[TowerTalk] Aluminium telescopic mast

[john]

As an alternative, who makes an inexpensive fiberglass or metal push up mast?  Say 30 or 40 foot.I'm thinking of making the "Unique HF Vertical" in the July QST page #39.Sent from my Verizon, Samsung Galaxy smartphone
-------- Original message --------From: Máximo EA1DDO_HK1H <ea1ddo at hotmail.com> Date: 7/17/19  9:32 AM  (GMT-07:00) To: Wes <wes_n7ws at triconet.org>, towertalk at contesting.com Subject: Re: [TowerTalk] Aluminium telescopic mast Hi Wes,.120" x2 = .240"  to .250" it is only .010" clearance (which is 0.25mm !)That's really tight, in fact I think it is not practical for telescopic portable use..058" x2 = .116" to .125" it is .009" clearance. Even less than previous one.It seems to me these sizes might be good for permanent use, Yagi elements, etc. But it seems not usable for field day style mast.I've been told the "good" clearance for portable telescopic use should be between .020" and .040".Thank you for the valuable information Wes.73, Maximo<http://foro.ea1ddo.es/>________________________________De: TowerTalk <towertalk-bounces at contesting.com> en nombre de Wes <wes_n7ws at triconet.org>Enviado: miércoles, 17 de julio de 2019 15:18Para: towertalk at contesting.comAsunto: Re: [TowerTalk] Aluminium telescopic mastMaximo,The easiest, although expensive, source ishttps://www.dxengineering.com/search/department/rigid-tubing?SortBy=Default&SortOrder=Ascending&N=department%3Arigid-tubing%2Bpart-type%3Aaluminum-tubingThe 0.058 inch wall tubing allows telescoping of tubes that are sized in 1/8"(.125) increments. The .120" wall thickness allows telescoping of tubes that aresized in 1/4" (.25) increments.  Note that these fit together much tighter thanthe mm sizes.Wes  N7WSOn 7/17/2019 7:49 AM, Máximo EA1DDO_HK1H wrote:> Hi all,>> Telescopic Aluminum masts are easy to make using metric tubes.> Using 2mm wall tubes, then 30, 35, 40, 45, 50, 55, 60, 65mm (and so on) external diameters you get the telescopic feature easily, leaving 1mm clearance between tubes.>> I was trying to do same with "american tubes" but I couldn't find any size to get same telescopic thing.>> Anyone knows how to make a telescopic aluminium mast using customary tubes?>> Thank you>> 73, Maximo>>>> <http://foro.ea1ddo.es/>>>> ________________________________>>> _______________________________________________>>>> _______________________________________________> TowerTalk mailing list> TowerTalk at contesting.com> http://lists.contesting.com/mailman/listinfo/towertalk>______________________________________________________________________________________________TowerTalk mailing listTowerTalk at contesting.comhttp://lists.contesting.com/mailman/listinfo/towertalk______________________________________________________________________________________________TowerTalk mailing listTowerTalk at contesting.comhttp://lists.contesting.com/mailman/listinfo/towertalk