Following logically from what you both say, my guess is that the load
capacitors are fed with current via a nut and screw or the like. The
current running from one surface of the chassis, via the screw head, along
the surface of the thread to the nut and connection on the other side to the
caps. Or have I got all wrong?
David
G3UNA
> >>
>> >
>> >What do you think happens when you use a tube for an antenna element?
>> >The whole element is charged. If you connect the feed line to only the
>> front
>> >side of the element there is still current on the back side of it.
>> >How do you think the current gets around to the other side?
>> >
>> >But try to measure the current on the inside of the tube. You will find
>> >none!
>>
>> REPLY:
>>
>> You raise an interesting question about current in a tube as opposed
>> to a solid rod. In a sire or solid rod, the skin effect current is
>> only present on the skin. In a tube however, I'm not so sure there is
>> no current on the inner surface of the tube because that is also a
>> skin. The issue is complicated because any skin current on the inside
>> of the tube also "sees" the other side of the tube, unlike with a flat
>> sheet where there is no other side. So that issue remains to be
>> proven.
>>
>> Because a sheet has two "skins", and has no other side like a tube
>> does, current flows on both "skins" of a sheet because it is repelled
>> from the center. When one drains off current from one skin, the
>> repulsion no longer exists and it is immediately replenished by
>> current from he other side. Otherwise my load padder caps would not
>> be connected to my load variable cap.
>>
>> Fascinating discussion.
>>
>> 73, Bill W6WRT
>
> Bill,
>
> My point is that there is no difference between the current on the outside
> of a tube verses the current on your flat bar or a solid rod.
>
> Each skin acts independently of the other. One side of a sheet never knows
> about the other side as far as current passing thru from one skin to the
> other. This is very evident in a tube which has an inner and outer skin.
>
> Provided the material is several skin depths thick, there is never any
> current on the inside.
> Not because the current from one side acts against the current on the
> opposite side but because the current on the "surface" sets up eddy
> currents
> just below the surface that oppose each other and cancel the deeper
> currents. No current ever makes it to the center of the rod or plate or to
> the inside surface of a tube.
>
> Current does not go "thru" the sheet or rod to get to the other side. It
> flows around the edges.
>
> If current went thru the shield of coax then the coax would not work as it
> does.
> There is no way for current to enter the center part of a tube or rod or
> flat sheet.
>
> 73
> Gary K4FMX
>
_______________________________________________
Amps mailing list
Amps@contesting.com
http://lists.contesting.com/mailman/listinfo/amps
|