[TowerTalk] PL259 Insertion Loss?

[Steve W3AHL]

While PL-259's and barrel connectors may not have enough loss on HF to worry 
about, they certainly make nice markers when sweeping coax runs with a TDR! 
You can see every connector's impedance bump.  Not so with N connectors....

The most common cause of excessive insertion loss I have seen with PL-259's 
is a solder ball on the end of the center pin spreading the mating female 
contacts.  After a few insertion cycles a cheap SO-239 may read 2-5 ohms 
through the center pin.  Then there are the connectors where someone scraped 
all the solder balls off with a knife, taking all the plating with it. 
Every ham club should offer classes on how to install coax connectors and 
what kinds NOT to buy at hamfest!

It takes a lot of heat to get a connector warm to the touch, due to thermal 
conduction of the copper center wire and shield of the coax.

Steve, W3AHL