Wednesday, April 23, 2014

Radio: an Illustrated Guide

Here's a cool comic book presenting a "how to" on putting together a radio program.
You can go to Amazon and buy a a copy of the Radio: an Illustrated Guide comic book for $75.. but that's just silly.. You can get it at This American Life for only $2 as a download to print yourself, or have one mailed to you for $5..

Radio: An Illustrated Guide is a comic book that explains how to make a radio program. Specifically, it explains how to make the public radio program This American Life. In comic book form, the producers of This American Life explain how to find a story, how to do an interview, how to edit sound, how to write for radio and how to mix a radio story. It also explains how the narrative structure of a radio story works, and how it's different from other kinds of stories. This American Life is the most popular documentary program on American radio, with a weekly audience of over a million listeners, on more than 380 public radio stations nationwide. It's produced at WBEZ Chicago and distributed by Public Radio International.

 Jessica Abel is the artist and she tells the story behind how the comic book came to be and provides some full page views on her website.  

You can also check out Brainpickings for a closer look.

Below are some screenshots along with snippets from customer reviews at Amazon, but it's better to read them in their entirety 

If you have ever entertained the notion of trying to slow society's slide into stupor by giving your take on things some sort of voice, this is a great manual for using radio as your format. The format, as an iluustrated guide, takes on the feel of a Boy Scout manual or some other type of DIY instruction....  ..a primer on first focusing on the work to be presented, then the techinical aspect of broadcasting it... 

I recently started a one-man show on a community radio station. I quickly learned it isn't hard to do, but its very hard to do very well. Wanting some tips on the cheap, I found this book....

 Having read "Radio", I can say it is packed with information not only on the production, but on how to tell a story...

 I didn't know what to expect when I ordered this. All I knew what that I knew nothing about radio. This little comic has changed that however. With its easy to read format and great illustrations I was able to understand the fundamentals of radio production in about an hour... ..If you want to know the absolute basics  

Jessica Abel and Ira Glass have done an admirable job of explaining the basics of what it takes to do radio reportage and story telling in a novel format, mainly that of a comic. Inexpensive, easy to read and even easier to understand, the book gave me a clearer idea of what it talks to engage in this field and how to do it properly. of production then buy it.

This book was recommended to me during a seminar on multimedia storytelling for photographers, so its value is not limited to those who only want to do radio. It's a comic book, but not shallow. Anything but... ..This is a little gem.

Download yourself a printable copy of
the Radio: an Illustrated Guide comic book at This American Life for only $2, It's a fun and insightful resource.

Friday, April 18, 2014

Radio in Comics

I recently found myself enthused over a radio broadcast themed comic book, and I just had to get a copy; which I'd like to tell you about. But before I do, let's take a quick peek at a few other radio-related comics.. I'll save the best for last...

Let's start by going back about a hundred years to what is probably the first comic strip having a radio broadcast theme..
The following is quoted from the Strippers Guide Blog..

The Stripper's Guide blog
discusses the history of the American newspaper comic strip:

Enlarge image - or - View full comic strips
"One of the very earliest radio-related comics is Radio Ralf, which arrived on the scene just three years after the first commercial-style radio broadcasts in 1919... ..but the original daily run of the strip was extremely short, apparently ending on July 8, a mere three months later.
Although the strip seems to have ended with only 70-some installments under its belt, the burgeoning interest in radio kept it from going peacefully into the comic strip graveyard. In 1922-23, Western Newspaper Union added reprints of the feature to their weekly line-up. Then McClure itself started selling the strip in batches, where it was snapped up by economically minded newspapers well into the mid-1920s."

Silver Age Comics pointed out a rare comic panel of a super hero who presents a radio broadcast theme..

Enlarge image
A 1963 issue of Adventure Comics introduced a peculiar Superhero applicant by the name "Antenna Boy". He even listened to Part 15  stations! He received an increadible reception, but utilmately his application was declined.. More at:
Silver Age Comics

Amateur Radio Comic Books introduces the young-uns' to HAM Radio:
Enlarge image
"The Adventures of Zack and Max.....
This story is designed to provide you with some basic information about ham radio, giving a glimpse into its history, its applications, and its relevance in the world today. Whether you’re a student or an adult, this book tells a story about ham radio which we hope you will read again and again."

