Bob, Fair enough. I’ll just stop worrying about it. =)
I believe that number sounds like per 100 meter, not per 100 foot. Once I have the actual coax, as someone suggested, I’ll just hook some ends up, and check it. =) Sadly, I don’t have an SA, so checking the attenuation might be problematic. Though, could I not just use a function gen (signal gen), and a scope? Trying to think… I don’t have anything that’ll do 1.5Ghz though (or even close). Meh, overthinking… what Paul said. =) I’m sure it’ll be fine. Will the T-bolt actually complain about poor signal, or just not work reliably? And lastly, I guess, there’s a setting on the T-bolt to compensate for cable length. I assume that’s compensation for antenna cable length? I know I can figure that out with an SG and Scope, assuming the propagation delay is what the spec sheet claims to be (most RG6 seems to be right around 80%) (the home depot stuff seems to be 79%). -Ryan Stasel > On Apr 22, 2016, at 14:38 , Bob Stewart <[email protected]> wrote: > > Hi Ryan, > > For the few years I've been on time-nuts, I understood the consensus view to > be to get a good quality RG-6QS satellite cable. A few of the posts in this > thread have made me wonder if the consensus is changing, or if it's just too > much trouble to stand up to the crowd. I've got about 300 ft of CerroWire > RG-6QS leftover from Home Depot in the garage. I looked at the datasheet, > and it's confusing. For the attenuation at 1000MHz, they list 21.45DB per > hundred with the superscript "1". However there is nothing on the page > noting whether that "1" means per 100 feet or per 100 meters. Looking at the > competition it would appear that that's per meter. Unfortunately, I don't > have the right connectors to hook it up to my SA to see. OTOH, 100 ft runs > from this spool don't show any noticeable (i.e. problematic) attenuation of > the signal. Maybe someone else with a spool of RG-6 in the garage could give > use some real world attenuation figures at L1? > > But, rather than over-engineering or over-angsting this issue, it's probably > OK to just pick one and use it. It's not likely to make any real difference > unless you have a run in the many hundreds of feet. > > Bob - AE6RV > > -------------------------------------------- > On Fri, 4/22/16, Ryan Stasel <[email protected]> wrote: > > Subject: Re: [time-nuts] RG6 or LMR400 for GPS Antenna (Symmetricom 58532A > and T-bolt) > To: "Discussion of precise time and frequency measurement" > <[email protected]> > Date: Friday, April 22, 2016, 4:09 PM > > Paul, > > LOL! So, along those lines… > one other question, since I can’t find my belden, I’ll > be buying some coax. Anyone have any opinions about RG6 for > CCTV vs CATV? My understanding is the CCTV version always > has a solid copper center conductor (which in my mind would > mean less voltage loss for the DC power going to the > antenna), or I’m still overthinking it and should just go > with standard RG6? > > Thanks! > > > -Ryan Stasel > >> On Apr 21, 2016, at 13:04 > , paul swed <[email protected]> > wrote: >> >> Ryan a > slight heads up. >> Time Nuts is not about > time accuracy as many people assume. >> > Its actually about the time we all waste looking for what we > know we have. >> We just measure that time > accurately. >> I do not use anti seize. > Nothing against it just one more glob of stuff to >> deal with. >> If you use > the heat shrink and it seals your done for my 2 cents. >> Paul >> WB8TSL >> >> On Thu, Apr 21, 2016 > at 1:07 PM, Ryan Stasel <[email protected]> > wrote: >> >>> > 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. > _______________________________________________ > 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.
