[TowerTalk] Metal Roof

GARY HUBER glhuber at msn.com
Thu Jan 11 14:29:12 EST 2018

I agree with Jim as I ran into the same problem at work. Twelve story office building with a copper roof. Any two meter transmission at that building roof area over two Watts and intermod products would cause problems in other VHF repeaters several blocks away. Our solution was split site, with the TX on another 12 story plus engineering floor on top.

Bonding the roof can be done... the problem is dissimilar metals in the roof panels and fasteners plus lack of a sealant to keep the screw - panel junction dry. There is another way to fix the problem... slate or tile roof heavy enough to resist the wind problem.

Gary ~ AB9M

Sent via the Samsung Galaxy Tab® 3 Lite

-------- Original message --------
From: Jim Brown
Date:01/11/2018 1:00 PM (GMT-06:00)
To: towertalk at contesting.com
Subject: Re: [TowerTalk] Metal Roof

Hi Skip,

The "interference" is probably passive intermod (rectification at one or
more joints in that roof) that is generating a spur on the input
frequency of the repeater.  If this is the cause, the joint(s) must be
bonded at multiple points.

73, Jim K9YC

On 1/11/2018 10:29 AM, Gilbert Kauffmann wrote:
>   My repeater is desensed.


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