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Not Just a Good Idea

Readers talk back about load management, IBOC power and radio's noise floor

Load Management

Skip Pizzi mentions a “proposal” for electric utilities to load-shed by temporarily disconnecting heavy power users.

At the main WXPR transmitter site on Thunder Lake Road in the town of Sugar Camp, Oneida County, Wis. That’s a reality, not a proposal, for WXPR Public Radio, Rhinelander, Wis., and its electric utility, Wisconsin Public Service Corp. (WPSC).

In 2003 WXPR installed a new site backup generator at its Sugar Camp transmitter site. Since then, WPSC, from Green Bay can (and does) remotely switch the entire site load to backup generator when needed and for tests. The site load includes WXPR’s FM and HD transmitters and the FM transmitter of a tenant commercial station. In return, WXPR gets a substantial power bill discount.

WPSC’s load-shed control is fed via a subcarrier on the broadcast signal of an area commercial FM station. A receiver at the WXPR studios decodes the command, which is fed on the STL to the transmitter site. A WPSC “shed” command automatically starts the generator and transfers the load in a couple seconds without human intervention at WXPR. Listeners usually do not notice the switch to/from generator.

This system is common for heavy power users in the WPSC service area.

I should explain why the subcarrier receiver is at the WXPR studios in Rhinelander. Normally it would best be close to the generator. However, we couldn’t get a reliable off-air control signal at the transmitter site. So the receiver is located at the studios in Rhinelander.

More tech details of the system: A “disconnect” command is sent from the WPSC system control center in Green Bay via telephone line to a commercial FM radio transmitter serving the Northwoods area and transmitted on a subcarrier. Each WPSC subcarrier receiver has a unique address, so any one or all electric customers can be “commanded” to disconnect and operate on generator. It’s a “failsafe” system, so loss of the command causes the customer equipment to switch back to the utility network.

At the WXPR studios a WPSC “disconnect” command closes “dry” contacts in the receiver. This is converted to a serial command and transmitted on a serial channel on our Moseley STL to the transmitter site, where it is converted back to a contact closure. A closure causes a Kohler generator transfer switch to start the generator and take the load from the utility network. It takes about two seconds to start the generator, bring up to speed and switch load. The actual load switch is almost instantaneous and usually not noticed by listeners.

A further complication is that the generator load capacity is exceeded if the two air conditioning units in our transmitter building are running. That’s likely to occur in very hot weather, at the very time the utility network needs to shed some customer load. So our HVAC controller in the transmitter building inhibits air conditioner operation when the building is on generator but allows fan ventilation. The two large fan openings can be seen in the photo.

There are four buildings at the WXPR transmitter site, three of which are partially visible, along with the base of the WXPR tower. The original transmitter building at left now houses a tenant LPTV transmitter and the generator controller. A second, partially visible, houses a tenant commercial FM transmitter. The building in the right background beyond the tower base contains the WXPR Nautel FM and HD transmitters, STL, etc. A fourth, not visible, houses a commercial television transmitter. The two TV transmitters are not served by our backup generator. The commercial FM and TV transmit and STL antennas are on a second tower.

Elmer A. Goetsch
Chief Engineer
WXPR Public Radio
Rhinelander, Wis.

I Told You So

I read an issue of The Leslie Report this summer with interest and did my best to avoid shouting at my computer screen, “I told you so!”

The headlines and text say it all: “Indoor Reception ‘Impossible’ to ‘Non-Existent,’ Say iBiquity and Greater Media,” “IBiquity, Greater Media Say Drive Tests Show ‘Serious Digital Coverage Deficiencies‘” and the line I loved the best, “Only the full 10 dB increase will permit reliable service to portable IBOC receivers and come close to replicating analog coverage” (my underline).

As a multitude of engineers implored before this commercially-driven debacle was foisted upon us: Be sure this is the best possible system and one that will work as well or better than analog.

But noooooo … the big commercial giants decided for us and “lobbied” the commission to implement it (read: shove it down our throats).

Now that is has been unequivocally proven that it will not, or ever, be as good as analog, we are stuck with this albatross. This whole scheme was designed for one purpose only: Make money for iBiquity! Well, how’s that working for you?

When broadcasters can’t just buy a transmitter but must also buy the “rights” from iBiquity to use it, owners are just rushing to give away their money, aren’t they?

This was a poorly-thought-out concept to begin with, but what do we engineers know?

What might have been a better alternative (not that I am advocating it, just presenting what might have worked better) is for all the receiver manufacturers to convert to a dual-use analog/DRM chip that would automatically decode the received format. After a decade or so, when the vast majority of radios were digital-capable, switch over all stations at once, ending analog broadcasting.

This would eliminate most all the current problems and be a seamless transition. The AM nighttime situation would also not be as big a problem, with the current iBiquity AM system being all but abandoned, just as AM stereo died its inglorious death (at the hands of Motorola).

Now that all the money has been invested (read: poured down a rat hole), it is time for the rest of the broadcast industry not partnered with iBiquity to take the albatross from around their neck and make their analog signal an engineering masterpiece, which a good analog FM is, and put some programming worth listening to on it.

