GatesAir FLX-40 one year in

I was at the WEBE transmitter site recently and took the time to look over the transmitter we installed last year:

GatesAir FLX-40 transmitter, WEBE Bridgeport, CT
GatesAir FLX-40 transmitter, WEBE Bridgeport, CT

Overall, I would say that this transmitter has been very reliable.  We had to install a UPS for the exciter and HD Radio exporter, but that is not a big deal. During the first power outage, the exciter went dark first. It took longer for the transmitter controller board to lose power, in the interim the controller turned the transmitter power all the way up. When the generator came online 10 seconds later, the transmitter returned to operation at 41.5 KW. This, in turn, caused one of the other field engineers to freak out and nearly lose his mind (stay away from the brown acid, FYI).

I installed the UPS a few days later.

WEBE TPO 35.3 KW with HD Radio carriers on
WEBE TPO 35.3 KW with HD Radio carriers on

The transmitter power output is 35.3 KW, which is getting into the semi-serious range. The reflected power goes up when it gets warm out and goes down in colder weather.  Over the winter, it was running about 50 watts.  Even at 138 watts, that represents 0.004% reflected power. The TPO forward goes to the 6 bay, 1/2 wave spaced antenna side mounted, 470 feet (143 meters) AGL. The station covers pretty well.

WEBE Pump station
WEBE Pump station, pump is running 2/3 speed and fans are running at about 1/2 speed

Overall, I would give the liquid cooling system an A grade. The transmitter still dumps a fair amount of heat into the room from the RF combiners and PA power supplies. Most of the heat, however, ends up outdoors. Previously, we had two Bard 5-ton AC units running almost full-time. Now, only one AC unit cycles on and off except for the hottest days of the year. The outside temperature when this picture was taken was 81 degrees F (27.2 C).

Next year, we will have to send a sample of the coolant to be analyzed.

Gates FLX-40, WEBE Bridgeport, CT
Gates FLX-40, WEBE Bridgeport, CT

I have had good experiences with the GatesAir FLX/FAX series transmitters. I would recommend this to a friend.

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, nighttime coverage over the 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 nighttime 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 were 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 database includes stations that are currently dark or stations that were 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 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 that 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 nighttime 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.

AM revitalization comments

I have been reading the comments regarding the FCC’s NPRM (13-249).  Clearly, many people are interested in keeping the AM broadcasting band both active and relevant.  Some of these suggestions have merit but are unlikely to be adopted by the FCC.  Others are viable and could alleviate at least a few of the technical shortcomings of the AM band.  The rest fall along expected positions.  Here is a brief rundown:

