Hi The bigger issue with unsuspended cables is wind and weather. It’s not just a static weight issue. When the wind blows the cable jerks around. You very much want to tie it off against the mast. You also want a strain relief loop at the antenna.
Bob > On Sep 3, 2017, at 10:44 AM, Artek Manuals <manu...@artekmanuals.com> wrote: > > Clay > LMR-400 is probably the best compromise , I doubt you will see any useful > improvement in system performance as a result of the improved 1.5db loss > characteristics of the larger cables. Losses due to atmospherics, > ionospherics and multi-path will be an orders of magnitude higher than the > additional 1.5 db of signal improvement with the larger cables. We are not > talking comms with some guy in a space suit on Mars here :-) > > AS for walking the mast up I have done a number of installations of this > sort and the use of a block and tackle at the eve point is not difficult, and > will be appreciated more and more the older you get . Mechanical > multiplicative advantages are easy to implement. Don't use block & tackles > which can pivot since depending on the weave/braid of the rope they will > twist around and bind. > > Dave > manu...@artekmanuals.com > > On 9/2/2017 7:48 PM, Clay Autery wrote: >> Thanks for the response... >> >> Not sure why you and the other guy both recommended RG-6 75-Ohm cable >> and F-connectors, when the nominal impedance of literally everything >> else in the system is 50 Ohm, including the antenna and the HP GPS >> Distribution Amp.... And then adding N to F adapters? >> >> Doesn't make any sense unless one has $$ as a top priority, already has >> a spool of RG-6 quad shield, etc... but I specifically stated that $$ >> is not a top priority.... Not really even in the top 5 or 10... >> >> The whole point of this exercise is to put up a semi-permanent SINGLE >> antenna/feed-line install that will supply all 4 ports of the HP amp >> with the least compromised signal within reason.... 4 now, and 8 >> whenever I can find the HP 8-way distro amp with external power input. >> >> Strain relief solution: Really depends upon which cable stock I end up >> using.... Obviously, the larger the cable, the more weight will be >> suspended under the antenna (approx. 38 feet, depending on where I pull >> the cable out of the mast at the bottom. (The mast is on a tilt-base of >> my own construction.... which brings up a valid consideration. it is >> already a chore to walk the mast up manually. The more weight added at >> the top and inside the mast, the more difficult a manual walk-up will >> be. I'd prefer to keep this a manual tilt for now... at least until I >> add the tri-band vertical dipole) >> >> LMR-400 would be less than 4 lbs total weight... I'd likely suspend the >> cable by the connector alone. (although, it wouldn't be JUST the >> crimp... The connector would have at a minimum, 1 layer of >> adhesive-lined shrink tube... probably 2, with the second, overlapping. >> Then a nice wrap of self-fusing tape and then electrical tape over that. >> Even LMR-600 could be suspended by the connector alone, at 5 lbs max in >> the 38 foot max vertical section. >> I do have several methods of secondary suspension within the top (and/or >> second) mast section though if I decide I need it. >> >> Also prefer to keep all the connectors N-type as much as possible since >> that is the station standard. >> >> 73, >> >> ______________________ >> Clay Autery, KY5G >> >> On 9/2/2017 6:07 PM, Mike Naruta AA8K wrote: >>> Clay, you may wish to consider using a quality RG-6 with F >>> connectors. Grounding blocks are readily available for the base of >>> your mast and the entrance to your house. Also, off-the-shelf >>> over-voltage protectors (Zap-Tech) are available. I even found an >>> F-to-N adapter for the antenna on Amazon. Watch out for the ones with >>> metric N threads though. >>> >>> For my 25 meter run I was going to use an existing one inch Heliax, >>> but pulled a run of Belden RG-6 instead after learning that Trimble >>> used RG-6. >>> >>> It worked well directly connected to a Trimble Thunderbolt; now it is >>> connected to a Symmetricon 58535A GPS L1 distribution amplifier. >>> >>> >>> My Blitzortung System Red station has been running fine in my attic >>> (Michigan) on a Motorola 97 Oncore patch antenna fastened against the >>> roof underside. It is looking through wood, shingles, and nails (and >>> a tree and antennas and utility lines). >>> >>> >>> How are you planning to do strain-relief on the vertical run of coax >>> inside of your mast? >>> >>> >>> Mike - AA8K >>> >>> _______________________________________________ >>> time-nuts mailing list -- time-nuts@febo.com >>> To unsubscribe, go to >>> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >>> and follow the instructions there. >> _______________________________________________ >> time-nuts mailing list -- time-nuts@febo.com >> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >> and follow the instructions there. >> > > -- > Dave > manu...@artekmanuals.com > www.ArtekManuals.com > > > --- > This email has been checked for viruses by Avast antivirus software. > https://www.avast.com/antivirus > > _______________________________________________ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.