In a message dated 1/10/02 6:43:00 AM Pacific Standard Time,
owner-towertalk@contesting.com writes:
> I am in need of a top quality mast for a tower installation. I purchased
> the tower from the widow of a SK. He only had a short (approx 10 foot)
> mast on the Tower, yet it has a full mast raising fixture installed. I
> would like to replace this mast with a 20 foot long Chrom-Moly or similar.
First things first. Why do you think you need a chromoly mast ($$$)? Most
hams who think they need chromoly really don't need to spend that much money
for a mast.
What's your county windspeed rating? What's your proposed antenna
installation? What kind of tower is it?
>
> Anyone out there know of a steel tubing dealer in the Detroit area, or as
a
> second choice Chicago area. I live 110 miles north of Detroit and would
> like to keep my shipping costs down.
>
> An additional question, how do I communicate the Ham language of a 2"
O.D.,
> 1/4" wall Chrom-Moly mast (or whatever the next step down would be) into
> the professional language that these tubing manufacturers use? I called a
> local dealer and we could barely understand each other. He kept wanting
to
> know the application that the tubing would be used for yet he had no idea
> what I was talking about when I described the application.
>
Hmm, what you want to buy is tubing with the necessary yield strength for
your application - I don't know why the person you were talking to didn't get
the picture (Maybe he/she didn't know much. They didn't know what a 2" OD
1/4" wall chromoly mast was? I'd talk to someone else that knows what they're
talking about.). My MARC (Mast, Antenna, and Rotator Calculator) program does
mast calcs and gives you the needed yield strength required (available from
<A HREF="http://www.championradio.com";>www.championradio.com</A>). Typical
ham HF stacks and moderate winds up to 80MPH or so will require something
like 60,000 psi yield strength which corresponds to an SAE 1026 or 1027
carbon alloy steel which most tubing suppliers seem to stock.
Cheers,
Steve K7LXC
Tower Tech
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