Elements of a Security System – Part 1, by J.M.

Editor’s Introductory Note: This detailed article series is by J.M., who you may remember as a SurvivalBlog Writing Contest First Prize winner in March, 2018, for his five-part article: Perspectives on Patrolling.

(This is the first installment in a five-part article series.)

When you talk to people about preparing, one of the most common themes you’ll encounter is that they want to ensure the safety and security of themselves, their families and their friends in the event something disrupts the ‘rule of law’. The reality is that even with active law enforcement in normal times there are thousands of break-ins, assaults, attacks, thefts and other crimes committed against people and property every day. Since most of us can’t afford to keep an eye on our entire property 24×7, we need some type of force multiplier that can let us know when an intruder is approaching or entering our property.

The goal of this article is to provide some ideas and suggestions regarding the design and implementation of a security system that can help you detect when an intruder is approaching your location and gather observational data so you can make a decision on what you should do about it, both in ‘normal’ times as well as after an event has rendered rule of law null and void. Note that I’ll only be focusing on detective-type controls to help you detect the presence of an intruder, as opposed to preventive controls to keep them out.

As with any project, the first thing you need to do is to define your goals. I’ve been building and expanding my home security/monitoring system for several years (or as my wife refers to it, the ‘never-ending project’), and I’ve used that experience, combined with what I’ve learned about preparedness over the years, to define some goals for what I’ll be discussing. These are:

  • Leverage technology where it makes sense, but keep it simple
  • Include non-electronic options where possible
  • Support a wide range of detection and observational options
  • Support security for fixed locations, with possible applications for mobile security
  • Keep it inexpensive
  • Make it flexible
  • For powered components, capable of being powered by 12V, 5V USB, or AA batteries

One critical point to keep in mind is safety – I’ll discuss various solutions that use things like primers and flares for alerting, so before you decide to employ anything that could potentially harm you or someone else you need to understand your responsibilities and liabilities. Even if your intent was just to alert you that someone was approaching, a shotgun primer or flare could still seriously injure a curious child that stumbles across your alarm system and you could end up going to jail as well as living with the responsibility for the rest of your life. Understand your local laws and regulations, and don’t do anything that could put innocent people in jeopardy. Disclaimer: The information in this article is for informational purposes only, and the author accepts no responsibility for any actions taken as a result of this information.

Powering a Security System

A lot of the sensors and alarms I’ll be discussing operate on electricity, so I’ve tried to standardize on a couple of power sources – 12C DC, 5V DC (USB) and AA batteries. The system I’ll be discussing is based on a centralized console with a dozen or so different sensors feeding into it that can be run off of a single 12V car battery for several months, which you could keep charged with an inexpensive solar panel. How much power you’ll need will obviously depend on what you want to include – a simple collection of tripwires, door switches and motion sensors won’t require much power, but if you choose to add in video cameras your power load will increase significantly. If you want to use wireless remote sensors you’ll need rechargeable batteries and some way to charge them, or you could rig up a way to power them directly with solar. You should also keep in mind that car batteries almost never put out exactly 12V, and some electronic devices can be picky about the input voltage they’ll work with. If you don’t have a solar system that provides a consistent 12V, I recommend using a regulator to make sure you’re getting a stable 12V. If you want to include 5V USB for rechargeable batteries or devices you’ll also need a 12V USB charger.

Since I’ve designed most of my system around 12V and I want to use it now and take advantage of the currently-available electrical grid, I have a 12V switching power supply I use to power everything so I can save my 12V batteries for emergencies. Since all of my wires run to a central location, in the event of a grid-down scenario I can easily replace the 12V power supply with a solar system or a car battery.

Note that if you’re using powered devices of any type, some of may be affected by an Electromagnetic Pulse (EMP) or Coronal Mass Ejection (CME) event. Simpler items such as lights and buzzers are less likely to be affected, but in a worst-case scenario, anything containing metal might be impacted. If you’re concerned about such events, you should consider protecting some of the more complex electronic components by storing them in an insulated metal container such as an ammo can or metal trash can until you need them, or as replacement parts for an already-deployed system.

Animal Security

Arguably the best security system in the world for detecting intruders is a guard dog. Not only will they let you know when someone is approaching, but they can also help defend you. I won’t be covering the use of canines or other animals for security purposes in this article, but they can definitely be used in conjunction with many of the ideas I’ll be discussing. Note that house cats are lousy for security, unless an intruder is dumb enough to actually step on one while they’re asleep.

