Paul Thurst – Page 160 – Engineering Radio

The folded Unipole antenna

In the 1990s, the folded unipole antenna was touted by many to be the savior of AM radio. There were many claims that a folded unipole antenna did not need a complicated ground system, a simple ground rod at the base of the tower would work fine. That turned out to be not exactly the case. Kintronic did a study (.pdf) that basically dispelled that notion, along with several others. The folded unipole antenna performed within a few percentage points of a series-fed tower under the same testing conditions.

three wire folded unipole on a guyed tower

Folded unipoles do have the advantage of a grounded tower. Grounded towers have a distinct advantage in lightning-prone areas, such as central Florida. I can attest through my own experience, a series-fed tower is much more likely to induce lightning damage to a transmitter or ATU. Folded unipole tower systems can also be used to co-locate other antennas, such as STL, cellular, PCS, etc. Making some extra rental money on an AM tower is not a bad way to go.

I began fooling around with MANNA-GAL, which is a NEC-2-based program. It is a free ham radio program, so it is a little clunky to use and it took a while to figure out, but once I did, it is fun. I modeled a unipole antenna for medium wave use and the results are pretty interesting. First of all, I drew out X-Y part of the system on graph paper because the program requires all wires (elements) to be entered in a coordinate-based format. The Z axis is the tower, since there is only one of those, that was easy. I played around with series vs. unipole systems and the results were fairly close to what they are supposed to be. One of the nice things about MANNA-GAL is it allows the user to change the ground conditions. To add a unipole to the tower, I put 3 wires spaced one to two meters away from the primary Z-axis wire, connected them to the top of the tower, and changed the drive point to the skirt wires.

The interesting part is when I added an above-ground counterpoise instead of a buried radial ground system. I think Ron Nott, of Nott, ltd. did much of this work too. What I found was that with between 5 – 10 above-ground radials of 90 degrees or greater, the efficiencies are within about 10 percent of theoretical for a 120-buried radial system. Again, the ground conductivity plays a big role in this, poor ground conductivity will reduce efficiencies equally for both systems.

As the tower height approaches 110 degrees or so, depending on the spacing from the tower of the skirt wires, the bandwidth really starts to open up. At 110 degrees the base impedance is about 120 ohms with about 80 ohms inductive reactance. Both the impedance and reactance slope slightly upward with frequency but are linear +/- 50 KHz of the carrier. This slight asymmetrical sideband distribution can be easily canceled out in the ATU with a few degrees of negative phase shift through the T network.

Again, all of this is theoretical, but I have found that NEC is usually within +/- 10% of real-world values. It is difficult to get a handle on ground conductivity unless measurements are taken. Even from season to season, that can change.

The above-ground counterpoise requires a partial proof, according to FCC 73.186. If this were a directional station, this would be required anyway. For a non-directional station, it is pretty easy, for six radials, it would probably take about one to two days of driving around with a FIM 41. The other consideration is public exposure to RFR from the radials. This can easily be measured with a NARDA meter. More radials will spread the induced currents out more, for higher-powered stations, 10 above-ground radials might be required.

There are several radio stations in the country that are successfully using above-ground counterpoises. It seems to be a good system and requires much less material and labor to install than the traditional ground system.

Therefore, if I were designing a new AM station, I’d use a grounded tower between 105 and 110 degrees with a unipole and 6 above-ground radials 90 degrees or greater.

Common Alert Protocol (CAP)

Since the FCC started the CAP clock ticking on September 30th, there has been a flurry of activity regarding the manufacture and installation of CAP equipment. CAP is integrated into something called IPAWS, which stands for Integrated Public Alert and Warning System. In other words, CAP is the vehicle that IPAWS uses to get information broadcast through radio, TV, Cable systems, etc. IPAWS encompasses all alert types including cellphone, texting, e-mail, and landline phone calls. Many states, including New York State, already do this. FEMA spells out the reason for IPAWS:

The advent of new media has brought a dramatic shift in the way the public consumes information. IPAWS, as the next generation emergency alert and warning system, capitalizes on multiple electronic media outlets to ensure that the public receives life-saving information during a time of national emergency.

Historically, the public depended exclusively on radio and television to receive alerts, but current research shows that the reach of radio and TV is less than 40% of the populace during the work day. While less than 12% of the population is watching TV in the middle of the night, an even smaller number is tuned into the radio, at 5% of the populace. Television and radio will continue to be valuable sources of public information, but their reach is decreasing. Further, these information sources can only target a state or regional sized area and do not encompass alerting for people who do not speak English or those with disabilities, including the 29 million suffering from hearing impairment.