Find an ample selection of free issues to download or read online at:

DIY Radio Rookies teach young people the art of Audio Production... "The Making of a Radio Rookies Story: From Day One to Air.Follow the journey of Radio Rookie Keith Harris as he reports and produces his first feature story with WNYC's youth media program. .. about everything from interview skills to how to report a personal story:

.Radio Gaga
"The local radio-station where most things never go according to plan. Martin, the young editor, desperately tries to usher the rest of the unbelievably incompetent staff to produce something resembling a radio-broadcast, but he is rarely successful.
Even though the backdrop for this comic-strip is a local radio-station, most of the stories revolve around the six people who work there and their chaotic private lives":

.. It's true that most of the strips have absolutely nothing to do with the radio station, however I did manage to find a couple in the mix..
Zoom in
Make bigger
See more Radio Gaga strips via:



Ok.. Well this post took a lot longer than expected'.. Now I'm tired of it and don't feel like telling you about the radio station comic book I was saving for last..  And it really is rather cool..
But oh well, I'm done.
I'll tell you about it tomorrow.

Thursday, April 17, 2014

Roku - The Poor Mans Barix

Roku LT is media player capable of streaming most any audio and video available on the internet. Measuring 3 x 3 x 0.9 inches the Roku LT is a dependable stand-alone miniature media streaming device which only requires a wifi internet connection and an AC power source.

The Roku line of products are intended for streaming movies and other content to a tv (which it does exceptionally well), but I have adopted it to extend my AM signal range by serving as an audio feed (via ShoutCast) to a second remote transmitter.. Thus it can be considered a "poor mans Barix unit".

Although, I'm still under the stage of experimentation for this use, and have only tried it consistently for a week or so at a time, as of yet have not experienced a single dropout or buffing issue with this unit.

In the event of internet signal loss, the Roku has proved to be self healing when using a shoutcast stream, in that it simply waits for the signal to return and then resumes.. 

However, if power is interrupted the Roku reboots and waits for user interaction, so a UPS might be desirable to avoid such an occurrence.. Another possible remedy is by incorporating the use of a Ruko app that works in any browser called "Remoku" (it's free), which enables a lot of additional controls to how it works, such as automatically starting up the Shoutcast channel to a specific stream... but I haven't actually experimented with it yet, so.. can't say much more about it.

These Roku units are intended to run 24/7, they do not even have a on/off switch, and they use minimal energy. Also note that the higher end models do have the option of using an ethernet connection, but I saw no need for one for my purposes.
I bought this LT model used for $38, then liked it so much I bought a new HD model just for home entertainment on sale for $49.
This certainly appears to be a viable and inexpensive alternative to a $600 Barix installation for feeding a second transmitter located away from the studio.
More info and manuals:

Saturday, April 12, 2014

Charles Hefti - Car Tunes, and the first(?) stereo broadcaster

The Low Power Hour is a radio program produced and hosted by Carl Blair of KDXradio. One of my favorite episodes originally aired on Dec 20, 2010..
The Low Power Hour No. 2 welcomes Charles Hefti, the creator of "Car Tunes," a low power application from the 1960s..

You can listen to it yourself below, but I'll attempt to provide a general overview of this particular episode to wet your appetite:

In 1962 Charles Hefti introduced "Car Tunes" in parking lots of drive-ins and restaurants..
Car Tunes utilized a tape driven message repeater (a new type of product at the time) along with a low power AM transmitter
An actual photo fabricated to be a Car Tunes audience
Car Tunes was intended to sound like a regular radio station playing the top ten songs of the time, plus
interesting topics of the day, along with advertisements for hot dogs and other concessions or products found at the particular locations of transmission.

Several different devices were utilized attempting to succeed in the Car Tunes broadcast.. which eventually proved successful.. The frequency of 1170AM was chosen, and regular programming ensued...   The response from the listening audience of the parked cars was overwhelming, and restaurants participating in the venture expressed an apparent increase in their sales.

