Electric Fences

[sanramonrover]

I have had great results with my 254NC (aka FO) station for the last three months, but...
Yesterday I installed an electric fence around my property. It has a single wire atop 2 meter steel pipes, insulated from the pipe with plastic caps and wire insulators, however...
My weather station is atop a 4 meter pole bolted to one of the fence pipes. Since firing up the electric fence, I have had an all time high temp of +180* celsius, plus an all time low of -37* C -all in the same day. WOW

So my recommendation is - don't install an electric fencer near a wireless weather station, or don't install the weather station near the electric fence.

So incase anyone wonders ¿why have an electric fence? to keep unwanted critters out of the property. But it sure messes up the daily readings.

[wd40]

I do run an electric fence during the summer. Thanks for the heads up. What are using for the ground in the electric fence? Thank that could be a problem?

Randy

[Gina]

I moved our fencer so that I could establish a really good earth - 5ft depth of galvanised pipe into soil that's in a really damp/wet place. It helped a bit but I still get interference from it and spikes on the temperature plot. I've set Cumulus to get rid of the bigger ones (>1C) with EWTempdiff = 1 in the ini file. When the better weather comes I expect to have another go at stopping the interference pickup. A new aluminium mast with the cable inside instead of on the outside may help. And I'll try to think of other ideas.

[rocketman_k]

In the past I've needed to establish a really good earth for some radio experiments. My technique was to bury 6 foot lengths of copper water pipe vertically by means of "water drilling" (This does not work in rocky soil!)

The technique is to couple a hosepipe to one end of the copper pipe (use a jubilee clip or similar) then run water at full mains pressure into the copper pipe. Push it into the ground then work it up and down to force it into the soil. The flow of water opens up the hole below the copper pipe and washes the debris up past the pipe. Keep it constantly moving, once you stop the sides of the hole collapse and it's impossible to move it again. With practice you can bury a 6 foot length vertically in a few minutes.

Hope that helps

Kelvin

[sanramonrover]

Thanks for the tip Gina. I assume I can stick the <EWTempdiff=1> anywhere in the ini file? I stuck it just after the
<EWInterval=0
EWFile=>

Guess I'll just wait and see if it works.

Rocketman - I was amazed when an electrician burried a 1 meter copper rod (vertically) using nothing but a few cups of water and that up and down motion you described! I did the same for my earth rods. All I have at hand are 1meter steel rods, at the moment sanded to bare steel. I know they will corrode, so will do better when I get back here. And I will decouple the steel pipe mast from the steel fence posts and move the mast to a wooden structure further away from the fence. then we'll see!

In the meantime, just for your entertainment - I went outside at 6 am this morning to check if there was any squirrel activity on our roof . We have had a squirrel IN the ceiling for the past two weeks (driving us crazy), so put the electric fence wire on top of the gate, near the rain gutters.

Well, the squirrel hopped down the roof, damp with dew, ran along in the rain gutter, damp with dew, then hopped over the side onto the top of the gate! Zap, Zap. And there was squirrel flying in the air, sommersaulting till he hit the ground. I had tears in my eyes (from laughter, you understand!)

We'll see if he comes back this evening.

[Gina]

Thanks for the tip Gina. I assume I can stick the <EWTempdiff=1> anywhere in the ini file? I stuck it just after the
<EWInterval=0
EWFile=>

I'm using the beta version and EWTempdiff was already there, I just changed the setting. I tried 0.5 but found I got flat-lining due to the normal change being bigger than 0.5C so increased it. Now I don't get any spikes bigger than 1C but the little ones remain, of course. I don't think it matters where in the ini file it's put but beware of another one that could take over.

[steve]

I don't think it matters where in the ini file it's put but beware of another one that could take over.

It has to be in the [Station] section - http://wiki.sandaysoft.com/a/Cumulus.ini - but note that in 1.9.1 you can just use the calibration settings screen rather than editing the cumulus.ini file.

[Gina]

It has to be in the [Station] section - http://wiki.sandaysoft.com/a/Cumulus.ini - but note that in 1.9.1 you can just use the calibration settings screen rather than editing the cumulus.ini file.

Ah yes, thank you Steve And I hadn't noticed it was in the settings screen - big improvement

[fractonimbus]

The subject of earths is an interesting one much discussed (certainly when I was active on air) by radio hams. Propagation by a vertical antenna is far less efficient when the ground resistivity is high. One recommended technique is to lay numbers of radial conductors (can be bare thick copper wire) connected to the ground stake. However, anything you can do to improve the soil conductivity will help. Clays are much poorer conductors than moist loams, and even poorer than marshy ground. You can improve the conductivity by adding an ionic salt (table salt for example) to moist soil, and keeping it moist. Sea water provides an almost perfect 'earth'. But you don't want to poison the soil, either

Years ago I also used the water drill technique to burrow down into the soil (rocky clay) and I then added salt to the hole to improve conductivity.

But some electric fence interference is going to be picked up by a conductor even with the best earth. Shielding of conductors might help.

And I wonder if adding numbers of ferrite beads along the fence line might not take the sharp edges off the high voltage pulses without reducing the ability of the fence to keep the beasts penned in?

DN

[Gina]

And I wonder if adding numbers of ferrite beads along the fence line might not take the sharp edges off the high voltage pulses without reducing the ability of the fence to keep the beasts penned in?

Now that's a thought It's not the RF component that stops the animals, it's the high voltage. I'll give it a try.

[fractonimbus]

It may depend on how the high voltage is generated - the spike could *be* the high voltage. Experimentation is necessary - if the beasts get out, there are too many ferrite beads

[sanramonrover]

Thank you Steve! I put <EWTempdiff=1.0> just after the other EW features in the [Station] section. There had been no mention of <EWTempdiff=> in my version, 1.9.0. Originally I had just put <EWTempdiff=1>, but it didn't work, so I assume it needs the decimal value.

I'll try all the other suggestions for beads, earthing, etc when I get back here.
Cheers

[sanramonrover]

Two thoughts: As long as an electric fence doesn't discharge, ie "snap" there probably won't be a lot of RF discharged. But with the damp nights, I get a lot of shorting across nearby leaves, damp insulators, etc. I doubt that ferrite beads would prevent spikes in this case.

Secondly: I did put the <EWTempdiff=1.0> in the [Station] area of the .ini file. There had not been such a line in there before - ver 1.9.0. Adding this line didn't prevent spikes from showing up on graphs, so wonder if 1.9.0 has that ability built into it? Or should I try 1.9.1?

[steve]

Secondly: I did put the <EWTempdiff=1.0> in the [Station] area of the .ini file. There had not been such a line in there before - ver 1.9.0. Adding this line didn't prevent spikes from showing up on graphs, so wonder if 1.9.0 has that ability built into it? Or should I try 1.9.1?

1.9.0 does have this; the difference with 1.9.1 is that it is available via the calibration screen rather than requiring cumulus.ini to be edited. Did you have Cumulus stopped while you were editing cumulus.ini?

I assume you didn't put those angle brackets in?

[sanramonrover]

Thanks Steve. yep, Cumulus stopped, edited Cumulus Configuration Settings (the .ini doesn't show up on Windows XP), then restarted. No <angle> backets included.
Its a very humid damp night here (4 am) so the fence is zapping regularly and causing spikes in the outdoor temp.