Community radio broadcasting

So, what is community radio?  One way to define community radio in the low power realm could be experimental radio with a purpose.  These ventures are usually undertaken by folks with a vision of community service.
     Sometimes the best opportunity is a partnership between a community focused person and a radio experimenter - one provides the bandwidth, the other, content and community outreach.
     Often, low power radio is a useful tool to reach a potentially large audience traveling through a particular geographic location.
     Low power community radio is often used to broadcast messages about the local attractions, research and related events. Topics can include information about wildlife, marine projects or announcements about educational events.
     In some cases, listeners responded to online surveys and indicated learning more about research, events and educational opportunities. Using this apprach, community radio broadcasters find that listeners are attending events and facilities heard about, on the radio!
     Your faithful blog editor has covered some of these operations in past posts, here is a summary of community radio posts found here:

• Four community radio stations
• TIS and community radio updates
• The high potential of low power radio
• Limited area broadcasting for community radio
• Commercial use of low power community radio
• Community radio stations built with the SeaGrant program
• Reaching target audiences with low power, community radio
• Opportunities for commercialization of low power community radio
• Low power community radio operations review, tunnels and drive-through 

     The FCC also offers a slightly different form of low power community radio called TIS or Travelers Information Stations, also called Highway Advisory Radio, for the purpose of disseminating information by broadcast radio to travelers. While this service is not available to individuals or groups, governmental entities and park districts may use this technology for a wide variety of purposes.
     Information Station Specialists is a well known source for TIS technology and the specialized services required.
     The Information Station Specialists (ISS) case studies page gives great insights into how these operatins are used, the station listing page provides an overiew of where these stations can be found and the funding sources page offers the who, how and with what needed to put a TIS on the air in your community.
     Also in the works is a proposal from the National SOS Radio Network, an organization with the goal of helping to create an easy, accessible-by-all emergency communications system freely shared by the public & emergency resources.
     Will your community be served by and benefit from the many opportunities presented by low power community radio?  The answer might be up to you!

FM receiver chips in cell phones - is anybody out there?

In the opinion of this blogger, the frequently confused and seldom effective National Association of Broadcasters (NAB), thought by many to be singularly responsible for broadcast radio's tailspin into oblivion, has surfaced again as the delusional  savior of the medium it has so effectively trashed over the last quarter century.
     Fresh off of a series of what I see as catastrophes that include questionable policy initiatives like ownership consolidation followed by a spectacular lawsuit fail over satellite radio and pushing stellar technologies like AM Stereo, HD radio and Digital AM radio, the NAB is back with 'FM chips.'
     Because animated cartoons from the 1930s often used the "I'm going down once, I'm going down twice, I'm going down the third time..." as a euphemism for a person drowning - I have to ask, is this the third time down for the NAB?
     At first, FM chips were proposed as an important safety issue, as noted in what I saw as the highly suspect "NAB extols broadcasters’ critical role during emergencies." 
     In the latest act of what looks to me to be a farce, Jeff Smulyan, a person I feel is one of the biggest fail-boys in broadcasting, has put forth his highly questionable cell phone FM chip plan to limit access to this supposedly hot market to broadcasters who pony up ad revenue - pay to play.
    Why does this look like payola to me?
     My complaint with the whole matter of FM chips in cell phones is that I have yet to meet users who have any interest in ths technology at all. I am obviously significantly geeked out, yet the very poor performance of the FM chips in the MP3 players and smart phones I have tried left me singularly unimpressed.  Worst of all, with the poor selectivity and sensitivity these chips (in addidtion to obvious antenna issues), this technology does nothing to increase the audience for low power radio.
     Fortunately, our good friends at the other NAB have issued a press release that helps put this whole matter in perspective, please see "NAB extols essential emergency service"
     In my opinion, it is so terribly sad to watch a once great medium continue to self destruct through an apparently never-ending series of painfully bad policy and product decisions.

How to make or where to buy low power FM broadcast antennas

Site analytics indicate many are searching for FM antenna information.   Here is a compendium of how to make or where to buy FM transmitting antennas for low power radio.
     After  identifying an open frequency, perhaps using these handy FM Frequency Survey Log Sheets and setting the transmitter for the chosen spot on the dial, the next step is to make an effective connection with potential listeners with a good FM broadcast antenna.
     The good news is that there is nothing unique about transmitting in the FM broadcast band.  From a radio theory perspective, the goal is to radiate a signal in VHF frequencies to where listeners are. All of the great research, calculations and configurations developed by ham radio operators  apply to the FM broadcast band in the 87.5 MHz - 107.9 MHz range.
     The most common low power FM broadcast antenna configurations are either omni-directional or somewhat directional.
Omni-directional include  1/4 wave whip, 1/4 wave  ground plane, Dipole and 5/8 wave vertical, the Slim Jim and the J-Pole.
     Directional antennas include the better-impedance-matching Inverted V and less complicated Flying V antenna.
Make or buy?

