All accurate accept the aging rate of any coax/heliax. Useful life =Years of expected life/woodpecker attacks. I would never have believed it but I am actually having trouble with those birds. :-) Just never know. Regards Paul WB8TSL
On Thu, Apr 21, 2016 at 5:33 PM, Tom Holmes <[email protected]> wrote: > Ryan... > > I've done a lot of tower work over the years, and have taken down quite a > few antennas, which of course meant removing whatever seal was used and > separating the connector halves. I have never found an N connector seized. > Usually a gentle twist using a pair of pliers will break the sleeve loose. > And I should point out that you don’t need to torque the sleeve any more > than gently when you mate the halves. Too much torque will distort the > internals and possibly damage things, or at least make the inherent SWR > bump a bit worse. > > Frankly, I would be concerned about the anti-seize compound migrating into > the inner workings of the connector and adding a bit of loss, which is > another reason not to use it. I'm not a big fan of the greases that are > suggested for use inside of connectors as a way to keep moisture out, again > because of their affect on the losses at 1575 MHz. > > My observations with various types of coax, such as Belden brand RG-8 and > RG-213, as well as Andrew Heliax is that even after 30 years outside in > Ohio weather, the outer jacket holds up quite well. Unsupported sections of > the RG types of coax that can flop around in the wind sometimes show cracks > and splits from years of flexing, however. The occasional punch through > from lightning has been found as well near the tops of 100' towers. > > Don’t get too uptight about the cabling; just do your best to make it > neat, reasonably well sealed (you are putting it in a pipe outside, that's > very good), and keep the bend radii gentle and you'll be fine. > > Have fun! > > Tom Holmes, N8ZM > > > -----Original Message----- > From: time-nuts [mailto:[email protected]] On Behalf Of Ryan > Stasel > Sent: Thursday, April 21, 2016 1:08 PM > To: Discussion of precise time and frequency measurement < > [email protected]> > Subject: Re: [time-nuts] RG6 or LMR400 for GPS Antenna (Symmetricom 58532A > and T-bolt) > > All, > > Really awesome answers, thanks! > > For the sealing question, it was more of a “should I bother with something > like anti-seize” or the like on the actual thread-thread N interface. The > actual connector crimp, was planning on just using a couple layers of the > heat-shrink with adhesive. That is all going to be internal to the mast > anyway, so direct weather contact should be minimal. It’s also on the side > of my chimney, that gets very little to no direct sun, so UV exposure > should be minimal. But good note on that regard. > > Pete, thank you very much for the info wrt the antenna and amp, and also > the fact the Trimble starter kit came with RG6. I’m going to see what my > seller wants for LMR400, but otherwise, I’ll just use RG6. It’s certainly > easier to handle. I did find some datasheets on the stuff that Home despot > (har har) sells (Southwire ( > http://www.southwire.com/ProductCatalog/XTEInterfaceServlet?contentKey=prodcatsheetOEM80)). > I swear I have a box of Belden somewhere, but I can’t seem to find it. > > Thanks again! > > -Ryan Stasel > > > On Apr 21, 2016, at 06:02 , paul swed <[email protected]> wrote: > > > > With respect to sealing. Everyone has a method. > > I use what I learned in the Navy. I could see how well the connections > held > > up in the worst conditions sun cold heat wet humidity... > > Layer of rubber tape > > scotch kote > > Layer of plastic tape > > scotch kote > > If done well the connector releases just fine even after 5 or more > years. I > > want to say 10. But then woodpeckers have a way of shortening the life of > > connectors and coax. > > The approach is really layers and the top to deteriorate over time... > > But as I say everyone has their own approach. > > Regards > > Paul > > WB8TSL > > > > On Wed, Apr 20, 2016 at 9:03 PM, Ryan Stasel <[email protected]> > wrote: > > > >> Bob/Paul, > >> > >> Thanks. And there's the rub... Who knows what the specs are on "generic" > >> RG6 QS. I'll see what my seller wants for their LMR400, but otherwise > yeah, > >> RG6 is just easier. I have both compression and crimp connectors for it, > >> including some RG6 N-connectors (yeah, they're probably for LMR300, but > >> they work). > >> > >> Other question: any tips for the exterior N connection? I can > >> "weatherproof" the actual cable-connector crimp, but I'm curious if > anyone > >> bothers to "lube" the N connector to keep moisture from otherwise > seizing > >> it up. > >> > >> Thanks! > >> > >> Ryan Stasel > >> IT Operations Manager, SOJC > >> University of Oregon > >> > >> Sent from my iPhone > >> > >>> On Apr 20, 2016, at 17:00, Bob Camp <[email protected]> wrote: > >>> > >>> Hi > >>> > >>> RG-6 Quad Shield should be fine as long as it’s meeting the published > >> specs. The advantage of LRM-400 is that you likely *know* where it came > >> from and what the specs are. > >>> > >>> If you decide to split the antenna between GPSDO’s, a powered splitter > >> is a really good idea. Each time you split another 2 ways, you loose 3 > db. > >> Get at least a 4 way splitter …. > >>> > >>> Bob > >>> > >>>> On Apr 20, 2016, at 4:41 PM, Ryan Stasel <[email protected]> wrote: > >>>> > >>>> All, > >>>> > >>>> I’m going to be installing a “permanent” antenna at home, and will > need > >> a run of about 100ft to get from my workstation, to the mast I’ll be > >> mounting the antenna on (Symmetricom 58532A). I’ve seen some indication > >> that both the antenna and the Trimble Thunderbolt won’t have any issues > >> with running over 75ohm cable, but thought I’d ask the “experts” whether > >> I’d be better off with some RG6 Quad-shield, or LMR400 (I’ve got a local > >> source that doesn’t know what LMR400 is, or what it’s worth)? > >>>> > >>>> Obviously I’d prefer to run and crimp RG6, but if I’d be better off > >> with LMR400, I’d rather run that now than go back into the crawlspace > >> again. =) > >>>> > >>>> Also, if it helps, I’ll probably have a Symmetricom/HP 58516A at/near > >> the T-bolt so I can experiment with other GPS(DO)s as well (especially > one > >> of the JRMiller boards I bought and built (but never finished) ages > ago). > >> Which brings the question, will the T-bolt provide the oomph needed to > >> power that splitter and the antenna over that length of cable? > >>>> > >>>> Thanks! > >>>> > >>>> -Ryan Stasel > >>>> > >>>> > >>>> _______________________________________________ > >>>> time-nuts mailing list -- [email protected] > >>>> To unsubscribe, go to > >> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > >>>> and follow the instructions there. > >>> > >>> _______________________________________________ > >>> time-nuts mailing list -- [email protected] > >>> To unsubscribe, go to > >> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > >>> and follow the instructions there. > >> _______________________________________________ > >> time-nuts mailing list -- [email protected] > >> To unsubscribe, go to > >> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > >> and follow the instructions there. > >> > > _______________________________________________ > > time-nuts mailing list -- [email protected] > > To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > > and follow the instructions there. > > _______________________________________________ > time-nuts mailing list -- [email protected] > To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > > _______________________________________________ > time-nuts mailing list -- [email protected] > To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
