New User Profile, Shack Photos and Amateur Radio Features Released

Recently, we released these new Amateur Radio related features to the community:

• Amateur Radio Callsign lookup and search support, prepopulated with all US Amateur Radio call signs and updated weekly
• Amateur radio operators now have a new badge identifying them as Amateur Radio Operators in the forums

Additionally, we released these new features for all of our registered members on the site:

• Members can upload up to 5 photos of their radio shack / desk / mobile setup to be displayed in their user profile
• Members can add a short biography about themselves to be displayed in their user profile
• Members can upload a profile picture that is displayed on your user profile page
• Members whose username is their Amateur Radio callsign automatically have their callsign information linked to their profile
• Members may manually link their Amateur Radio callsign to their profile if their username is different from their callsign

To get started with the shack photos feature, head on over to your account page and click the "Shack" tab.

• Your Account - Shack

To get started with the biography and user profile picture features, head on over to your account page and click the "Bio" tab.

• Your Account - Bio

To get started using the Amateur Radio callsign lookup and search features, click the "Databases" drop down menu item at the top of the page, then click the "Amateur Radio Database" entry.

• Amateur Radio Callsign Database

To manually link your amateur radio callsign to your RadioReference.com username, open your account profile and fill in your amateur radio callsign in the appropriate field. If your callsign does not exist in our callsign database, you will be given the opportunity to submit your callsign details to the database.

Enjoy!

Lots of traffic

Many have inquired why the site was running so slowly this afternoon. Well, there was a double homicide shooting incident on the Virginia Tech campus today which resulted in tens of thousands of listeners flooding in to the audio portions of the site within a period of about five minutes. Virginia Tech is a highly technical community so they are more online than most.

The site was mentioned by students being interviewed on CNN, as well as numerous viral posts in the social media circuit (Facebook, Twitter etc), which drove a large amount of traffic to the site in a short period of time.

Luckily, we learned an important lesson a few months ago when CNN mentioned us during the east coast earthquake, so we put in place "throttles" to prevent too much traffic from taking the site down until we could provision new servers. On that day when CNN mentioned us on the air, so much traffic so quickly to RadioReference caused our database servers to crash under the load and we were down for over 45 minutes! Running a platform that can instantly see tens of thousands of people flocking to it out of nowhere can be challenging since it is difficult and costly to keep servers constantly provisioned and prepared for such traffic. But, the good thing is the site stayed up and running, albiet slowly, and we were able to provision new servers to better handle the additional traffic we were seeing.

For those that want the nitty gritty on what happened today - we have a proxy server that load balances requests across our Web servers and also throttles requests so if we hit a traffic spike like we did today, we won't overwhelm what is already running. We currently throttle to 2000 req/sec and we were maxed out for most of the afternoon. After the news hit we brought up 2 additional Web servers and a database replica server to handle the load and things are back to reasonable levels of performance.

With that said - for those of you that were having trouble getting your RR fix this afternoon, our apologies.

The monthly bill

Has anyone ever wondered what RadioReference's monthly costs are to provide our services? I figured I would take a moment to share with the community what we pay each month in hosting expenses. We obviously have other expenses, like taxes, payroll, commissions, etc, but our largest expense is our Web hosting hosts (servers, bandwidth, etc).

Our primary Web hosting partner is Amazon Web Services, which provides a fantastic cloud computing model which is critical for our ability to scale up and down based on demand, and pay only for what we use. We have also partnered with ServerBeach to provide a server external to Amazon Web Services for mail and monitoring activities.

Below is our latest invoice for the month of July's hosting on Amazon Web Services... (click the picture to see the invoice full size)

That's right, right about $8,285.00. We also paid ServerBeach approximately $200 for a server hosted with them. That means on a typical busy month we are looking at ~ $8500/month in hosting and bandwidth costs.

How does all this break down?

- $2700/month in server costs (web, database, archive, audio, and management servers)

- $1300/month in storage costs (audio archives, backups, databases, files etc)

- $4500/month in bandwidth (all those audio feeds)

Hopefully this gives a good perspective as to what it costs to run a high traffic, bandwidth intensive Web property.

Next up... our technical architecture. Ever wondered how many servers we have, what they do, and what software we run? Stay tuned!

Coming in early June, Premium Feed Broadcaster Offering

We are excited to announce that in early June we will release a premium feed broadcaster offering. This is primarily intended for public safety agencies and commercial entities, however any feed broadcaster could upgrade their feed. The features include:

1) 90 day archive retention
2) Ability to automatically trim dead air from archives
3) Brand free set of Web players
4) No ads on your Web players or feeds
5) User defined lead-in audio feature
6) Private Feed support with delegated administration (you can restrict access to your feed to only users that you specify)
7) Complete access to all mount points and server details - do what you want with your feed, anywhere, anytime.
8) Full archive access via API to display archive files and lists on your sites/systems.
9) Full downloadable statistics

Our current offerings will not change, and you reserve the right to switch between being a normal RR feed broadcaster or a premium broadcaster at any time.

