Survival Electronics, by M.B. Ham

As an electronics and computer engineer for the past 30 years my personal skill sets are of limited but interesting value after TEOTWAWKI. Given that there may be very limited electricity, and/or the fact that CME/EMP may destroy most electronics devices, the need for these skills may be rare. I feel that these skills will be mostly useless unless you are part of a sustainable group of retreatists that have electricity and devices that use it. I plan to be part of such a group, and so I am planning ahead to make sure that my skills can be applied when required. This will require that I consult with the group on what brands and models of devices will be on hand. With this information I can stock up on spare parts, test equipment, etc. Electronics will fail and will have to be repaired. Comm gear, generators, vehicles, security systems will all need to be maintained and without proper planning even a knowledgeable technician will be unable to accomplish very much.

When I need to repair a device, whatever it is, I need several things:

1.    Schematic diagrams – These are the blueprints on how an electronic device operates. Diagnosing and repairing anything will be difficult without the schematics.

2.    Test equipment. The most basic tool is the VOM (volt-ohm meter). With this tool and the schematics you can identify and fix many problems in consumer electronics.

3.    Spare parts. This is sort of obvious, but you can’t fix things without parts.

In my way opinion, the availability of schematics and spare parts should determine what devices you are going to stock in your retreat. State-of-the-art comm gear is great if you have five spares and a dedicated support team to fix them, not so good if you are 40 miles and three years removed from civilization. A device needs to be sustainable by less than factory methods, and in the field, post-TEOTWAWKI, this will near impossible for individuals. For that reason, I lean towards older gear that has survived to this point. I look for gear that has easily obtainable spare parts that can be replaced by hand with common electronics tools. This means discrete components (resistors, transistors, etc)….. no surface-mount components and as few integrated circuits as possible. We have to go back to the 70’s and early 80’s for this stuff. Most of us will not have the equipment or spare parts needed to repair currently available electronics. The parts are just too small, to specialized. Furthermore, there are no schematics available for a large portion of modern, throw-away electronics.

This is why as an individual, or as a group, planning to support your electronics gear should take time and care. I am planning on buying as near identical and as many as I can find of particular pieces of gear. This will be gear that I can obtain parts and schematics for, NOW. I want as few different models as possible. I want complete spare units, spare parts, and good quality, well-protected schematics. I want these units to provide me with the needed functions, but as few bells and whistles as possible. I want to be able to test, tune, and modify the gear beforehand, and then put it into safe storage until needed. When looking for manuals, schematics, etc., look at sites like for almost any electronic equipment. Ebay is also a great place to get service manuals, schematics, etc.

Knowing how to fix electronic gear, or even being able to attempt to fix it will be a big plus if it’s gear that has become important to your daily life. Things like comm gear, battery chargers, solar controllers, generators, etc. While maybe not defining life or death, these devices will be able to help you be safer and more comfortable. Having a member of your group that has these capabilities, will become very important when something is broken. If you decide to take this on yourself, and have never been involved in electronics repair, consider taking a class at a local tech school or college. Whatever source of education you you choose, make sure you will get basic electronics theory to start, and then move to more advanced topics. A great place to start learning about electronics is watching this collection of online tutorials. Be sure that you get the principles of transistor theory down, since this is the type of circuitry we will be most likely to be able to repair. More modern equipment is still based on transistor circuits, but the transistors themselves are more often than not part of an integrated circuit that is more specialized, harder to find, and harder to replace. Once you become a bit more acquainted with the theories of electronic circuits I would also suggest that you play around with some ham radio equipment. Attend some local group meetings, get to know the old timers, ask questions, and get some gear to experiment with. Ham radio guys are some of the most savvy electronics guys around, and they are generally very pleasant and generous with time and knowledge.

Consider getting a n amateur radio (“ham”) license. There are plenty of useful, practical ham projects you can build, either from individually sourced parts or from the many companies that offer kits. Start with a simple receiver, since you can listen for signals from other hams. After that, build a matching transmitter and antenna. Once you get that accomplished you have made great strides in your skills. Along the way you will learn about power supplies, amplifiers, etc. Soon the mysteries of how things work will be distant memory. Much of the theory can be applied to other gear that has electronics as part of the larger functionality, such as a generator. The skill to fix a down generator or battery charger will be without a price.

