Storms Passing By

Last week's storms were a good test of my sky hook, even though no aerial wire is yet attached. It was bending quite a lot, but the guy ropes held it in place, and It seems to me that bending is better than breaking.  I believe we had wind gusts forecasted at 50 - 70 kph. I don't know if this is what we actually got, but it felt like a sample of the worst we normally get around here.

This weekend the weather was clearing, but I thought I'd like to get further with the Softrock before trying any new aerial ideas.

In the end I decided just to press on and get the main board assembly finished. I decided not to stop for all the tests at each stage as it really breaks the flow of the soldering, so to speak. Just stopping at each stage to test the power rails to make sure of no shorts seemed enough for now. I can run through a full signal test when it is all assembled.

Some observations:

The build instructions advise fixing the PCB when working on it. I don't find this necessary. In fact being able to spin the board around quickly to get to it from all angles seems a great benefit. The board is heavy enough to sit well on the surface. The four corner screws no doubt helped here.

Winding the coils: I found it useful to start the single windings from the middle. It is easy to estimate the middle of the recommended length of wire, then doing half the turns in one direction then the other half from the middle going round the other way seemed to quite convenient. It also means half the length of wire to pull through each time. 

I noticed that the bandpass filters have an undocumented phase reverse in the way the PCB is laid out. The circuit diagram shows the top of the T100 secondary winding connected to pin 3, but it actually goes to pin 2, and conversely the bottom goes to pin 3 instead of pin2. However the circuit does not show any phase "dots" identifying the matching ends of primary and secondary, so I assume it is not important. Apart that is from the secondary pair needing to be correctly connected to get the centre tap, I assume that phase reverse between primary and secondary is not a problem.

Power testing: For some reason the current scale on my multimeter seems to have stopped working. It is probably the built-in fuse but I don't have a replacement. In the end I skipped the first test of each stage with the 100 ohm series resistor, and settled for a 10 ohm in series. This seemed to me to represent a safety measure for any shorted power rails. A quick test for voltage drop would show up a short quickly enough to remove power. It also meant I could measure current consumption by the voltage drop of about 1 volt across this, and I could leave it in circuit for the actual rail tests and other voltage test points as it did not drop enough to interfere with normal operation. This sped up the power test before moving on at each stage.

The story so far:

The underneath:

Anyway, this weekend I got the main board assembly finished, a couple of bandpass filters done, and started on the 80/40m PA stage. I'm hoping next weekend to finish the PA and to get the PC connected up and Rocky software installed  for some signal tests.