The cost for this offering will be $14.95/month per feed.

Look for more details coming soon, including the release date.

Listening to RadioReference Live Audio Feeds using the Logitech SqueezeBox

As you probably know, RadioReference has over 1800+ live audio feeds of public safety communications from all over the world. With the recent release of the ScannerBox plug-in for the Logitech Squeezebox, you can now listen to all of those feeds directly from this full featured Wifi enabled music player.

If you aren't familiar with the Logitech Squeezebox, this device is a dedicated internet radio station player. With the release of the ScannerBox plug-in, you can now instantly listen to all of RadioReference's live audio feeds on this great "appliance."

For more information, on the plug-in, see the links below and watch the YouTube video.

ScannerBox Plug In
Logitech Squeezebox

RadioReference and Incident Page Network (IPN) Announce Incident Syndication Partnership

RadioReference is pleased to announce that we have formed a partnership with Incident Page Network (IPN), the world's premier incident notification network, to syndicate incident alerts on RadioReference Live Audio County pages. Most incidents displayed will be delayed up to 2 hours, however critical and large scale incidents will be displayed in real time.

In addition, existing IPN subscribers will be soon be able to associate their RadioReference.com Username with their IPN profile, allowing all incidents to be displayed on RadioReference.com pages in real time for existing IPN subscribers.

More details and information on this partnership can be seen here:

Incident Page Network - The RadioReference Wiki

These new features will be rolled out during the evening of Monday, February 8th 2010

Enjoy!

RadioReference Infrastructure Updates Coming For September

I wanted to spend some time this evening to document out for you some
of the cool infrastructure updates that we have coming for RadioReference.com.
We've seen tremendous growth this year so this is really
necessitated. We are planning to move our entire hosting platform
over to Amazon Web Services, which is a cloud based computing
environment that lets us build our infrastructure on demand, and pay
for what we use. It is a little more expensive that traditional
hosting providers, but it provides tremendous flexibility for us.
You can see more information on Amazon Web services here:

Amazon Web Services

With what we have architected moving forward, we can scale within
minutes to support millions of visitors to our site - something that
isn't quite so easy with our current architecture. In fact we
recently in the last 6 months moved to a much larger infrastructure
environment, only to exceed the capacity at times after all the
growth..... and during the summer no less, which is the slowest time
for our business. Clearly, we need to take significant action.

So, what do we have planned? What are the technical details? For
those of you that like this stuff... Here is what the site will look
like after the switch in the next few weeks. We will have:

1 Web Proxy Server. This server will proxy all requests to back end
Web servers, allowing us to load balance requests to LOTS of Web
servers versus the two that we have today. It will be a front end to
the entire back-end infrastructure of Web and database servers, and it
will have a hot standby that can come up quickly (in minutes) in case
of a failure.

3 Web servers... to start. The proxy server above will balance
requests across each of these, on round-robin basis. These Web
servers are the cloned the same so I can literally bring online as
many of them as I want and add them to the Web proxy server
configuration. Understand that the bottlenecks that we sometimes see
in site performance happen at the back end Web servers and/or database
servers. A single proxy server could easily funnel 5,000 requests a
second to a back end infrastructure without even breaking a sweat. We
will also look at deploying, on demand, additional servers just for
the forums so that when they get busy from 3:00 PM to 11:00 PM we can
add servers to support the requests, and then bring them down when
things get quiet. If we get a huge influx of traffic, I could bring
up 30 servers if I needed to.

1 Master database server. This thing will be a monster, with 8
virtual cores and 16GB of RAM. All database writes will go to this
server. Meaning anytime something needs to be changed in the
database, this sucker is going to handle it.

2 Slave Databases... to start. A slave database server replicates all
information from the master listed above but functions in a read only
mode. One will be a primary slave server responsible for offloading
read requests from the master server (the master will still serve a
lot of read requests, but this is a start). Another slave database
will be dedicated solely for database backups and snapshots. If we
have to bring up a bunch of Web servers because of increased demand,
we can also bring up slave database servers to serve those Web servers
all their read requests. Again, we can bring up as many of these as
we need to. we are also looking at advanced caching techniques for
the database servers as well (memcached).

1 NFS Server. NFS stands for "network file system", and allows us to
put all of our Web content on a single server and let all the Web
servers reference it. That way we only have to put things in one
place and if we have 100 Web servers they can all reference the same
data.

1 Management Server. This server will update statistics on all the
servers, monitor each of the servers for problems, and alert us when
something goes bad. No more dead server at 11pm and it gets fixed at
7am.

2 Master Audio Servers- These servers will receive all of the audio
feed broadcasts that are hosted on the site. Our plan is to have one
master server for every 1000 audio feeds. We can grow this as needed.

