July 2010 – Page 2 – Engineering Radio

How do you listen to streaming audio on an Android smart phone?

Update:There is a better way: www.engineeringradio.us/blog/2011/03/tunein-radio/

Ahh, since I posted about my android, a few readers have emailed me and would like to know. If you have tried to stream audio using a smartphone web browser, you have found out that it simply doesn’t work. The web browser is unable to decode the radio station stream because most of them are in AAC, AAC+, HeAACv1 or some other codec. At this point, most people give up on the idea and move on. I, on the other hand, determined that it should be doable.

First, I attempted to down load a few apps, but they either crashed or didn’t do what I wanted or weren’t in the right language, or something.

Clear Channel has something called iHeartRadio, which is a clearing house for mobile users that want to listen to Clear Channel radio streams on their iPhones. I don’t know, once you have heard one Kiss-FM station, you’ve heard them all as far as I am concerned. Most other Clear Channel programming is boring and uninspired.

What I finally ended up doing was going to Moodio and reading up on a few things. Here is a good step by step way to use Moodio to listen to radio station web streams on any mobile device.

Be aware that not all data plans are the same. ATT, Sprint, and others now cap data transfer and charge extra if a subscriber goes over. Know your plan.
On a regular computer, go to Moodio (http://www.yourmuze.fm/)
Set up a user account
Select from there list, the stations you want to listen to. They have many US stations as well as many from Europe. If the station you are looking for is not there, you can request that it be added.
Select the default data rate. Since I have unlimited data, I chose the highest rate for the best sounding audio. Others may want lower data rates so as not to exceed data caps.
Point your mobile device web browser to www.m.yourmuze.fm
Log into your account
The stations on your listen list will be displayed.

That is a lot of steps to take. Somebody has to be very into radio or a radio station to do something like that. A forward thinking radio station or group will be writing or paying somebody to write mobile streaming apps for their stream(s). A forward thinking radio station or group would then feature links to these apps prominently on their web pages. Very prominently if they are in a PPM market. Ahem, very prominently if they are in a PPM market.

That is what a forward thinking radio station would be doing…

Satellite dish wasp fade

More bee-related RF stories. This happens often this time of year, the paper wasps have worked hard all spring to build their nests up in size, and during July, they become large enough to block the aperture of the antenna mounted on a satellite dish. As the nest fills up with eggs and larvae, it becomes denser and blocks more RF from the antenna. Soon, the signal on the satellite receiver drops, and audio dropouts occur.

I have noticed that the newer generation satellite receivers are not as good as the older Starguide III and II units. The Starguide receivers were pretty light-duty when compared to the Scientific Atlanta 7300 or 2300 series units. Those things were built like tanks, took up a lot of rack space, and so long as one replaced the power supply capacitors every so often, never failed. The newer satellite receivers are very intolerant of phase shifts or carrier disruptions. Many times, the signal strength might look to be above the dropout threshold (usually 4.5 to 5 dB), but the audio still occasionally cuts out. That symptom is almost always bees in the feed horn.

3.2 meter comtech dish — 3.2 meter COMTECH satellite dish

This dish is mounted up high above the roof of the building on 6-inch well casing. In order to service the feed horn, one has to either rent a cherry picker or loosen the azimuth bolts and spin the entire dish around so the feed horn is over the roof area. Then an eight-foot step ladder is a need to get to the feed horn. Luckily, it is a flat roof. Needless to say, I made sure the feed horn had the proper cover over it so that no bees could get in.

satellite feed horn with insect cover — Satellite dish feed horn with insect cover installed

Bee fade is best cured with a can of Raid Hornet and wasp spray. The culprits are almost always paper wasps, which, I can tell you from experience, have a nasty sting. Once the nest is cleaned out of the antenna aperture, a proper cover must be installed. If one finds that they don’t have a proper cover, I have found that a top from a spray paint can work as a temporary cover until a proper one can be installed. I would not call a spray paint can cap a permanent solution because the sun will eventually degrade the plastic and it will fall apart.

The sad story of WCVR

I have been the road warrior lately if you haven’t noticed a certain decline in the blog posts… One place that seems to keep pulling me back is Randolph, VT, which is about as close to the geographical center of Vermont as one can get and still be on a roadway. There resides the silent FM station formerly known as WCVR, to be returned to the air as WXVR by Vermont Public Radio.

