Gone and apparently forgotten

Can a 50,000 watt AM station disappear from the airwaves and no one notice?

The answer is yes, if you live in the Albany, NY area.  WDCD, 1540 KHz, (formerly WPTR) has surrendered its license to the FCC last Friday, September 28, 2018.  Seventy years on the air and quite the legacy as a Top-40 station in the 60’s and 70’s.

Unfortunately, the station had fallen on hard times the last few years, being silent twice for long stretches of time.  In the end, I suppose it was simply time to pull the plug.

This was my first CE gig in the early 1990’s.  What I remember was, I had a lot of fun working there.

So long and thanks for the memories.

 

A tale of five signals

I am currently finishing an interesting project involving putting up two translators on a diplexed AM tower which also holds a mobile phone/data tenant as well.  All-in-all, this seems to be a very efficient use of vertical real estate.

WMML WENU tower, Glens Falls, NY
WMML WENU tower, Glens Falls, NY

The AM stations are WMML and WENU in Glens Falls, NY.  The AM stations are diplexed using a Phasetek diplexor/ATU.

Diagram showing WENU/WMML tower with W250CC/W245DA antenna installed
Diagram showing WENU/WMML tower with W250CC/W245DA antenna installed
Diplexor diagram, WENU/WMML Glens Falls, NY
Diplexor diagram, WENU/WMML Glens Falls, NY

The translators are W250CC and W245DA which are using a NICOM BKG-77/2 two bay 3/4 wave spaced antenna mounted at 53 meters AGL.  The translators use a Shively 2640-04/2 filter/diplexor which as a broad band input port in addition to the translator input ports.  Since these translator signals are only 1 MHz apart, the higher power Shively filter was installed because it has better rejection characteristics.  The broadband input port allows the NICOM antenna to be used as a back up for any of the three FM stations; WKBE 107.1, WNYQ 101.7, or WFFG 100.3.  Two transmitter sites for those stations are mountain top locations which are very difficult to get to in the winter time.  Having a backup site available takes some of the pressure off during storms or other emergencies.

Shively 2640 -04/2 filter for W250CC and W245DA

The NICOM FM antenna was mounted on the tower when W250CC went on the air in October of 2016.  When it was installed, the base impedances for both AM stations were measured.  For some reason, WENU 1410 KHz seems to be more sensitive to any changes on the tower, thus the WENU ATU needed a slight touch up.  When working on diplexed AM systems, it is also important to make sure that both trap filters, which are parallel resonant LC circuits, are tuned for maximum rejection of the other signal.  During this particular installation, nothing was added to the tower and no change in the base impedance for either station was noted.

Shively Filter, connected to transmitters and antenna
Shively Filter, connected to transmitters and antenna

As a condition of the construction permit, measurement of spurious emissions of all stations sharing the common antenna needed to be completed to ensure compliance with FCC 73.317(b) and 73.317(d).  I made careful measurements of the potential intermod products between the two translator frequencies.  This measurement was completed with my TTI PSA6005 spectrum analyzer.

The primary concern here is mixing products between the two transmitters. Both transmitter are BW TXT-600 with low pass filters before the output connector. There are three frequencies of interest;

  1. (F1 – F2) + F1 or (97.9 MHz – 96.9 MHz ) + 97.9 MHz = 98.9 MHz
  2. F2 – (F1 – F2) or 96.9 MHz – (97.9 MHz – 96.9 MHz) = 95.9 MHz
  3. F2 + F1 or 97.9 MHz + 96.9 MHz = 194.8 MHz

That, plus harmonic measurements out to seven or eight harmonics of the fundamental frequency should be enough to demonstrate compliance with FCC out of band emissions standards. Being that this site has LTE carriers, it is very important to measure the harmonics in those bands. Mobil data systems often use receiver pre-amps, which can amplify harmonics from the FM band and make them look out of compliance. Having a base set of reading to fall back on is always the best course in case the “out of tolerance” condition gets report to the FCC.

Measurements on these frequencies must meet the emissions standards outlined in FCC 73.317 (d), which states:

Any emission appearing on a frequency removed from the carrier by more than 600 kHz must be attenuated at least 43 + 10 Log10 (Power, in watts) dB below the level of the unmodulated carrier, or 80 dB, whichever is the lesser attenuation.

