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?