Sunday, September 30, 2018

We Used to Build: Rolling Your Own Radios, Part 2

Many of you are worried about EMP. This concern is valid to a certain degree, but probably not in the way you think. The usual single high-altitude air burst over the center of CONUS should be less concerning than shorter range tactical EMP attacks in urban areas, particularly the coastal regions.

Many of you do the expedient of wrapping a couple cheap HTs and maybe a portable shortwave receiver in  an anti-static bag and then placing them in an ammo can. That works, but then the radios are useless when you need them the most, which is now and not when maybe after your TEOTWAWKI fantasy happens.

One solution is to run some uber-cheap sacrificial gear when you think your TEOTWAWKI SHTF fantasy is about to be fulfilled. I consider that an expedient, the last step in PACE planning. A better solution is to run EMP-resistant tube gear, especially tube rigs that can run off 12V DC.

Here is a 12V mobile transmitter that was found at a local hamfest.
It is a home brew rig. Someone built this from scratch. Sadly, the builder is a silent key.

You don't have to build something from scratch, or figure out something that was homebrewed before you were born.

After World War II, surplus gear such as this BC-229 receiver got many hams on the air. It is another 12V tube rig, part of the SCR-AR-183 aircraft HF radio set.


Look at the build quality of that rig. It was made before your baby boomer (grand)parents were even born, and will still be working after they pass away. Look at the manual that includes full schematics and wiring diagram. This radio was designed to be maintained and fixed on a jungle airstrip in the middle of nowhere. Compare the build quality and documentation of this rig to your Baofeng HT. If you think a Chinese HT is equal to something that was built with old-skool American pride, and that it will last as long as this BC-229, you are deluded.

I don't, of course, expect a beginner to be able to work on gear of this caliber. That is why you should first build up your library, study, find an elmer that can help get you up to speed, and start with some solid state kits first.

You have been given links and information to get you started. You also have these wonderful online resources known as search engines to help you along. In the next posting, I will talk about simple tube gear that even an impoverished radio experimenter would be able to work with.

In the meantime, we are in the middle of the autumn hamfest season. A nationwide list is available at http://www.arrl.org/hamfests-and-conventions-calendar. You now have enough information to visit a hamfest and look for certain things.

This is an example of some of the material covered in my Come As You Are and Get On The Air radio class being held next year in various cities. Specifics are at https://www.sparks31.com/p/2019-classes.html. I'm now accepting deposits ($50) for all classes. To enroll, please visit https://squareup.com/store/sparks31.

2 comments:

  1. One of your best articles in a while, which is saying something. I really need to get a kit built.

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  2. Reblogged at https://lowervalleyassembly.us/2018/10/02/sparks31-building-your-own-radio/

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