Harmonic frequencies to be measured:

Harmonics for 96.9 MHz fundamental Harmonics for 97.9 MHz fundamental Comments
193.8 195.8
290.7 293.7
387.6 391.6
484.5 489.5
581.4 587.4
678.3* 685.3* US LTE Band 71
775.2* 783.2* US LTE Band 5
872.1* 881.1* US LTE Band 5
969.0 979.0

*Frequencies that fall within the mobile data LTE bands. Traces where recorded and saved for these frequencies.

All of that information, once compiled is attached to the FCC form 350-FM, which, once filed grants Program Test Authority.

BW TXT-600 V2 translator transmitters
BW TXT-600 V2 translator transmitters under test and measurement

Status of AM revitalization

It has been about five years since the AM revitalization initiative was first proposed by the FCC and about five years since the first rules changes took place.  Those rules changes included:

  1.  FM translators for AM stations
  2. Allowing stations to use MDCL (Modulation Dependent Carrier Level)
  3. Changing some of the antenna radiation efficiencies requirements
  4. Changing some of the allowable interference towards other stations requirements
  5. Loosening some rules regarding proofs, MOM, night time coverage over city of license, etc

Things that were not addressed:

  1. Receiver quality and technical advances
  2. Ambient noise levels on Medium Frequency (among other) bands
  3. HD Radio or any other digital modulation scheme

Things that were discussed then changed subsequently as a separate initiative:

  1. The main studio rule, which was eliminated for all broadcasting stations

What has been the net effect of these changes?  Has any of this revitalized AM radio?  The net effect has been approximately more of the same.  There have been many stations that have applied for and received licenses for FM translators.  Those stations, in most cases that I am aware of, receive some benefit of extra revenue because of this.  Stations with carrier power levels of 10-50 KW have taken advantage of MDCL technology to save some money on their electric bill.  Nothing wrong with that.

For stations that use a directional antenna, proofs of performance and other DA matters with the FCC have become slightly easier.  Medium Frequency (MF) directional antennas are very large, require a lot of land, are expensive to build, license and maintain.  I know of several stations which have downgraded from a class B station with a directional antenna to a class D station with a single tower and greatly reduced night time power.   Those downgraded stations certainly benefit from an FM translator.

I have heard from more than one AM station owner who says after four years, they are going to “turn in their AM license and just keep the FM.”  I am sure that they are not informed regarding translator rules.  Perhaps, however, the FCC will allow this in the future; a sort of back door commercial low power FM station classification.

The AM band zenith occurred in November of 1991, when there where 4990 licensed AM stations in the United States.  As of June 30, 2018, the total stands at 4633.  That is a decline of 357 stations.  There are currently 90 AM stations listed as silent.  That represents a decline of approximately 9 percent or less than 1/2 of one percent per year.

The last number of AM stations actually transmitting HD Radio that I found was approximately 110, which differs from the iBiquity (and FCC) number of 240.  The FCC data base includes stations which are currently dark, or stations which where transmitting HD Radio at one time but have since turned it off.  Either way, it is a small percentage of licensed stations.  As of this time, AM HD Radio appears to be a non-starter.  In other parts of the world, Medium Frequency DRM seems to be doing well.  The difference seems to be that the DRM operation is all digital and the digital carriers have a much higher power level than that of the hybrid AM HD Radio being used here.

Of those 4633 standard broadcast stations, approximately 260 belong to iHeart radio, Cumulus owns approximately 120 and Townsquare owns approximately 80.   That accounts for 460 stations.  The remaining 4000 or so stations currently on the air are owned by medium sized corporations or individual owners.  The reason for the distinction; I have noticed that the large corporate owners tend to concentrate resources and effort on those licenses that will make the best return, e.g. FM stations.  Of course, there are a few exceptions to that trend, often in major markets.

Of those 4000 or so remaining AM stations, most seem to be treading water.  They are making enough money to stay on the air.  There are a few AM stations that are doing remarkably well.  Those are the ones with primarily  local content.  The vast majority of AM stations are running some type of syndicated talk.  News/talk and sports radio are the two most common formats.  Conservative news/talk seems to be the bread and butter.  Liberal news talk has been tried, but none have succeeded.

