View Full Version : continuity across pl259

04-26-2022, 08:40 PM
Trying to find problem with high swr.

> (http://www.cbjunkies.com/member.php?u=6547)
should there be continuity on the antenna pl259 connector on the back of my radio. Trouble shooting high swr and noticed I had continuity from my antenna stud to the mount. Antenna good, mount good, stud good, coax good, it was the radio that was causing it. Is this correct for there to be continuity across the center pin and sthread of PL259 on radio.

04-27-2022, 06:43 PM
Not knowing what your radio is.... I can not answer specifically....
But in general.... both antennas AND radios CAN show direct DC shorts when they are perfectly fine.

The reason is this: tuned RF circuits are made up of capacitors and coils. Coils... are nothing but "wound up wraps of wire". WHen you apply RF energy to a coil....it develops what is called "impedance" ... which is a lot LIKE resistance....but it only applies to RF signals.

So a coil.... that has the PROPER impedance... somewhere near 27 MHz.... will STILL measure a dead short on an ohm meter. So it is possible that there is a coil inside your radio.... attached to the antenna socket pin... and THAT is what your ohm meter is seeing and calling a short.

Many antennas.... do the exact same thing. They have coils or tuned elements that are complete "DC shorts" but they tune up properly when RF is applied. You did not mention what kind of antenna you had either... and what kind of mount. All of these can contribute to really "rotten" SWR.

If you can give a little more info.... I can try to help!


Alabama Buckeye
05-03-2022, 01:28 AM
Sounds as though you have a short on the SO-239 (F) on the radio. Examination inside would be my first look-see. Clarity in terminology goes along ways towards understanding. PL-259 is a male connector not normally found on neither radios nor antennas. A "stud" suggest males connector but not in all conversations.

PL-259 are most often on terminal ends of coax which connect to SO-239 on radio and antenna.