Topband: RFI - and lots of it

[Paul Christensen]

That's one reason why I like to augment a NEC-required mechanical connection with silver-solder.  The mechanical connection will degrade with time but it will take significantly longer for a silver-soldered connection to degrade, absent some really acidic soil condition.

Local code here now requires two (2) grounding electrodes at the service entrance spaced to cover the "sphere of influence."  That means two eight-foot rods require 16 ft. spacing.  As I recall, the 2008 issue of NEC allows one electrode if one can demonstrate 25-ohms earthing resistance.    Not sure if that's still true with the newest NEC changes.   But what measures 25 ohms today may measure a lot higher as time goes by.

Paul, W9AC 

-----Original Message-----
From: Topband [mailto:topband-bounces at contesting.com] On Behalf Of Dan Edward Dba East edwards
Sent: Thursday, October 29, 2015 10:28 AM
To: Matt Murphy <matt at nq6n.com>; Tom W8JI <w8ji at w8ji.com>
Cc: Jim Murray <adkmurray at yahoo.com>; low bad reflector <Topband at contesting.com>
Subject: Re: Topband: RFI - and lots of it

I, for one, wonder how good my service entrance ground is...mine is probably 20 years old, and while the top looks ok, there's no way to know what's going on down 4, 6 and 8 feet...my utlities are underground, if that means anything...
as a starting point, should a guy drive a new one? or 2 or 3, spaced some distance apart?
( gosh, top band sounds lousy this fall, for me, anyway...sigs are well down from normal strength..) 73, w5xz, dan
 


     On Thursday, October 29, 2015 8:17 AM, Matt Murphy <matt at nq6n.com> wrote:
   

 I'm in the process of setting up my station in a new QTH and plan to install a station ground at the cable entrance.

Tom, is there a best practice for bonding to the mains ground? Any approaches to avoid?

73,
Matt NQ6N

On Thu, Oct 29, 2015 at 7:07 AM, Tom W8JI <w8ji at w8ji.com> wrote:

> I have and electrician coming next week who says he will check things 
> out
>> and first of all ground the breaker panel to two ground rods 7 feet apart.
>> I thought the grounding was put at the meter but he says they don't 
>> do that anymore. I think the old meter, before we had the new one put 
>> in had a ground rod beneath it but nothing now. The only ground I 
>> could find to the panel is a skimpy wire going to a water line. All 
>> of which looks corroded etc.. I know many dollars were spent on 
>> renovation and restoration of this place but I'm afraid to much 
>> emphasis was placed on cosmetic and not enough on electrical as I 
>> look more closely, pretty depressing. >>>>>
>>
>
> Jim,
>
> Just keep in mind when  you do the work, the quality of the house 
> ground to earth is far less important than having everything entering 
> the house being bonded to act like one common point.
>
> One of the biggest mistakes in amateur radio grounding over the 
> decades has been having the shack antenna and control cable entrance 
> ground non-existent, and the common shack desk equipment ground to an 
> independent ground.
>
> The shack ground must be bonded to the mains ground so everything 
> entering the house is as close to one potential as you can get it.
>
> Correcting things may not cure your RFI, but it always makes things 
> much safer and more reliable.
>
> 73 Tom
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