Requirements Planning

If you’ve read any of the other articles I’ve had posted on SurvivalBlog.com, you’ll know that I’m pretty big on planning before starting any project or activity; I’m a huge fan of the 5 Ps: Proper Planning Prevents Poor Performance. To start with, you need to understand what human resources you’ll have available to support your security requirements. If you have a full platoon of trained personnel available that can provide a 24×7 watch across your entire property in any weather conditions, you probably don’t need to worry too much about augmenting your security system. However, if you’ve only got a limited group of family or friends, or the property you’re trying to protect is large or has complex terrain, then you probably won’t be able to maintain a full-time watch everywhere and will want to employ some force multipliers to help out. If you don’t have enough people to always have someone awake to watch or listen for alarms, you’ll want a system that provides alarms that are loud enough to wake you up. Your available personnel resources (both quantity and quality) will drive a lot of your requirements for a security system.

The next factor you need to consider the physical layout of what you’re trying to protect. This includes the terrain around your house or compound as well as the layout of your house and other buildings. A house and barn sitting on a rise in the Midwest USA with miles of visibility in all directions will require a much different approach to detecting intruders than a small cabin next to a lake in the middle of the New England woods. I recommend investing some time to walk around your property and adjoining areas to gain an understanding of possible approaches, obstacles, views and visibility, cover and concealment, etc. Work with another person who can stay near or inside your house to tell you where you can and can’t be seen (radios will help with this). Use a detailed map of the area you’re trying to protect and mark the most likely approaches, obstacles, locations of possible concealment, etc.

Seasonal Imagery

Your assessment should also consider how different seasons and weather conditions might affect an intruder’s actions as well as your security system requirements. One useful tool to help with this is a detailed satellite image of your property; you can capture a screenshot using Google or Bing maps satellite view and have it printed and laminated at your local office supply store. If you choose to do this, use the highest resolution monitor you have available to get the crispest possible snapshot picture – if you have access to a 4K television/monitor and your computer supports an HDMI 1.4 or higher output connection, use that to get a super high resolution snapshot. Your local town office might also be able to provide you with detailed topographic maps of your location and surroundings.

(To be continued tomorrow, in Part 2.)


  1. Primers are not loud enough. Take a 12ga shot gun shell, cut it with your pocket knife and let the BB’s falls out. Nail the device to a tree etc pointed down so as to protect a child etc.

  2. Lance,

    You’re correct that primers won’t be nearly as loud as a shotshell with a full load of powder. One of the points I make later in this article is that you should have layers of security detection, so while a fully-loaded shell would be your best choice for an alert that’s quite distance away, a primer may be appropriate for something that’s a lot closer.

  3. Security will be job one. Everything else supports that objective. Manpower for most will greatly lacking. Every trick, hack, or tactic in this article should be considered. If we dont’ see’em, hear’em or smell’em coming, then it is over before it starts. You loose.

    I wish I had time, perhaps this winter. Organizing with you community is the best defense for those without their own. Defend at a distance, not at the mail box. Don’t let them into the area in the first place, then potential intruders will be reduced to mostly neighbors, and lowers the threat from outside.

    One of the best plug and play force multipliers is the Murs Dakota Alert Sensor. We all should know about those by now, if not, please see a video on it. Although only 1/2 watt transmitter and a limited range, external antennas can greatly improve the distance at which these can be deployed. I make my own, but I cannot beat this. The least expensive and most effective antenna external antenna for these:


    Request a cable length of at least 15 feet or more, specify the cable end, and the frequency it should be tuned for. In this case, a good center frequency should be 153.500Mhz.

    Hoist the antenna has a high as possible and the range could be improved as much as 3 times as the terrain permits. I’ve reliable results out to 6 miles in ideal terrain. Place them along the road as far away as possible in pairs separated by 50 to 100 hundred yards. Used in pairs we now have ‘gates’ that allow the user to determine, direction of travel, number of vehicles, and speed of their approach. It also provides redundancy. Do not rely on any electronic device entirely. Rain cause the sensor to become somewhat unreliable, and can produce false alarms, or no alarm.
    That another is using pairs is the best way to deploy. Higher voltages into it improves the range and reliability in the cold and wet, yet that sort of alteration is not available to all.

    Of course this sort of thing is not appropriate during normal times, or in all locations. How useful is this? For instance if one has a dirt road 1 mile long and the maximum safe speed is say 35 mph, then the vehicle may need 6 minutes to arrive at your location. 6 minutes is a lot of time when you are in a hurry. If one can hear the sensor from 2 miles away, then the likely time of arrival could be 12 minutes. Set this up now if possible and learn to listen and interpret the traffic coming and going. It is surprising how effective this can be. If on a spur off the main dirt road, placing a sensor at the point of intersection also makes sense.

  4. Tunnel Rabbit,

    Thanks for the great comments! I cover some of what you’re referring to later on in the article, but you provided some good details that I wasn’t able to include.

    1. Had to quit work and come in. To remove any confusion for those not into radio, here the link to the antenna and cable combination mention in the previous post about MURS Dakota Alert Sensors. for the best results, this roll up type of Slim Jim is easy to hang with a light weight made of a non metallic material, or use cordage to create light tension, so that it is strung to it’s design length. Attempt to space the antenna way from the tree or pole at least 19″, and on the side facing the receiving antenna. It is not difficult to do.


      This antenna has a broad bandwidth of at least 8Mhz on the VHF side and should cover the Business band, Public Service and Marine Band as well. Ask the manufacturer. The UHF is good for GMRS, and has the narrow band with of only 4 Mhz. Ask if it will cover the UHF business band.

      Verify what type of connect is on your sensor. Older models use the BNC type, so select the BNC Male option. The recent production use SMA connectors. I cannot at the moment verify which, so talk to the vendor, or research it. These take either the SMA Male, or the SMA Female. These antenna also work well with standard radios, mobiles, or handhelds. Adapters are available on the site. The Baofeng UV5R takes a SMA Female. Mobiles typically use PL259 cable ends. An SO239 (aka. UHF) to SMA Female adapter for the Baofeng UV5R, allow this and other antennas to be attached to the Baofeng UV5R. Transmitting on a Baofeng on a homemade copper Slim Jim on 70cm, I could hit the Blue Mountain repeater 80 miles away with ‘full quieting’ with only 4 watts. The slim jim is a good antenna for many applications, but not all. It is great for scanners, but somewhat deaf in some cases.

      For those wishing to mount an antenna on a roof top this is far better. These are what I make and have tested over the years.:

      For MURS:


      Cable into the house should have PL259 ends sold separately. Use the UHF to SMA Female for Baofengs.

    2. Re: Antennas for MURS Dakota Alert Sensor

      I almost forgot. To increase the range of the sensor, the first and least expensive method is to install an external receiving antenna. I would get the copper pipe version for this purpose. For OPSEC, I would not transmit on this antenna because it would greatly increase the range at which I could heard, unless there was no other way to establish reliable communications. We want to limit the range, by using the lowest power or ‘smallest’ antenna we have to avoid detection, yet effect solid comms. However, we want to hear as well as we possibly can, and that means using an external antenna. We could therefore hear each other better, and yet limit the range we broadcast, if we use an external antenna to ‘hear’, and the antenna on the Baofeng, to talk. This set up on all stations, improves reliable comms, and reduces the chance of detection. We can also better listen for threats that are using low powered radios, and any radio at distance.

      Well to get back on topic, first install an external antenna to listen to the sensors, and if that does not provide the range needed, then install an external antenna on those sensors that have difficulty reaching your receiving antenna. This is the sensible way to get it done, rather than installing external antenna on all sensors. The one advantage of installing antennas on all sensors, is that receiving station that is a hand held, would have a better chance of hearing the sensor. Test the reception of both the fixed receiving station, and the mobile hand held’s at all locations within the retreat, and install antennas as needed…

      I don’t mean to hijack the thread, but intend help when time permitting ,to support your fine efforts. This is an outstanding article, and topic could not be more important. Thanks for listening….

  5. A dog poses the same liability threat as a primer or shotshell warning device, or more so, since a dog can pursue a child or innocent party who happens to attract the animal’s attention. I remember Dear Abby or Ann Lander’s advice to persons seeking to buy guns for protection to get a dog instead. A dog requires full time attention and adjustment of one’s lifestyle to meet its needs. A gun will not jump out of a drawer and shoot someone by itself. A dog can–and will–go through an opening to attack anything that moves, regardless of its age or intent toward you. Despite what many owners insist, dogs are creatures of instinct, not reason. And you are responsible for its actions.

  6. I would like this author or Tunnel Rabbit to write an article about the Murs Dakota Alert Sensor unit, and the modifications mentioned. I have used the Murs Dakota Alert Sensor unit for years, but disconnected it because of the false alarms from deer. Thanks,

    1. Ozark Redneck,

      My mom was born bare foot in a dirt floor cabin near you.

      Others have had a similar concerns. Situation: The unit functions well, with no ‘false alarms’, for awhile, then begins to ‘alert’ frequently, and repeatedly issuing ‘false alarms’. According to the manual this the unit signaling that the batteries need to be replaced. Install fresh alkaline batteries, and see if it stops putting out ‘false alarms’. If it does not, then reinstall the ‘old’ batteries, and see what happens. If I recall correctly, when the 6 batteries only provide 7.2 or less volts, the unit will signal with a low battery alert. Eneloop batteries when fully charged will test at about 1.45, verses fresh alkaline batteries that will test at 1.5 to 1.6. Rechargeable batteries do not last as long. If using the unit in the cold climates, battery life is greatly diminished. I would use the lithium type if necessary.

