All, So, went digging into my crawlspace just now, and found my RG6 that I thought was Belden. It’s actually Coleman 92003, which isn’t quad shield, but has a spec sheet that actually shows attenuation at 1500Mhz!
https://www.platt.com/CutSheets/Coleman%20Cable/92003.pdf Interesting that there seems to be a “hump” between 1200 and 1500Mhz, as the attenuation jumps quite a bit, whereas it’s relatively flat between 700 and 1200Mhz. Then another bump above 2200Mhz, which is what this cable is rated to. It’s sun resistant, which is good. Anyone see any reason to not use this, and instead use some generic Quad Shield? It is gas injected, which supposedly improves it’s susceptibility to crushing, or other deformation of the insulator… but I can’t say I’ve seen this actually shown anywhere (I guess because it’s HDPE rather than LDPE insulator). Thanks again everyone for all the input! It’s been pretty great to read this thread… even if it’s a bit “academic”. =P -Ryan Stasel On Apr 23, 2016, at 7:26 AM, billriches <[email protected]<mailto:[email protected]>> wrote: RG6 for CCTV has copper shield and solid conductor. RG6 for CATV has aluminum shield and solid conductor. 73, Bill, WA2DVU Cape May -----Original Message----- From: time-nuts [mailto:[email protected]] On Behalf Of Ryan Stasel Sent: Friday, April 22, 2016 5:09 PM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] RG6 or LMR400 for GPS Antenna (Symmetricom 58532A and T-bolt) 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]<mailto:[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]<mailto:[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]<mailto:[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]<mailto:[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]<mailto:[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]<mailto:[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]<mailto:[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]<mailto:[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]<mailto:[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]<mailto:[email protected]> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. --- This email has been checked for viruses by Avast antivirus software. https://www.avast.com/antivirus _______________________________________________ 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.
