[Antennas] Ground rod questions (Ground currents)

[Philip (KO6BB)]

Terry,
You may have hit the nail on the head so to speak.  And you're right, I 
realized a long time ago that the ground 'shouldn't' make a difference at 
2M, but it does.   I just unbolted the ground cable from the under-bench 
buss (leading to the station ground system).  While the AC Voltage and 
currents bounced around some on the DVM, I read an average of 250mV between 
the bench-buss and the external grounds.  When I measured the AC current it 
averaged about 100mA, certainly a significant current for a supposed ground 
system (and I've made sure that ALL the cables, hot, neutral etc are 
securely tightened in my own service box).  The ground is still damp under 
the surface from the heavy soaking I gave it last week so it would take 
quite some time before it got that dry again.

But disconnecting the ground completely DOES raise the noise level in the 
radios.  So I would guess that I probably do have the best ground in the 
entire park of about 240 Mobile homes (each mobile home has a ground rod at 
the service meter).

It looks like the best thing that I can do is probably like I planned, 
replace the old (rotted) short rods with longer ones and go with about five 
long rods daisy chained together and just make sure I have the best possible 
ground for my station and moisten it as needed (I certainly can't go to 
every mobile home and rework their grounds!)   I DO KNOW that some of the 
older homes in the park probably have very questionable wiring anyway, my 
neighbor has an intermittent loss of a neutral or something and burned up 
every TV, computer and microwave in his home!  He's had electricians and PGE 
come out to locate the problem and they haven't found it (I did a brief 
check and it was good at his service entrance).

But my noise problem goes way back before his wiring problem as I put the 
present ground system in when I moved in nine years ago and it made a BIG 
difference then.

73 de Phil,  KO6BB
http://ko6bb1.multiply.com/ (My OTR Blog)
http://www.qsl.net/ko6bb/   (Web Page)

DX begins at the noise floor!
RADIO: Yaesu FT-2000.
Antennas:  Butternut HF-2v,  88' Ladder-Line fed dipole.
Merced, Central California, 37.3N 120.48W  CM97sh

----- Original Message ----- 
From: "Terry Conboy" <n6ry at arrl.net>
To: <antennas at mailman.qth.net>
Sent: Tuesday, June 30, 2009 12:06 AM
Subject: Re: [Antennas] Ground rod questions


>I wonder if Phil's ground is actually a noise generator.  It would be
> really interesting to check the 60 Hz current flowing into his
> collection of ground rods before and after watering them.  Or check with
> a voltmeter between his mobile home It's quite possible that he is the
> best ground in the whole trailer village, but when dry, it may produce
> noise as minor arcing or spitting generates trash all the way up through 
> 2m.
>
> It's highly unlikely that the ground system is actually effective for 2m
> RF, so it might be worth thinking of the "ground" system as the source
> of the noise, rather than a sink for noise.
>
> 73, Terry N6RY