Digital is not a good enough reason for listeners to flock to your signal; they need something to excite them. Radio was a fantastic medium when it was all live and always different. Digital repeater radio doesn’t cut it. Get back to what works, and you will be surprised at the results.

Mike Vanhooser
Nova Electronics

Good Diagnosis, McCoy

Great article by Frank McCoy in Radio World about WiFi radio delivery vs. terrestrial delivery (“The Problem Isn’t Demand, It’s Bandwidth,” Sept. 1)!

That article, along with the FM option coming to new iPods, ought to have a lot of radio people sleeping a little bit better tonight.

Rob Robbins, Ph.D.
91.9 The CALL

Noise Floor Issues

I was very pleased to see an article in the latest world about the increase in ambient noise floor being a severe problem for broadcasters, especially in that it touched on the major issue of RF noise from consumer electronics (“Can Radio Get Noise Floor Issues Under Control,” Aug. 12).

Touch lamps especially seem to be the bane of my existence.

I have a solution for many of these problems, and I understand that people might consider this extreme. But many of the RF noise source issues can be solved by the FCC actually enforcing the Part 15 regulations.

There are an incredible number of products being sold today which do not even begin to meet the Part 15 emission standards. I do not think it is even possible to build a touch lamp which will meet the Part 15 standards. Manufacturers do not take the standards seriously because they know they aren’t going to be enforced. In many cases, the vendors selling products in the US are just taking something manufactured abroad and have no idea there even are any FCC standards.

Last year I was dealing with a US-made computer which was purchased by a customer of mine at a local AM station, which emitted so much trash that they could not reliably receive their own station in their office.

The power supply was a cheap unit of Asian manufacture with no FCC certification. When I called the manufacturer, they didn’t seem to understand what the problem was, and offered to send me an FCC certification sticker that I could put on the computer as if somehow this would magically make everything all right.

Manufacturers don’t take noise standards seriously, and they aren’t going to take them seriously unless pressure is put on them. Consumers don’t care; they don’t understand the issues and many of them are not willing to pay more money for properly designed devices for a noise improvement that may only benefit their neighbors. The FCC doesn’t care for reasons that I really don’t understand. But until the FCC starts to care, until we make them care, the problem is just going to get worse and worse.

Scott Dorsey
Kludge Audio
Williamsburg, Va.

Don’t Forget This Noise Source

The article “Can Radio Get Noise Floor Issues Under Control” failed to mention the digital signal of HD Radio as a contributor to the noise floor.

Stanley Swanson
Yuma, Ariz.

Who Is an Engineer?

I have to take issue with the writer of “What Is a Professional Engineer?” (Reader’s Forum, May 20).

The Association of Federal Communications Consulting Engineers took this before the FCC back in 1974 and requested that the commission allow only state certified Professional Engineers (P.E.) to be able to file the engineering data on FCC license applications. The commission at that time rejected this notion, stating that most states’ P.E. testing had nothing to do with “radio engineering” and was focused on civil, structural or mechanical engineering as a requirement for the construction of roads, bridges and other heavy construction projects. Furthermore, the states were much different in their testing as to the state of the art.

I graduated in 1971 with a BSEE and my senior class was called to a meeting with the State of Wisconsin Architects & Engineers Board to introduce senior-level engineering students to the “Engineer in Training” (EIT) application program and initial testing to become a P.E. In this state, in order to get a P.E. at that time, you had to qualify with a bachelor’s degree in electrical, mechanical or civil engineering, then take the EIT test, then follow with four years of “engineering work” as a “trainee.” Sample tests were passed out at this meeting, and after looking them over, they were primarily mechanical and civil with emphasis on statics, dynamics, soils, concrete strengths and other mechanical issues. The lone problem concerning electricity was a municipal street lighting network employing 500 watt incandescent lamps!

After I saw this, and with my interest in electrical power and RF, I dismissed the P.E. as a joke and never wasted my time getting it. I had received my First Class Radiotelephone License at age 17 (with Ship Radar Endorsement), and the Second Class Radiotelephone license test at the time had questions that required the applicant to actually draw the circuits, not multiple choice!

Since then I have come in contact with many who have P.E. stamps and I hate to say it, but many throw this around like they are VIPs. A municipal official in a discussion I had some years back stated that the many consultants with P.E. after their name were “Pitiful Engineers.”

So as far as I am concerned, the FCC in 1974 carefully examined this and acted correctly.

With respect to the heavy construction trades, civil, mechanical and electrical projects requiring a P.E. (mainly for legal protection), it may be justified.

John C. Aegerter
Brookfield, Wis.

RW’s New Look

[RW’s new look] is the best improvement since Steve Dana started this rag … and took my suggestion about making a box for the address label, rather than the haphazard way of slapping it on a part of the front-page story, which of course caused me to run to the nearest phone booth (remember those) and don my Superman outfit so my laser vision could read under the label.

Keep up the good work.

“Uncle” Bill Spitzer
WLS Communications
Rapid City, S.D.