Acid bath

Spurred-on by a very nice result on the local copper mine a couple of evenings ago, I decided to try what must be another unique experiment last night.

Parys Mountain copper mine.  Lots of precipitation ponds.  My experiment was from the ponds seen at far centre left, near the road.  Coast is seen at top.

 

After the main mine had been exhausted, copper continued to be extracted at the site through a simple replacement chemical reaction, where ponds of mine drainage are created, scrap iron thrown in, and after some time, copper is deposited where the iron once was.  

Just one of a complex of precipitation ponds used at Parys Mountain.  Image (C) Pixaerial/J. Rowlands.

 

The pools were also commonly used to cure rotten cattle's hooves - a treatment that appears to have been successful.  The waters were even written up in a very early British Medical Journal paper, where they were said to cure a large number of human ailments.  In those days, there was no scientific method as such, so there is no real proof.  What they didn't know back then was that, apart from iron and copper, the waters contain dangerously high levels of toxins, such as lead and arsenic!

For those with an interest, the displacement reaction to extract copper is nicely explained, courtesy of ScienceABC:

It's been a wet spring and early summer, so most of the ponds that have always dried out in previous years by now, are still full of water.

I decided to take advantage of the situation and seek a pond that looked to be more than just accumulated rainwater, and instead full of water that had percolated over time through the rock waste heaps.  

Out in the bath-warm acidic waters of Parys Mountain.

I found a fairly dark, acidic pool which probably had a good mineral content, and deployed my antenna in the middle of the warm water, which was at about body temperature. 

By coincidence, the pond was half a wavelength in length and breadth at 14MHz!  It had a reasonably open aspect, but only the top of the antenna, where current is lowest, had any view of the sea.  The lining layer of clay at the bottom was just thick enough to provide some support for the clothes line screw that holds my antenna up, helped with some rocks to steady it against a fairly stiff wind.

Unfortunately, it wasn't a great night for DX.  There was a very strong 'D' layer formation, so just about all signals were ~1000km.  

All the same, choosing the five DX stations that were heard, the outcome was only a 1dB enhancement at the acid pool, compared to my delta at home.  Allowing for 'design' gain difference, this amounts to ~4dB real difference on receive.  Not insignificant, but certainly not the kind of result seen when the antenna was at the same mountain, but with a clear view of the sea horizon.  

On transmit, the result was similar: 3dB weaker at the acid bath to the DX stations.

Another reason that partly explains a poorer result at the acid bath is the lengthening effect of the watery environment; on applying the analyser to the antenna at the end of the run, I found the resonance was down at around 13.9MHz.  Not a huge effect, given WSPR is at 14.0956MHz, but it's certainly not helping.

Could have been good, but wasn't particularly.

Of course, the location with a view to the sea was also where I have detected anomalies at VHF.  So I will have to try another site on the mountain now that is not above the mine drainage channel coincident with these anomalies.  That way, I might be able to extract the effects of mine waters from sea horizon.  Maybe...