2 Relay Audio Servers... to start. Relay servers are what you connect
to when you listen to a live audio feed. We can add as many of these
as we need to support all the listeners, up to millions of listeners.
Our plan is to have 1 relay server per 3000 listeners.

3 Audio Archive Servers. The audio archive servers, well, archive all
the audio. Each are connected to a 1TB disk store. Our plan is to
have one archive server per 500 feeds.

So many will ask, how much will this cost per month? I would estimate
that our charges per month will exceed $4,000/month. If we have to
scale to meet additional demand we will pay for what we use. But, the
benefits far outweigh the costs and we will be prepared to scale up to
large events and traffic that are invariability going to come our
way. We don't have a choice but to invest, and our existing services
are costing about $3000/month so this is a great business move for us.

And... many will ask, when is this going to happen? Well, half of our
audio infrastructure is already on the new system, and we've moved all
of the static Web content (logos, images, styles, etc) to Amazon's
Cloud Front. The rest of the infrastructure is already up and
running, but going through load testing to make sure things go
smoothly when we switch. I would expect that by the end of
September, we will be fully moved over to this new environment, and we
will be welcoming hoards of new visitors and users.

Thank everyone for your support, and I welcome your feedback.

RadioReference Spring 2009 CD-ROM Released

RadioReference.com announced on April 15, 2009 that the April 2009 release of the RadioReference.com Database CD-ROM is now available for sale through ScannerMaster.

Priced at $29.95, the CD-ROM provides a complete off-line copy of the RadioReference Database and wiki, including conventional and trunked frequencies assignments for all United States cities, counties, and states, and a select set of international locales. In addition, maps, images, 10 codes lists, and other data are included for selected areas.

New for this release is an updated style and look, as well as the complete copy of the RadioReference Wiki for offline access to this reference source.

The CD-ROM is now in stock at ScannerMaster, and can be ordered at the following location:

RadioReference Database CD-ROM

More Information on the CD-ROM can be found here:

RR CD Apr2009 - The RadioReference Wiki

RadioReference Mobile Interface Feature Updates

New features have been rolled out for the mobile interface at:

http://m.radioreference.com

1) Retrieve Frequencies/Information based on Zip Code (US Only)
2) Frequency Search by State
3) Additional frequency details display for individual frequency entries (inputs,etc)
4) System ID and Custom Frequency Table information now available for trunked systems.

I've got more features and functionality planned - but these are some of the more highly requested updates that we make.

Enjoy!

RadioReference.com Acquires ScanAmerica.us, Adds 500+ Live Public Safety Audio Feeds

San Antonio, TX -- April 21st, 2009 --RadioReference.com LLC (RadioReference) announced today its acquisition of ScanAmerica.us, the Web's leading provider of online radio communications and public safety scanner audio feeds. This acquisition adds over 500+ live public safety scanner feeds to the RadioReference platform and provides a future foundation for the tremendous growth and popularity of listening to public safety communications online.

"Live public safety communications being broadcast online have experienced tremendous growth over the past two years and RadioReference has explored many avenues for offering this feature to our members," says Lindsay Blanton, president of RadioReference. "The ScanAmerica team has done a tremendous job of building their online community and their technology is well architected and top notch. This is a perfect fit with our strategy of adding additional content to the site."

ScanAmerica is the web's leading provider of online police and fire scanner feeds. Founded in 2008, the site quickly amassed over 550 feeds from all over the United States and receives visits from over 220,000 people per month.

"This transition to RadioReference is perfect for the online scanner community," says Gordon Edwards, owner of ScanAmerica. "The combination of our best-of-breed broadcasting services along with the RadioReference database will result in tremendous benefits for both communities - most importantly being increased audience and visibility."

ABOUT RADIOREFERENCE.COM:

RadioReference.com is the world's largest radio communications data provider, featuring a complete frequency database, trunked radio system information, and FCC license data. With over 210,000 members, RadioReference provides the most comprehensive collaboration platform for scanner listeners and public safety communications professionals.

New Features and Changes for 4/9/2009

I'm pleased to announce two new features and updates to the Web site:

1. Premium Subscribers can now set their default display for input frequencies. See the "Database" tab under your account settings page.

2. We will now be moving all unstructured content (links, maps, logos, code lists, files etc) to the Wiki for each county/agency/trs page. Each entity's new wiki page can be accessed by clicking the "Collaboration" tab on any agency, county, or trunked system page. For information on this can be found here: Collaboration Tab.

Hopefully these changes will make it not only easier to view data in the database, but also easier for every person in the RadioReference community to contribute all kinds of revelvant information for their areas. Don't forget, anyone with a RadioReference.com account can edit and add content in the Wiki, so please use this resource to its fullest.

Enjoy!

