Motivation
About ~15 years back, I bought this book called "The Electronics of Radio" by David Rutledge. I bought that book after hearing about a QRP club project by Northern California QRP Club (Norcal). The rig was named Norcal 40a (a CW rig that works in the 40m band). The main designer was Wayne Burdick, N6KR, the founder of Elecraft Inc.
The beauty of this rig is that the book completely describes everything about it and I have always been interested in things that one can completely understand.
Fast forward, 2019. I attended the Lamaakan amateur radio club annual meet at Hyderabad and met Rahul VU3WJM (sadly SK, 2022). He gave me a couple of PCBs for the qrp-tech version of the rig that was built with permission from the designer. Since then, I did nothing to build it.
Last week, I took the book out and started reading a bit. I thought I could gather the parts, if not, replace the parts with something else and build a working rig.
I will be updating this blog with the progress. Progress will be slow. I will be working on it only on weekends and the month of May is busy, so not many free weekends.
I will be doing the problem sets in the book and documenting my solutions..
First steps
In order to get started, I thought I would get two things:
- get an LC meter
- get a signal generator.
I had an old LC meter built from Phil Rice VK3BHR circuit. I brought it back to life today.
In order to have a signal generator going, I took out my old NJQRP DDS board (based on AD9850) and breadboarded it with an arduino nano. Unfortunately, I can't seem to get signals out of it yet. I will be working on getting it working in parallel with the NC-40 experiments.
I also got my Rigol Oscilloscope out and got it going. The LC meter is working great and I could see the signals from internal LM311 based oscillator circuit on the scope.
I have also got a cache of polystyrene capacitors. May not be the exact values I need but I can mix and match and make it work with series/parallel combinations... LC meter is very handy to measure the values as the labels on the capacitors have faded.. But they seem stable. LC meter showed steady values and the oscillator on the LC meter was steady on the scope..
The first part I am going to build is the audio amplifier.
I also noticed that some of the holes on the board are covered with solder paste. Also the top and bottom layers do not seem connected by the vias, which means, I will have to remember to solder on both the sides. That is going to be a pain and replacing parts would also be difficult, but I am going to be extra careful (ICs on IC base etc..).
An SMD based NC-40a would have been nice.
A few nylon standoffs were lying around, so I used it to raise the PCB so that nothing gets shorted while building. When it comes to enclosing the board in a metallic enclosure, I will possibly replace it with metal standoffs.
