Topband: Strange resistance between Beverage ground rods

K1FZ-Bruce k1fz at myfairpoint.net
Tue Nov 15 14:43:02 EST 2016


 
True Yuri. 
 
Yes, much of it- low in frequency. This is why we wind our isolated 
antenna transformers to pass 160 meters and above,
with very low primary to secondary coupling capacity to minimize 
passing of these frequencies. 
 
 
73
Bruce-k1fz 

On Tue, 15 Nov 2016 13:47:40 -0500 (EST), Yuri Blanarovich  wrote:

       Don't forget that in the ground there are "travelling" Eddy currents,
being generated by all kinds od "services". The worst are in the areas
where trolley services, electric trains and other high power services
use ground as the other conductor or just being there. They can get so
bad that they can "eat" gas lines, water lines and cause accelerated
corrosion and breakage. They would definitely affect any "ground"
measurements and interfere with measurements. 

Yuri K3BU.us
MVmanor.com
  
 
 
 On Tue, Nov 15, 2016 at 01:24 PM, Jon Zaimes wrote:
 
 > As I recall mine are typically in the hundreds of ohms or low
thousands, never as high as
> 20k, even on a 950 ft wire. 
>
> I do see large variations of these across my 12 acres, even 
> significantly different readings on each wire in a staggered phased 
> pair. 
>
> We have two different soil types, which may be a factor. 
>
> My ground rods are typically 3-5 feet, and water table is usually a 
> few inches deep or less. 
>
> 73/Jon AA1K
>
>
> Sent from my iPhone
>
>> On Nov 15, 2016, at 9:20 AM, Herbert Schoenbohm wrote:
>>
>> I have reflection transformers at the end of every two wire 
>> Beverages which I try to test by measuring the wires on the feed 
>> end. I remove the transformer from the two wire WD1-A and check the 
>> resistance between the two wires which tells me that through the 
>> reflection transformer I have continuity. It measures about 40 ohms 
>> wire to wire, this is done when I notice any performance change of 
>> the antenna. Now come the next test that baffles me completely. When 
>> I measure from either wire to my ground rods alone, to see what the 
>> return resistance is, I get reading in the vicinity of 20K across 
>> the 900 foot run. I understand that if the reading was very low it 
>> would defeat the whole Beverage principle. But is 20K Ohms 
>> reasonable, very good, or marginal? I use three foot foot rods at 
>> either end and when I pull one out yesterday before moving it the 
>> bottom 1/4 was moist and muddy. That Southern end of several 
>> reversible Beverages is located about 100 feet or less from a sal
> t marsh or salt pond. I also have to such antennas made up of ladder 
> line a DX Engineering components. They all appear to be working well 
> even though large grass has reach and covered portion of some of them. 
>>
>> But my question is what is a reasonable or good return ground 
>> resistance for a 600' or 900' Beverage. I haven't found any sources 
>> of information expect the saying that the higher Resistance the 
>> better. Is this correct?
>>
>> Herb Schoenbohm, KV4FZ
>>
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