     Along with the pithy info noted above, much of which include handy instructables, some additional how-to readings follow below.  Our friends at PCS Electronics have created PCS Electronics guide to home made FM broadcast antennas and FM DX Antenna Co offers an FM transmission tips page.  Bob Grove, publisher of Monitoring Times magazine, created a nice Antenna Book and your tax dollars paid a consultant to draft Expedient AM and FM Broadcast Antennas for radio stations facing some kind of disaster.

     If you're not up to building an antenna and you'd like to click a buy now button, try PCS Electronics wide variety of FM low power broadcast antennas or visit FM DX Antenna Co. and their tunable and fixed-frequency 1/4-wave ground plane FM broadcast transmitter antennas.
Connecting your Antenna
     Two primary concerns when connecting your antenna are signal loss and matching.  The importance of these varies inversely related to power output.  A transmitter with lots of RF output power will not suffer from signal loss but matching will be critical. 
     For a very low power transmitter the opposite is true - signal loss is vastly more important than matching.
Antenna Matching
     If matching is most important then matching will happen in two places. The first place to match is at the antenna connector. The output impedance of most FM transmitters with an external antenna connector is most often 50 Ohms.  The impedance of a typical configuration FM transmitting antenna is almost never 50 Ohms (Oh #%*+!), so this first matching task is a balancing act. 
     Enter the balun (see what I did there?).  Balun comes from "BALanced UNbalanced" and serves an intermediary that presents the correct impedance to the transmitter and antenna.  Baluns and other impedance matching techniques can be either built in to the antenna or added as a third element between the antenna and transmitter.
     The second form of matching is to match the electrical length of the antenna to the be resonant with the wavelength being transmitted. There are several online calculators in the links noted above and a quick rundown of the math for that is here. Analog transmitter energy travels in waves and if the antenna is resonant then the waves will deliver the most energy - to us that means more range. 
     For transmitters of any significant power output, an SWR meter will be helpful in making final, fine tuning adjustments to your antenna assembly.
No Antenna Connector?
     One last item that comes up from time to time - what about transmitters that don't have an external antenna connector?  These units are often sold as FCC certified for Part 15 and as such, don't provide any connection.
     Here is a favorite cheat - connect 2-1/2 feet of wire to the negative battery terminal or power input connection. Making this unbalanced dipole with one approximately resonant leg that will usually move the range out to a block or so.  For more information of hacking those little Part 15 units, please see an earlier post entitled The Mod Squad.
     FM low power broadcasters have a little easier time getting an antenna up and running but AM or FM, low power or otherwise, WATCH OUT FOR OVERHEAD POWER LINES and other hazards when erecting any kind of antenna

Shortwave, surviving magazines and the "P" word

Last things first. Never really been too interested in pirate radio - the thought of putting a lot of work into something that can be so easily found and turned off...  Pirates have, however, provided useful examples of interesting technologies and other information that can be used in other ways.
     The Free Radio Cafe is a nice example with some short wave info (more on that in a moment) and the earnestly created Low-Power FM Broadcasting forum with links and some private handbooks and manuals.  Private, because visitors need to sign up for a log in to download those materials so, sorry, no links.
     Speaking of shut down, the pirate in this story - Busted! - 95.9 FM gets shut down by the FCC took video of the event, showing  once again that most FCC field inspectors are fairly reasonable, somewhat geeky bureaucrats.  Overworked and underpaid humans like the rest of us who just want to get to quittin' time and have a favorite beverage.
     Speaking of bureaucrats, John Anderson, media professor and long time FCC observer shares another update on enforcement: FCC Grossly Overstates Anti-Pirate Activity. I can't remember the last time I saw any enforcement action on shortwave...
     Speaking of shortwave, wandering around the web in February, I discovered Rick's Pirate Radio Blog, a nice shortwave list which, as a long time shortwave fan, got me thinking about putting up my long wire again.
     Nothing listed in our 13.56 MHz experimenter band, reminded me of good old Carl Blare's KDX Radio site.  Carl has a sweet, old school html table matrix of handy radio experimenter links and if you'd like to start populating that 13.56 MHz shortwave band, check out Carl's hard work on his Big Talker Shortwave transmitter prototype.
     Not sure how American Bandscan caught my eye but it's a nice summary of station comings and goings and then saw good old Monitoring Times is still plugging away - wrote and article for them back in early 2005 about monitoring part 15 stations.
     Also found another old favorite, Nuts and Volts still kicking, with continued great new tech reading.
     Those stamp sized computers look like a great way to do station automation...
      Despising dead trees, was delighted to see both now offer digital subs so a late Valentine's day present this year will buying both!