More on lighter evenings - NOT amateur radio

At the moment the evenings are lighter for 5 mins more at dusk than a week ago. The light follows a sine wave curve and the rate of change speeds up as we go through the winter into spring. As I said recently, the evenings are lighter by an hour at the end of January. At the website below you can change the location and the date.

See http://www.timeanddate.com/sun/uk/cambridge

Long sunny days no more? Until next year.

As the nights get longer and the days get shorter in the Northern Hemisphere, it is useful to know when the sun rises and sets. A useful UK reference is http://astro.ukho.gov.uk/nao/miscellanea/UK_SRSS/. 

It amazes me that we are half way already to the shortest day! I don't want to wish my life away, but I always welcome the time when the days start to lengthen again. Even more, I welcome the return of migrant birds from Africa in April such as Swallows, House Martins and Swifts.

481THz update: 1.6km test

Today I did my first test beyond the end of my street and in daylight.  I set up my 1.082kHz subcarrier CW beacon and 100mm optics pointing out through my double glazed bedroom window and aimed it at a local feature called the Devil's Dyke which is 1.6km (1mile) exactly from home. This is the furtherest line-of-sight (LOS) path I have from home.

Then I went up to the Devil's Dyke and started looking with my handheld 100mm optics receiver. Much to my joy and surprise I heard the beacon before I spotted it by eye. The beacon could be copied over a stretch about 50m along the path. S/N I'd guess at around 20dB (by ear) in speech bandwidth in daylight. Next time I'll take the laptop and measure S/N with Spectran.  1.6km is my best distance so far. I'm using a BPW34 detector with some reverse bias with the PIN diode's anode connected directly to the FET gate in a KA7OEI optical head. This feeds into a feedback biased common emitter stage into a crystal earpiece. Recovered audio was a bit low in the wind.

Some progress in the right direction.