Recently in Radios & Communications Gear Category

I'm not used to sitting back seat in a small plane. Tonight I did sit backseat, during someone else's instrument training (missed approaches, VOR/RNAV/GPS approaches, etc.) and found I learned an incredible amount about instrument flying that is sometimes hard to absorb when you are in the hot seat (as I usually am).

I took the opportunity in the back seat to watch the plane's altimeter over the PIC's shoulder as I correllated it with altitude readings I was taking with the SU-1 barometer modification on my Yaesu VX-5R handheld HT. At 4000 and 5000 feet altitudes in the San Francisco Bay area, over 2 hours of flying with reported surface barometric pressures of between 29.94 and 29.98 inches of mercury, without calibration, I was getting agreement ranging from 0 to 200 feet. It'll be interesting to see how much better the agreement is after I RTFM and do a pre-flight calibration.

My pilot friend David recommended this colossal collection of aviation-related essays by Gene Whitt.

If you only encrypt important things, even without decrypting the message the simple fact it's encrypted means its important. This is information that you have given freely to whomever it is that is watching: "Pay Attention, This One Is Important."

I cannot stop the buggers from knowing everything about me if they decide I'm a target. But I can throw chaff. Encrypt everything.

As PGP's developer Phil Zimmerman said, "PGP is for small secrets."

Curt Howland

Recommended by Monica White: the blog "Bizarre Science."

A couple of weeks ago, my friend Steve Pegram passed along a detailed and fascinating online version of a military report generated last summer, "SOLDIER WEAPONS ASSESSMENT TEAM REPORT 6-03". Much of the report is rather dry, given the nature of such a document, but scattered throughout are a great many little observational gems such as this:

...soldiers rank reliability and durability as key weapon characteristics and are not willing to trade them for anything – to include weight. Similarly, soldiers do not consider the weapon as part of their load, but rather as an enabler. They are willing to carry the weight if the weapon or device increases his lethality. This is best illustrated by soldiers purchasing their own magnified optics and the strong desire to carry an additional sidearm or shotgun for defensive and offensive purposes. Lethality is more important to the soldier than any other consideration or factor.

Here's empirical verification of the usefulness of white lights in combat, a point which I've had driven home by anecdotes from trainers at every school I've attended:

Several soldiers were observed with flashlights taped to their weapons and some using the Weapon Flashlight Mount. But all soldiers described using the tactical light for temporary target incapacitation.

Abolishing the FCC does not mean airwave anarchy. What it means is returning to bottom-up law rather than the top-down process that has characterized telecommunications for the last 80 years...

...If the FCC had been in charge of overseeing the Internet, we'd likely be waiting for the Mosaic Web browser to receive preliminary approval from the Wireline Competition Bureau.

Declan McCullagh (cited by Anton)

I remember the odious BBC television licensing fee from my days in London long ago, but had thought the fee had been repealed. Not so, reports UK-resident Australian Monica White:

For those of you who don’t live in the UK, you may be interested in the phenomenon that is the TV License – I was truly surprised by it a year ago. Essentially, if you have a TV or receiving equipment, you are obliged to pay the government £121 per year to view the BBC channels.

Don’t watch the BBC? I’m afraid that TV Licensing doesn’t believe you. EVERYONE who owns an operational set must watch the BBC. They're compelled to. There’s something in the water.

TV Licensing ‘Enquiry Officers’ also seem to get a hoot out of slapping £1000 fines onto anyone within spitting distance.

This was snapped a few days ago on the way up through northern California on the way to Oregon. In the background is the beautiful, 14,162 foot, potentially deadly volcano people around here call "Mt. Shasta". I have some of these shots from the way out to Oregon, and some taken under snowy conditions on the way back to California, taken yesterday on New Year's Eve... maybe I'll post them sometime, entitled "Thirty-Six Views of Mt. Shasta" under the artist name "The Cowboy Hokusai". Or maybe not.

In the lower right hand corner, in the foreground, is my trusty Valentine One radar and laser detector. Excepting a year I spent in Japan, I've used this thing in three different vehicles - and numerous rental cars - for five years, and am incredibly happy with it. I spent about $450 for it and its accessories, but I'm sure I've saved several times that price in speeding tickets I didn't receive.

It's great to get feedback on one's blog postings, especially when it results in the personal discovery of a great resource. Blog commenter Ricky James runs the compendious and incredibly interesting SciScoop: Exploring Tomorrow, which I strongly recommend telling all your friends about. So much to explore!

