• Win a Free Scanner!
• Spurious Emissions
• Archives Now 30 Days
• New Hear from Here
• Gray Hamfest
• JMH MotoTRBO
• Feed Stats
• Chapter 21 Answers

Most of our efforts this month have been on solving our Unknowns Database.

Check out the Radio PhoneBook (link at bottom) for more.

Scanner Giveaway/ Drawing

	We're giving away a new Radio Shack Pro-404, 200 channel handheld scanner to one lucky winner. Those that sign up for a chance to win will also receive a coupon for use at our local (Abingdon, VA) Radio Shack!
To sign up for a chance to win please follow the link on our homepage at http://www.scannerfood.com No Purchase Required to win. Contest Guidelines Frequency Coverage: 28-54,108-136.9916, 137-174, 406-512 See the complete specifications at RadioReference.com Drawing date to be announced in next month's newsletter, Stay Tuned!

Spurious Emissions Washington County, VA's Public Safety repeater atop Brumley Mountain has recently begun emitting a spurious emission or suspected harmonic above and below its intended frequency of 155.490. We were surprised to find this at distance away from the transmitter as far away as one of our frequent monitoring locations in Northeast Tennessee. The bottom spur extends the strongest from 155.345 to 155.375 while the top 155.610 to 155.640 We independently tested to ensure we were not experiencing degraded selectivity on our receivers. We sent word to the appropriate county official about this issue and wish them a speedy fix! Spurious emissions are usually eliminated by using tuned cavities that only allow certain frequencies to pass, repeater operators may sometimes refer to these as "cans". These types of cavities may also be used so that one antenna can even be used simultaneously for transmit and receive; this configuration is called a "duplexer". One cavity will be used to "reject" while another is used to "pass" certain frequencies. When used in a duplexer configuration, a configuration of four "cans" is typically used. Cavities may also be used alone when a separate antenna for transmitting and receiving is used to limit emissions in and out to the intended frequency. This is critical on the receiver as nearby transmitters can desensitize the receiver with adjacent signals. Having only your frequency on the output has the same quantifying affect as it is usually the closest transmitter to your receiver. Cell sites in particular use cavities to transmit the slew of frequencies through a few antennas at the top of the tower. Rejection Cavities In the example on the right, a combination of reject and pass cavities limit and mix the two frequencies so one antenna can be used. A prevents the transmitter from transmitting from anything other than its intended frequency; B specially prevents the received frequency in or out. C and D work the same way limiting the receiving frequency to the intended frequency only. The importance of operational A and B not only affect the performance of the receiver but prevent spurious emissions to other nearby systems by keeping only the intended frequency from being emitted. Combiners allow one antenna for multiple transmitters. Rejection cavities block the transmitting frequencies only, additionally tuned cavities may be used so that frequencies other that the transmitter are also blocked. A multicoupler allows multiple receivers to use one antenna by preventing any interference from the receiver from feeding into the other receiver inputs.   These are just some simple illustrations as repeater systems can be very complicated including additional filters and cavities, however each additional component adds loss to the system just like a long section of coaxial cable.

If you've ever subscribed through Radio Reference.com to listen to our feeds' archives or any of the nation's other feeds you'll be
pleased to know that archives have been increased from 15 to 30 days.

If you would like to be able to go back and reference archived information, sign up for an account at RadioReference.com
and subscribe to the premium service. This is great to find out "what happened" when you miss it live.

Premium Subscription Information Page

Gray, TN Hamfest

The Gray Hamfest is Saturday October 15th at the Appalachian Fair Grounds.
http://www.grayhamfesttn.org

Tickets: $6 (at gate)
Youth: 12 years of age and under are free
Hours: 08:00 to 14:30
Talk-in: 145.290 MHz [PL=103.5] or 146.520 MHz (Simplex)

They are giving away an Icom IC-7000 HF rig, several Woxun HT's and a bunch of other great prizes.

There will be a VE testing session at the nearby Gray Methodist Church, see http://www.grayhamfesttn.org/vetesting.htm for more details. It's a great time to get started in Amateur Radio!

JMH new MotoTRBO System

Johnston Memorial Hospital has requested a modification to their FCC license WNCA503 to incorporate a four+ channel MotoTRBO repeater system for use at the new hospital just outside Abingdon, VA.

Unfortunately, this type of system cannot be received with any scanner.

Each MotoTRBO repeater can support up to two user talkgroups simultaneously, thus the system capacity could be as many as four channels repeated and several simplex talkgroups/channels if desired. The old analog system 453.025 was not updated on the license to be used at the new location. The town of Abingdon is no stranger to MotoTRBO with its Police, Fire, Parks/Recs, Street Department, and Schools all on MotoTRBO systems.

New Hear from Here

We completed a two week analysis of what you can hear from Bristol, VA.
This is the byproduct of unknowns research, and very useful in its own self!
If anyone ever tells you there's nothing to listen to in Bristol, prove them wrong, there's plenty!

Take a look our research file for the project and a peek inside it's multi-step process.

Have a Uniden scanner with "search and store" capability? Contact us and we'll walk you through
documenting your area, you never know you may become our newest frequency sleuth!

Fall Fire Season

Fall fire season is here... not only does burning leaves start wildfires but careless smoking and campfires fuel a majority of these potential killers. Practice safe burning and obey your local burning restrictions, there're there for a reason.

There’s also another danger we seldom remember, house fires. Every year when the first cold weather hits the region there are dozens of house fires due to dirty furnaces and flammable objects touching baseboard and wallboard heaters. The sad reality is no matter how much we educate and prepare there is always the statistic. Do your part to keep yourself and your family safe.

It doesn’t hurt to keep an ear on the scanner too, wildfire information can be the difference between life and death and knowing the extent of a neighborhood fire can not only keep you safe but alert you to a neighbors crisis and start the flow of goodwill. With the downturned economy a house fire hurts everyone more than ever. And finally, please don't interfere with any firefighting operations, let the experts do their job.

Feed Stats courtesy of radioreference.com

For select recordings see the Media Section.


Wide Area Feed


Washington County, VA

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 has 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 want 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 Chapters 10-12 Test Chapters 13-14 Test Chapter 15 Test Chapter 16-17 Test Chapter 18 Test Chapter 19 Test Chapter 20 Test Chapter 21 Test Answers to follow in each new newsletter
Answers to chapters 1-6 HERE Answers to chapters 7-9 HERE Answers to chapters 10-12 HERE Answers to chapters 13-14 HERE Answers to chapter 15 HERE Answers to chapter 16-17 HERE Answers to chapter 18 HERE Answers to chapter 19 HERE Answers to chapter 20 HERE Answers to chapter 21 HERE

General Area Covered