[Elecraft] bonding of grounding systems

[W B Reese]

Dear Ken & Ron,

I would like to add a few words to Ron's excellent discussion.

In my experience, using braid is a poor idea unless it is 
protected.  Moisture attacks the braid generating copper oxide and changing 
it from a single wide conductor to thousands of small conductors, all woven 
and the inductance is thus increased.  That's why in every broadcast 
station I've ever worked at all the outside grounding is done with strap.

Here at my home in Santa Rosa I am about 2 miles from KSRO, a 5KW station 
on 1350KHz.  Although I don't have any measure of the field strength in 
volts per meter, I can assure you it is high.  I have experienced problems 
with the rain gutters around my house during daytime when they are at full 
power.  There is a spur at 3850 on 80 meters when the signal mixes with 
1150 KHz KPLS, another 5KW station in town.  My problem was resolved when 
we put in plastic rain gutters and KPLS went dark.

Let me advise you to check this station for harmonics and spurs.  Use a 
general coverage receiver and tune it to one of these harmonics or spurs, 
then go looking for conductors in you house area and armed with al legator 
clips short around any joints where corrosion may be generating a 
rectifier.  Observe the results on the general coverage receiver, and when 
you find it, create a good bond at that site.

Remember, to generate harmonics & spurs, you need a mixer (2nd detector), 
which is simply a discontinuity on non linearity.  That's how your 
super-heterodyne works.

Good Luck!

At 08:39 PM 5/23/2004 -0700, you wrote:

>The usual means
>is to use a very wide conductor - either braid or a wide copper sheet - and
>keep it as short as possible.
>
>
>Ron AC7AC
>
>-----Original Message-----
>...One of the local A.M. stations had increased transmitter power with the
>result of wild RF running all over the place. It seems standard AC service
>ground systems stink for handling stray RF. ... I was always plagued by RFI
>until I went to this type of system. Has anybody else on the group ran into
>this?
>
>Ken W8OB


TR WB6TMY
K2/100/KAT100
S/N 0838
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