Last May, the Supreme Court overturned the Professional and Amateur Sports Protection Act of 1992.  That federal law prevented gambling on outcomes of professional and college sports games.  With the overturn of that rule, individual states can now legalize sports betting.  It will be interesting to see what states allow legalized sports gambling and whether that has any effect on the various sports radio formats.  I can see where individuals and odds makers may want to get good inside information regarding team dynamics and so on.  The sports network that can furnish such information may be in a good position to carve out a niche.

Music can and does sound good on AM when it is done correctly.  There is a great misconception that AM fidelity is poor.  That is not necessarily so.  There are a good many AM receivers these days which have much better bandwidth than the previous generation receivers.  I am noticing that car radios in particular sound much better.  Yes, there are still problems with electrical noise and night time interference.  There are still technological improvements that can be made for analog AM on the receiver side.

In summary; the revitalization efforts have benefited some AM stations in some areas.  The truth is, that many AM stations have been let go for so long that there is no saving them.  Other AM stations that are still viable are making a go of it.  In nautical terms; there is six feet of water in the hold, the pumps are working and the ship is not sinking… for now.

WKIP

This was the radio station that I listened to (or rather, my parents listened to) when I was a very young kid.  From this source, things like school closings, weather, lunar landings, news, sports and traffic could be heard.  At one point, there was a guy called the “Traffic Hawk,” (real name Don Foster) who flew in a Cessna 172 east and west over main street in Poughkeepsie advising drivers of any slow downs in the area.  That’s right, Poughkeepsie, New York, population 30,000, had it’s own eye in the sky, broadcasting live from the aircraft overhead.  Actually, I think he also flew up and down South Road (US Route 9) in the vicinity of the IBM plant, which employed quite a few people in those days.

There was also a guy who tried to break the Guinness Book of World Records by staying awake the longest, this happened several times.

For me, it was the school closings.  I hated school with an absolute passion.  Everyday, I would ride the school bus and say a little prayer; “…please God, make it today.  Make the boiler stop working, or the electricity to go out.  Make the kitchen catch on fire or the roof to cave in.  You are a great and mighty God and I don’t ask for much.  Please destroy my school today.”  Alas, God did not seem interested in this.

Anyway, back to the topic at hand.

WKIP first signed on in 1940 with the studios and transmitter located at The Nelson House, 42 Market Street, Poughkeepsie.  That building is long gone and  the location appears to be the parking lot for the Dutchess County Office building.  Being neighbors with some influential guy from Hyde Park made for a nice dedication speech:

It signed on with a power of 250 watts on 1,420 KC on June 6th, 1940. Soon thereafter, it changed frequency to 1,450 KC as a part of the AM band shift brought about by NARBA.

Over the years, the station went through several ownership changes. The first major technical change came in 1961, when the station transmitter site moved to it’s current location, then called Van Wagoner Road, now Tucker Drive. The station increased power to 1,000 Watts and installed a direction antenna for daytime use.  It is one of those rare night time non-directional, day time directional stations.

The directional antenna consists of two towers; tower one is 180 degrees tall (103.4 Meters or 340 feet) with 35 degrees of top loading.  That is used for both the day and night time array.  Tower two is 85 degrees tall (48.8 Meters or 160 feet) and is used only for the daytime array.  This pushes the major lobe of radiation towards the north.  I don’t know the reasoning behind that, but somebody spend a good amount of money to make it so.

Here is a air check from the early 1980’s.  Weather on that day was “Sunny, cloudy, whatever… take your pick.”

Good old Steve Diner.

Today, the station looks like this:

The 1961 WKIP transmitter building with tower
The 1961 WKIP transmitter building with tower

When I was growing up, my cousins lived within walking distance of this. We used to come over than throw rocks at the tower when the station was unmanned on Saturdays and Sundays. At least, I think it was unmanned because no one ever came out and yelled at us.

WKIP backup transmitter, phasor and main transmitter
WKIP backup transmitter, phasor and main transmitter

Mid 1980’s MW-1A still runs. The BE AM1A is the main transmitter. The phasor is the Original 1960’s Gates Phasor.

This video shows how the studios used to look, before they were rebuilt by Clear Channel Circa 2002 or so. At about the 2:02 mark, you will see the room pictured above as it looked in 1990.

The space between the video above and the picture below looked bad with nothing in it. It looks better now.

WKIP clock
WKIP clock

That clock is a collectors items and belongs in a museum.