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Building the FM band

Update and bump: I hate to rehash old stuff, but I added quite a bit of information to this post, including .pdfs of all the Barbeau letters, blue prints, etc. I’ve been doing quite a bit of work at this site lately, so it is in the front of my mind. I have also been reading about the Rural Radio Network, which covered western and central New York.

WFLY transmitter site, August 1949

WFLY transmitter site, August 1949

Several years ago, I rescued a old filing cabinet that was being trashed. This particular file cabinet was moved to a transmitter site during the great radio consolidation of the late 90’s and early 00’s. In it, I discovered a treasure trove of early documents about two radio stations from the Albany NY area. I thought it would be interesting to document the building of one of the early FM stations in Albany, WFLY.

Albany is the capital of New York.  There were several early (prior to 1940) AM radio stations in the Albany area:

  1. WGY previously owned by General Electric in Schenectady, signed on in 1922
  2. WHAZ, previously owned by RPI (Rensselaer Polytechnic Institute), signed on in 1922
  3. WOKO (now WDDY), signed on in 1930
  4. WABY, (now WAMC-AM), signed on in 1934

General Electric, who worked closely with RCA in radio development and experimentation, was working on TV in 1928 and FM radio in 1938/39.  There were also several early (prior to 1950) FM stations in the area:

  1. GE owned W2XOY on 48.5 MHz (circa 1939), later W85A, WGFM, and WRVE 99.5 MHz.
  2. Independently owned W47A on 44.7 MHz (circa 1940), later WBCA 101.1 MHz, now gone.
  3. WTRY owned  WTRI-FM on 102.7 MHz (circa 1947), off air by 1954.  102.7 frequency later used by WEQX in Manchester, VT
  4. Troy Record owned WFLY on 92.3 MHz (circa 1948).

These stations operated from transmitter sites in the Helderberg escarpment on land that was formerly owned by the Albany Bible Institute.  It is interesting to note that two of the four FM stations did not make it past 1955. In 1967, WTRY did make a second attempt at FM, launching WDKC on 106.5 MHz, which is today known as WPYX.

It would appear the Troy Record initially applied for an FM broadcasting license in late 1946.   The paper trail that I have starts in early 1947, when the station hired consulting engineer Ernest Barbeau of Schenectady to oversee the construction process for the studios and transmitter site.  Ernest Barbeau, in an introductory letter to Frank York, publisher of the Troy Record, notes himself as a former GE engineer and assistant to W.R.G. Baker, General Electric’s television pioneer.  At the time, it was already understood the height means almost everything in FM broadcasting.  There are several letters dealing with land acquisition and transmitter building construction.

Below is a chart of all the various Barbeau letters written in 1947.  I have scanned and uploaded .pdf files of each letter, sorted by date (the entire archive is available here (6.5 Mb .zip)):