RadioReference.com 2009 Spring Updates

RadioReference 4.0 is Live!
After months of hard work, the new complete site redesign, titled RadioReference.com 4.0 was recently released to the community. This new version of the site highlights the most important and significant changes to RadioReference.com since inception.

Some of the new features and functionality with the 4.0 release include:

• A complete new theme, graphics set, and common design across all site components.
• Users can now see their submissions and status at the Your Account - My Submissions page.
• New common top menus for easier navigation across different site components.
• FCC license display settings are remembered on county FCC license listing pages for Premium Subscribers.
• Premium Subscribers have a better view of their subscription status across the site.

...and many other features. If you haven't already seen the new design, stop by and take a look!

RadioReference Senior Leaders
Because of our significant growth over the past year, we recently announced three leadership positions on RadioReference.com. These three individuals, all highly experienced folks in our community, take responsibility for key components of RadioReference. They are:

• Eric Carlson (ericcarlson), who takes lead responsibility for the RadioReference Database.
• Wayne Hayes (wayne_h), who takes lead responsibility for the RadioReference Forums.
• Mike Agner (ka3jjz), who takes lead responsibility for the RadioReference Wiki.

For more details on their activities and responsibilities, see the Blog Post regarding this announcement.

Database Team Updates
From Eric Carlson, Lead Database Administrator and Manager

The RR Database continues to expand its coverage of conventional and trunked data around the world. Additionally, we are continuing to supplement existing data with alpha tags, function tags and geographic tags. All three types of "tags" are intended to make it much easier to program scanners via computer software. If you see missing tags in any area of the database, please let us know what we're missing by clicking the "Submit Info" link on the toolbar at the top of any page.

Also, you may have noticed we are now tracking Project 25 trunked system zone IDs separately from site IDs and also showing all trunked site IDs in both decimal and hexadecimal format. These enhancements allow us to properly track site information and help mitigate confusion that arises from different scanners showing site IDs in different formats.

In addition, we've heard from many asking "Where have input frequencies gone?" in the new release of the database. Don't worry, they are still present. You can enable viewing of input frequencies by choosing the "Enable Input Frequencies" option at the top of any frequency list in the database.

The database administration team is also steadily moving toward standardizing the database organization across all regions. We are developing internal standards and documentation to facilitate a consistent structure to the database as you browse from region to region. Please bear with us as we continue to improve the quality of the database. The database administrator "handbook" will be posted shortly for you to review if you wish to see exactly what our policies and procedures are.

Forums Team Updates
From Wayne Hayes, Lead Forums Moderator and Manager

With the growing interest of the RadioReference forums and our dedication to being the source for radio related discussions, we've added many new topic areas. Areas such as Amateur Radio, New Scanner Users, GMRS and subdivided the Tavern (formerly "The Wasteland"), to name a few. It's an overwhelming expansion but with growth comes reorganization. Stop by, maybe there's something new that will pique your interest.

Wiki Team Updates
From Mike Agner, Lead Wiki Administrator and Manager

We have heard a number of comments about how the wiki is very difficult to navigate, and how the current Wiki homepage is cumbersome. While we tend to agree, it does link to and categorize a number of topics. As this is being written we have well over 1200 articles making it the single largest radio related wiki in the world.

With the new implementation of 4.0, a new dropdown menu structure has been implemented for navigation. If you examine the blue toolbar at the top of each page, you will see a "Wiki" menu item in the center of the toolbar. The topics in this dropdown menu are good starting points, and far simpler to navigate than the huge first page. From time to time, we may move topics in and out of the dropdown menu to give a little variety to what is presented. Your suggestions as to what topics you would like to see presented are solicited.

In addition, some months ago, with a release of a popular freeware software package for the Uniden DMA scanners called FreeScan, a user manual was developed to advertise the package as well as to create a user-maintained reference manual. To the best of our knowledge, this is the first scanner software application to have its documentation placed into a wiki. Since the wiki is all user generated content, every RadioReference subscriber has the opportunity to contribute additional content to this online manual.

Finally, don't forget that the Wiki can be edited by anyone with a RadioReference user account. You are encouraged to use the wiki to document local content, scratchpad information about a trunked system or communications network, or start your own reference source for something radio related. See the New Article Guidelines page for information on how to create and edit articles on the wiki.

XML1.1 Web service deprecation pushed out to July 30th, 2009

At the request of a few software developers, I've agreed to push out the
retiring of the existing "1.1" version of the Web service, currently in use
primarily by Starsoft and Butel. The new deprecation date is now July 30th,
2009. This push back should hopefully give these application developers the
time they need to convert to the new Web service, which provides additional
features and functionality.

It is important to note that this will be the only push out of the date.

