[TowerTalk] PL259 Insertion Loss?

Jim Brown jim at audiosystemsgroup.com
Sat Jan 14 09:36:25 PST 2012


On 1/14/2012 8:59 AM, Tony wrote:
> I was wondering if anyone has done any tests of their own or if they
> know of a reliable source on the web for this kind of data?

Yes, tests have been done on REAL Amphenol PL259 connectors, and their 
losses are negligible below 300 MHz.  A VE1 (was it VE1RGB?) did some 
tests that he sent me, and I did some of my own tests.  I had made up 
100 ft and 200 ft coax runs for a DXpedition using low loss Commscope 
quite similar to LMR400, and to test them, spliced 1300 ft together and 
measured loss from 1 MHz to 500 MHz using HP test gear.  The total loss 
up to 400 MHz was less than Commscope's spec for that length of cable at 
500 MHz.  This was for 11 barrels and 22 PL259s.

One of the problems with the internet is that people repeat what they've 
read as if it's fact. There's no good reason why a properly installed 
PL259 connector should be lossy.

On the other hand, most connectors and adapters, including the ones sold 
by nearly all ham vendors, and at hamfests, are cheaply made JUNK, and 
they ARE lossy.  I've had Tees and adapters fall apart in my hands, and 
go intermittent for no apparent reason, and overheat running 1kW for as 
little as an hour.

Bottom line -- REAL Amphenol connectors are NOT lossy, but no-name JUNK 
connectors and adapters CAN be VERY lossy, and unreliable.

73, Jim Brown K9YC


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