Wednesday, December 10, 2014

Operation Rock Garden Update

While I wait for #3 to bug me about her radio again, I'm working on my 10DE7 project.

Here's the skinny:
I took some parts that look like this:

and turned them into this:

and in the processed learned something about phasing.

Some project notes,
I did make the connection between taps 9 and 7 permanent, that is, soldered the wire in place. I made a short jumper with spades so I could experiment with places to put them on the taps. The first time, I soldered a jumper wire between pins 8 and 9, and didn't get the results I wanted. I thought for a minute that I had a bad transformer. I learned a couple of things in the process.

1. Autoranging digital VOMs can mess with your head. I kept getting jumpy measurements in the milivolt range, and it kept making me nervous. Verifying some readings with an analog meter really helped me settle down.
2. When dealing with AC transformers phasing matters. I should have realized from the schematic of the taps that the phasing a the bottom of one set of secondary taps would be out of phase with the top of the next set, but it took a little experimenting to figure that out.
3. When dealing with an unknown quantity, don't solder things down. I know better, but sometimes I don't do better.
4. Alligator clips for VOMs have their place.

I got to bed pretty late last night, so probably no shacktime tonight.

I have to think some more about plate voltages anyway.

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