March 2012 – Page 2 – Engineering Radio

GPS Jamming devices: FCC says No!

The FCC has become concerned about Jamming devices for Cellphones, GPS and WiFi. So much so, they have released Enforcement Advisory No. 2012-02, which specifies fines in excess of $100,000 per incident.

The advisory states:

In recent days, there have been various press reports about commuters using cell phone jammers to create a “quiet zone” on buses or trains. We caution consumers that it is against the law to use a cell or GPS jammer or any other type of device that blocks, jams or interferes with authorized communications, as well as to import, advertise, sell, or ship such a device. The FCC Enforcement Bureau has a zero tolerance policy in this area and will take aggressive action against violators.

I have ~~two~~ three thoughts:

GPS jammers are increasingly being employed by those who are concerned about their privacy. That set of people can range from truckers who don’t what their bosses to know every aspect of their journey, citizens concerned about GPS tracking devices on their vehicles, or ordinary people who don’t want the phone company tracking their every move via GPS-enabled cellphones.
If only the FCC were as diligent and judicious in pursuit of other interference issues in the radio frequency spectrum. A few immediately spring to mind; IBOC to analog adjacent channels, broadband over power line, electrical noise on the medium wave band, illegal 2-way radios on RPU frequencies, etc. Of course, there is no money in those issues.
Wasn’t the FCC about to allow LightSquared to install high-powered 4G data transmitters all over the place, thus jamming GPS anyway? I know they nixed that plan after the general uproar over the loss of GPS by things like aircraft in flight, etc.

It remains to be seen how, exactly the FCC is going to find things like this:

Hypothetically speaking, in a mobile operating environment while traveling down the interstate at 70 MPH with thousands of other vehicles, it would be the proverbial search for a needle in a haystack. This would be especially true for a GPS-only jamming device, which would require a very small amount of power to jam the weak satellite signals. It presents an interesting problem for the cash-strapped enforcement bureau.

Not all jamming devices are this small, however. After doing a Google search for GPS jamming devices I notice that some of them are great big honking things, with heatsinks and fans, capable of generating large signals on every cellphone, WiFi, 3/4G, and GPS frequency. Those larger jamming devices would be very easy to locate and disable.

Perhaps if the technology wasn’t so pervasive and readily abused by certain corporate and government entities, the desire to jam it wouldn’t exist.

Why be a Broadcast Engineer?

That question was posed to me this afternoon by a coworker. It is, indeed, a good question. Certainly, broadcast engineering is more of a vocation than a career, especially where it concerns radio stations. Why would anyone work for low wages, long hours, little or no recognition, 24/7 on-call, and or unappreciative management?

Further, in this risk-averse, zero-defect, micromanaged environment, what is the upside to being a radio, RF, or broadcast engineer?

I suppose one would have to have some appreciation for history. One of the reasons I cover radio history here or certain historical events is that without knowing the roots of radio, one would be hard-pressed to find today’s version of radio broadcasting even remotely interesting. Understanding that before there was the internet, web streaming, Spotify, Youtube, Sirius/XM, television, cellular telephones, 3G, 4G, and so on, radio was mass media. Radio was people-driven, and people-oriented, not an automated computer programmed from afar. People tuned in for the music but also the personality and the personal connection.

Growing up in the late sixties and seventies, radio was my link to the outside world. As a young boy living in rural upstate New York, my mostly agricultural surroundings seemed a bit provincial. Through radio, I was able to listen to the clear channel stations from New York City, Chicago, Detroit, Nashville, Charlotte, Pittsburgh, Washington DC, Cincinnati, etc. The street that I grew up on did not get cable TV until 1980, prior to that, the rooftop antenna received exactly two channels when it wasn’t blown over by a storm. The black and white TV was often broken, sometimes for over a year. It was of no great consequence, however, when nightly under my pillow, the battery-powered transistor radio was employed until midnight or later.

When I got older, shortwave radio kits were built and listened to.

Through that medium, I learned about life outside of my small town.

Author, sitting in front of Atwater-Kent Model 20 regenerative receiver

The upside is being a part of something that can still be great, although those stations are getting harder and harder to find. Still, there is a certain pride to a job well done, a clean transmitter room, and a well-tuned machine working into a properly tuned antenna. Does anyone even appreciate that anymore? I do. Lou Dickey, John Dickey, Bob Pittman, Leslie Moonves, and other CEOs may not care that the transmitter site is clean and well-kept. They may, in fact, question it as a waste of salary. I appreciate it. Fellow engineers will appreciate it, too.

Starting a transmitter, especially a high-powered tube transmitter, is a joy all its own. Nothing against Nautel, they make fine transmitters, however, when pressing the on button, the outcome is almost assured: The transmitter will turn on. Not so with certain tube-type transmitters. Pressing the plate-on button for one of those can have many different outcomes. There is a certain thrill when it all works right, the first time. There is a certain pride in driving away from a transmitter site, listening to the radio, and knowing; I caused that to happen.

The 90th anniversary of…

Many of the US’s earliest commercial radio stations are celebrating their 90th anniversary of broadcasting this year. I’ve seen announcements for WOR, WGY, and a few others.

It is fun to go back and look at the old pictures of those stations during the golden age of AM radio. If nothing else, it reminds us of what used to be and will likely never be seen again. Stations like WGY employed hundreds of people in their hay day; actors, musicians, announcers, news people, salespeople, support staff, engineers, etc. These days, WGY likely employs less than ten, certainly not more than twenty directly.

There are a few stations bucking that trend, but very few.

So here is to what once was and happy birthday to the hollowed-out shells of their former selves.

The old humming console

We are starting to work at a new client’s studios. It is a bit like stepping into a 1980s time machine, as the newest console seems to be the Broadcast Audio console in the FM studio. I feel I should wear a wide colorful tie and part my hair in the middle when working there. There is also an older UMC console in the second production room.

A what?

Exactly.

It seems the UMC console (UMC was a Connecticut-based console manufacturer that was later sold to Broadcast Audio) was having an intermittent hum problem on all the audio buses.

After poking around under the hood for a few minutes, I decided I should begin with the basics. Checking the power supply for ripple seemed like as good a place to start as any. This console has a 30-volt and a 12-volt power supply. The 30-volt supply checked out good, but the 12-volt supply, not so much:

2.7 volts AC on the 12-volt DC power supply. That will put some hum on the audio, all right. I tried to replace the power supply main filter capacitor, but it had no effect. The regulator must also be bad and it is a Motorola part number which is likely not made anymore.

This is a pretty standard off the shelf power supply, I should be able to get one from Mouser for about $60.00 or so for a linear unit, which will be cheaper than us trying to trouble shoot and repair the old one. In the meantime, I took the 10 amp 0-30 volt bench supply and pressed it into temporary service. The console is working again, for now.

At some point, all this old, um, stuff needs to be replaced.