Thanks to my friend Steve Pegram for passing along this incredibly interesting thread on the AR15.com Forums: "USMC after-action gear assessment". Pay particular attention to the reports on the adequacy of 5.56mm vs 7.62mm carbine/rifle ammunition, and the spectacular satisfaction of operators with their M16 & (especially) M4 carbines.

Especially interesting is a point I've known all along: a lot of issue military gear quickly gets replaced with individually selected commercial "sporting goods" equivalents, e.g. Panoptx goggles replacing the awful issue crap.

Another interesting point: the M9 pistol still sucks. It should be replaced with the Glock or whatever the individual soldier wishes to otherwise carry.

You can't have your cake and eat it too; either the Net is a business and you pay for routable IP space, or it's a communist free love fuck fest, and it's your god-given right to have portable routable IP space.

Jeremy Porter

Daniel J. Boone reports on another reason why, as a lawyer, he isn't a member of the ABA: this pile of festering compost, a recommendation to regulate what they call "pirate" WiFi.

Forwarded with permission by Steve Pegram on behalf of a friend of his, who has asked to remain anonymous. - ed

"Go here and download USAPhotoMaps.

It is free and is one of the absolutely slickest little GPS map display programs I have come across. It does NOT have a lot of features (like route planning or any of those fancy functions) but it will give you a taste of what is possible and you will see what satellite imagery maps look like and you can also display USGS topo maps of your chosen area. What it does is download aerial photos (satellite imagery) and USGS topo maps from Terraserver and creates a scrollable, zoomable, GPS enabled moving map with your position located by a dot in the center of the screen.

Find out what your GPS coordinates are and load them into the set-up screen. On command, (if you are connected to the internet) the screen will automatically download and fill up with your choice of A) 1-meter satellite imagery or B) USGS topo map imagery centered on the coordinates you entered. Once downloaded, you can instantly swap out the overlayed satellite imagery with the topo map.

You do NOT need a GPS receiver to make this work. Also, even on a dial-up internet access, the process is not too painful if you are not too greedy and try to slurp up too big of an area. You can shut off the download anytime you like just by clicking on STOP DOWNLOADING.

Again, this is one of the slickest, cutest and easiest to use GPS moving map display software programs I have yet come across and best of all it is FREE.

Daniel J. Boone writes about a site I wish I'd paid attention to earlier: Doing Freedom. Talk about some controversial articles: take "Improvised Claymores" as a good example!

[PREVIOUS INSTALLMENT]

Penetration and blocking of radio waves

Radio waves are attenuated by almost all objects they pass through, e.g. air, people, trees, buildings and the ground. Dense objects such as earth or metals block radio waves very well. Only a few feet of either can make radio communications impossible. However, radio waves also bounce off objects, and this effect can be used to allow communications around corners and inside otherwise impenetrable objects such as steel buildings. Higher frequencies tend to bounce and penetrate more, thus UHF radios are the most suited for work inside buildings and cities. There is a practical limit to this however, and beyond 400-500 MHz the penetration of radio waves starts to fall off again.

[PREVIOUS INSTALLMENT]

Polarization

Radio waves have an orientation, usually vertical or horizontal. Note how external TV antennas have all their elements lined up in a flat fashion (horizontal polarization), while CB and two-way radio antennas point straight up (vertical polarization). Having the polarization different between antennas can cause significant signal loss, thus it is important to always mount antennas in the same direction (vertical for most two-way radio applications).

My thanks to friend Steve Pegram for pointing me to the Geocaching website. It looks like great fun, and an excellent way to learn and hone GPS land navigation skills. I might jump into the game myself sometime soon...

[PREVIOUS INSTALLMENT]

Gain

In radio terms, gain means multiplication. Gain is used with respect to amplifiers and antennas. Amplifiers obviously have signal gain, as that is their purpose. Antennas can also have gain. They accomplish this by focusing the energy supplied to them into a beam. Antenna gain works in both directions, transmit and receive. Gain is specified in dB units. dB units are a logarithmic measure, which means that the gain increases at an ever-faster rate for a constant change in numbers. Some simple rules to follow if you don’t understand what logarithmic means are as follows:

[PREVIOUS INSTALLMENT]

Power

Transmitter power output is the amount of energy that is sent to the antenna. Power is measured in Watts, just like electrical appliances. However the antenna can affect how much of this power actually gets sent into the air. Some antennas absorb or reflect large amounts of power (up to 90% in some cases) back to the transmitter. Such poorly performing antennas are usually seen at lower frequencies when size of the antenna is more important than efficiency.

"Made for the ultimate outdoor enthusiast, Garmin's Rino 120 features the latest GPS technology, both FRS and GMRS 2-way radio frequencies, patented technology, a built-in basemap of North and South America, 8 MB of memory and much more."

