UHF connectors for flexible cable are coaxial interconnect components designed to terminate stranded-conductor coaxial cable, as opposed to solid or semi-rigid cable. The category includes UHF plugs (male, commonly referenced as PL-259 style) and UHF jacks (female, commonly referenced as SO-239 style) built with crimp, solder, or clamp-nut termination methods that accommodate the flexible braid shield and stranded center conductor found in cables such as RG-58, RG-8X, RG-8, and RG-213.
Function and Working Principle
In a UHF connector for flexible cable, the center pin is joined to the stranded center conductor by soldering, crimping, or set-screw clamping, while the outer shell is joined to the braided or foil shield through a clamp nut, crimp ferrule, or solder shield sleeve. Because flexible cable braid and stranded conductors move and flex with the cable, the termination method must maintain continuous mechanical and electrical contact under repeated bending, vibration, and pull load. The connector body then presents a standard UHF threaded interface, allowing the cable-mounted connector to mate with a corresponding UHF bulkhead jack, adapter, or another cable plug of the same series.
Core Performance Characteristics
| Parameter |
Typical Value / Description |
| Frequency range |
DC to 300 MHz |
| Impedance |
Non-constant impedance, nominally treated as 50 Ω |
| Contact resistance |
Center contact ≤ 3 mΩ; outer contact ≤ 2 mΩ |
| Insulation resistance |
≥ 5000 MΩ |
| Dielectric withstanding voltage |
1000–1500 V RMS |
| Cable compatibility |
RG-58, RG-8X, RG-8, RG-213, and similar flexible coaxial cable diameters |
| Termination methods |
Solder, crimp, or clamp-nut (screw-on) assembly |
| Body material |
Brass with nickel or silver plating |
Product Highlights
- Compatible with common flexible coaxial cable diameters used in mobile, amateur, and CB radio installations.
- Available in solder, crimp, and clamp (screw-on reducer) versions to match field assembly tooling or factory production methods.
- Threaded coupling interface allows direct mating with UHF bulkhead jacks, UHF adapters, and other UHF cable plugs.
- Reducer/adapter inserts allow a single connector body to accept multiple cable diameters, such as RG-8X versus RG-58.
- Nickel or silver-plated finish options support different corrosion-resistance and solderability requirements.
Variants and Detailed Comparison
Within the UHF connectors for flexible cable category, the primary distinction is the termination method used to attach the connector to the cable braid and center conductor.
| Termination Type |
Assembly Method |
Typical Tooling |
Common Use |
| Solder type |
Center pin and shield sleeve soldered to conductor and braid |
Soldering iron |
Field repair, amateur radio, low-volume assembly |
| Crimp type |
Center pin and ferrule crimped onto conductor and braid |
Hydraulic or ratchet crimp tool |
Production cable assembly, consistent high-volume output |
| Clamp (screw-on) type |
Braid clamped by a nut and cone/washer assembly, center pin soldered |
Wrench, soldering iron |
CB radio, marine radio, field installation without crimp tooling |
UHF Flexible-Cable Connectors vs. UHF Bulkhead Mount Connectors
| Category |
Mounting Reference |
Termination |
Typical Role |
| UHF connectors for flexible cable |
Cable end |
Solder, crimp, or clamp to cable braid/conductor |
Antenna feed line, jumper cable, patch cable |
| UHF bulkhead mount connectors |
Panel or chassis |
Solder cup or PCB mount, secured by panel locknut |
Fixed feed-through point on equipment enclosure |
UHF connectors for flexible cable are selected according to cable diameter and termination method, while UHF bulkhead mount connectors are selected according to panel cutout and mounting style. The two categories mate directly through the shared UHF threaded interface.
Application Cases
- Amateur and CB radio antenna feed lines: RG-8X or RG-213 flexible cable is terminated with a crimp or clamp-type UHF plug to connect the antenna feed line to the transceiver's UHF bulkhead jack.
- Marine VHF radio jumper cables: Short flexible cable jumpers with solder-type UHF connectors on both ends link the radio unit to an external antenna cable run.
- Production cable assemblies: Crimp-type UHF connectors are applied in factory settings where consistent pull strength and repeatable termination quality are required across large assembly volumes.
- Field service and repair: Clamp or solder-type UHF connectors allow on-site cable repair or connector replacement without specialized crimp equipment.
Installation and Maintenance Guidance
- Match the connector's reducer/insert size to the actual cable outer diameter; an incorrect reducer size can result in a loose braid connection or damaged dielectric.
- For solder-type connectors, avoid excessive heat dwell time on the center pin, which can melt or deform the cable's inner dielectric and shift impedance.
- For crimp-type connectors, use a crimp tool and die matched to the connector manufacturer's specification to achieve the correct crimp diameter and pull strength.
- For clamp-type connectors, tighten the clamp nut evenly so the braid is compressed uniformly around the cone, without cutting through individual braid strands.
- Inspect cable jumpers periodically for strain at the connector-to-cable transition, particularly in mobile or vibration-prone installations, and re-terminate if strands are visibly broken.
- Keep the mating thread and center contact free of dirt, moisture, or corrosion; clean with a dry cloth or contact cleaner rated for RF connectors before mating.
Frequently Asked Questions
Which cable sizes work with UHF connectors for flexible cable?
Common compatible sizes include RG-58, RG-8X, RG-8, and RG-213, selected according to the connector's center pin bore and reducer/insert size.
Is a crimp or solder-type UHF connector preferred for production cable assembly?
Crimp-type connectors are commonly used in production settings because the termination is repeatable with consistent pull strength once the correct crimp tool and die are used, while solder-type termination depends more on individual assembly technique.
Can UHF connectors for flexible cable be used with semi-rigid or hard-line cable?
Standard UHF connectors for flexible cable are designed for stranded braid and conductor cable; semi-rigid or hard-line cable requires connector versions specifically designed for that cable construction.
Do UHF flexible-cable connectors mate with UHF bulkhead mount connectors?
Yes. Both categories share the same UHF threaded mating interface, so a cable-mounted UHF plug or jack can mate directly with a corresponding UHF bulkhead jack or plug.
How is cable diameter mismatch handled with a fixed-size UHF connector body?
Reducer inserts or step-down adapters are fitted inside the connector body to adapt a single connector design to a smaller cable diameter, such as using an RG-8X reducer inside a UHF connector body designed primarily for RG-8 or RG-213.
Yangzhou Jingcheng Electronics Co., Ltd. (JC Company), founded in 1999, produces UHF connectors for flexible cable together with related UHF, SMA, N-type, BNC, and TNC series connectors, cable assemblies, and passive RF components under ISO9001 quality management, with production referencing MIL, IEC, and GB standards for mobile radio, marine, and communication cable applications.
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