RadioReference Senior Leadership Position Announcements

RadioReference Members,

As you know, RadioReference has grown from a small radio communications oriented Web site to one of the larger sites on the Internet, requiring a tremendous amount of care and feeding to keep growth strong and participation high. There is no doubt that RadioReference is the "go to" destination for anyone looking to participate online regarding scanning and radio communications.

With this in mind, I've decided to form and staff 3 new senior leadership positions reporting to me that will take on formal responsibilities for different components of the Web site. This will allow us to have a group of individuals that will help drive how we bring great features, functionality, and a good end user experience across the database, the forums, and the wiki.

I take great pleasure in announcing the appointment of these three individuals into the following positions:

Lead Database Administrator and Manager - Eric Carlson (ericcarlson)

Eric has agreed to take the position of Lead Database Administrator, and will be responsible leading our database administration team, developing and formalizing policies and procedures for database management with your involvement and mine, and recruiting and making sure that our approach results in quality and accuracy in the database.

Lead Forums Moderator and Manager - Wayne Hayes (wayne_h)

Wayne has agreed to take over the head moderator position for our fast growing and very active forums. He'll be responsible for leading our team of moderators, making sure that we are on top of rules in the forums, and recruiting a team of focused and localized moderators that can make sure that the forums remain a friendly and welcoming environment. Expect to see great changes in the near future in the forums as we focus more time on improvement and growth.

Lead Wiki Administrator and Manager - Mike Agner (ka3jjz)

Mike has agreed to take the lead on wiki administration duties, which he's already been doing very well. The Wiki has become a very important and go to reference source for radio related information, and Mike will be working to better promote the use of this important reference source so that more folks participate and we continue to integrate more components of the Wiki into the overall Web site.

Please join me in welcoming these folks to their new formalized roles, and support them as much as possible as they begin to execute on their responsibilities over the next few months.

RadioReference Records It's 200,000th Registered User

RadioReference.com reached an important milestone on January 12th 2009 registering it's 200,000th member.

Some other notable statistics for 2008 include:

11,926 submissions of radio communications data were sent and processed
53,124 new members
277,254 posts to the user forums
41,220,258 page impressions
244,082 changes to the RadioReference Database

2009 will bring even more exciting statistics and changes for RadioReference, as we release a new branding and Web site, new features and functionality, and a better overall user experience!

XML 1.1 Web service deprecation notice

The existing REST based RadioReference.com web service (XML 1.1) will be formally deprecated on April 1st, 2009. The script will be removed from service at midnight on that date.

I encourage all developers of applications that are using this interface to to migrate support to the new SOAP based Web service, documented at:

http://wiki.radioreference.com/index.php/RadioReference.com_Web_Service3.1

The WSDL for the SOAP based Web service is at:

http://api.radioreference.com/soap/?wsdl

We are deprecating the REST based Web service because it makes no sense for us to duplicate maintenance and new feature releases across multiple Web service types.

VHF/UHF Spectrum Analysis using the RF Space SDR-14

One of the most impressive developments in the radio communications community over the past few years is the advent of software defined receivers, which can provide great tools for spectrum analysis. Hobbyists today can not only view entire swaths of spectrum at one time to view activity, but can also record entire spectrum chunks for later playback and analysis using SDR tools.

This article will walk through the RF Space SDR-14 software defined receiver, and review how it can be used to analyze different user segments in the VHF/UHF spectrum.

To start, an introduction is in order. The RF Space SDR-14 is a 14-bit software defined radio receiver that operates in the 0.5-30 MHz band. It provides not only extensive spectrum analysis capabilities but also functions as a great receiver with numerous demodulation capabilities for the HF spectrum. Since the SDR-14 is a software defined radio, all controls and interfaces with the radio is done using software applications installed on a PC. The most popular application written to exploit the SDR-14 is SpectraVue.

As mentioned above, the SDR-14 functions as an HF software defined receiver, however it can be configured to accept the 10.7 MHz IF output from another receiver, and tune that receiver, to combine as a very powerful monitoring station and spectrum analysis platform for any band range. I have been using an AOR5000A in conjunction with the RF Space SDR-14 with excellent results, allowing me to click on certain portions of the spectrum and automatically tune the AOR receiver.

Showing some of the capabilities of this combination or AOR receiver and RF Space spectrum analysis tools, I'll review some annotated screen shots of different monitoring targets. You can click each screenshot to view the full size image.

The first we will review below is a screenshot of the SpectraVue application monitoring a 250 KHz wide chunk of spectrum between 260.350 and 260.600 MHz - where US Military UHF communications satellites have downlinks. The RF Space can realistically monitor about 10 MHz of spectrum from another radio's IF, however the narrow swath of 250 KHz allows us to monitor military satcom transponders transponders and see what is happening within each of them.

