Lab Tests: SMA, BNC, TNC and N Connectors

Lab tests show post WW2 connector designs perform exceptionally well up to 500 MHz. The SMA, BNC, TNC and N connectors are great.

PL-259/SO-239 Return Loss and Attenuation Test

We pit the PL-259 (and SO-239) against more recent connectors. This is the list of contenders plus a description of the test setup.

Pretty Lousy? (PL) 259 Connectors

Various PL259 and SO239 Connections

The PL259/SO239 (aka UHF) connectors have harsh critics and religious defenders. Questionable measurement techniques complicate matters. Let’s clear things up.

Dipole Generates Static in PL-259

Irrespective of the fact the solder-the-braid PL-259 connector is probably the worst RF connector conceived by the mind of man1 and the fact the spark shown in the video is in an area that should be a direct short, the video, shown below, wonderfully shows the ease with which static charge can build on a dipole antenna.

That’s not the point though. If we were to cut off the connector we would surely still see a spark from center conductor to shield. If the cable were near station ground we would expect a spark jump. That large a charge has to go somewhere.

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Good Source of Crimp PL-259 for 0.4″ Coax Cables

A few years ago I installed lengths of LMR-400 Direct Burial coaxial cable in my back yard. I wanted good connectors for my investment. I seriously considered the superior N connectors, but my DX Engineering Coax Switch uses SO-239 connectors. While not the high quality choice, I succumbed to tradition and sought out suppliers for the PL-259.

Money was really no object since the connector is often the weak link in the system and deserves quality. I just made an investment in 240 feet of LMR-400 cable and wasn’t about to shortchange the connector.

Read moreGood Source of Crimp PL-259 for 0.4″ Coax Cables