Today, the internet, including video and email, and cellular and residential phones are increasingly popular and therefore, valuable, sources of information. One study showed that the Internet has a 62% usage rate, averaging at 108 minutes a day. While television remains the most popular source for information, the Internet ranked either first or second at both work and home.

CAP figures into this by acting as a method to move data between IPAWS and EAS. The basic CAP converter polls a CAP server, somewhere, for messages. When a message for a geographic area is received, the CAP converter processes it and converts it to an EAS format, which is then sent via high-level audio to the station’s EAS encoder decoder unit. The EAS unit receives the information and then has the final say (or station personnel if the EAS unit is in manual) as to whether the EAS message gets transmitted.

FEMA will be setting up a national CAP server in the next month or so, expect an announcement from them in November. Each state can also set up a CAP server for state and local government use. This will be implemented on a state-by-state basis. Currently, there is no information on the New York State Emergency Management Office’s (NY SEMO) website, hopefully, they are aware of all of this and will be updating their system shortly.

The CAP converters installed in individual stations will access the CAP servers via secure HTTP connections. They will also be able to download software updates from the manufacturers via the same method.

The surreal trip to the WICC transmitter site

What could be so bad about going to an AM transmitter site on a peninsula off of the Long Island Sound. Sounds pretty nice, right? It began just so, driving through the town of Stratford Beach parking lot to the construction gate, the towers were visible off in the distance. A nice crushed gravel road across the barrier island, I have certainly been to worse places.

WICC towers pleasure beach island — WICC towers Pleasure Beach Island, CT

And then, things begin to look a little bit different. It is really hard to put into words, seems like some other country.

Pleasure Beach Bungalows — The beginning of the Pleasure Beach Bungalow Colony

It turns out this is not quite a nice trip after all.

Pleasure beach lawless zone — Pleasure Beach Lawless Zone

I’ve been to several so-called “developing areas” like Port Au Prince, Hatti for example. Nothing ever looked this bad.

Pleasure Beach ocean side bungalow — Pleasure Beach Ocean Side Bungalow

I can imagine some family coming here every summer to spend time at the beach.

What anarchy looks like.

Pleasure beach burned out cottage — Pleasure Beach burned out cottage

The back story is this: From the 1920s until 1996, Pleasure Beach was a nice seasonal oceanside bungalow colony, complete with an amusement park. These cottages (but not the land they were on) were owned by people from the surrounding cities and towns and the entire area appeared to be quite nice in its day. Then, in 1996, the wooden bridge that connected Pleasure Beach to Bridgeport burned. There are several theories; crackheads, radical environmentalists, etc. The city of Bridgeport did not rebuild the bridge, which meant the only access was by walking from the Town of Stratford beach parking lot, a trek of at least a mile or longer. In 2007, the town of Stratford decided not to renew these land leases, and the building owners were forced to remove any remaining items they wanted by barge. Soon thereafter vandals began walking down the peninsula from Stratford. Slowly, most of the bungalows were broken into and several were burned. This is mostly the work of “kids,” who, because they are under the age of 18, get a slap on the wrist and returned to their parents. Oh, those wacky kids, what will they do next?

Truth be told, they should be the ones out here cleaning this up, for free.

Finally, this year, the city began tearing down and cleaning up the remaining buildings, trying to put the former bungalow colony “back to nature.”

The transmitter site for WICC moved here in 1932. This building contained a nighttime operating studio, kitchen, bathroom, and bedroom. I can imagine hanging out here some summer night, spinning tunes, and having a good time. The former amusement part is just out of the picture to the left. At the amusement park, there was a carousel, a big snack bar, a dance hall, and an area for portable rides like Ferris Wheels and such.

Now the building is full of disused gear, old carts, transmitter, and tower parts, the water has been shut off and I’d not want to be out here at night under any circumstances.

The antenna array consists of two 300-foot Milliken towers, originally installed at WNAC (Now WRKO) Boston, MA. They were moved to Pleasure Beach Island in 1932. Many people mistakenly think these are Blaw-Knox towers. Milliken preceded Blaw-Knox by several years. They built and designed towers around the world for radio and electric transmission. In the late 1930’s they were bought out by Blaw-Knox, which kept the design. I love these tapered self-supporters, they have survived several major Hurricanes since 1932. The south tower is about 150 yards from the Long Island Sound. Salt air seems to do them no harm, either.

WICC Milliken tower, south looking up — WICC Milliken south Tower, looking up

The station operates at 1 KW day, 500 watts night, DA2. The towers are 60 degrees tall, spaced 149 degrees. That is a little short, however, they are surrounded by salt water, so the signal goes like gangbusters. Because they are short, the impedances are low, about 10 ohms for nighttime and 30 ohms for daytime. Since the towers are so wide, the impedances are flat far beyond 50 kHz on either side of the carrier, which makes it a nice broad-banded antenna system. The 1932 phasors and ATUs were redone in 1972. All of the common point impedance measurements are still posted on the wall.

