masts

[John A. Ross, IV]

>One source of masts used by some in Maryland is the local fence
>installation company (Long Fence Co.)
>
>I go in and tell them "I want your strongest 3" pipe."  I haven't been
>knowledgeable enough to even know to ask "what schedule is it?" but I do
>know I have bought 21-24' lengths for about $50.  One has been up for
>eight years holding a 6-element Telrex 20 at 120' on the thrust bearing,
>with an 8-element Telrex 15 eight feet above it.  So, empirically, they
>seem to be strong enough.
>
>Anyone know what "schedule" these pipes are likely to be and whether I
>have just been lucky or whether heavy duty fence posts are a good choice?
>
>Rich Boyd KE3Q


This is not meant as a flame Rich, but rather as food for thought:

Situation #1
------------
You put $1000 worth of antennas on a $50 "piece of strong pipe of
unknown character", and then it breaks....

You now have $1050 worth of scrap metal....

Situation #2
------------
You put $1000 worth of antennas on a $200 mast.(Type 4130 or 1026
Carbon Steel for example) You can now use the formulas cited by others here
and figure out exactly how much wind your mast can handle.  You can now
sleep well knowing (as opposed to hoping) that you will have $1200 worth of
metal in the air for good, long time.

Even if I were the type to trust unknown pipe, I wouldn't want to recommend
others take that same risk. I just try to imagine the feeling they would
have if it failed on them...

If I may, allow me to slightly malign K1VR's sig file:

"Big antennas, high in the sky, are much better than broken antennas
 scattered across your backyard"

73, John
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John A. Ross, IV  - WB2K / VE2QRZ [Zone 2]  (wb2k@ritz.mordor.com)
Summit, New Jersey
Contest DXpedition Registry ---------> http://www.mordor.com/wb2k
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