Max-Gain Systems has a number of extensible/collapsable fiberglass masts, some of which might meet your needs, although MGS does not actually recommend mounting a rotatable antenna on one of their push-up systems.
https://mgs4u.com/product/mk-4-series-25ft-masts/ can extend up to 25 feet, but the top section is only one inch in diameter, so it might not support a 6M5X yagi.
https://mgs4u.com/product/mk-8/ can extend up to 50 feet when guyed and attached to a strong base, but to get up to 20 feet you only need to use 2 or 3 of the biggest nested sections so it might be more suitable for holding the 6M5X at 20 feet up.
MGS also sells fiberglass tubing and rods, so you could put a solid rod inside the third section to strengthen it. You could also "double up" sections, i.e. glue a 2.25"OD tube inside of a 2.50"OD tube to make the lowest section at double the wall strength, then a 1.75"OD tube inside of a 2.00"OD tube as the second section that would slide into the first section, and then get a 1.50"OD solid rod as the third section. In fact, instead of gluing together a 1.75"ID and a 2.00"ID tube, you could just buy a 2.00"OD tube in 1/4" wall thickness. (Most of their fiberglass tubes only come in 1/8" wall thickness.) Since they sell the tubes and rods in 4 foot and 8 foot lengths, a 3-section mast extended to 20 feet would allow for 2 feet of overlap per section which would be plenty.
For more details on their fiberglass offerings, go to https://mgs4u.com/telescoping-fiberglass-tube-and-rod-price-list-2/
Good luck. John, W0JT/5, EL09vu20
On Thu, Jul 26, 2018 at 7:24 AM, Paul Overn via AMSAT-BB <[email protected]
wrote:
I know this isn't exactly satellite related, but I've asked for help in other places, and the feedback has been sparse. You guys have always been very helpful. I'm looking for a portable antenna mast that I can use between passes while satellite roving. I would like it to be able to go to at least 20', hold a 5 element M2 6 Meter yagi, be able to fit in a small truck and be portable. I have looked at numerous military surplus masts, like at Go-vertical-usa, but they will not return any of my correspondence. I have looked into many "home brew" solutions, but I'm just not that handy.
Anyone have any good sites I can go to for something that fits my needs? Thanks in advance for your help!
Paul Overn KE0PBR Twitter: @KE0PBR `·.¸¸.·´¯`·.. ><((((º>`·.¸¸.·´¯`·.¸><((((º>`·.¸¸.·´¯`·.. ><((((º> _______________________________________________ Sent via [email protected]. AMSAT-NA makes this open forum available to all interested persons worldwide without requiring membership. Opinions expressed are solely those of the author, and do not reflect the official views of AMSAT-NA. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb