Monday, September 19, 2016

The Hype of Digital Modes

Digital appears to be the craze in Ham Radio today. It consisted of only one option decades ago but now digital popularity and it's many forms are amazing. Here is an incomplete list of some the available digital modes:

  • Fusion (C4FM)
  • D-STAR
  • DMR
  • AMTOR
  • Hell (Hellschreiber)
  • MFSK
  • Packet Radio
  • PACTOR
  • RTTY
  • Phase-shift Keying
    • PSK31
    • QPSK31
    • PSK63
    • QPSK63
  • CW
The obvious question from this point is where does one start. The answer is more complex than the question itself because each of the modes can require different equipment, different skill sets, and different levels of patience to master. For example, the original digital mode of CW takes time to learn and become proficient. However, the result is a fine tuned skill that works in poor band conditions. 

All digital modes have an advantage over analog voice due to its narrow bandwidth and possible error detection and correction ability. For example, PSK31, one of the most popular digital modes today, is only 31Hz wide and is the easiest digital mode to use (in this writer's opinion). It only requires a radio, and antenna, and a sound card equipped computer. Some of the newest rigs on the market offer a built-in sound card interface that eliminates the need for a computer sound card. All one needs to do is connect the computer to the radio, tune to a specified frequency, and launch the software. 

Anyone who wants to develop their communications emergency skills needs to understand and follow the digital modes of communication. If we find ourselves in a national communication emergency I guarantee that few people will be pushing their 1,500 watt amplifiers. Most will be running as little wattage as possible. This means that transmissions could be more on the line of 5 watts due to power conservation. 

Most people do not realize that in a true long-term disaster solar and batteries will be the only things powering communications. Therefore, power conservation will be critical to long-term success. So instead of saving your pennies for that shiny new Ameritron amp, you may want to invest in a better antenna system. Ask the guys who live in the QRP (low power) arena, they have been known to break a pileup using 5 watts or less. To do that requires efficiency and understanding your hobby. That is the goal I set for my station. You will learn a lot on low power. 

We will cover some of the digital modes more in detail in days to come. Stay tuned!

Wednesday, June 8, 2016

Portable Antennas

Portable antennas have always been a fascination of mine. As much as I would love to have a 100' tower and large yagi antenna above my shack I realize that is not realistic when it comes to mobile or portable HF operations. It is true that field day each year there are those who drag a portable tower system on a trailer with a monster array to place on top. This is great if you have a team of people to help and a place to erect the tower.

A few years back I was attending a field day event when a friend arrived with his crank-up tower loaded and mounted on a twin-axle trailer. At the start of the event he lowered the trailer stabilizers and began to assemble the antenna and mount it to the top of the tower. Next with his wench and a homade lift he brought the tower to a vertical position to allow the crank-up procedure. For the next 2 1/2 hours in 90 degree weather with 80%+ humidity he cranked away. Being prideful and desiring the the badge of self-accomplishment he refused any help. When the tower was fully erected he connected the coax to the antenna switch system and walked to a shade tree where he spent the next three hours recovering from his accomplishment. Six hours into the event he was finally able to enjoy his efforts. Needless to say the antenna and tower system produced some great results but was it worth the cost?

If I am looking at carrying my portable HF system and an antenna with me when I attend a field day event, go on vacation, or when I need to get out of dodge, then the trailer, tower, and monster antenna setup is not practical. I need a small system that I can throw in a backpack or hard case and hit the road. I really like my Yaesu FT-991 which offers HF, VHF, and UHF bands. Therefore I need a practical solution to go along with me. 

First let's talk about the HF side of the fence. This is usually the most difficult item to select or build in a portable configuration. Antennas are compromises in the best of situations. We do not live in a vacuum and our locations are always influenced by our surroundings. Not knowing what band will be usable we desire an antenna that covers multiple bands while at the same time we need something we can easily carry, assemble, erect, and tune. With those qualifications our field of commercially available antennas has drastically narrowed. 

http://www.dxzone.com/buddipole-deluxe/


Outside of the good old fashioned wire dipole, there are a few out there. The ones that come to mind for quick setup and operation are the Buddipole, Buddistick, and the Super Antenna (MP1DX). Even though these antennas have the same goal in design, they each have different characteristics. The Buddipole operates in a dipole fashion. You erect a vertical pole and the attach two radiators to a T-connector. Depending on your location you may need a guy wire system to stabilize the setup. Your radiator setup determines band. Changing bands requires a little effort in changing the radiator setup. People have reported surprisingly good results with this system. 

The Buddistick is more suited as a vertical antenna with a wire counter poise. It is designed for operation under 250 watts. This can be mounted on a tripod or clamped to a picnic table or rail. The vertical pole the antenna is mounted on can be raised surprisingly high. This antenna is very easy to setup and reports are positive to its use. 

The Super Antenna is also a vertical but has a higher power rating than does the Buddistick. The Super Antenna doesn't require radials but when added becomes a very interesting performer. Like the Buddistick it can be clamped to a table or mounted on a tripod. Changing the frequency is done by moving a tap on the loading coil. This antenna also receives good reviews. 

Many times we like having VHF along for the ride. If this is the case eliminate the Buddistick from the list. The other two are capable of operation in the VHF band. 

You may be asking why I did not include a discussion of the wire dipole in my list. It does a great job but has one major limitation - installation requirements. You have to tie the ends of the antenna to something at height. Some locations do not have trees or structures to accommodate this requirement (beach, etc.). Otherwise it would have floated to the top of my list. 

This topic like so many others has opinions that reside in both sides of the fence. I would love to hear what you think and what portable antenna you prefer. 

Tuesday, May 17, 2016

Family Communications Plan

You are at work, your wife is at home, and the kids are at school. Something big happens. An 8.5 earthquake tears the city apart. Immediately cell phone towers go offline and the few that survived are completely jammed. Power is out and land line telephones are inoperable. You don't know the overall damage and if your family is safe. The highway system is blocked. What are you going to do? There is an urgency and helplessness that puts you into a state of mental shock. What is the plan?



Did you know that the majority of people do not have a communications plan in the event of an emergency or disaster? Do you have one? Most people reading this don't have one. A Family Communications Plan should consist of information that all family members need to know in the event of an emergency. This items include relative's phone numbers and addresses, out of town contacts, emergency meeting places, how to access important family and medical documents.and much more. Also be aware that school systems have a plan in case of a disaster. Make sure you know and understand what that plan is so you know what to do if your kids are in school when it happens.

FEMA has created a planning document to help outline the necessary steps to prepare for a disaster. It can be downloaded here. Take time to go over this with your family and then rehearse what you plan. This can save you hours of worry and frustration in the event...

Monday, May 16, 2016

Communication Receivers

When you are in the "want to know" state of mind how do you find your information? Do you go to the AM/FM portable radio that you have on the shelf? That is a good way to get the local news but what if the disaster or emergency situation has taken local radio off the air? What if people decide they need to be with their families rather than manning a radio station? In a major disaster, these are great possibilities. Television may suffer from the same problems.

The greatest source of information is usually from other people. This is what has made the social media service known as Twitter valuable for real-time information. Twitter's active feed explodes with information on any major newsworthy event. You can see what is happening just by typing in a search term or hashtag of the location or event. Twitter suffers from a major problem though. It operates from a cellphone or web based service. In a major disaster Twitter, like radio and television, may not be available. 

So how do you get the information if all commercial services are not available? You rely on amateur or distant sources. Amateur (Ham) radio has always had the ability to communicate over long distances using a modest radio and antenna on HF frequencies. Contacts around the world happen everyday. In a disaster information is passed from the affected areas to the surrounding regions effectively and efficiently. This information is usually first hand and fairly accurate. Actually I would say that in most cases it is more accurate than the salted versions you see on the nightly news. 

For ham radio operators this gear can be quite expensive with top end transceivers exceeding $7000. Another option to "hear" what is happening is a Communications Receiver. This gear does not have the ability to transmit and therefore is receive only. The fact that they do not have the transmitter as part of the package makes them considerably cheaper. Many of these receivers run $800 and higher. There is still a cost involved but you usually end up with a great piece of gear.
The ones you need to be looking for should be classified as all-band (or multi-band) and multi-mode. All-band or multi-band means that it will cover multiple band designations. A band designation is one dedicated to a particular radio service. For example, Citizens Band (CB) covers between 26.965 MHz and 27.405 MHz. Ham Radio has band allocations throughout the RF spectrum. Shortwave has band allocations. Therefore having a receiver that encompasses various bands across a large frequency range is ideal. My preference for frequency range is 100kHz - 60Mhz at a minimum.  If I can find a great deal on a Communications receiver that goes into the 3Ghz top end that would be perfect.

A multi-mode receiver is one that can listen on different modes. A mode would be considered a type of signal or method of modulation. FM (Frequency Modulation) is a mode. USB (Upper Sideband) is a mode. LSB (Lower Sideband) is a mode. AM (Amplitude Modulation) is a mode. You want to make sure to have at least AM, and SSB (which includes both USB and LSB). If your receiver can listen to above 87Mhz then you certainly want it to have FM. If you are an advocate for Morse Code then CW is your mode.  

Older Communications Receivers are still in high demand. The older Kenwood and Icom radios are usually found in very good shape with many years still left in them. Most major companies have left the "receiver only" market to invest their resources in commercial and amateur transceiver products. However one still stands strong in this area. They are AOR Communications

If you decide to invest in a Communications Receiver then make sure you learn all you can about the radio. These are not as easy as pulling the one off of the shelf, turning it on, and listening to the news. They require a little skill and understanding of the bands to achieve satisfaction. However, in a disaster, they are handy pieces of equipment. 

Do you own a Communications Receiver? Tell us your experience.

Saturday, May 7, 2016

All-around All-out Bug-out Radio

I was recently asked what would be my all-out, all-around, bug-out ham radio. This is a tough call and an easy choice at the same time. I believe I would choose the Yaesu FT‑857D if I needed all mode and lightweight travel. This is an incredible little radio designed for backpack use. 

When it comes to mobile HF I have always been a fan of the Icom 706 series of radios. There are a couple of issues with the 706 that I don't like if I had to carry one with me all day. The Icom is heavy and power hungry on FM. The Icom 706 series of radios are very impressive, however the Yaesu FT-857D offers a radio that is designed for HF portable operation. Let's take a brief look. 




The size is impressively small. If you are on the move the size and weight of items you care is critical. The specifications of this little jewel is 6.1” x 2” x 9.2” weighing only 4.6 pounds. On the Yaesu website they claim that the FT-857 is the world’s smallest HF/VHF/UHF transceiver! Think about the actual dimensions. This radio can easily fit into a backpack. Actually there are special radio backpacks designed exclusively for this radio. They have an antenna access port, battery compartment (some with a battery), and an accessory area for items such as an antenna tuner. 

This radio has a 200 channel memory bank that can be broken down into 10 memory groups and is capable of HF/6M/2M/70CM. Power output is rated up to 100 watts on HF, up to 50 watts on 2m, and 20 watts on 70cm. 

Keep in mind though that with any radio the weakest link is usually the antenna. There is no exception with this radio. It has an antenna connector for only a 50ohm system. The reciever is not as sensitive as Yaesu's top end gear however it will get the job done providing you have a decent well-tuned antenna system connected. (continued below...) 




Ham Radio transceivers are in the plenty category and the major manufacturers are trying to keep up with diversity of the hobby. The demand is currently in the digital arena and their focus is there. There aren't too many companies making true on-person lightweight rigs. But they are out there and many are a little pricey. 

If you are looking for the "box store radio" then put the FT-857D radio on your radar. It's a great little rig but it's not perfect. If you love experimentation and understanding the challenges there are some better options. The question is, are you up for the task.  Let me know what your experiences are with ultra-portable wide coverage multi-mode radios. 

Wednesday, May 4, 2016

J-Pole Antennas

In my last article about inefficient HT antennas I mentioned that a good gain for an HT should be 2 dB or higher. If this makes your eyebrows raise in question please read that article before ruling me out of presidential race. In this article I want to talk about an antenna that I frequently connect to my radio gear. It is called the J-Pole or J antenna. This is a very strange looking antenna but has some interesting performance characteristics. The following is one of the products that can be found at jpole-antenna.com.


I added the picture to be able to see what one looks like in it's most basic form. You can purchase these fairly cheaply (~$25) or even build one for yourself at rock bottom scrap prices. Actually it is more fun to build and you can learn a great deal in the process. I have used these for years and experienced some amazing results. (continued below...)





If you are using one of these for an HT you will have to mount or hang it at a stationary location and then run your coax cable to your HT and adapt to the antenna connector on the HT. There are many different types of J-Pole antenna designs as well as materials used to construct one. Some have had great success with ladder line. 

A few special notes about the J-pole antenna, depending on the construction materials, is they usually have a large bandwidth, a great radiation pattern for a vertical, and a gain ~2.5dB. It beats a quarter wave vertical antenna by a decent margin. In mounting the antenna you want to make sure it has no electrical connection to the object (mast, house, etc) it is mounted to.  It is best fed by a balun if coax is used otherwise a balanced feed line is acceptable. 

This is just a basic overview of the J-Pole. I will be adding construction tips soon. In the meantime, what have been your experiences with the J-Pole? 

Monday, May 2, 2016

Antenna Gains for Portable HT Radios

Antenna Gain is basically the antenna's ability to radiate energy in a particular direction. Portable HT radios have a small vertical antenna mounted to the case of the radio. Usually the manufacture's antenna has a mediocre gain or negative resulting in poor performance. This is not usually noticeable due to the fact that most people use these radios to hit line of sight repeaters for contact with others. If the operator wants to use this in a simplex mode then antenna gain becomes evident. (continued below...)




Keep in mind a vertical omnidirectional (radiating in all directions perpendicular to the antenna) is never as good as a directional antenna such as a Yagi (offering high gain in one direction). Most people want a small portable antenna that radiates in all directions with an HT radio. Therefore the operator usually accepts the compromise. However, I have to ask is a -5 dB gain worth that compromise? If your HT antenna is rated at -5dB gain and you are transmitting at 5 watts then your actual output is only 1 watt. While most HT antennas are not rated that bad they are still in a negative gain design.

There are aftermarket antennas that can offer a greater gain than what comes with the radio. Most of these antennas are 1/2 wavelength for 2 meters making them considerably longer than those that came with the rig. Most radios come with a 1/4 wave or less antenna. A gain that is considered good for an HT vertical is 2 or more dB. Many will disagree with the fact that 2 dB is good considering that a Yagi can easily, depending on the configuration, achieve 9 dB's or greater. However, if one understands that the factory antenna are usually a negative dB, then seeing a 2 dB gain is actually good.

Without a reflector and director it is difficult to increase the gain of a vertical to any major degree. Also keep in mind there is not a good ground plane when it comes to HT's, therefore you are off to a bad start. The first objective is to get the antenna to the best electrical radiating design for the frequency that you will transmit. In theory this would be 1 full wavelength. In the case of the 2 meter call frequency the length would be over 6 feet in length. How would you like to carry that on the top of your HT?  Just a note, using a vertical antenna in a full wavelength design would better be served as a loop. I won't get into the electrical aspects of that in this post. 

At the 2 meter call frequency on an HT, it would be better to reduce the antenna by 1/2 wavelength. This would make the length of the antenna to a little over 3' 2". This would be more manageable and still better than the factory antenna. This should give you a little to think about when trying to improve your radio. There are plenty of antenna options on the market that would improve the efficiency. Let me encourage you to experiment and work with others who have tried different antennas of their rigs.

Many companies offer different high gain options for your radio. Below are a few after market options for dual-band antennas.

Diamond Antenna Dual-Band HT Antennas SRHF40
Rated at 6 dB gain


Comet Antennas SMA-24 
Rated at 2.3 dB gain on 2 meter and 3.5 dB gain on 70cm

If you are looking for a new antenna for your HT then make sure it can handle the output power you want to transmit. You will also need to make sure it has the matching connector that mates to your transceiver.

The subjects of antenna design including antenna types, length, loading, material, thickness, and engineering is well beyond this article. However if you are interested in designing and experimenting then the reference you need is the Antenna Book published by the ARRL. It is not for the faint at heart but is an invaluable resource.

Let me encourage you not to look for the smallest antenna you can find to put on your radio. It won't give you the performance you desire and certainly won't be good for your radio.

What antennas have you found that works best for your HT?


Saturday, April 30, 2016

Operating Simplex FM

We have all listened to or participated in uhf or vhf Ham Radio nets. A common practice on a repeater net is to take mobile or portable check-in's toward the beginning of the net. This can be for any number of reasons but most specific is to allow people who have the potential of moving out of range to go first or to allow people who do not have sufficient power or antenna systems more time to relocate to make contact. (continued below...)




We depend on these nets to practice orderly and efficient relay of messages for future times of need. What we don't realize though is that many, if not most repeater sites are located in areas with smaller potential for power emergencies. Many of these areas are not prepared in the event power is not available for extended periods of time. Not to mention any weather related event could take the antenna system out of service. Then what would we do for local communication efforts?

Most Ham Radio operators do not practice simplex nets in the VHF or UHF bands. This takes a special skill and turns things around a little. I heard a couple of ham radio operators the other day joke at the fact that there were people who wanted to run UHF and VHF simplex nets. They said all repeater sites today have backup power systems and ham radio operators need to practice their nets on the repeaters. I must say these hams are misinformed. Besides, what is going to happen to their precious repeater when a major storm destroys the repeater antenna?

It is important to know the capabilities of your radio equipment if you have to operate in simplex mode. This is where you do not use a repeater and all transmit and receive is on the same frequency. You will find that the distance is much shorter.

If you are running a UHF or VHF simplex net call for the high power stations to check-in first. This will allow you to operate in a greater geographic area. The high power station may be able to relay traffic from a distant low power station. Utilization of relay stations is important on these types of nets.

The overall key is to practice in simplex mode. Know the range limitations of your equipment. Work on solutions to be able to relay messages across distances. This may require you practice with friends who are also preparing for communications disasters as well. You can even use HF operators to connect to distant stations and relay traffic to and from your VHF net. Explore the possibilities!

Have you operated in VHF or UHF nets? If so, I would like to hear about your experiences. 

Friday, April 29, 2016

External Power Sources for Portable Devices

Have you ever reached for your cellphone in an emergency situation to find out that it is dead? Believe it or not this happens more than you think. App updates on smartphone devices can increase battery drain. Being out of range of an active cellphone tower can drain your battery in a more rapid pace as it searches for available towers. Older phones do not retain their charge as long and sometimes we have used our devices much more than we thought. The result is a dead battery and no way to call or text.

Portable power has been an emerging solution for some time. Essentially most portable power packs are a rechargeable battery in a shiny case.  These portable power packs are usually charged by a USB cable connected to either a computer or a USB wall adapter. The charge time depends on the depletion of the pack and the battery size. (continued below...)




To charge a cellphone you usually need your charge cable that has your phone plug on one side and a USB connector on the other. Once you connect your phone to the power pack your phone will begin its charging process. Depending on the brand and capacity you may be able to use your phone while it is charging. 

Most battery packs allow for two or three charges before the pack has to be recharged itself. These are great tools and good to have in case of an emergency. Always have one or two of these fully charged in your go-bag.

Here are a few examples.

There are a few things to keep in mind when purchasing one of these packs. First notice the mAh rating. They can range from 2,000mAh to over 28,000mAh. The higher the rating the more charge it holds and the more recharges it can supply to your cellphone before recharging. For example, if you have an iPhone and a 2,000mAh rated battery you will not get much more than 1 charge out of the external battery. If you had a 28,000mAh rated battery you could probably charge the iPhone over 6 times before recharging.

Make sure your device can accept the voltage supplied by the pack, that it does not exceed the mAh rating of the battery, and will accept the connector type of the battery.

What has been your experience with rechargeable power packs?


Thursday, April 28, 2016

Traditional HT's Versus the Chinese Brands

There has been a large interest in the cheaper Chinese manufactured handy talkies. These new and quickly changing models seems to be more popular everyday. This has been primarily due to the low cost.  I do not blame anyone for giving these "cheaper" radios an eye in this day of rising costs and lower wages. Are these radios up to the task of being a great solution in the event of an emergency? (continued below...)


First, I want to say that any radio is better than no radio. I do not want to convey the message that people should not have one or two of these stored away in a faraday box or in a go-bag. I do however, want to caution the consumer to understand the functionality of these devices before throwing $60 or $80 for one to use as their primary radio. There are some limitations to these devices and you need to be informed before making your purchase. Think about the following items.

Many of these radios are virtually impossible to program by hand. It can be done, however it is not an easy task. Most people find the need to purchase a software program to aid in the programming. If this would be the case, you will need programming software and a programming cable. This is an additional cost. Another option of programming is to find a friend with the same model and clone their frequencies into your radio.

Because these items are difficult to manually program in the field without software you may find yourself struggling to program your radio if you are relocated in the event of an emergency. The frequencies needed may be different than those in your radio. If you do not have a way to easily program or clone it to new frequencies, then you may be stuck with the call frequency and a lucky hit on a repeater frequency.

In the early models of these radios there were numerous quality issues from software bugs to complete failures. For example, if you look across the Internet for problems with Baofeng, you will see many complaints with squelch, noise, and receiving issues. It appears the cheaper radios do not have the quality filters and receivers as some of the higher priced name brand competitor's products. Keep in mind as each new version of the radios is released many of these problems are corrected. As higher quality filters and receivers are added to these radios then the price will gradually climb.

If I was in the market for a new HT today that would be my primary radio, I would consider the following:

  • What radios are easily programmed by hand?
  • What radios have a strong receiver and good filters to protect against intermod? (In high RF areas this is a major problem)
  • How many bands do you want to RX/TX on the HT?
  • What output power do you want the radio capable of?
  • What features do you want in the radio? (dual watch, scan, cross band repeat, digital, APRS, etc.)
  • What are the Internet reviews of the models you are interested?
  • What is the quality of the customer service? (Try it our before you buy)
  • What is your budget?
Do your research and homework. You do not want to be a Ham Radio operator that wishes he or she would have bought a different radio in the event of an emergency. 

Don't forget you usually get what you pay for. 

Wednesday, April 27, 2016

How to Build A Faraday Cage

Faraday Cages are fairly easy to build and do not require a lot of material. Most people probably have most of the items lying around the garage or can obtain them at the surplus or hardware store. The idea of a faraday cage is relatively simple. Shield the object from electromagnetic energy with a metal cage or mesh. There should be minimal or no gaps and the object cannot touch the shielding that surrounds it. (continued below...)



Different items can be used for the metal shield. Some people have had success un using an ammo can while others have taken a cardboard box and lined it with multiple layers of heavy duty aluminum foil. Depending on what is used aluminized duct tape may also be needed. The following are only a few of may ways to build a faraday cage.

Metal Trash Can
Metal trash cans with metal lids are one option. The solid metal container not only provides a weather shield but also does well in protecting against a strong electromagnetic pulse. There are a couple of items to consider. First make sure the lid seals completely against the can itself. The better can and lid combos are the ones where the old overlaps the can. The concern is not air-tightness but rather to eliminate any major gaps in the container.  Second, make sure you line the interior with something like cardboard to create a gap between the metal and the items in the can. If the can is large enough you can put the items inside a cardboard box and set the box inside the can. Remember the protected items cannot touch the metal of the can.

Metal Lined Cardboard Box
Obtain a cardboard box the size necessary to store the items you wish to be protected. Any cardboard box can be used, but thick cardboard would be preferred. NOTE: The thickness of the cardboard does nothing to shield electromagnetic signals but rather offers a greater gap between the shield and the items you wish to protect. Remember the items inside the cage cannot make contact with the shield. Next, obtain a metal shielding material. The following are adequate items for the shield (pick one):

  • Heavy duty aluminum foil (need enough for three or more layers around the box)
  • Fine wire mesh
  • Reflective mylar from a cheap space blanket
If using aluminum foil, then wrap the outside of the cardboard box with three layers of the heavy duty material. Otherwise using the wire mesh or reflective mylar, completely enclose the outside of the box with the selected material. Make sure there are no gaps where the materials connect against each other. Also make sure the material holds to the cardboard. Insert any items into the box that needs protection. 

Ammo Can
Find an ammo can at a surplus store, gun show, or sporting goods store. Make sure the ammo can is metal. A plastic ammo can will do no good. Line the inside of the can with cardboard to insulate any device from touching the outside of the can. Place items that need protection inside the can. Obtain aluminized duct tape (or any conductive tape) and tape around the lid to conductively seal the can. 

Some people have said that a microwave oven can also make a good faraday cage. In theory this should work because the lining of the microwave is designed to keep harmful radio waves from exiting the unit when it is in operation. The same lining should help protect sensitive equipment from outside electromagnetic energy. However some have reported their testing of microwave ovens did not perform as expected. Note that the microwave oven is designed to shield the energy produced by the magnetron at its frequency of operation. Also assume the quality of some ovens may be in question. Therefore don't stand too close when nuking your leftovers.

If possible, ground your faraday cage by attaching a conductive wire from the box/cage/can to a ground rod in the ground. This does not aid in shielding your equipment but it does help in making the box safe. If an EMP occurred and the box was not grounded it is possible that the box become energized with no way of escape. This energy could be transferred to you by making contact with the cage soon after the event. 

The success of the faraday cage depends on a number of things. The following checklist of questions is important: 
  • Is the cage well sealed with little or no metal gaps? 
  • If using aluminum foil, are there sufficient layers of foil on the box?
  • Is the equipment to be protected isolated from touching the metal of the cage? 
  • Is the box grounded for safety?
If you have assembled your box you can test basic functionality by putting a small radio inside the box. Make sure the radio is on and the volume turned up. Sealing it inside the box should cause the radio lose signal. This is a basic test and not all inclusive. Keep in mind that a faraday cage will not remove all frequencies and therefore is not the perfect solution in all applications. But it can help protect against certain wavelengths of electromagnetic energy. 

Another factor that would determine success of the faraday box is the power of the EMP and the distance from detonation to the faraday cage. Too close and you won't have to worry about it. 

Have fun!


Tuesday, April 26, 2016

Cell Phones in a Disaster

The question comes up all of the time. Are cell phones a good solution for communications in a disaster? The short answer is don't count on it. Cell phones do have a few characterizes that are admirable however their reliance on an operating tower in the vicinity makes them a very poor solution.

Cell phones typically have a range of no more than 45 miles. In many cases their range can be as small as 25 miles. They have to be within that distance of an operating cell phone tower. This may not be a problem in a metropolitan area but rural areas may have few options for nearby access. Cell phones are dependent on the tower itself. If the tower(s) cease to operate there will be no service and your cellphone is not much more than a glorified pocket camera. (continued below...)



In an actual disaster towers that do remain active will soon become clogged. Everyone will have the same idea and attempt to locate the ones they love. This situation could possibly shut the system down within minutes. In a clogged system the best possibility to relay a message to another person by cell phone is a text message. A standard SMS (not iMessage) has the best chance to reach the recipient. The small footprint size of text can "sometimes" make its way through a congested cell phone system. 

Keep in mind disasters can also take down the power grid. Most cell phones consume a large amount of power and must be recharged every day or two. Without connectivity to a cell phone tower the cellphone goes into search and acquire mode. This is where the cellphone is "seeking" an active tower. Typically this draws much more power and can reduce the cellphone battery operating time in half. 

For the category of dependable communications in the event of an emergency mark cell phones off your list. It can be a hit and miss depending on the circumstances. Their possibility of usefulness is better only at the beginnings of a disaster while the network isn't clogged, towers are still up, and there is enough electricity to operate the device.

There are better options. Keep tuned in for more. 

Monday, April 25, 2016

The Possibility of an EMP

EMP stands for Electromagnetic Pulse. It is created as a result of a nuclear explosion or a non-nuclear e-bomb. The result of an EMP is an overload of electrical systems and electronic devices. These systems and devices usually do not survive an EMP. Circuits and systems must be replaced with new unaffected electronics and this can take some time. The result of an area that has been hit by an EMP looks like the stone age with little or no electrical or electronic capacity. (continued below...)



Recently some stories (WND) have surfaced claiming that North Korea has two nuclear satellites orbiting above the United States. The report states that these satellites have the potential of creating an EMP above the Earth's surface. Whether or not this is true, the subject of EMP's is something to take into consideration. EMP's can disrupt the normal operation of society. Without electricity there will be no trips to the grocery store, no evening meals at the Cracker Barrel, no running water, and no watching Survivor on Wednesday nights. This is a worst case scenario.

Electronic damage from EMP's is certainly a high risk as a pulse of electromagnetic energy can enter into any electrically connected item. EMP's can also damage any item that the pulse can reach by conductivity. It would be the same way as receiving a radio signal through an antenna. If the electromagnetic pulse can propagate into an electronic circuit by over the air conductivity the circuit can be damaged. Scientific test have proven radios with antennas longer than 30" are very suseptible to EMP's.

Many online theories take the damage created by EMP's much further than the evidence supports. So be careful what you read in the area of damage possibilities. For instance some say that an EMP will disable all automobile transportation. While an EMP can certainly damage the electronics in cars it really depends on the age and design of the automobile. Newer cars with fiberglass or plastic bodies are much more susceptible to damage because of their dense electronic control and lack of adequate shielding. Older cars with strong metal bodies and minimal electronics are at a much lower risk of damage. Maybe the used car lot is looking better all of the time.

Protection against EMP's are something the United States Deaprtment of Defense is actively testing. It is known that a sealed metal barrier is effective in protecting against EMP energy whereas wood, plastic, or fiberous materials offers little little or no protection. Ham Radio groups have trained in building what is known as a Faraday box for protecting valuable Ham Radio gear. Soon you will find detailed instructions for building a Faraday box on CrashComms.com.

There are a lot of myths concerning EMP's. The best thing to do is research and understand how an EMP can effect you .

Sunday, April 24, 2016

Crash Comms

Tornados, hurricanes, earthquakes, solar storms, terrorism, power grid failures, or any catastrophic event can cause mass communication failures. All of these can occur without warning and put you and your family in the dark when it comes to contacting loved ones or getting the pulse of society around you. 

Imagine not being able to locate your kids. You last saw them when they grabbed their bags and ran out the door for school. A major catastrophic event occurred and there is no cell phone service. Land lines are down and traffic is at a standstill because of the panic in the area. What is the plan to determine the safety of your family? What is the plan to reconnect in person? 

Do you have a plan for your family in case the inevitable occurs? This site will begin to cover the necessities and the options for communication and safety. We live in a changing time and we must be prepared. In the days to come this site will begin to fill with information to aid you and your family. Check back frequently for more updates and information. 

In the meantime sign up for our newsletter. We will keep you updated.