WICC Harris SX-1A, Phasor and Harris BC1H — WICC Harris SX-1A, Phasor and Harris HC1H

The main transmitter is a 1990 Harris model SX-1A. It seems to be reliable enough, my experience with the SX-1 is it has an overly complicated control system. The backup is a Harris BC1H, a sort of hybrid solid-state tube unit, which is also reliable.

Frequency voltage meter — WICC frequency and voltage meter

This high-tech test and measurement center is attached to the incoming electrical service. Over the years, there have been some quality control issues with the incoming electrical service, mostly due to Osprey building nests on the crossarms. During rain storms, these nests catch on fire and kill the power to the site. The power company is in the process of redoing the electrical service to the building.

This is a video of the former amusement park and cottages shot two years ago when the cottages were more or less intact. It is a bunch of stills set to Pink Floyd music:

Looks like they all just got up and left.

Simulcasting: The sound of broadcasters running out of ideas

There seems to be a growing trend lately; Stations that had previously separate programming being simulcast. There are two big ones around here: WGY and WHRL and WPLJ and WXLM.

Lets begin with the first one: WGY, now WGY AM/FM.

WGY (Clear Channel Communications) has been the regional powerhouse since it’s inception in 1922. It consistently ranks in the top 5 Arbitron ratings for Albany/Schenectady/Troy NY and is well-received in the community. It carries the standardized Clear Channel talk radio format of Limbaugh, Beck, Hannity, etc. As of September 20th, WHRL 103.1, class A licensed to Albany changed its call sign to WGY-FM and began simulcasting WGY 100%. 103.1’s 60 dBU contour is entirely within WGY 2.5 MV/M contour.

It would seem that radios, even bad radios, would have no problems picking up WGY’s signal within the 103.1 listening area. According to Clear Channel Management:

The decision to simulcast our 24-hour news/talk format on the FM will open up our content to an even wider audience. Despite the huge audience we currently enjoy, the fact is a significant portion of the Capital Region audience never thinks to visit the AM dial.

There is some small amount of truth to that statement; the younger segment of the population generally never listens to AM. Yes. The reasons, however, are not just because it is AM and they are prejudiced. More likely, there is nothing on the AM dial that interests them. Satellite-syndicated talk is not everyone’s cup of tea, so to speak.

The other side of the coin is the former WHRL had an alternative rock format, which never did all that great (I have a theory on why Alternative Rock, AAA, and other such formats never get good ratings, but not right now). They also had a station staff, which by the time they pulled the switch, was down to one person. The Capital District Business Review notes:

According to BIA/Kelsey, a media research firm in Chantilly, Va., WGY did about $2.8 million in revenue in 2009. WHRL took in about $875,000.

Which is really not bad for a class A FM in market #63, during a recession. Apparently, not good enough, however.

The second example in our little story is that of WPLJ and WXLM. WPLJ 95.5 (Citadel Broadcasting) is of course one of the heritage FM stations in Market #1. WXLM 104.7, now known as WELJ broadcast from the far eastern end of Long Island (Market #18), so the respective coverage areas do not overlap. Prior to September 24th, that station was doing a News/Talk format.

That end of Long Island is pretty affluent, a local (unique) station might even prosper. In fact, up until 2003 it did quite well for itself, then known as “The Beach.” However, nothing lasts forever, and in 2003 Citadel Broadcasting purchased the station.

It has gone through a number of changes since then, most recently a syndicated news talk format. Unless I am missing it completely, during the last ratings period, this station did not even show up in the book. As of September 21, it began to simulcast the co-owned out-of-market AC station, likely for the drive-by PPM listeners in it. Again, no word on the fate of the former radio station’s staff (if there was one).

So what gives? Consolidators have already cut staff levels to the bone with voice tracking, syndication, and automation. Even a voice-tracked syndicated station still needs some staff members; the occasional morning show, somebody to do promotions, and some form of program direction due to things like music logs and other such behind-the-scenes work. Staff require salaries and salaries are expensive. Anyone that has ever looked at a company’s P&L can tell you, salaries are the number one expense. If, however, the entire format is blown out, and something can be plugged in to fill the void that costs nothing and has no overhead and no staffing, well, now they are really saving money. That money from reduced expense is much better (far easier) than actually earning more money and it goes right to the bottom line.

This never-ending drive to reduce expenses at the expense of everything else drives programming quality and thus entertainment value down. Who wants to listen to the radio and be bored? Not I. This continuing trend is what will ultimately spell the end of terrestrial radio.