In this screenshot, we can see the 4 Active UHF SATCOM transponders:

1. Relaying unknown data bursts on 260.375
2. Relaying a Spanish bootlegger's communications on the 260.425 transponder but comms centered on 260.430 MHz. The transponder is 25 KHz wide so the communications come through loud and clear.
3. Relaying 16 KHz VINSON encrypted US Military voice
4. Relaying a Spanish bootlegger's communications on the 260.525 transponder but comms centered on 260.530 MHz.

It is interesting to note that Spanish, Portuguese, and Asian bootleggers at times use all the 25 KHz wide transponders, with communications in LSB, AM, and FM.
Next, let's take a look at the 5 KHz transponders on the Gapfiller Military SATCOM satellites. This screenshot shows (13) 5 KHz wide transponder in action, annotated with different traffic occurring on those. You can clearly see in the screenshot weaker active transponders for a different satellite on the left, and the 13 stronger transponders for the target satellite.

Now that we have reviewed some advanced monitoring targets, we can take a look at some more common monitoring targets that hobbyists focus on. Below is a screenshot of a 10 MHz wide section of spectrum in the VHF aircraft band. This shows a key benefit of using the SDR for spectrum analysis -- you can watch almost the entire VHF aircraft band on one screen, and click to tune a specific transmission on the AR5000 radio.


Further, why search the federal government VHF land mobile spectrum on a standard scanner when you can watch the entire band in one window? Below is a screenshot of the SDR monitoring 162-172 MHz, providing the ability to see all activity and click to tune the AOR radio to specific transmissions:


And finally, where I live, the federal UHF band in San Antonio TX is quite busy with a large wide area military trunking system active between 406-411 MHz. The screen capture shows activity over time in that spectrum, showing active data and voice channels.


In summary, you can see that the RF Space SDR-14 opens up a whole realm of possibilities for radio communications enthusiasts. The ability to watch entire blocks of spectrum and then point and click to tune an transmission makes finding new and unknown monitoring targets a breeze.

For those that are interested in adding this fine piece of communications equipment to their shack, Scanner Master offers the RF Space SDR-14 for sale on their fantastic Web site. Click the link below for more details on how to order.

RF Space SDR-14 on Scanner Master

Next up, we'll review the RF Space SDR-14 monitoring the HF bands. Utility, broadcast, and Ham listeners and operators will get a whole new perspective on how HF Spectrum is used.

RadioReference.com and Scanner Master Corp. Renew and Extend their Partnership

RadioReference.com, the Web's premier resource for radio communications information, and Scanner Master, the nation's oldest and largest Scanner-only dealer, today announced the renewal and extension of their joint-marketing partnership.

Through this partnership, the most comprehensive line of scanners, software, antennas and communications-monitoring accessories, sourced from around the world, are offered to the world's largest online community of two-way radio users. RadioReference is also developing exciting new products services which will be marketed through Scanner Master starting later year.

Richard Barnett, president of Scanner Master Corp., remarked, "Our partnership with RadioReference.com is our most important. It allows us to present scanners and accessories to an enormous audience of dedicated radio professionals and hobbyists. Through this relationship, we strive to provide unmatched service and a wide product mix to the RadioReference.com audience through our strict focus on scanners and scanner users.

Lindsay Blanton, president of RadioReference.com LLC, said, "Scanner Master is widely recognized in the radio communications community as the leading provider of scanners and communications equipment to the industry. This, coupled with their leadership in innovating new products and offerings for the industry means that this partnership will continue to grow and be very successful."

With its extensive frequency and trunking databases, news sections and user forums, RadioReference.com is the one-stop repository of radio communication information.

For over 30 years Scanner Master has served the radio community through its line of popular Scanner Master and Monitor America books as well as through the sales and service of scanners, accessories, software, antennas and other custom products.

VHF Low Band Skip - Tips and Tricks to monitoring

Now that the summer months are upon us, VHF Low Band Skip reports have been coming in fast and furious on the RadioReference Skip Forum. This article will give you some tips and tricks on how to monitor public safety and military communications from all over North America with a simple antenna and scanner. The trick is timing, and patience.

VHF Low Band Skip is caused by a phenomenon called Sporadic E skip. Sporadic E skip occurs when patches in the E layer of the ionosphere, about 65 miles above ground, become ionized. This layer normally refracts shortwave and mediumwave signals but is transparent to VHF radiation. When patches of the E layer become ionized, great skip opportunities from 28 MHz to 75 MHz occur, allowing you to monitor communications in this band cross-country, and sometimes worldwide when "double-hop" skip occurs.

Hunting for skip.

One very valuable tool for looking for E skip patch openings is the DX Sherlock 1.7 - V-UHF QSO real time maps tool. This tool, provided by vhfdx.net, shows real time contacts made by amateur radio operators on 6 meters (50-54 MHz). Usually, when a number of contacts are being made cross country, a sporadic E skip opening is occurring.