Date From To Subject
Jan 3, 1946 (sic) Barbeau York FM CP granted
Feb 5, 1947 Barbeau York Studio location
Feb 8, 1947 Barbeau York Coverage area, transmitter power, tower type
Feb 21, 1947 Barbeau York Scheduling
Mar 7, 1947 Barbeau York Transmitter/tower type, with attachments
Mar 9, 1947 Barbeau York Electric/phone service
Mar 15, 1947 Barbeau York DC consulting engineer John Barrons
Mar 23, 1947 Barbeau York Scheduling
Mar 23, 1947 Barbeau Barrons Transmitter site location
Mar 29, 1947 Barbeau Williams Transmitter site location
Mar 29, 1947 Barbeau York Transmitter site location, studio location
Apr 4, 1947 Barbeau York Helderberg land owners
Apr 4, 1947 Barbeau Rogers Camp Pinnacle
Apr 9, 1947 Barbeau York Transmission line
Apr 9, 1947 Barbeau Van Antwerp Camp Pinnacle
Apr 9, 1947 Barbeau Sherwood Transcription service
Apr 21, 1947 Barbeau York Helderberg land owners
Apr 21, 1947 Barbeau Rogers Camp Pinnacle
Apr 21, 1947 Barbeau Rousseau Helderberg land owner
Apr 21, 1947 Barbeau La Grange Helderberg land owner
Apr 21, 1947 Barbeau York WOKO
Apr 21, 1947 Barbeau Barron Transmitter site
Apr 23, 1947 Barbeau York Studio location
Apr 23, 1947 Barbeau Rousseau Studio location
May 1, 1947 Barbeau York Rogers land
May 21, 1947 Barbeau York Rousseau land
May 29, 1947 Barbeau York Camp Pinnacle
May 29, 1947 Barbeau Watson Studio Floor plans
Jun 2, 1947 Barbeau York Rogers land
Jun 2, 1947 Barbeau Rogers Camp Pinnacle
Jun 10, 1947 Barbeau Velie (York) Camp Pinnacle
Jun 10, 1947 Barbeau Reed Camp Pinnacle
Jun 21, 1947 Barbeau Velie (York) Camp Pinnacle
Jun 23, 1947 Barbeau York Helderberg Land
Jun 27, 1947 Barbeau York Helderberg Land
Jul 3, 1947 Barbeau York Camp Pinnacle
Jul 5, 1947 Barbeau York Helderberg land
Jul 15, 1947 Barbeau York Schedule
Jul 23, 1947 Barbeau York Camp Pinnacle
Aug 11, 1947 Barbeau York Telephone facilities
Aug 14, 1947 Barbeau York Telephone facilities, STL, land surveyor
Aug 16, 1947 Barbeau York Land Survey, building location, costs
Aug 20, 1947 Barbeau York Land transfer
Aug 20, 1947 Barbeau Barron Transmitter building locations, FCC
Aug 25, 1947 Barbeau Rousseau Studio location
Aug 25, 1947 Barbeau Winslow Watson
Aug 29, 1947 Barbeau York Telephone service, STL
Sep 8, 1947 Barbeau York Pep talk
Sep 15, 1947 Barbeau York Land transfer, survey, Watson, studio location
Sep 20, 1947 Barbeau Barron Antenna type, mounting
Sep 23, 1947 Barbeau York Pep talk
Oct 4, 1947 Barbeau Linge Antenna mast
Oct 6, 1947 Barbeau York FCC STL
Oct 6, 1947 Barbeau York Call letter choice
Oct 7, 1947 Barbeau York Well drilling, politics
Oct 10, 1947 Barbeau Barron WBCA interference
Oct 14, 1947 Barbeau IDECO Tower
Oct 14, 1947 Barbeau Lehigh steel Tower
Oct 14, 1947 Barbeau Truscon Steel Tower
Oct 14, 1947 Barbeau American Bridge Tower
Oct 15, 1947 Barbeau York Scheduling
Oct 15, 1947 Barbeau York Building location, tower type, height
Oct 18, 1947 Barbeau York Antenna mounting
Oct 20, 1947 Barbeau York Access Road Location
Oct 27, 1947 Barbeau York Antenna location, scheduling
Oct 27, 1947 Barbeau York Land title, survey, well drilling, antenna height, FCC
Oct 28, 1947 Barbeau Torlish Well Drilling
Oct 30, 1947 Barbeau York Well Drilling
Oct 30, 1947 Barbeau Barron Antenna mounting
Nov 4, 1947 Barbeau York Scheduling
Nov 5, 1947 Barbeau Schenectady Steel Support mast
Nov 5, 1947 Barbeau York WTRY construction progress (WTRI-FM)
Nov 5, 1947 Barbeau Barron Antenna mounting, STL
Nov 6, 1947 Barbeau York Land survey
Nov 7, 1947 Barbeau Torlish Well drilling
Nov 17, 1947 Barbeau York Progress report
Nov 17, 1947 Barbeau Barron Antenna mounting
Nov 17, 1947 Barbeau American Bridge Tower
Nov 26, 1947 Barbeau Barron Transmission line
Nov 29, 1947 Barbeau York Transmitter building design
Dec 2, 1947 Barbeau York Access road
Dec 3, 1947 Barbeau York Contractors
Dec 8, 1947 Barbeau York Contractors
Dec 9, 1947 Barbeau York Contractors, tower erection
Dec 9, 1947 Barbeau Zane Construction of Blaw Knox tower
Dec 9, 1947 Barbeau York Tower erection, observations of WTRI tower
Dec 11, 1947 Barbeau York Land clearing, building location
Dec 12, 1947 Barbeau York Building location, driveway
Dec 14, 1947 Barbeau York Studio location
Dec 29, 1947 Barbeau York Construction start

This is a treasure trove of information on how this, and perhaps other early FM and TV stations went about finding land and building remote transmitter sites.  Remember that before this, AM transmitters could be placed in any convenient location with enough space for the tower and ground system.  The line of sight nature of VHF required high locations, which in the Northeastern US,  means prominent hills or mountains.  Sadly, this paper trail goes away in 1948.

