Charles... Rohn's HDBX series would go to 50 feet, free-standing. It is a real pain to climb because the braces cross in an 'X' pattern, but is quite sturdy. Two reasonably fit climbers plus a one person ground crew could put it up in a few hours once the base is ready. These towers tend to twist more than rock, unlike Rohn 25, 45, or 55.
For your minimal load GPS antenna, even the BX series would be adequate, but I don't believe there is a 50 foot version. Now that I think about it, Rohn sold off all of the various BX series, and it is now marketed by Thomas & Shelby. Any piece of tubing you would try to take to 50 feet would likely buckle under its own weight and length pretty quickly (all of you ME's and physics majors can correct my terminology and choice of failure modes off list, the point being that it WILL fall down if you can even get it put up), and would definitely need to be guyed. This leads me to another possibility, if money is not a concern. One ham friend of mine has a 120 foot tower that is based on those tapered lighting supports you see along the freeways. It is galvanized and consists of three sections that simply nest for about a 10 foot overlap. Of course, it takes a crane to assemble. Remember, I said if money is not a concern...but it does look very nice and serious and professional. Climbing it is not for the faint of heart, believe me! Tom Holmes, N8ZM Tipp City, OH EM79 > -----Original Message----- > From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On > Behalf Of Charles P. Steinmetz > Sent: Friday, September 03, 2010 1:08 AM > To: Discussion of precise time and frequency measurement > Subject: Re: [time-nuts] Freestanding mast > > Stanley wrote: > > >ROHN 9H50 34 Foot Telescopic TV Wireless Antenna Push Up Mast > > Interesting suggestion. Rohn is well known to me, though I don't > typically think of them for things like push-up masts. > > For those suggesting 6-10' of pipe, at my rooftop I get a reception > cone of about 50 degrees elevation and above during the vegetated > months (say, mid-March through mid-November), and about 30 degrees > and above in the dead of winter, due mostly to dense tree cover that > is 60-80 feet tall. So, I'd really need to get 20 feet + above the > chimney (50+ feet above the ground) for a significant > improvement. The suburban residential lot size doesn't leave me much > to work with (no centrally-located tower, therefore no guys unless I > negotiated easements with the neighbors, and Hell will never be that > cold...). I doubt I could get a permit for 80' of Rohn 55. Maybe if > I put a wind generator on it.... > > Thanks again, > > Charles > > > > > > _______________________________________________ > 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.