Mike: Can you tell us about the nature of the ground system used on WM? I
checked your web site but I did not notice any information about the
grounding method used.
For years I thought I had a reasonably good AC service ground. It
turned out that it was good enough for basic electrical safety, but not good
enough to provide a low-impedance path to ground for really effective RF
noise dissipation. I had four 8ft 5/8 diameter ground rods spaced 6 feet
apart and bonded with #6 along the side of my house foundation and close to
the service panel location.
One would think that would be a reasonably ground. Now it turned out that
my house has about a 2ft eave overhang and that roof extension was
preventing rain water from getting to the soil near my ground rods that were
perhaps 4 to 6 inches away from the foundation. So the soil near the ground
rods never had enough moisture content to be a true low-impedance ground.
Also, I always had lots of noise on my branch circuits in the house. I went
through a few cases of ferrite cores and that did help some, but it was not
the cure to the problem.
I also had some basement hydrostatic pressure issues with water
seeping up through the cement floor. It is an older house and the cement is
only a few inches thick. Heavy rains would create an unpleasant situation of
having to mop or shop vac the water creeping through the cement.
So I got tired of this situation and decided to run a French drain
along the east side of my house to divert the water and provide a
hydrostatic pressure break a few feet from the foundation. In the middle of
digging this 50ft trench (by hand) I realized my AC service ground belonged
at the bottom of the trench.
So I spent some money on copper water pipe and ran a pair of 3/4 inch
copper pipes connected with T couplers for a 20 ft length. Each pipe is 3/4"
* pi for circumference area with is about 2.35 inches each of surface area.
(If you visit a broadcast transmitter site, the grounding straps are about 4
inches wide. It is the marginal cost return width for a low inductance
path). That copper pipe bus went to the bottom of the trench and ground rods
were driven at each end and in the middle. Everything was bonded with #6
back to the service panel. I also ran some wide copper flashing (Home Depot
8 inch wide x20ft long roll is $40) from the service panel into the trench
in addition to the copper pipes and bonded together. I wanted as much low
inductance as possible for the ground conductors and I also wanted them wide
to maximize capacitance.
The result was I finally was able to shield a device like a wall wart
with tin plate flashing, ground the flashing to the service ground, and be
able to hear the noise disappear. There simply was not enough moisture in
the earth for my simple four ground rod and #6 wire ground system close to
the house foundation to be a low impedance RF path....
I'm not suggesting you dig a big ditch, just think about ways to achieve
a lower impedance ground path with the resources you have available....
73, Mike wa3tts
----- Original Message -----
From: "N8OOU" <n8oou at meekfarm.us>
To: "Discussion of the Lowfer (US, European, & UK) and MedFer bands"
<lowfer at mailman.qth.net>
Sent: Friday, January 13, 2017 4:19 PM
Subject: Re: [Lowfer] SIW (WM) in CT
> Mark,
>
> Thanks for your report, I'm glad to hear that my signal is still traveling
> your way. I just checked the WM lowfer meters and from my end, the juices
> going in to the beacon are normal. Our weather here has warmed the past
> couple days, the snow is gone, and ground has thawed. I may have more
> ground losses than a few days ago when everything was frozen.
>
>
> 73 de N8OOU - Mike Meek
>
> On 01/13/2017 10:17 AM, lmlangenfeld wrote:
>> You're in up here this morning, Mike, but not great (well below usual
>> daytime GW copy). Thus, I am inclined to agree with Jay that something
>> out of the ordinary is going on with WM.
>> GL,
>> Mark -- WA9ETW/WI2XHJ -- EN52fs
>>
>>
>> Sent from my U.S. Cellular® Smartphone
>> -------- Original message --------From: N8OOU <n8oou at meekfarm.us> Date:
>> 1/13/17 9:50 AM (GMT-06:00) To: "Discussion of the Lowfer (US,
>> European, & UK) and MedFer bands" <lowfer at mailman.qth.net> Subject: Re:
>> [Lowfer] SIW (WM) in CT
>> Jay,
>>
>> Thanks for the capture showing the WM beacon. I am personally happy to
>> see that you were able to acquire enough to bits to make an ID.
>>
>> I am not taking your comments as throwing stones. For that past couple
>> years I have seen that WM can not compete with the signal strength of
>> others in the band. I know there are several contributing factors in
>> that equation. My current configuration is running about 75 mA of
>> antenna current, and I can light only three bulbs of an NE-2 tree.
>>
>> I will be the first to admit my lack of LF technical expertise, and test
>> equipment to put a first rate station on the air. Also contributing is
>> the amount of funding for this hobby.
>>
>> A third factor is the physical location of the beacon. A look at the FCC
>> ground conductivity map shows the beacon is located in a grade 8 portion
>> of the state, compared to other areas of IL which are 15. Two thirds of
>> my farm is river bottom ground where the Wabash river run long ago, the
>> rest is a 30+ foot higher sandbar created by the river which is where
>> the transmitter/antenna are located.
>>
>> I have been trying different configurations of antennas over the past 2
>> years to improve the signal including using an Ashlock Loop with his
>> hardware. I am currently working to construct the next antenna revision.
>> There is a possibility that no matter what I construct, or how much
>> money I spend, I will never have a strong signal compared to my peers
>> because of my location.
>>
>> Thanks for listening.
>>
>> 73 de N8OOU - Mike Meek
>>
>> On 01/13/2017 06:35 AM, jrusgrove at comcast.net wrote:
>>> Nice quiet morning with SIW peaking 20 dB out of the noise. Full capture
>>> at
>>> http://www.w1vd.com/grabber.html .
>>>
>>> Note the difference in signal level between SIW and WM ... WM not
>>> visible for
>>> the most part. SIW is 787 miles at a heading of 276 degrees ... WM is
>>> 798 miles
>>> at a heading of 260 degrees ... an inconsequential difference. This
>>> leads me to
>>> believe
>>> there's a problem at WM. Perhaps the transmitter is not developing full
>>> power, the antenna isn't
>>> really at resonance,
>>> there's a problem with the antenna coupling system or the ground system
>>> resistance is extraordinarily high. I've
>>> received all of the midwest beacons that have been on the air over the
>>> past 16
>>> years ... most with similar signal levels to that of SIW.
>>>
>>> Not throwing stones here ... just trying to point out a potential
>>> problem at
>>> WM. I'm looking forward to seeing a more robust WM one of these days!
>>>
>>> Jay W1VD WD2XNS WE2XGR/2
>>>
>>>
>>>
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