Here are some of the highlights found in the letters above:

  • Washington DC consulting engineer for the project is John Barrons, who at one point suggests a different transmitter location closer to the city of Troy.  Barbeau insists that the Helderberg location is best because the GE engineers chose it for their FM and TV experiments.
  • Negotiations with several land owners along the edge of the Helderberg escarpment are finally successful, with a 10 acre parcel of land purchased from Mr. La Grange, noted as being across Camp Pinnacle Road to the south of the WBCA transmitter and adjacent to the west of the GE parcel, cost $2,000.  From this, I surmise the former W47A/WBCA site stood above the WPYX site at the old “wireless cable TV” (MMDS) site.
  • Land survey completed by Mr. J. Kempf of Albany.
  • The FCC application is completed with new transmitter location, antenna height and frequency of 92.5 MHz.
  • At one point, Barbeau tried to hire Walter Watson, an RPI architecture student, to draw up the studio floor plan, paying him $15.00.  At first Watson agrees, then backs out of the deal.  Frank York hires an architect to draw the studio floor plan and the transmitter site building plan.
  • Once the plot of land for the transmitter site is purchased, several different building locations and antenna configurations are discussed.  It is noted that both WBCA’s and WGFM’s original antenna was mounted on a pole at ground level.  The later station was moved to a makeshift tower.
  • WBCA management raises concern with the FCC about potential interference from the new station’s transmitter and potential STL, noted as an S-T link.
  • In September of 1947, Frank York expresses some concern with viability of project, Barbeau sends several “pep talk” letters saying that FM radio is the future of broadcasting.
  • The building site is chosen, land cleared, access road installed, work done by Orsini Brothers Construction from Altamont, clearing and road work cost $2,000.
  • The call letters WFLY are chosen, they are the initials of Frank Lloyd York.
  • An 80 foot Blaw-Knox self supporting tower is purchased and installed by Zane Construction, cost of tower is $1,700 installation was another $200.00.
  • Well is drilled by Stewart Brothers well drilling from Guilderland, cost of $5.90 per foot drilled, total cost unknown.
  • Transmitter building work began, building is noted as a two story, concrete block construction, work done by Orsini Brothers.
  • A GE BY-4-C four bay circularly horizontally polarized antenna and 3 1/2 inch Andrew transmission line is installed on tower.
  • Building construction progresses, telephone and electric service installed.  Three phase electrical service cost $2,100 from New York Power and Light.
  • Studio site chosen in at the Troy Hotel in downtown Troy.
  • Living quarters constructed on second floor of building for full time transmitter engineer.
  • A GE BF-3A 3 KW FM transmitter purchased and shipped.
  • Building construction completed.
  • Transmitter installed and tested.
  • Telephone circuits between new studio installed and tested.
WFLY transmitter site building elevations

WFLY transmitter site building elevations

WFLY transmitter building floor plan

WFLY transmitter building floor plan

WFLY electrical drawing showing grounding and tower

WFLY electrical drawing showing grounding and tower

The transmitter site construction was finished in the spring of 1948.  The studios were completed in late July of 1948 and the station signed on the air on August 18, 1948.  This is the transmitter site that they ended up with. as it looks in 2015:

WFLY transmitter building, New Scotland, NY

WFLY transmitter building, New Scotland, NY

In addition to the construction, there was quite a bit difficulty from the WBCA management, who were concerned about possible interference.  WBCA was part of the “Continental Network” and received most of it’s network programing via direct over the air relay from W2XMN/W31NY, 43.1 MHz, in Alpine, NJ.  They complained to the FCC about potential interference on both their over air network relay (43.1 MHz) and the Studio to Transmitter Link from downtown Schenectady on 950 MHz.  In the end, the FCC was unimpressed with these arguments and granted WFLY its operating license.

The transmitter building was made twice as large as needed because the Record had plans to launch a TV station and possibly a radio facsimile service.  In addition to this, there were complete living quarters on the second floor which included a bathroom, shower, kitchen, bedroom and large living room area.  This was in the era before remote controlling of transmitters was permitted by the FCC.  It took a hardy soul to live at the remote transmitter site full time.  Even today, it is far outside of town and can be difficult to get to in the winter time

These mountain top transmitter sites did not exist prior to the advent of TV and FM.  The amount of planing and work went into launching this station is quite impressive. For the early FM radio stations, this type of effort and expense was probably typical.

Good only in Europe

And some parts of Asia:

Equipment rack outlet with 220 Volts to ground.

Equipment rack outlet with 220 Volts to ground.

It seems the power company has some work to do. The other leg measures 28 volts to ground, which to me means the Neutral has been lost somewhere. Fortunately, the transmitter was running on 240, which looks normal on the voltmeter. Everything in the rack; the remote control, exciter, STL, etc has been damaged or destroyed.

Then of course, there is this:

Utility line

Utility line

That is the power and phone line in those trees, as it leaves the road and travels approximately 1,700 feet through the woods.  It is a private line and the utility will not do any work until the trees are cleared away.  In all fairness to the current owners, who have owned the station for not quite a year, this situation has been like this for a long time.