Previously in the late 1950's, Charles Hefti became directly involved with a extraordinary event in radio broadcasting.. Keep in mind that in those years stereo recordings were a new capability, and stereo radio broadcast did not yet exist, but Hefti in direct involvement with stations KMOX and KCFM 93.7 produced a stereo broadcast by having KMOX broadcast the left channel while KCFM broadcast the right channel in unison.. (or visa verse). Home listeners would tune in both stations on two different radios, and then sit between them to experience the amazing stereo effect!
Later Hefti superseded that feat with the accomplishment of having the second station in the U.S. to have an actual stereophonic broadcast.

You can't prove she wasn't listening to Car Tunes..
But back to the story of Car Tunes.. It's a great little story, and to hear all the details events surrounding those broadcast, as well as topics described above, in his own words, all you have to do is have a listen to this fun and fascinating interview in this episode of The Low Power Hour by cicking the following link:..

If you would like to hear more Low Power Hour episodes, or would like to air them on your own station (free!), You can contact Carl Blair via his website at or at the forums

Friday, April 11, 2014

Amplitude Modulation in layman terms..

Here's a copy of a great post by Bob Felmly explaining what modulation is. The comment originated in a forum thread here:

There are two ways to explain amplitude modulation or AM.  The correct way and the one that is easy to understand and makes sense to the layman.

For starters, the carrier or continuous AC wave produced by an AM transmitter ideally is a pure sine wave.  Its strength depends on the power applied and the efficiency of the device.

Radio frequency power can travel large distances without wires.  Audio frequencies can not.  The radio frequency power is used to transport or carry the audio without wires connecting the origination point to the end point.

When you add your program audio to the radio frequency carrier, the loudness of the audio causes the amplitude of the carrier to change in step with the audio.  The audio is impressed on the carrier or modulates the carrier.

The audio is an AC signal.  The voltage of the audio alternately is positive and negative.  That causes the carrier to alternately increase and decrease at the audio rate.  The extra power is the audio.  If the carrier is 100 mW the audio needed for 100% modulation would be 50 mW.

The maximum the carrier can decrease is 100%.  If the audio is too loud the carrier can't go beyond 100% in the negative direction as the carrier would shut off at that point.  Trying to go beyond 100% in the negative direction creates RF interference over a wide range of frequencies and must be avoided.

Depending upon how the audio is impressed on the carrier, the carrier can increase more than 100% in the positive direction.  This does not have the same effect as more than 100% negative modulation because the carrier does not shut off it simply keeps getting larger.

When the carrier is modulated more than 100% in the positive direction this is called asymetrical modulation.  Technically, this is distortion but the end result is the received signal sounds louder.  Special modulators allow the positive going signal beyond 100% but limit the negative going signal to no more than 100%.

The other way to explain amplitude modulation is when the audio is mixed with the carrier, new frequencies are generated.  Among others you end up with the carrier frequency, carrier frequency plus audio frequency and carrier frequency minus audio frequency.  The new plus and minus frequencies are called sidebands.  When these three frequencies are mixed together the algebraic sum of the instantaneous voltages produces the modulated output signal.  A lot less words but a little more difficult for some to grasp.

The frequency difference between the plus and minus sidebands is the bandwidth of your signal.  Another words, the bandwidth of your signal is two times the highest audio frequency applied.  The AM broadcast band channel is 10 kHz so the maximum audio frequency should be 5 kHz but that seems to have been relaxed over the years.

OK, that's my stab at it.  Rip it up.
by MRAM 1500 kHz Charter Member - Association of Low Power Broadcasters Chairman - ALPB

A Technical Article About Amplitude Modulation...
Here is a LINK TO A GREAT ARTICLE which explains the process.

Wednesday, April 9, 2014

Get your free Wall-Sized Map of Effective Ground

Click to enlarge (This is not the wall size map, see below for link)

Ground conductivity plays a major part in the effectiveness of your Part 15 AM broadcast range (or any other type of AM broadcast). Knowing the ground conductivity of your particular area is a useful indicator to determine what level of signal performance to expect.

