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Old December 19th 06, 08:25 PM posted to rec.radio.shortwave
dxAce dxAce is offline
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First recorded activity by RadioBanter: Jun 2006
Posts: 7,243
Default Getting ready to hook up a random and hav a question...



bpnjensen wrote:

dxAce wrote:
HFguy wrote:

wrote:

I have read that the best way, quiestest, to hook into a random wire is
at the far end, attach a balun, go thru a ground block attached to a
ground rod, bury the coax as it runs to the house, go thru another
ground block which is connected to another ground rod then into the
house.

I have 2 options here, one is the above (about 150 feet of coax), the
other is to hook into the random at the near end, thru a balun, feed
into the attic to a ground block that has about 40 feet of ground wire
attached coming from the ground rod, then to the receiver.

Which is the better? Is there enough difference to warrant the extra
expense of the 1st option, more coax, over the 2nd?

The first method is better because you can use a short ground wire
between the balun and the ground rod to make an effective RF ground. The
balun should be located close to the ground (earth) so the grounding
wire to the rod can be kept to a minimum length (no more than 2-feet).
The ground wire in the second method is much too long to be an effective
RF ground. It could act more like an antenna for picking up common mode
noise.


Before this thread got started I'd never really heard of the practice of using
the extra length of coax and hooking up the random wire at the far end versus
the closer end.


dxAce, Don't you have your antenna feeds connect to your wires a fair
distance from your house anyway? (I say this based on a cursory look at
the photos on your website...)


Yes, I'd say they're about 50-75 feet out back.

Thus, in your circumstances, it may not be all that critical...in which
case I might not have stumbled across it either. If I could connect
farther from my house, I would - but in my case, it would put the
lead-in adjacent to one of two sets of electrical lines that partially
rim my yard. Living in the city can bite sometimes (to put it mildly).


Sorry, I still don't get it. The antenna is where the antenna is!

Now I could imagine that it would make a difference ( though slight ) if for example
I were to feed my 200' wire at the far end ( east end ) in which case it might just
receive just a bit better to the west depending upon the frequency.

By the way, my matching transformers are grounded at the feedpoint with about 9' of
ground wire ( horrors! ).

http://www.iserv.net/~n8kdv/pics.htm

Antenna pic is looking west, at the end of the then 100' wire, now extended to 200'.
Pic was taken in Nov. 2001.

dxAce
Michigan
USA