Topband
[Top] [All Lists]

Re: Topband: Easy Inverted L for 169 (NCJ M/A 2011) Info

To: "Ward Silver" <hwardsil@gmail.com>, <topband@contesting.com>
Subject: Re: Topband: Easy Inverted L for 169 (NCJ M/A 2011) Info
From: "Bill Wichers" <billw@waveform.net>
Date: Thu, 10 Nov 2011 16:50:18 -0500
List-post: <topband@contesting.com">mailto:topband@contesting.com>
Heh, been there, done that ;-)

Handy design data from the telecom/utility industry:

10 foot clearance (minimum) over finished grade where vehicular traffic
is not expected.

17 foot clearance (minimum) over roadways.

That "17 foot" number is used by the telecom industry for
phone/cable/fiber lines crossing regular roads so it should clear any
normal vehicle. It's not an easy height when maintenance is needed
though. Keep in mind too that the clearance should be at the lowest
point in the sag of your cable. Also, most of the commercial cables
don't stretch (EHS steel support strands are common) with ice loads,
most ham antennas will so you'd need to allow a little extra height
margin to deal with ice loading and the resulting additional sag.

  -Bill

[snip]
> > How high off the ground does the feed point need to be on 160 to be
> > considered elevated enough to use tuned radials?
> 
> 1.1 Antler or 1.1 UPS trucks high - whichever is greater.  I don't
think
> anybody has to ask me how I learned this.
> 
> 73, Ward N0AX
> 
> _______________________________________________
> UR RST IS ... ... ..9 QSB QSB - hw? BK
_______________________________________________
UR RST IS ... ... ..9 QSB QSB - hw? BK

<Prev in Thread] Current Thread [Next in Thread>