You just need to take extra care with "cleanliness" and preparation of any
mechanical/electrical connections. Aluminum oxide is an excellent insulator
so you have to clean (burnish/sand) all connection points and apply "no-cro"
paste as quick as possible. The oxidation only takes moments to take place.
73 de Perry - K4PWO
----- Original Message -----
From: "Jeff Carter" <towertalk@hidden-valley.com>
To: <towertalk@contesting.com>
Sent: Wednesday, September 12, 2007 2:46 PM
Subject: Re: [TowerTalk] Copper grounding bus bar
> I've always wondered about that, skin effect being what it is and all.
> Why
> wouldn't aluminum be just as good in this particular application?
> Considering cost, why wouldn't it be vastly better?
>
> I've never met anybody who was worried about the propagation velocity of
> their
> ground system. Then again, I don't know everybody, either...yet.
>
> Jeff/KD4RBG
>
> On Wednesday 12 September 2007 15:38, Jim Lux wrote:
>> Terry wrote:
>> > I'm looking at copper sheet on these sites to be used as a SPG plate
>> > about 16" x 16". What would be the minimum thickness to be
>> > "self-supporting" as opposed to laminating it on some substrate as
>> > Polyphaser does?
>> >
>> > 73 de Terry KK6T
>>
>> unless you want to solder directly to the plate, why not use aluminum.
>> It's a lot cheaper, much easier to work with (drilling thick copper is a
>> chore, tapping even more so, prepare to buy many spare taps and use lots
>> of lube.. soldering to a big sheet of thick copper would require a
>> fairly high output torch, too). I'd find it hard to believe that the
>> conductivity difference would be significant (for DC & line frequency,
>> the thickness of the aluminum helps, for RF, it's a big flat surface
>> either way). A wide variety of lugs are available, and a nice tapped
>> hole in the aluminum will make fairly good contact.
>>
>> If you feel that the copper is important, slap a big piece of copperclad
>> PC board material on top of the aluminum, or stick copper flashing on.
>> You could also put copper foil tape on the aluminum in places where
>> you think it's important. 3M makes a kind with conductive adhesive.
>>
>>
>> _______________________________________________
>>
>>
>>
>> _______________________________________________
>> TowerTalk mailing list
>> TowerTalk@contesting.com
>> http://lists.contesting.com/mailman/listinfo/towertalk
> _______________________________________________
>
>
>
> _______________________________________________
> TowerTalk mailing list
> TowerTalk@contesting.com
> http://lists.contesting.com/mailman/listinfo/towertalk
_______________________________________________
_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk
|