Re: PL259 - how tight?


Hi Richard,

Thanks four thoughtful question. Probably nobody has. Trouble is that a missing or bad return current connection (which this is all about) may not have a great effect on SWR or loss. That return current will in most cases find an alternative path, e.g through equipment bonding wires, third prong on AC wires, etc. So while you still may have what looks like a god connection to your antenna, it will have a huge effect on the leakage of RF to the shack, affecting both reception and possible RF interference with equipment in the shack. I have wrench tightened connections on all my my patch cords in the shack and I know I have an exceptionally "air-tight" shack. Witness, I can use my 2nd K3 to transmit a 100W carrier to a dummy load in the shack and it's just in the noise when listening to my main K3S connected to the (fairly distant) outdoor antenna. That path goes:

K3S - Directional coupler - LP100A - KAT500 - Alpha Delta switch - cable to antenna field.

The directional coupler makes me sniff the TX signal for a scope and a DSR used as a spectrum analyzer.. The Alpha Delta switch makes me choose whether the external antenna field get routed to the shack or somewhere else.

That's a lot of patch cords. I have made them all myself using Amphenol PL259s and LMR240 coax.

Now, back to the original question (which no responders have really touched upon). Is there any harm done in wrench tightening the connections? Humorous posts aside, my original post states that I use a fairly small wrench (12") and a very slight tug on the handle. The sleeve moves a noticeable amount and then comes to a dead stop. I do not tear down my connections ever, even if a thunderstorm is approaching, so the extra effort is no problem. If I get a warning of bad thunderstorms, at most I will switch the two Alpha Delta switches in the antenna path (one additional one outside) to ground. I have never had any electronics damage from thunderstorms (but we don't live in Tornado Alley either).

AB2TC - Knut

On Thu, May 2, 2019 at 02:30 PM, Richard Smith wrote:
I enjoy reading all the anecdotal accounts.  I wonder if someone actually measured the connection?  RAS

On May 2, 2019, at 12:57 PM, John McCann <gr8dxr@...> wrote:

Oh yeah, that should do it!

Tight as a tick in a summer campground...

John N7MZ


On 5/2/2019 6:31 AM, Ben Loper wrote:
I like to use a 6 foot length of pipe on the handle to give me some leverage. I have my wife sit on the radio while I put my full body weight on the pipe. That will lower your SWR about 3 points

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