Via the FCC you can download a high resolution ground conductivity map broke up in 48 parts to optimize for printing on multiple 8 1/2 inch by 14 inch papers and assembled to the full size 43 x 69 inches map. Free download available at:
 Here's an example of one part of the map:

Map of Effective Ground Conductivity in the United States (A Wall Sized Map), for AM Broadcast Stations

 Figure R3 of 47 CFR 73.190 of the Commission’s Rules contains a map of the estimated effective ground conductivity in the United States. This data is used to predict the propagation of AM signals across the United States. A higher ground conductivity indicates better AM propagation characteristics.  The map shows that the ground conductivity in the U.S. ranges between 0.5 and 30 millimhos (or millisiemens) per meter.  The conductivity of seawater is 5,000 millimhos per meter, resulting in the best propagation of AM signals.

Tuesday, April 8, 2014

Part 15 radio in State Parks

In the early 1990s the NOAA Office of Sea Grant first began taking a closer look at broadcasting public information using low power AM and published a booklet called "Low Power Radio - An Effective Communication Tool for Making Waves" in 1992, and then in 1998 the Oregon Sea Grant Program along with the Oregon Parks and Recreation Department  performed a study to determine the pros and cons of broadcasting their state park information by utilizing Part 15 instead of the more expensive TIS systems. Their semi-final results of this study was published in 1999 in another booklet entitled Low Power Radio: An Antidote For Coastal Visitors Looking But Not Seeing!

A slightly updated (or alternate) version of the same can be downloaded here:

A few excerpts:

This project evaluated the effectiveness of a 100 milliwatt low power radio broadcast in providing coastal resource interpretation to visitors parked at a scenic overlook. LPR is a limited broadcast range AM radio station that park visitors can tune-in on their car radio to hear pre-recorded messages.

There are several advantages of using 100 milliwatt LPR units in coastal parks instead of a 10 Watt transmitter placed along the highway... 

There is a 100 milliwatt LPR system that broadcasts within a radius of 0.5 square miles from the station,or a 10 Watt system, which broadcasts in a radius of approximately 15 square miles (DeYoung, 1992). The Federal Communications Commission (FCC) does not require licensing for the 100 milliwatt station and commercial advertisement messages are allowed. Sponsorship by a governmental organization and FCC licensing is required for a 10 Watt system. While the 100 milliwatt system can have commercial messages, music, or other sound enhancements, the 10 Watt system cannot.

Project Rationale and Objectives
While the 10 Watt system has a larger broadcast range, its use has several disadvantages. This size system costs about $10,000, requires government sponsorship and a FCC license to operate. Additionally, the 10 Watt LPR system is often used in mobile vehicle settings, where a driver or passenger must see instructional signs and locate the broadcast frequency while traveling at high speeds. Conversely, a 100 milliwatt LPR system costs about $3,500, has few restrictions and can broadcast messages in localized areas to more stationary visitors (see Table 1)
(click image to enlarge)

The 100 milliwatt LPR system can have commercial or sponsor messages, so there are several avenues available to fund the purchase of additional LPR stations. One option is to have a business, or several businesses, purchase the radio unit in exchange for broadcasting a sponsorship message recognizing their contribution toward the broadcast. Another option would be to place sponsor logos on signs or brochures promoting the broadcast and/or provide recognition in the audio message itself. 

Use of 100 milliwatt broadcasts in parking areas provides greater opportunity for visitors seeing signs, attention to message content, and likely leads to greater retention of the broadcast information. Tune-in rates during the 10 Watt Forest Talk evaluations ranged from 1.3% to 8%. While the Boiler Bay project had a tune-in rate of 10% during the first week with only four signs visible, it jumped to 16% during Weeks 4 and 5, a rate which is double the highest Forest Talk listenership. The 100 milliwatt LPR stations must have an adequate number of signs displayed so visitors have the opportunity to tune in to the broadcast.

Whether the OPRD interest level increases enough to widen the LPR broadcast application in coastal parks remains to be seen. The Boiler Bay project results intrigued the Port of Newport and Hatfield Marine Science Visitor Center. Both locations now have a 100 milliwatt LPR station. Results from this study indicate that LPR broadcasts are a promising communication technology for providing park visitors with helpful information.

Thursday, April 3, 2014

Ignore this page.
I'm just throwing up some stuff to call images from on the forums..
Graymark 533 Transmitter: