Joe Subich, W4TV
lists at subich.com
Tue Apr 24 19:38:08 EDT 2018
> This load equals 39 sqft projected area including exposed mast. About
> 75% of the tower rating at 100 mph. I live in an 80mph zone.
Have the load checked by a professional engineer. Most towers are
specified for load at the tower top (or within 1 - 2 feet). Spreading
the load up the mast can greatly increase the effective load on the
... Joe, W4TV
On 2018-04-24 7:19 PM, kstover at ac0h.net wrote:
> OK Tower Talkers. I need wisdom and guidance.
> I am finally in a position to start building my retirement station meaning a
> BIG upgrade in the tower and antenna department.
> Here is my plan.
> 70’ AN Wireless HD tower
> 25’ 3”x3/8 wall 4130 Chromoly mast, 20 foot out the top.
> ½” hard line from the man cave to the tower. I haven’t decided where to put
> the coax switch yet, top or bottom.
> Rotator, either a K7NV prop pitch or an Alpha Spid BIG RAK Anything with PST
> in the name need not apply.
> Antennas. I have to do all this on one tower.
> Right now I’m leaning toward a JK Mid-Tri (20-10), a JK 1712 Jr for WARC .
> and a 402T for 40m, in that order up the mast separated by 10ft.
> 16 sqft for the Mid-Tri, 9 sqft for the for the 17/12 Jr. 9sqft for the 402T
> and 5 sqft for the mast.
> Another possibility is an Optibeam 11-5 for 20-10 WARC inclusive, the 402T
> at the top then a six or seven element 6m beam in the middle
> This load equals 39 sqft projected area including exposed mast. About 75% of
> the tower rating at 100 mph. I live in an 80mph zone.
> The mast will take the load all the way up to 125-130 mph depending on
> antenna scenarios.
> For the low bands I’m going to shunt feed the tower
> SteppIR is not an option. They break too much. Save the anecdotes.
> Same thing for PST whatever. They break too much. Save the anecdotes.
> Since my disability my climbing days are pretty much over. I need to pick
> products that are built hell bent for stout.
> Nobody makes a crankup tower that will take that load. I could downsize the
> antennas and go with a xr5-jk but it’s two elements per band on five bands,
> I still haven’t figured out how the Navassa 5-jk works. 5 bands on a twelve
> foot boom. Must be some “Weird Science” (Quantum Mechanics) going on.
> Thanks for the input.
> R. Kevin Stover AC0H
> ARRL, FISTS, SKCC, NAQCC and a bunch of other acronyms.
> One of the guys that made sneakernet irrelevant, in my little corner of the
> “If it doesn’t work the first time you push the button it won’t work the
> 20th…Just stop.”
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