Dauntless Aviation
 
FAA Written Test Prep
Checkride Oral Exam Prep
Pilot eLogbook System
Aircraft Systems Reviews
EASA Theory Exam Prep
China ATPL Theory Prep
UK PPL/IMC Theory Prep
Transport Canada Theory Exam Prep
Aircraft Recognition Tutor
SimPlates IFR Plates
FAR/AIM Reference
All Software and Apps
Aviation Freebies
Free Aircraft Checklists
MetalWings Diecast
 
Products by Platform
 
Support
Knowledgebase / FAQ
Contact
Employment
SBD Dauntless
 
Bulk Purchases
Site/Lab Licensing
Affiliate Program
 
Home

Important Message
Great news! Our website is now again accepting orders via a secure, trusted merchant services provider. It's working great for nearly everybody. However, if you're affected by a tweak or two that we still need to make, please try using a different PC or Mac based browser and make sure you're not in private/incognito mode. If you still have issues, please reach out to us our team is very actively monitoring the situation and responding as we can. As we said though, it seems to be working great for nearly everybody now.

Aviation Glossary :: UHF (PL-259/SO-239) Connector  Aviation Glossary :: UHF (PL-259/SO-239) Connector FAA Written Test Preparation
Aviation Glossary Welcome to the Dauntless Aviation Glossary!

At Dauntless, our editorial staff maintains the web's largest unified glossary of aviation terms. This glossary is built from a combination of official, quasi-official, and proprietary sources (including original material that we develop oursselves). Uniquely, we often provide multiple definitions of a given term so that you can find that which best applies to you. In order to maximize your learning efficiency, this glossary (and similar ones for our international users) is incresingly fully integrated into our aviation learning apps, including our FAA written test prep and FAA practical test prep software and apps. If you like this glossary, you'll love them with their polished learning environments and world's best and clearest content (please do give them a try.).

UHF (PL-259/SO-239) Connector
UHF (PL-259/SO-239) Connector
The UHF connector, also called the Amphenol coaxial connector, is a World War II threaded RF connector design, from an era when "UHF" referred to frequencies over 30 MHz. Originally intended for use as a video connector in radar applications, the connector was later used for other RF applications. This connector was developed on basis of a shielded banana plug.

UHF connectors are generally usable through what is now known as the VHF and HF frequencies and can handle RF power levels over one kilowatt. There is variation between manufacturers with the choice of dielectric, the PTFE types being favored where low loss is desired. The average power handling of the PTFE versions is essentially set by heating of the center pin, and is therefore frequency-dependent, as the RF resistance rises as the skin depth falls. At low frequencies, the power handling is rather better than that of the similar-sized N connector. The UHF connector is the most common connector in amateur radio applications up to 150 MHz. In the US, the silver-plated version with Teflon dielectric is used in UHF applications up to 450 MHz for the 70 cm band.

Despite the name, the UHF connector is rarely used in commercial applications for UHF frequencies, as the non-constant impedance (the impedance drops to 30-40 Ω for about a centimeter in the central region of the connector) means they create significant electrical signal reflections above 300 MHz.

The most popular cable plug and corresponding chassis-mount socket carry the old Signal Corps nomenclatures PL-259 (plug) and SO-239 (socket). The PL-259 can be used with large diameter coaxial cable, such as RG-8/U and RG-9/U, and the smaller diameter RG-58/U and RG-59/U with the use of UG-175/U and UG-176/U adapter sleeves. "PL-259" refers to one specific mechanical design, but the term is often used for any compatible UHF cable plug. The thread is 5⁄8 inch 24tpi UNEF standard. Other UHF connectors with a similar—but incompatible—metric thread have been produced. The center conductor jack on the SO-239 will also accept a 4 mm banana plug.

In many applications, UHF connectors were replaced by designs that have a more uniform impedance over the length of the connector, such as the N connector and the BNC connector, but they are still widely used in amateur radio, citizens' band radio, and marine VHF radio where mechanical robustness and ease of use are more important than a small mismatch. The "classic" PL-259 connector is resistant to damage even if stepped on accidentally.

One reason for the popularity of the UHF connector is its ease of assembly. While crimp connectors exist, the solderable screw-on connector is more common because no expensive specialized crimping tools are required. The connector is not suitable for outdoor applications by itself, but can be made weather resistant by wrapping it with self-adhesive silicone C-Tape.

UHF connectors were also used for the input and output of composite video signals for older video equipment (such as VTRs and monitors) dating from the late 1970s and earlier. They were known by BBC engineers as "F & E" connectors, after Films & Equipment, a manufacturer.

source: Wikitionary / Wikipedia and Related Sources (Edited)

Ace Any FAA Written Test!
Actual FAA Questions / Free Lifetime Updates
The best explanations in the business
Fast, efficient study.
Pass Your Checkride With Confidence!
FAA Practical Test prep that reflects actual checkrides.
Any checkride: Airplane, Helicopter, Glider, etc.
Written and maintained by actual pilot examiners and master CFIs.
The World's Most Trusted eLogbook
Be Organized, Current, Professional, and Safe.
Highly customizable - for student pilots through pros.
Free Transition Service for users of other eLogs.
Our sincere thanks to pilots such as yourself who support AskACFI while helping themselves by using the awesome PC, Mac, iPhone/iPad, and Android aviation apps of our sponsors.

Disclaimer: While this glossary in most cases is likely to be highly accurate and useful, sometimes, for any number of editorial, transcription, technical, and other reasons, it might not be. Additionally, as somtimes you may have found yourself brought to this page through an automated term matching system, you may find definitions here that do not match the cotext or application in which you saw the original term. Please use your good judgement when using this resource.


© 2024 Dauntless Aviation • 4950C York Road 110, Buckingham, PA, 18912, USA • Contact UsPrivacy Policy / Terms / Conditions