WCVR went on the air in 1982 and was a community-oriented country station for 17 years. Then in 1999, it was sold to Clear Channel and things began to go downhill. Over the next decade, the station transferred ownership four times. Finally ending up with absentee landlord Vox Radio. By the time the station was sold to Vermont Public Radio last May, the years of neglect were compounded and the main transmitter was no longer running. The transmitter site was raided before the transfer and things like spare parts, a backup transmitter, and a dummy load were removed. As one engineer from VPR noted, the only thing of any value is the Shively antenna.

This story probably repeats itself a thousand times throughout the country as a small market, formerly community radio stations are left to die on the vine by big-time corporate radio gurus in Atlanta, San Antonio, and Las Vegas.

Said station has a McMartin BF5-K transmitter that is not currently running and by the accumulations of dirt, debris, and other evidence, has not run in quite some time.

The beauty of a McMartin FM transmitter is it is a grounded grid. Can’t get much simpler than that when it comes to FM transmitters. The downside is, of course, McMartin has been out of business for almost thirty years. Thankfully, Goodrich Enterprises is still around and still supports them.

The first order of business was cleaning out the filthy, and I mean absolutely filthy building. Several hours with a broom, dustpan, and shop vac got rid of most of the dirt and made my skin less likely to crawl. Then came the fateful attempt to run the transmitter. Loud arcs, power supply hum, and dimming lights revealed that all was not well. All of the fluorescent lights were out, new bulbs did not fix the problem. So, to the Grainger to pick up new fixtures and install them. Now, at least, we could see what were doing.

Next, step-by-step troubleshooting of the High Voltage power supply. Step one, resistance checks on the HV transformer and filter chokes to the ground. Next forward and reverse resistance checks on the rectifier stacks. All of those looked good. Next, we isolated the HV transformer and the rectifiers and turned the transmitter on; no problems. Next, we added the metering and filtering capacitors and turned the transmitter on; no problem. Finally, we found the problem with the HV power supply RF filter on the side of the PA enclosure. In a McMartin FM transmitter, there is a little box mounted on the outside of the PA enclosure that holds half the parts in this circuit. Taking that box off revealed a bad 200 pf 7.5 KV doorknob capacitor that was shorting to ground. Lots of arc marks, soot, debris, and other stuff make me think that this problem had been going on for a long time. I can kick myself for not taking a picture.

Hopefully, this thing will run for a few months while a replacement is sought.

Compounding that issue is the leaking transmission line connector at the bottom of the antenna, which was fixed, but there appears to be another leak somewhere else as the line still does not hold pressure for very long.

VPR is going to broadcast their Classical Music format on this station, starting as soon as we can make the transmitter run.

UPDATE: Pictures:

300 foot WCVR tower, Randolph Center, VT

Transmitter building:

WCVR Mc Martin BF-5K transmitter:

Arcing power supply filter section, the bad door knob capacitor has been replaced, still evident are the arc marks on the PA cavity:

Mc Martin BF-5K transmitter on the air:

We’ll see how long that lasts.

Radio World Redux

I was reading the July 14th radio world, online because I still haven’t subscribed, and found this blog quoted by the editor. More specifically, on page 4, the editor writes about this post where I debate keeping my radio world subscription. Without actually naming the blog, asks how well he (the editor) is doing his job.

One of my aims in writing this thing is to provoke thought. The fact that the editor of Radio World is asking his readers about the direction the publication is heading is a sign that, at least in one case, I have been successful.

My other aims are:

pass along useful information
tell my story
write stuff (I am compelled to write things)

Regarding Radio World itself, I still read the digital version of the magazine found on the Radio World website. The importance of impartial reporting of radio broadcasting’s technical issues cannot be overstated. These days there are many pressures being applied to Radio in general from things like the FCC, Big Group Radio, MMTC, Ibiquity, NPR, the recording industry, and others. Some of these groups do not have the radio industry’s best interests in mind, but rather are looking to improve their take. Indeed, some of the schemes proposed are technically flawed or downright destructive. Biased reporting degrades the integrity of any publication and diminishes its value and when it comes to the most-read technical trade magazine, that is alarming.

I applaud Radio World for its recent publication of articles that bring to light HD-Radio’s technical issues. That is a welcome development and such things should continue. Technical writers need to be technically minded people, not someone that retypes press releases. When it comes to new technology, the hard question need to be asked and answered, that is a reporter’s job after all.