[BULK] - [TowerTalk] sheet metal roof

[Steve Katz]

Depending on how big that metal roof is, I'd be more concerned with losing
antenna gain than with SWR...if the roof's big enough, it will become your
"earth" and send a lot of signal up at a higher angle than you'd like,
reducing gain at the horizon.  -WB2WIK/6

"Success is the ability to go from failure to failure with no loss of
enthusiasm." -Winston Churchill

> -----Original Message-----
> From:	K4IA at aol.com [SMTP:K4IA at aol.com]
> Sent:	Wednesday, September 24, 2003 8:41 AM
> To:	corneliuspaul at gmx.net
> Cc:	towertalk at contesting.com
> Subject:	[BULK] - [TowerTalk] sheet metal roof
> 
> Can't help with the modeling question but I have a Mosley tribander
> mounted 
> about 18 feet above a metal roof.  On 20 meters, the roof has "some"
> effect but 
> not a lot.  My lowest SWR is a little bit higher than I would have wanted 
> maybe 1.5:1.  Mosley warned me the roof might couple with the antenna and
> pull 
> the lowest SWR point lower in frequency.  That didn't happen to me but it
> looks 
> like what you are experiencing.  You didn't say what the lowest SWR was.
> Is 
> the SWR low enough that you can just shorten the antenna to bring the dip
> up 
> where you want it?
> 
> If you are not being heard, I suspect there is something else going on.
> Are 
> you sure you don't have any issues with the coax, the feed, a balun, or 
> feed-line radiation distorting the pattern?
> 
> Radio k4ia
> Craig "Buck"
> Fredericksburg, Virginia USA
> FISTS 6702 CC 788 Diamond 64
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