Don, in this case the lock washer would jam into the opening for the connector. If you look at the setup in the manual you'll see that panel hole is oversized and the engineers put an o-ring on the connector that centers it in the hole. The inside surface of the panel is masked to provide good contact with a large flat washer that goes against the rear panel opening and provides a good surface for the nut and lock washer that secures the connector to bear against.
The connector has a hex cut on the inside ferrule. Tightening is done with a wrench or pliers on the nut outside while holding the hex cut ferrule on the inside to keep it from turning. 73, Ron AC7AC -----Original Message----- From: Don Wilhelm [mailto:[email protected]] Sent: Saturday, April 2, 2016 4:07 PM To: Ron D'Eau Claire; 'Mike Cox'; [email protected] Subject: Re: [Elecraft] KE: issue with installation of K3EXREF interface One "trick" that I have adopted when tightening chassis mount BNC and SMA female connectors is to put a mating connector on the outside of the connector. That mating connector can be held tightly with pliers or a wrench without damage to the female connector that you are trying to tighten, and you can secure the nut with a wrench. The mating connector may or may not have coax connected to it - that makes no difference. The other thing that is often shown in manuals which is IMHO incorrect is that the star washer should go between the grounding lug and the chassis so the teeth of the star washer bite tightly into the metal of the chassis as well as into the grounding lug - assuring a good ground path. Another plus for the latter star washer positioning is that once the star washer begins to 'bite', the grounding lug is not apt to turn as you secure the nut. 73, Don W3FPR On 4/2/2016 6:52 PM, Ron D'Eau Claire wrote: > Were you only holding the nut while tightening and the ferrule cracked? > > That is the first case I've heard of in the 5 years the K3EXREF option > has been shipped so it's possible there's an issue with some units, > especially since there are two cases. > > I'm curious because we might need to alter the procedure in the manual > a bit if it's something happening during installation. > > 73, Ron AC7AC > > -----Original Message----- > From: Elecraft [mailto:[email protected]] On Behalf Of > Mike Cox > Sent: Saturday, April 2, 2016 2:59 PM > To: [email protected] > Subject: Re: [Elecraft] KE: issue with installation of K3EXREF > interface > > Mine broke off too. It appeared for be a crimped ferrule but it split > and fell off as though it were already fractured. I carefully soldered > the coax braid to the connector to maintain the electrical connection. > I was careful not to overheat and melt the dielectric of the coax > which could have shorted the center conductor to the shell. It's working well! > > Mike, AB9V > > On 4/2/2016 16:16 PM, Jim Spears wrote: >> While installing the K3EXREF SMA-TMP cable, I ran into an interesting >> issue which I do not yet know if it is a problem or just interesting. >> >> >> >> There is a ferrule or something similar over the cable where it >> attaches to the SMA fitting that is installed on the back panel. >> while tightening the hex nut down, I must have torqued something as >> the ferrule broke into two pieces and fell off. I finished off the >> installation and verified that the GPSDO does provide a suitable 10 >> MHz > signal into the radio. >> >> >> So the question becomes: is this interesting or a problem? I took a > close >> look and the problem might be improper grounding of the shield to the >> chassis at the SMA connector end. >> >> >> >> If it is deemed to be a potential problem, I can request a new cable >> from support. It will not take long to replace the cable. >> >> >> >> Jim/N1NK >> >> ______________________________________________________________ >> Elecraft mailing list >> Home: http://mailman.qth.net/mailman/listinfo/elecraft >> Help: http://mailman.qth.net/mmfaq.htm >> Post: mailto:[email protected] >> >> This list hosted by: http://www.qsl.net Please help support this >> email >> list: http://www.qsl.net/donate.html Message delivered to >> [email protected] > ______________________________________________________________ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:[email protected] > > This list hosted by: http://www.qsl.net Please help support this email > list: http://www.qsl.net/donate.html Message delivered to > [email protected] > > ______________________________________________________________ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:[email protected] > > This list hosted by: http://www.qsl.net Please help support this email > list: http://www.qsl.net/donate.html Message delivered to > [email protected] > ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[email protected] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [email protected]
