0.35 dB/ft).

What frequency range does this assembly support?

This assembly is rated DC – 300 MHz, limited by the lowest-rated component across the cable and connectors.

What is a BNC connector?

BNC (Bayonet Neill–Concelman) is a quick-connect RF connector featuring a bayonet locking mechanism for fast mating and unmating, rated from DC to 4 GHz. Its ease of use makes it standard in test and measurement equipment, video distribution, two-way radio accessories, and laboratory bench setups where cables are frequently connected and disconnected.

Other RG178 Configurations

BNC MALE to SO239 UHF Female on Other Cables