RG178 cable

Cable

RG178

RP-SMA MALE

End A

RP-SMA MALE

$1.00

SO239 UHF Female

End B

SO239 UHF Female

$3.00

50 Ohm DC – 300 MHz

RG178 — RP-SMA MALE to SO239 UHF Female

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

Length Price
1 ft $7.99
6 ft $10.49
25 ft $19.99
Need a different length? Use the Cable Builder

Specs Summary

CableRG178
Diameter1.75MM
Impedance50 Ohm
FrequencyDC – 300 MHz
Velocity Factor69%
RP-SMA MALE InterfaceReverse polarity SMA threaded
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.

RP-SMA Connector

RP-SMA (Reverse Polarity SMA) uses the SMA threaded coupling mechanism but with the male/female pin convention reversed — the jack has a pin and the plug has a socket. Originally standardized to prevent connection of uncertified antennas to consumer WiFi equipment, RP-SMA is now the dominant connector on commercial WiFi routers, access points, and 2.4/5 GHz antennas.

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 RP-SMA and UHF cable assembly is well suited for ultra-compact internal wiring in test equipment and small wireless modules. The combination of reliable RP-SMA 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.

Other RG178 Configurations

RP-SMA MALE to SO239 UHF Female on Other Cables