[TowerTalk] Cleaning Aluminum Eelements

[Eric Gustafson]

Hi Bill,

Been meaning to answer this one for a while.  But just haven't
had much time to spend on the reflector 'till lately.

73, Eric  N7CL


>From: "Bill Heinzinger" <w9ol@dataflo.net>
>Date: Mon, 20 Mar 2000 15:26:59 -0600
>
>>
>>  > Cleaning the outside is easy. How do you clean the inside
>>  > of those small diameter elements?
>>  >
>>  Why would you need to do that? RF observes the skin effect
>>  and only travels on the outside of the conductor.

The reason to clean the inside of the joint is that the charge
carriers (electrons in a metal) must be _conducted_ from one
piece of tubing to the other one.  This means that they have to
cross the connection at the point (s) where the conductive tubing
pieces touch one another.  The larger the surface area and lower
the resistance of this connection the better.

>I always thought skin effect meant it flowed on the SURFACE of a
>conductor.  How does the RF know if it's on the outside surface
>and not on the inside surface????  :-)

If it is on the inside, it "sees" a conductor to external
(non-conductive) medium boundary in all directions perpindicular
to the axis of the conductor within a distance of less than 0.5
wavelengths.  If the RF "sees" this condition it knows it is on
the inside of a conductor which it cannot propagate down on the
inside of.

If the distance to the next conductor to other medium interface
in at least one direction perpindicular to the conductor axis is
more than 0.5 wavelengths, then it "knows" it is inside a
waveguide where it can easily flow down the inside surface.  But
even in this case, it is still mostly flowing close to the
conductor surface due to "skin effect".  It is just that the
surface is the inside one.

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