1.37 — RP-SMA FEMALE to SO239 UHF Female
Custom low loss 1.37 RF coaxial cable assembly with RP-SMA FEMALE and SO239 UHF Female connectors.
Cable
1.37
End A
RP-SMA FEMALE
End B
SO239 UHF Female
Specs Summary
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Assembled and tested in-house
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About This Assembly
Specs Summary
1.37 Cable
1.37mm coaxial cable is a miniature 50-ohm cable slightly larger than 1.13mm, balancing compact size with improved power handling and lower signal loss. Used for internal antenna leads in smartphones, routers, and IoT devices where the 1.13mm cable would be too lossy but space constraints still prohibit larger coax.
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 internal antenna leads in routers, smartphones, and compact IoT devices. 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.
1.37 Signal Loss
Approximate attenuation at common RF frequencies.
| Frequency | Loss / 100 ft | Loss / ft |
|---|---|---|
| 100 MHz | 7.8 dB | 0.078 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 | 41 dB | 0.41 dB |
| 5.8 GHz | 67 dB | 0.67 dB |
Frequently Asked Questions
What is 1.37 coaxial cable used for?
1.37mm coaxial cable is a miniature 50-ohm cable slightly larger than 1.13mm, balancing compact size with improved power handling and lower signal loss. Used for internal antenna leads in smartphones, routers, and IoT devices where the 1.13mm cable would be too lossy but space constraints still prohibit larger coax.
What is the signal loss of 1.37?
At 1800 MHz, 1.37 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 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.
