Date:         Thu, 25 Mar 2004 10:08:30 -0500
Reply-To:     David Brodbeck <gull@GULL.US>
Sender:       Vanagon Mailing List <vanagon@gerry.vanagon.com>
From:         David Brodbeck <gull@GULL.US>
Subject:      Re: CB antenna mounting - Structural strength
Comments: To: Mark Carrig <stratmanx@YAHOO.COM>
In-Reply-To:  <vanagon%2004032508571607@GERRY.VANAGON.COM>
Content-Type: TEXT/PLAIN; charset=US-ASCII

On Thu, 25 Mar 2004, Mark Carrig wrote:

> My question is, is the fiberglass rack strong enough to support the 3'
> antenna in moderate road winds that you encounter when driving at speed ?
>
> Will it crack, of fatigue ?

I would be very concerned about that.  Not so much from wind load, but if
anything hits the antenna.  With a 3' antenna sticking up above a 6' van,
it *will* hit something sooner or later -- a tree limb, a drive-thru
overhang -- heck, I hit a bird with an antenna once.  I think it's very
likely you'll crack the rack if this happens.

Why not sacrifice just a little height and mount it to the solid metal
pillar behind the door?  I had a 5/8-wave 2m band whip antenna mounted
pretty close to that location, with a gutter mount, for quite a while.  It
worked well, and never suffered any damage, even the time my mechanic put
the van on the lift without removing it and shoved the antenna into the
roof of his service bay.

If you really have to mount it to the luggage rack, I would think about
making an L-bracket inside that bolted to the cab roof, and then bolt the
antenna mount through the rack and to that bracket.  At very least, use
some big fender washers inside the rack to spread out the load.


David Brodbeck, N8SRE
'82 Volkswagen Diesel Westfalia
'86 Volvo 240DL wagon