This is in response to an earlier letter where a reader asserted that his knowledge as an electronics engineer will be of little use after TEOTWAWKI. He is wrong, we will not abandon all the technology invented over the past 100+ years. Say for example we are hit with the big solar event, several EMPs and most solid state electronics are destroyed. One component that will survive is the vacuum tube. There will still be means to generate electricity here and there that will not be affected, hydroelectric generators will still spin, steam turbines, some of these can be homemade on a small scale. Once you have any electricity you can use vacuum tubes to build all kinds of communication gear. Sure there are some very high priced tubes geared to the high fidelity audio market, but all the old radio and television tubes from yesteryear can be had from free to just a few dollars from various sites and garage sales. You can build a decent sounding audio amplifier with some 6GH8A tubes and a number of different horizontal output tubes for example.
Tubes are easy to design with and very forgiving. The circuits are simple. If you keep on hand a collection of tubes, resistors, capacitors, some various sizes of magnet wire to make your own transformers and coils and old transformers to modify, most laminated (E-I core types) power transformers can be de-laminated and redesigned and rewound by hand if need be, even some old tube radios, the possibilities are endless. Sure you will need some way to solder things together, a fire and a chunk of copper with a handle even works in a pinch as a soldering iron. You just have to think 100 years ago.
An old fan with a modified motor on a pole can make a small amount of electricity from wind, all you need to do is take it apart and put some magnets in the rotor, maybe isolate some windings, this is easier done now with machine tools.
An electronics engineer should start thinking what he needs to have on hand now before the SHTF. Do not discount your knowledge, just think old school, and you will be amazed what you can do. No you can’t make a computer easily but you can really help your community more that you think. As an electronics engineer I love the challenge of fixing anything. Thank you James for all you do and God bless. – Jimmy in California
JWR Replies: I agree! Don’t under-rate ingenuity and resourcefulness. Speaking of which, I’ve posted a YouTube video from France once before in the blog, but it is apropos to repeat the link: Hand-Making Vacuum Tubes. OBTW, tomorrow, I plan to post an article that I penned about 1950s-vintage general coverage receivers that use vacuum tubes.