[Antennas] Mast design equations & rules of thumb?

Sat, 6 Mar 2004 08:52:35 -0500

I live in Florida near the ocean and there are many places to buy the old AM large verticals. They were mounted with hardware so
they could be lowered when going under bridges. I have two of these and the plan is to use them as a vertical at the house. (yet
another future project of course). But in any case check with your local boat dealers to find out who may be selling these old
verticals used or salvage.
Bill Marx W2CQ

> I have heard of but have not found a source of long and I mean long marine SS
> whips.  These are a lot longer than CB whips.
>
> Have you looked at using good spruce to make a tip-over then put wire and whips
> on it for your antenna?
>
> Chris opr VE7HCB
>
> From:           "JAKidz" <[email protected]>
> To:             <[email protected]>
> Subject:        [Antennas] Mast design equations & rules of thumb?
> Date sent:      Wed, 3 Mar 2004 08:08:18 -0800
>
> Greetings:
>  I'd like to build a tip up, free-standing 1/4 wave 40m vertical, base
> at 11 feet, out of small town available materials (e.g., chain link
> fence rail, electrical conduit, water pipe). No guys (small lot with a
> bunch of house stuff in the way) so support has to be close to the
> base. Due to CC&R's, I have to tip it up for use and down the rest of
> the time so wind loading would be moderate at most. What diameter and
> wall thickness does the base need to be to withstand repeated bending
> from being pushed up but not overkill? Only one old guy is the pushup
> force so it can't be 34 feet of 3 inch water pipe on top of the 11
> foot base. I'm guessing that for less weight but adequate rigidity, it
> is best to have reduced cross-sections with height but how many and
> how long for each is optimum? I figure a Radio Shack steel CB whip can
> top it off. Any good thumb rules or design equations for such things?
> As fence rails and metal electrical conduit come in a variety of wall
> thicknesses, I'd like to run the numbers for some confidence that the
> thing isn't like to make a big dent in my noggin or my roof.
>
>  Thanks and 73,
> John, K7JG.
>
> - - -
>
> Your moderator for this list is:
> Larry Wilson KE1HZ [email protected]
> _______________________________________________
> Antennas mailing list
> [email protected]
> http://mailman.qth.net/mailman/listinfo/antennas
>
>
> - - -
>
> Your moderator for this list is:
> Larry Wilson KE1HZ [email protected]
> _______________________________________________
> Antennas mailing list
> [email protected]
> http://mailman.qth.net/mailman/listinfo/antennas
>