Off to the lakeside!

Well, it's been a windy, wet few days, but it started to look a little better this morning.

So, instead of our usual walk around a local lake, we decided to take the 14MHz WSPR receive kit along with us.

Cefni reservoir, central Anglesey, taken when I went up in a helicopter a couple of years ago.  Huge cyanobacterial bloom due to a very shallow, highly fertiliser-polluted lake.  Operating was from lower right, near the dam.

It took about a minute before someone told me I wasn't supposed to be fishing from the shore at the moment.  I get this all the time, coast or lake.  I should really have a sign, saying 'I'm not bloody fishing!' on it, to save my effort of explaining!

Anyway, I was interested to see if the freshwater would bring benefits.  I thought the much clearer boundary between what is water and what is dry land might give a sharper difference in the signals assisted by water to the west, and those not, from the east.

For comparison, I ran my identical 1/4 wave vertical at home at the same time.

At the lake.  Foam in the water is from a decaying cyanobacterial bloom.

I couldn't stay more than about 40 minutes, and there were only four stations coming in from the US at the time, thanks to very strong D layer formation.

But this was enough to show that the signals over the water - it is only a small reservoir - were up to 10dB stronger than those being heard at home.  There was one case - AJ8S/1, where the lake signal was -14dB, but was not heard at all from home.  That might signify an even stronger enhancement by the water, but we can't quite be sure by how much.

Beautifully, all the signals from the east showed only a median 0.25dB better signal from the lakeside, which is near enough to zero, and shows that the cut-off at the lake is, as I expected, very much sharper than that seen at the seaside, where there are large areas of seawater-saturated sand all around the antenna, giving good enhancements from all directions.

This result also confirms the noise assessment I made a few weeks ago, which was a difference of only about 1dB less noise at the seaside.

So, to summarise, lakeside = +8.5dB to the west, compared with my home antenna, and  ~0dB to the east.

Brilliant!