• New Weather Radio Station
• New Unknowns
• Smyth County Update
• Live Feed Hum Fix
• Abingdon Digital
• Homemade 450 MHz Yagi
• Chapter 7-9 Test

That's just a few, check out the Radio Phonebook (Link at the end of newsletter)

New Noaa Weather Radio Transmitter The National Weather Service is now transmitting a new Noaa Weather Radio station, callsign WZ2500 from atop Sand Mountain in Wytheville, VA. Operating on a frequency of 162.450 MHz with a WRG300 transmitter emitting 300 watts of power. The station officially began broadcasting on June 26th at about 3 PM becoming the tenth station to operate in Virginia. The new transmitter gives much needed coverage to residents of the New River Valley. Assigned, this is latest in a series of grant provided build-outs across the country by the USDA's Rural Development Telecommunication Project. Grant money from the USDA alone totaled $48,800 and paid for the transmitter, antenna, and backup generator. The station didn't go on the air without problems. After its initial testing began in May, interference issues with a local fire department repeater caused some initial hiccups. With those problems resolved we are pleased to have reliable reception in the more rugged parts of northern Grayson County. USDA's Grant Program - http://www.usda.gov/rus/telecom/weather/weatherradio.htm The National Weather Service in Blacksburg Virginia welcomes comments by calling 540-552-0084 or via email to RNK.SKYWARN@NOAA.GOV WZ2500's Coverage Map

The Wide Area feed has been experiencing an increasingly annoying AC hum. Recently, we corrected this issue and made some enhancements to the lightning protection systems. Having anything plugged up in a raging lightning storm is asking for trouble, however when it's a live feed, that's it's most important time to stay on the air.





See if you can hear the difference

http://live.scannerfood.com

Wide Area feed Schematic (updated)

Ground Loop Isolator

Abingdon, VA Digital License Updates

WPBU769

The above callsign has an ammendum attached requesting the FCC grant the below new frequencies for use on the town's new MotoTRBO system. Two simplex channel designations have been heard "Police Tac 1", and "Fire Tac 1" both apparently using 153.9725 listed for mobile use.
While MotoTRBO cannot be decoded with your typical scanner, digital speech decoding software and a simple but tedious modification to your scanner can make it possible. We'll have more on this procedure in a future newsletter.

Homemade $15.00 450 MHz Yagi (~ 10dB Gain)

Remember the higher the frequency the more difficult it becomes to get the signal from the antenna to the receiver. In our case we needed something with more gain for the UHF business and public safety band.
With a lot of your unknowns being in this range, a directional antenna is just what we need.
Commercially available Yagi's in this range vary from $40 to over a hundred bucks!
With ten foot of the copper tubing costing less than nine dollars and already having everything else we needed this should be an easy build. Here are some tips.

Having a drill press makes drilling the holes much easier, also the use of a vice would make the process much easier...hrm maybe I need Santa to bring me a nice one. First, I measured out the hole placement and since I had enough tubing I decided to make it a 7 element. The number of director elements only increases gain and boom weight! If you decide to get exotic and have lots of elements don't over stress your boom, they can get heavy with lots of elements. Since I didn't have a vice I drilled the first hole (this would be the director element). I left enough room on the end to attach the mounting bracket or to leave room to use a handle for handheld use. I then inserted a 5/16'' wooden dowel I had to use a guide for drilling the remaining holes straight.

Directors and Reflector
I Drilled the holes and cut my tubing with a pipe cutter, its convenient to straighten the tubing as your cutting versus waiting till after its cut. Remember you can always fine tune it after its assembled since the copper tubing is flexible. Using some Q-Tips I moistened the inside of the holes and then used my 5/16" dowel to slap on Gorilla Glue. Inserted each piece of copper tubing until centered. Using the glue dowel I marked center to make measuring each side of the boom easier.
Driven Element
The driven element is basically a director cut in half, each end has a plastic dry-wall expanding plus slipped inside the copper tubing. This is to insulate either side from making contact once both have been slipped inside the dowel rod as pictured below. It's important to not increase the length of the driven elements more than a few millimeters, if they are longer than the reflector the antenna looses its ability to be directional. The directors and reflector are solid lengths all the way through the boom.

Dry-wall Hanger Plug

Driven Element Electrical
We don't plan on using this antenna for transmitting so the SWR (standing wave ratio) is not really a big concern, neither is matching the antenna. While this can increase reception capabilities we simply are attaching the shield and center of the coax to each end of the driven elements respectively. While copper tubing can be fun to solder to, 1/4" is usually managable with a very hot iron. Drilling a very small hole in the element just a few cm out from the blue plugs above make soldering the coax leads much easier. To finish things up we drilled an additional hole in the boom before soldering the leads to route the coax back through the boom for strength. We also used some heat shrink tubing and glue to further the reinforcements. While the elements are not perfectly straight it'll do for now, when I get a feeling of OCD'ness Ill have it perfect.

Click for larger

Recommended Reading Two- Way Radios and Scanners for Dummies ISBN: 978-0764595820 Perfect for anyone new to the hobby and an excellent refresher for us that have become a little rusty. This is the most up to date publication that effectively covers multiple radio services available. I have been mentoring someone new to the scanner hobby and provided a little reinforcement. If you're wanting to test your skills, here are some sample tests I quickly drew up to make the subject matter a little more intensive. Chapters 1-6 Test Chapters 7-9 Test Answers to chapters 1-6 HERE Answers to follow in each new newsletter

General Area Covered