Monday, May 23, 2016

Back Country Communications

I work in rural EMS, and the counties I serve are quite diverse in landscape. I am frequently dispatched to areas poorly served by cell towers and radio repeaters, creating significant communications difficulties. Because of this I have begun carrying a bag of communications gear, the contents of which I will share with you today:

1) Baofeng UV-82 Radio:


They have other colors if you click around. The UV-82 pictured on the left is a 5 watt version with a price that hovers around $30, and the UV-82 pictured on the right is the 7 watt version with a price that hovers around double what you pay for 5 watts. I own both models and both work great. I started carrying the UV-82 5 watt model as my work radio last September, and it has withstood plenty of 3-4' falls out of the truck onto concrete, getting splashed with IV fluid, and all of the other abuse I normally impose upon my equipment. One of the local fire departments owns a few baofengs for use in their burn trailer, and I am told that those will not die either. You really get more than you pay for with these radios.

Both are dual band, covering the common VHF and UHF spectrum used by emergency services. They also cover some ham bands, the weather bands, and the FM music radio bands. The flashlight on the top looks gimmicky but in practice it has been a nice convenience when I forget my real flashlight. Some areas of great pomp and wealth are converting to the inferior 700mhz system for some stupid reason, which is not compatible with these radios. Why are they converting to a frequency that works worse and costs more than the one they had before? I don't know...

2) Programming Cable:

The above linked programming cable appears to ship from within the USA, so you don't have to wait for a month and a half for it to come from China. Although you can field program the Baofeng without too much trouble, the programming cable is really nice to have around. Don't use the disk that it comes with; download chirp from danplanet. Don't be discouraged figuring the program out. It looks intimidating but keep at it. Feel free to email me if you need some pointers: drew.rinella [@]

3) Better Antenna:

The stock antenna works fine. This telescoping antenna works great. Next to a slim jim it is probably the best antenna upgrade you can get. 

I also carry a small slim jim that I got off ebay, but slim jims are obnoxious if you just want a quick performance increase. 

4) Spare battery, battery clamshell, and battery eliminator:


Having a spare battery is a no-brainer. Having a spare battery clamshell that takes AAAs is genius! When using the AAA clamshell, I've found that alkaline batteries die within a couple hours, while NiMH batteries last just as long as the regular spare battery. This is because the impedance of alkaline batteries increases as they drain, while NiMH battery's impedance remains low. 

A battery eliminator is nice to have in the truck or ATV. This allows you to plug your radio directly in to the DC cigarette lighter system of your vehicle so you're not constantly having to change out dead rechargeable batteries.

5) Rechargeable AAA batteries, battery pack/charger, solar panel:


With this setup I can power my radios indefinitely.

Eneloop NiMH batteries are advertised to retain 70% of their charge after a decade of shelf storage, which is remarkable for a NiMH battery since they are known for high rates of self discharge. In practice they have performed well. The PortaPow battery charger also doubles as a battery pack power source at the push of a button, eliminating the need to carry two devices.

I own the X-Dragon solar panel shown on the left and it charges batteries great, and will charge any USB device including your cell phone. However I just found the Sunkingdom panel pictured on the right, and it looks about $20 cheaper for the same advertised wattage output. I can't speak to how well that one works but the price looks unbeatable. If anyone reading this buys that panel, please post a comment here with how well it works. 

6) Further considerations:

Voice communications work fine in line of sight, or close to it, within the public safety bands. Digital works even better.

A couple months ago I was playing around at the dining room table at work, sending digital signals to my buddy in the kitchen, and suddenly I got a text from my wife who had received the digital signals... 13 miles away.

Consider that... inside a building, stock antenna, 13 miles.. on a 5 watt portable! I have been able to repeat that result on many occasions. If there is a disaster while I'm on duty that compromises or overloads the cell towers, I can still contact my family at home to make sure they're safe before continuing on with my duties. 

But, digital communication is a slightly more complicated subject and I think I've reached the end of my writing attention span for today. Stay tuned for part II of back country communications coming soon.

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