When learning to repair electronic devices, test equipment such as multi-meters, oscilloscopes, signal generators, etc. are needed to troubleshoot, and then you need tools like soldering irons to effect repairs. Start with simple repair jobs like replacing cords, broken wires and then tackle more intricate work as your skill level increases. Replacing discreet electronic components is fairly easy if you have decent vision and good tools. You must remove faulty components before you install new ones, and that usually involves heating a solder join on a circuit board with a soldering iron, and then removing the molten solder from the component leads with a ‘solder-sucker’. A solder sucker is a hand-cocked vacuum device that has a spring-loaded plunger that is used to create a small vacuum at the tip of a tube when the plunger is released. The vacuum removes the heated solder and leaves the component leads free to be removed. Here’s a great video to show you how its done. installing the new component is easy, just place the leads of the new component through the circuit board holes, quickly heat the lead with the solder iron and apply solder to the point where the lead goes through the board. Clip any excess leads from the component and you are finished. When soldering some components like small signal transistors, you might to use a heat sink to keep the device from getting too hot during soldering. Us a small alligator clip attached to the untrimmed component leads during soldering. This will allow the alligator clip to dissipate some of the heat from your soldering iron.

As far as electronics go, with some sense of power availability, a properly planned retreat need not be “roughing-it”. Conserving power may indeed be required, but there could be instances where the preferred method of cooking something is with a microwave. Perhaps an electric clock, radios (news and music, not comm), maybe a record player. Whatever the device, consider looking for gear that is not digital, has no digital displays, no keypads, etc. Older microwaves had a timer and a start button… very easy to repair or bypass, and less suspect to failure from EMP or lightning. I would prefer to equip my retreat with all of the devices I use now, just older, or at least less sophisticated models that would be easier to keep running. I look for these at thrift stores, yard sales, swap meets, eBay, and Craigslist. If the price is right, and there are more than one, I buy several since the best spare parts source is a complete spare unit. Not only that, a working unit can be a very good tool for troubleshooting a failed unit. Now, before the SHTF is the time to test, repair, and modify your gear.

Once you have gained some knowledge and are familiar with electronic gear, start looking for some to put into inventory. Go to eBay and look for an older radio transceiver for CB or ham bands, then try and find the schematics and/or service manuals for it. For this type of gear it can often be had as a part of a collection known as “Sam’s Photofacts”. These were published as service guides for electronics repairmen, and will contain most everything you will need to repair and tune your radio. If you can’t find the schematics, consider a different piece of gear. Things like refrigerators, AC units, microwaves and electric ovens will often have schematics attached to the inside of the housing or chassis. For things like battery chargers, generators, etc, schematics may be hard to find. As soon as you buy a piece of gear, start hunting for the schematics, service manuals, and any operators manuals. Contact the manufacturer or distributor and ask for them, if they are available most often they will sell or just give them to you. Look on the companies web site, often the docs you are looking for will be available for download. Once you have your documents, make copies of them and store them in two separate, well-protected places.

While looking for gear to purchase, don’t overlook gear that is not functional. The easiest gear to repair is often gear that will not power on. This can often be traced to a bad power cord, switch, or fuse. When you are at a flea market, thrift store, garage sale, etc., and see a non-functional piece of equipment, you can usually get it for a very low price. Take your time and look for obvious problems such as cords or fuses. Ask the seller if they know how the unit behaves. I the correct power is available, ask to plug it in. I once bought a very nice television that would not power on for $1 at a yard sale! It turned out to be a bad connection on the back of the set where the power cord attached. Very cheap prices can be worth the gamble, and if you can’t fix it, there may be parts you can salvage for other gear. If all else fails, you can throw the equipment away and have only lost a very small investment, and you may have learned something in the process. Don’t be afraid to open things up and take a look around! Often you can spot a loose wire, or a bad component just by looking. Bad components often become discolored or burnt, and some bad capacitors are often swollen or burst open. These are easy to spot and should be fairly easy to replace with some patience and some practice.

For spare parts, look at the parts list and/or schematics. Try and find replacement parts for transistors, diodes, and tubes. When an exact part number replacement is not available look for a parts substitution from ECG, NTE, or a similar company. It’s probably not worth trying to stock spares for resistors and capacitors, but instead stock up on these in small bulk assortments. Resistors and capacitors are available in large assortments of common values. If a replacement is needed and no exact replacement is handy you can often just get close, or combine two or more components to get the required value. Other spare parts you may want to consider are things like microphones, power connectors, antenna, and fuses. (Unless you just have to, don’t operate your gear without the correct fuses!)

Above all, remember that most electronics devices are happy and safe when they are dry and have the correct power supply voltages applied. If you keep them dry and don’t drop them, stomp on them, or shoot them they will keep working. To that end, store and operate your gear in dry environments, and make sure you have thought to provide the proper input power for them. Whenever possible, try and buy equipment that uses a common supply voltage such as 120 VAC or 12 VDC (at least here in the US). In coming articles I intend to discuss how to build small power supply systems that can be switched or adjusted to provide different supply voltages to several different pieces of gear at the same time, from a common input power source. I also have articles planned for antenna design and construction, and an article for passively reducing your transmitter output to limit the effective range and your RF visibility.