Another valuable tool is of course your scanner. Some precursors to sporadic E skip come from meteor scatter transmitter sites which broadcast near 40 MHz for telemetry and weather reporting. Meteor scatter transmissions are similar in nature to sporadic E skip transmissions, except the radio communications broadcast bounces off on ionized trails from naturally occurring meteors vaporizing in the atmosphere. These vaporization trails allow ground stations to communicate over long distances from remote areas. Some frequencies commonly used by Meteor scatter systems include:

40.53 SNOTEL - Snowpack Telemetry in the Western States
44.20 Meteor Communications Corporation

Plug those frequencies in and scan them often. If you hear data (you'll know it when you do, it is a loud buzzsaw sounding data transmission) on these frequencies, chances are a nice band opening is occurring.

Common Reported Skip

Some of the more commonly public safety agencies that show up on skip across the nation include:

42.00 - 43.00 MHz Missouri Highway Patrol
42.00 - 43.00 MHz Tennessee Highway Patrol
33.90 Hamilton County (Cincinnati) Fire / EMS Dispatch
39.00 - 40.00 MHz California Highway Patrol

Some of the more commonly heard Military stations include:

30.45 Fort Hood Range Control
38.90 Fort Irvwin CA Range Control / Fort Knox TN Range Control

In addition to those public safety agencies and military operations, there are numerous other fire departments, police departments, SOs, pagers, Mexican taxi drivers, military range controls, military helo towers, public works, and other operations that occur.

The full set of low band allocations in the United States are:

30.0000 to 30.5500 U.S. MILITARY
30.5800 to 31.9800 PARK SERVICE
32.0000 to 33.0000 U.S. MILITARY
33.0200 to 33.1000 HIGHWAY SERVICE
33.1200 to 33.4000 BUSINESS RADIO
33.4200 to 33.9800 FIRE DEPARTMENTS
34.0000 to 35.0000 U.S. MILITARY
35.0200 to 35.6800 PAGERS
35.7000 to 35.9800 BUSINESS RADIO
36.0000 to 37.0000 U.S. MILITARY
37.0200 to 37.4200 POLICE
37.4400 to 37.8800 BUSINESS RADIO
37.9000 to 37.9800 HIGHWAY SERVICE
38.0000 to 39.0000 U.S. MILITARY
39.0200 to 39.9800 POLICE
40.0000 to 42.0000 U.S. MILITARY
42.0200 to 42.9400 POLICE
42.9600 to 43.1800 BUSINESS RADIO
43.2000 to 43.6800 PAGERS
43.7000 to 44.6000 BUSINESS RADIO
44.6200 to 46.0400 POLICE AND PARK SERVICE
46.0600 to 46.5800 FIRE DEPARTMENTS
46.6000 to 47.0000 U.S. MILITARY
47.0200 to 47.4000 HIGHWAY SERVICE
47.4200 to 47.6600 EMERGENCY SERVICES
47.6800 to 49.5800 BUSINESS RADIO
49.6000 to 50.0000 U.S. MILITARY
50.0000 to 54.0000 HAM RADIO 6 METERS

Search through those frequency ranges and see what you hear! Most Sporadic E Skip occurs from sun up to sun down, however some of the best sporadic E skip openings can occur well till midnight.

Antennas

You might ask, what antenna do I need on my receivers to pick up this skip? Well, most people reporting activity have received low band skip just using a rubber ducky on a handheld scanner, however using a dipole wire antenna cut for 40 MHz will probably give you the best results.

Whatever you hear, whenever you heard it, be sure to post your findings and logs to the Skip / Tropospheric Ducting Forum on RadioReference.com.

Have fun!

Decoding NOAA APT Weather Images

There are a lot of things in the radio communications hobby that are exciting... but for many monitoring satellite communications is at the top of the list. One of the more interesting satellite monitoring targets are the NOAA low earth orbit satellites, which fly in sun-synchronous polar orbits around the earth and continuously transmit satellite photos. These picture transmissions occur in the 137 MHz band and are easily monitored with a scanner and easily decoded with free software. In this post, I'll review how I was able setup a process to receive and decode these pictures using an AOR AR5000 Radio, a computer with a sound card, and free decoding software.

Currently, there are 3 production NOAA satellites, NOAA 15, 17 and 18. They transmit on the following frequencies:

NOAA 15 137.500
NOAA 17 137.620
NOAA 18 137.100

The transmission mode is FM, with a bandwidth of 30 KHz. There are very few scanners and communications receivers that have a IF bandwidth selection of 30 KHz, however you can still receive the signal using the standard mode selection of FM for your radio.

To get started, you will want to dedicate a receiver for satellite monitoring - the receiver should have a good outdoor antenna with a clear view of the sky. The easiest method is to use a discone antenna, or other roof mounted antenna. There are antennas that are designed specifically for the circular polarization of the NOAA Satellite signals, however a standard discone or other common outdoor scanner antenna should work fine.

