Thanks everybody for your thoughts
I think I will put my dollars elsewhere
NN6CH
Chris Hoelzle
choelzle@cox.net
Laguna Niguel, CA
-----Original Message-----
From: TowerTalk [mailto:towertalk-bounces@contesting.com] On Behalf Of GARY
HUBER
Sent: Monday, December 05, 2016 10:54 AM
To: jimlux; TT TowerTalk
Subject: Re: [TowerTalk] Screened walls and floors
It may be worth noting that some sheet rock (plaster board), ceiling panels,
and insulation (foam board) have metallic backing which increase the
difficulty of electromagnetic ingress or egress. Screen room? no,
attenuation of signals or interference ? to some degree, yes, maybe, based
on twenty years working in RF communications in large commercial buildings
with these materials and metallic oxide glass and metal floor pans for
concrete.
73 ES DX,
Gary - AB9M
On 12/5/2016 12:19 PM, jimlux wrote:
> On 12/5/16 8:55 AM, Grant Saviers wrote:
>> We built a Faraday cage big enough for an engineer and equipment and
>> learned that a special screen material is needed. Regular copper
>> screening has lots of crossovers that aren't really connected or
>> worse are oxidized contacts and can make the noise worse. A tech was
>> assigned to solder the wires in strips every 4 inches x,y,z, which
>> took a couple of days and made for a very unhappy tech. The results
>> were ugly but RF ok.
>
> You want "welded screen" as opposed to "woven screen" - standard steel
> hardware cloth would probably work.
>
> "real" screen rooms are made with aluminum or galvanized steel sheet
> (which is probably cheaper than screen, and a whole lot easier to make
> sure it connects to everything).
>
>
>
>
>
>>
>> I don't see a benefit for a station. IMO, it's a better use of time
>> to concentrate on a good building perimeter ground, the entry plate,
>> good chokes, and insuring no RFI sources from equipment inside the
building.
>
>
> Indeed...
>
> And you will find it very inconvenient that cellphones and VHF/UHF HTs
> don't work (or work poorly) in your shack, too. The old shack at JPL
> was a building with metal lined walls, and if the door closed, you
> can't raise the JPL repeater with a HT.
>
>
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>
>
>
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