  • Clear Channel, iBiquity: Allow stations to transmit in all digital mode.  Likelihood: Possible.  The hybrid version of AM HD Radio has been a failure on several fronts; added interference to adjacent channels, self-interference, poor adoption, wonky CODECs, etc.  However, letting stations choose to broadcast in all digital AM HD Radio may decide the issue once and for all.  As long as the all-digital carriers fall within the current analog channels, this would be fine.  Actually, I would add that stations transmitting in all digital be allowed to choose DRM as well as HD Radio
  • REC Networks, MMTC: Move AM stations to former TV channels 5 and 6.  Likelihood: Unlikely.  It would be a neat solution, however, there are currently many full and low-power TV stations still using those frequencies.
  • Clear Channel, SBE, MMTC, Crawford, et al: Allow AM stations a special translator filing window.  Likelihood: Almost assured.  This has been broached by the FCC itself.  I would add that Class D and Class C stations be given priority.
  • SBE, du trial, Lundin and Rackely, MMTC et. al: Remove the “ratchet rule,” reduce antenna efficiency requirements and city of license contour requirements.  Likelihood: probable.  Over the years, the FCC’s rules and regulations designed to help AM broadcasting’s technical product have done the opposite in many cases.  This is especially true of the “ratchet rule.”
  • SBE, du Trial, Lundin and Rackely, MMTC: MDCL (Modulation Depended Carrier Level) Likelihood: Possible.  MDCL does not do much to improve AM signal quality, but it can save the station owner some money on the electricity bill.
  • Alabama Broadcaster’s Association, et al: Better FCC enforcement.  Likelihood: Not very.  This is another area where interference and AM noise problems can be fixed.  Given Ajit Pai’s desire for “non-regulatory” relief, stepped-up enforcement seems to be a non-starter.
  • Hatfield and Dawson: Eliminate substandard AM stations.  Likelihood: Not very.  Getting rid of substandard stations and letting the remaining AM stations enjoy a little breathing room is actually a big step in the right direction.  H&D notes that the FCC should petition congress for tax relief for those stations that choose to surrender their licenses.  Unfortunately, it does not appear likely that the FCC, congress, and the current station owners would go for it.
  • du Treil, Lundin, and Rackely: Do away with skywave protection for class A stations  Likelihood: Possible.  The argument goes; skywave listening represents a very small number of mostly hobbyists (AM DXers) as other, better methods for program distribution exist for serious listeners.  Sad but true.
  • du Treil, Lundin, and Rackely: No more new AM stations.  Likelihood: Possible.  There is a cogent argument to be made regarding the overcrowding of the AM band.  Stopping any further crowding is a good idea.
  • SBE, Cohen, Dippell, and Everist, et al: Tighten regulations on electrical noise emitters.  Likelihood: Unlikely.  The FCC does not have the mettle to tighten regulations against powerful manufacturing and technology lobbies.
  • iBiquity: Do not let anything get in the way of the HD Radio rollout.  Likelihood: Is it possible to get in the way of something that is standing still?

Talking amongst engineers and AM broadcasters, many of these ideas have merit.  The real question is, will any of this bring more listeners?

CES 2014 and the Digital Radio question

I have been busy of late, however, still keeping abreast of the news of the day.  Along with that, CES 2014 wrapped up recently.  No huge developments, especially when it comes to Broadcasting.  However, there was one item of interest; the updated technical specifications of IEEE 802.11ac.

It is of interest here because of the implications of mobile/portable data developments and their impact on traditional AM and FM broadcasting. The new specification calls for 1.2 Gbp/s per device in the initial release, increasing that throughput to 6 Gbp/s in later releases.  These data rates are for overall transmission, including the WiFi overhead.  Actual usable application data (layers 5-7) would be about 20 to 30 percent less.  Even so, 900 Mbp/s is a phenomenal data rate.  Truly I say to you; this is the future of digital broadcasting.  HD Radio™; may well prove that the “HD” stood for “Huge Distraction.”

The new 802.11ac specification uses MU-MIMO, high-density modulation, larger channel bandwidths, and beamforming technology in the 5 GHz WiFi spectrum.  Of course, the question is, at what distances will this system work?  If it is like conventional WiFi, then 100-200 feet is about all that can be expected.  However, there are also many people interested in wireless broadband (WiMAX) service as an alternative to traditional wired ISPs. For that application, having many outdoor 802.11ac nodes connected by a backbone could potentially blanket a city or campus with free high-speed wireless data.

Example of cjdns network
Example of cjdns network

Along the same lines, there are many people involved in creating mesh networks of various types; be they ad-hoc mobile networks, darknets, bitclouds, etc. Mesh networking is a very interesting topic, for me at least.  The network protocols are getting better and more secure.  WiFi hardware is becoming less expensive and more reliable.  As more and more people put effort into developing protocols like cjdns, local mesh networks will become widespread unless they are outlawed.  You know; because of teh terrorism!!1!!

As it stands today, I can drive for two hours in mostly rural upstate NY and CT streaming my favorite radio programs and have nearly seamless handoffs and very few dropouts.  This is on my three-year-old, beat-up 3G HTC android phone sitting in the passenger seat of my car.

Digital Radio is here, it is simply not the In Band On Channel system that legacy broadcasters have chosen.