I've been seeing the Garmin Rino 120 GPS Unit and 2-Way Radio advertised in some of the outdoors magazines I read, and am pretty impressed.

I've not gotten my hands on one, but the screenshots and list of features are mouth-watering, e.g.

• Voice scrambler for secure communications
  
• Vibration mode for "silent" calls to other Rino users
  
• Patented Peer-to-Peer Positioning lets you send your exact location to another Rino user within a 2-mile range
  
• Clear reception with a range of up to 2 miles using FRS, 5 miles with GMRS
  
• Each channel has 38 sub-audible squelch codes for semi-private conversations
  

I've not read the specs on the actual implementation of the claimed security features, but they're certainly worth investigating. If any readers have tried a Rino, please feel free to add your comments.

Oh, and do check out the Tactical Radio Communications series we've begun to syndicate on this website.

[PREVIOUS INSTALLMENT]

Mode

There are two main methods of sending information (in this case your voice) over radio waves. Amplitude modulation (AM) and frequency modulation (FM). AM is the older of the two methods, and transmits a voice by varying the power output of the transmitter in proportion to the loudness of the audio. Dead silence means the transmitter produces no power. As the audio becomes louder the power output of the transmitter increases. The transmitter and receiver can be fairly simple in design. AM has one major drawback: any interference on the same frequency is simply mixed into the desired signal. This makes AM very susceptible to lightning, atmospheric noise and any other transmitters in the area. Another drawback of AM transmitters is that they require special ‘linear’ amplifiers, which are not very power efficient.

[PREVIOUS INSTALLMENT]

Frequency

Radio waves behave differently at different frequencies. The radio spectrum is broken into bands, usually by segments that have similar behavior, and sometimes by type of service (such as Short Wave, AM, FM and TV). The lowest range commonly used is the AM Broadcast band (0.5-1.3MHz). Next is HF (1 to 30 MHz), this band includes short wave radio. VHF-Low (30-50MHz), FM (88-108MHz), VHF (109-172), UHF (400-512MHz), Cellular and Paging (800-950MHz). Frequencies above 1000MHz (1GHz) are called microwave as the behavior of radio waves above this region changes significantly.

You will notice there are several large gaps between the bands listed. The military or TV stations use frequencies in these gaps. Some general characteristics that change with frequency are as follows. Distance traveled: the lower the frequency, the farther a radio wave will travel. Penetration of structures (due to bouncing and scattering) gets better as the frequency goes up. Antenna size becomes smaller as frequency increases. Another characteristic affected by frequency is node size. Nodes are areas where the signal dramatically changes strength over a very short distance. This is caused by two different reflections of the same signal meeting at the same place and canceling each other. You can see this by moving a portable FM radio tuned to a weak signal. You will notice that the signal comes and goes every few feet. What you are seeing are nodes.

A few days ago, I mentioned that I'd be running a serialized version of the forthcoming book "Tactical Radio Communications" by my engineer friend Eric Cartman. Below is the first installment. Readers' feedback, as we post these, would be most welcome. - Editor

Introduction

"Radios can be a very effective tactical or strategic tool. One can coordinate and deploy groups of people, perform surveillance, summon help and keep in touch with others over long distances when other forms of communications are unavailable. However, if used unwisely, a radio can be a security breach, a tactical disaster waiting to happen and even a beacon the enemy uses to discover your location.

Currently available radio equipment runs the gamut of size, power output, frequency, features and cost. Everything from a 50 dollar hand held radio from Radio Shack to a 5000 dollar all band all mode transceiver with 1000 Watts of power can be yours. The introduction of unlicensed FRS (Family Service Radio) has led to an explosion of cheap hand held radios sold in any sporting goods store or catalog. Although these radios at first appear to be a great step forward from the old CB radio, there are several reasons you should avoid them.

To make a reasonable decision on what equipment to buy, you need to understand the basics of how radios and radio waves work. We won’t cover the theory of how radio works in great detail, as this is not really relevant to buying and using a radio. Rather we will cover the behavior of radios and radio waves as they relate to the real world of the radio user.

An engineer friend of mine who's working on a book on tactical radio communications has offered to run large parts of it here on Survival Arts. There's so much material, I'll be breaking it up on a near-daily basis over the course of several weeks.

Radios can be a very effective tactical or strategic tool. One can coordinate and deploy groups of people, perform surveillance, summon help and keep in touch with others over long distances when other forms of communications are unavailable. However, if used unwisely, a radio can be a security breach, a tactical disaster waiting to happen and even a beacon the enemy uses to discover your location.

Stay tuned.