Next, you will want to download and install the APTDecoder software package. APTDecoder is a free software package for recording and decoding signals transmitted by NOAA APT enabled weather satellites. It runs on Windows and is a very powerful tool for decoding the NOAA APT signals.

Your next step is to determine what your current station's latitude, longitude, and altitude is. This is important, since the NOAA satellites are in orbit around the earth, and you'll need to use APTDecoder to predict when the satellite passes overhead. Write these three pieces of important information down for input into APTDecoder.

Configuration of APTDecoder

After starting APTDecoder, launch the application and click Settings -> General Settings. You will want to enable the auto-recording and processing feature which starts the decoding process for you when a satellite comes into range.


Next, choose the Image Properties Tab and the Enhancements sub-tab and choose the Histogram equalize option. This will help to lighten the picture after decoding so it is more easily viewed.


There are a number of other features that can be enabled, such as auto radio control and more picture settings, but the above settings should get you started.

The next step is to define your ground station particulars. Choose Settings -> Ground Station, and enter your Latitude, Longitude, and Altitude. Then click Add, then scroll through the list to find your new entry and click Select.

Now that your ground station is configured, you'll need to download the latest Keplerian elements for the satellite orbits. Keplerian elements are 2 line text data sets which describe how a satellite is orbiting the earth. These are updated often and need to be refreshed to ensure accurate predictions on satellite passes. Click the Satellite -> Keplerian elements menu item, highlight the first URL entry, and click the Download button on the right. The modified timestamp should show an updated timestamp for the current date and time.

Now that you have configured the software, it's time to connect your receiver to the computer. If a satellite is actually overhead and in range, APTDecoder will start recording immediately. If this happens, just click cancel.

Connecting Your Scanner to the Computer

APTDecoder uses the sound card installed in your computer to decode the transmissions from the scanner. Connect an audio cable from the headphone or audio out jack on your scanner to the mic in jack on your sound card. Then, to set the audio level properly, choose the Tools -> Check audio level menu item in APTDecoder and follow instructions in the meter to set the audio level properly.

Decoding a Satellite Pass

With the application configured, APTDecoder is now tracking each of the 3 NOAA Satellites and is providing predication and tuning information to you in the interface. It is time to prepare for one of those passes and decode the transmitted data.

At the top of the APTDecoder window interface, you'll notice the phrase "Tracking NOAA-## on 137.620 MHz....." This top line is telling you the next satellite that is about to come into range (or is in range), on which frequency, and the specific time that the satellite will pass over your ground station. At the bottom, you'll see a line that says "Next: NOAA xx on 137.620 .........", this is the next satellite pass AFTER the one that is being tracked (sort of the "next, next" pass).

Reading the top line on the interface, tune your scanner to the frequency that APTDecoder says the next Satellite will be on. Remember, this line is telling you which satellite will be next, on which frequency, and when. In the following example below:


This tells us that NOAA 17 is next, transmitting on 137.620 MHz, and will come into range (AOS = Aquisition of Signal) at 17:06 UTC. The current time is 15:11 UTC, so we have about 2 hours before the next pass. To see where exactly each of the 3 NOAA Satellites are in relation to the earth, you can choose the Flat Earth Monitor tool (Tools -> Flat Earth Monitor).

To setup and decode the pass, tune your scanner to the proper frequency as indicated on the top line, plug in the audio cable, adjust the audio levels, and wait.

NOTE: Remember that NOAA APT transmissions on the 137 MHz band have a bandwidth of 30 KHz. If your radio has the capability to change the IF Bandwidth to 30 KHz, you should enable that setting. There are very few radios that have this capability (the Icom R9500, Icom R9000, and the AOR AR5000 are the ones I am aware that can), however it is reported that most scanners in standard FM mode (typically 15-20 KHz) will work OK, but don't expect a perfect decode unless you have a wider 30 MHz bandwidth.

When the satellite comes into range, APTDecoder will immediately start decoding, and you should begin to see each line decode and scroll. In the beginning of the pass, don't worry if there is a lot of noise, the satellite may need a few more minutes to get into range. The initial decode of the picture will be very dark looking, however after the entire pass finishes the decode will look just fine.

Each NOAA Satellite transmits two photos - a visible earth image on the left, and an infrared image on the right.

Start of decoding will look like the below. Don't forget, the initial picture will look very dark, however when the pass finishes the software will auto-process the image for proper light levels.


Still decoding...with the Flat Earth Monitor enabled showing the satellite transmit footprint around my ground station (you can enable this during the decode):


Finished. You can see both the visible image on the left, and the infrared image on the right.


That's it. Once that decode finishes the next upcoming satellite pass details will be displayed on the top line and you'll want to adjust the scanner frequency if needed.

I hope this was an enjoyable post, and that if you've never been able to decode NOAA Satellite transmissions this will be a good first step for you.