Making progress, probably 60% completed, all tests look ok so far.

 

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Also building  up my equipment. I purchased a used Tektronix 465 Oscilloscope on eBay for $100. For many years I used this in the  lab but have not really touched hardware for 18 years now. A 465 use to be my right hand when I spent time daily in the lab. As I remember when we purchased them new, they were a few thousand dollars in the mid 80's. It is definitely aging but will work  fine for the frequencies into 10's of megahertz I'm going to be using for now. There are a  number of oscilloscope "heads"  with USB interfaces and software that will run on  Windows but the cheap ones have no bandwidth and the good ones start at $1000 and go up, definitely not in line with my budget for this hobby!

 

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One thing I'm a bit uncomfortable with is winding the coils and transformers. They are the  little copper colored items on the band pass filter you can see above.  You have to just make sure you wind exactly to specification because measuring inductance into the 10's of nano henries is basically impossible with the type of equipment I have.... Well not quite, there are meters for fairly cheap which go into the micro henry range and beyond that you really have to build a tuned circuit with a known capacitance and measure the frequency after doing the math.

The  state of "hobbyist" software defined radio seems to be stuck on pure C libraries and  Linux OS. Starting to look at some of the windows embedded as a possible driver for future endeavors.

Another discovery, and no surprise, is that working under 50 Mhz is one thing and I can do that fairly easily but to get up into the 2-100 ghz range, it is a whole different ball game. At that point I think the thing will be to purchase sub-assemblies and figure how to glue  them together with software. At that point you can't even have wires, everything is on carefully calculated PC boards and integrated circuits.

That's all for now.