      Tips and Tricks

      There are several way to power these. The safest way is buy an after market AA battery holder that has place for more than 6 AA batteries. To extend the time that rechargeable will power the unit, add one more rechargeable, and any extra batteries that the holder can hold, should have dead batteries wrapped in aluminum foil to serve as ‘place holders’. These ‘place holder’ provide no power. The unit will tolerate more than 9 volts, even 12 volts, but 12 volts may reduce the life of the unit. If we have rechargeable with voltages of 1.4 volts x 7 = 9.8 volts, as compared with 6 fresh alkaline with 1.6 volt x 6 = 9.6 volts. By add one more rechargeable battery we are near the same starting point as are the alkaline batteries.

      Another trick is to use a small 12 vdc SLA battery, or car battery and universal voltage transformer set to 9 vdc. The battery can be charged with a 10 watt solar panel using an inexpensive charge controller. This could be done with units that a set up at longer distances.

      Cheap Trick

      Use an old and failing car battery that has a ‘bad’ cell or two, and tests between 10vdc to 8vdc. There is often plenty of capacity at that voltage, even in cold temperatures to run these sensors that sip power.

      There is more than one way to skin a rabbit. These units are very useful, but they often frustrate the user. Read up. It would be a huge loss if one could not operate their sensors correctly. And just like anything else, take one out of the Faraday cage and use it for awhile to gain experience with it. In a time of stress, getting a ‘false alarm’, could be nerve racking, when all it needs is batteries. In a pinch, but only in a pinch, would I connect directly to 12vdc. With higher voltages they are more reliable in the rain, and cold. My first choice would be to add an ‘extra’ rechargeable AA battery, or two sets of 7 battery packs, wired in parallel to double the ‘run time’ when using rechargeable, or regular alkaline, should the lithium type were not available. Just keep the voltage below 10 vdc to be safe. The most stable source of power would be the 12 volt car battery with the universal voltage adapter set to 9 vdc. So as not to ‘waste’ a good car battery, use one that no longer starts a car.

      Universal voltage adapter. Always confirm polarity with a volt meter before connecting.


  7. Dear Tunnel Rabbit, It is good to know that we are related! But unfortunately your genes on electronics did not get to me. So I am going to save your reply and test it. Thanks! and stay safe!

  8. All Good Ideas here, covering any Perimeter larger than a suburban backyard takes a lot more than looking out a Window now and then… Here’s an additional idea for Perimeter Security – use of small, camera-equipped Drones for the Quick-Response to an Alarm from the remote sensors. A Drone can be Launched in less Time than it takes to get Dressed to go wandering out to Identify a Threat, and it Flys a lot faster than a Ground Vehicle, never mind a Man on Foot.

    A Drone flying several hundred feet above is much less noticeable to and Intruder than another Person or Ground Vehicle, which is what the Intruder would be looking for. If an Interception of the Intruder is called for, the Responding Personnel can be Guided effectively to an Engagement.

    With a Thermal- Imaging Camera, Nighttime Recon can be extremely Effective, and this type of System would also be useful for Hunting Game in the same manner.

    My own experience with doing this on a 1200-Acre Farm has been very effective, a Drone Sweep of the Perimeter saves Hours of running around on a 4-Wheeler checking Fences, playing “Find the Cow” and so far, on two occasions, it made it Very Easy to locate and have Arrested some Firewood Thieves in a Back Lot that borders a Gravel Road.

    We Heard some Chainsaws running, a little closer than the Neighbor’s Yard, sent the Drone over the Woods, identified they were Trespassing, and met the Sheriff’s Deputies on the Road, right at the ‘Targets’.

  9. The current ASF situation in the East part of the EU is representing a constant threat to the EU livestock sector and the recent expansion of the disease has also demonstrated the ability of the virus to spread long distance. ASF is a disease for which there is no effective vaccine and its control relies on early detection followed by rapid eradication. Considering the epidemiological situation and the possible economic consequences of the introduction of ASF, it is extremely important that free territories are maintained free by preventing the introduction of the disease. For such purpose, bio security plays a key role in preventing ASF, and given its epidemiological cycle, simple measures may prove effective in mitigating the transmission pathways of the disease, also in the backyard sector. In certain countries, in case of occurrence of epidemic diseases, there is the attempt to try to decrease the local risk of further spread, by reducing the number of backyards, especially in the areas surrounding commercial holdings, and afterwards prohibiting this type of farming practice. Given the socio-economic relevance of the backyard sector, such discriminatory approach needs to be carefully evaluated since it might lead to poor compliance of the measures enforced to control the disease.

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