[Today’s run: 2 miles with the dog]
I have made some progress on my 10 Mhz GPS disciplined oscillator (GPSDO). Most of the work I need to complete is power supply arrangements then mounting things in the enclosure.
I downloaded Eagle CAD, a free circuit drawing program. With that I laid out a circuit board for dual +5/-5 regulators. I printed the circuit board pattern off with the laser printer on some slippery paper, the cover of one of the many women’s clothing catalogs that come to our house in the mail. Then I used a hot iron to transfer the pattern to circuit board material and some ferric oxide to etch the board.
My circuit board works, but it is kind of ugly. The etching took off more copper than I wanted in some places and not enough in other places. I think I need to do a better job with the iron-transfer for one thing.
But I now have a working board that will drop the existing +15/-15 down to +5/-5. I already had a board to rectify and regulate the 24 volts coming from my oscillator heater transformer. That will also act as supply to another set of regulators for +12, +5, and +3.3. I will end up with two separate power systems, one dedicated to the -5 to +5 which is used by the controller module to adjust the internal 10mhz oscillator to match the GPS signal, and one for everything else.
I’ll be using the iron-on method on that board also. I hope it turns out better.
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I have been on the air a little more in the past few days. The 20 meter band starts to open up in the morning and I have been able to hear lots of stations from Japan and Northern Europe. I had a nice contact today with a guy in Norway. He said the temp there was 14C. I told him ours was 100F. He thought that was way too hot. Can’t say I disagree with him.