Aerial grounding and QRM pick-up: theory & practice
In article ,
Dirk Claessens wrote:
On 2007-09-21, Richard Clark (67.168.144.41) wrote in
message
Please keep in mind that the same coax shield can support TWO
currents: one on the outside and one on the inside. Even though it is
the same metallic conductor, the shape creates two circuits because RF
currents on the outside cannot penetrate to the inside (that is how it
shields). Instead, those currents on the outside travel to a common
point such as the feed and gain entrance.
This is complicated, but I now (begin to) understand the true source of
the problems I had in the past. I'm not going to post a list here of
antennas I've been experimenting with to get rid of the QRM...
[..]
The soil here is partly clay/ partly sand. In winter it becomes quite
moist. Would that adversely affect the situation?
It has happened to me (Seattle = Rain City). The "earth" connection
you use at the AC plug is NOT a shield, instead it is a safety ground.
It is in close proximity to a lot of noisy circuits.
[..]
So the safety ground is a bad RF ground in most situations.
Thanks again for the clarification Richard!
i know this is prob a dumb question reading the last part i agree
but i say how come ? they say all points are to be tied together at
enterance of house so what is the diff between any two proper grounds
connect points then?
|