Something fun

So, I spent wasted several hours on this SDR website over the holiday weekend:

University of Twente SDR website

University of Twente SDR website

This is a web based SDR hosted by the University of Twente in Enschede, Netherlands. I enjoyed listening to the European medium wave and shortwave stations available.  Something that is always fun to checkout: UVB-76 on 4625 KHz.

Have fun!

PS: A special thanks to all those who have donated to the cause via the donate button on the upper right side bar.  I had enough money to buy a FUNcube dongle SDR.  I think I have all the other necessary hardware to launch one of these sites myself.  If or when that happens, I will post a link here.

The side mounted FM antenna

In an interesting development, the FCC has taken notice of some pattern distortion from the side mounted FM antenna of KFWR, Jacksboro, Texas.  For those, like myself, not familiar with Texas Radio, that is in the Dallas/Fort Worth market.  The crux of the issue is co-channel interference to KCKL in Malakoff, Texas.  These two locations meet the spacing requirements in 73.207 (215 km).  The issue is with the side mounted ERI antenna and what appears to be intentional pattern optimization.

From the FCC order to show cause:

ERI’s president, Mr. Thomas Silliman, acknowledging that KFWR’s antenna “was mounted in a favorable direction, but… has not been directionalized and therefore is legal.” Mr. Silliman adds that the custom lambda tower at the top of the new KFWR tower was specifically designed for operation at KFWR’s frequency of 95.9 MHz, and that the tower’s lattice structure is “repetitive at the half wave of the specified FM frequency.” Thus, “if one picks a favorable mounting position on the tower, every element in the array sees the same favorable mounting result. Mr. Silliman also states that vertical parasitic elements are used to make the vertical radiation pattern “more circular” and reduce the vertically polarized gain to the east. In a subsequent pleading, ERI elaborates that its computed values “are relative to an RMS measured field of 1.0.” Mr. Silliman concedes that the mounting of the antenna on a certain tower face constitutes “pattern optimization,”arguing later that this is a common practice used by all antenna manufacturers, but states that it is the ERI’s policy “not [to] increase the directivity of the antenna pattern.”

The FCC concludes that the directionality of the side mounted antenna, in this case, is clearly intentional. The radiated power towards co-channel KCKL was calculated to be 274.5 KW, which is in excess of the 100 KW limit and orders KFWR to reduced TPO from 25 KW to 9.1 KW.

We have lots of these out in the field:

Side-mounted Shively 6810 antenna.  WSPK, Mount Beacon, NY

Side-mounted Shively 6810 antenna. WSPK, Mount Beacon, NY

In fact, I believe the majority of our FM stations use side mounted antennas.  Some of them are mounted to a leg and some are mounted to a face.  Usually, I try to place the antenna on the tower so that the bays are facing the desired audience.  This information is given to the manufacture when ordering the antenna so that proper mounts can be furnished and the mounting distance between the tower and antenna properly calculated.  That is about the extent of any “optimization” that is allowed.

As the FM band gets jam packed with FM signals, this may become more of an issue in the future, particularly around dense signal areas around major metropolitan areas.

Accidents, mistakes, mishaps and other tales

Lets get started:

Results of a deer vs automobile accident

Results of a deer vs automobile accident

It does not look like much, however, that is about $5,500.00 worth of damage. What you don’t see is the mashed oil cooler and radiator. This happened on my way from one place to another during the early morning hours. I was traveling at about 55 MPH when a deer bolted from the woods and entered the roadway from the right. I did not have time to break.

In a ditch

In a ditch

A momentary lapse of attention causes loss of $80.00. I think I was adjusting the defroster as I was driving down the road when suddenly, I felt the car tilt over to an alarming degree. You can see the tow truck getting ready to pull it out. Fortunately, there was no damage to the vehicle.

Troubles with the neighbor

Troubles with the neighbor

This is on the access road to one of our transmitter sites. The station has a legal right of way through this property, however, the neighbor seems to object. I spoke with him and showed him a copy of our deed, he has since changed plans.

One side of a balanced audio connection disconnected

One side of a balanced audio connection disconnected

This is the downside of using category cable to make audio connections. The wires are not as rugged as say Belden 8451. This was causing problems because it is at an AM studio/transmitter site.

Burned 30 amp three phase contactor

Burned 30 amp three phase contactor

Three phase, 30 amp, 240 volt contactor installed in a 480 volt system. Lasted a few years, anyway.

White face hornets nest

White face hornets nest

New tenants on one of our towers. This is a white faced (or bald faced) hornets nest. They are really paper wasps, but that difference aside, these beasts are nasty, aggressive and have a painful sting. Normally, I am a live and let live kind of person, but in this case, they gotta go.

Dummy load attached to plywood

Dummy load attached to plywood

This is at one of our AM clients site. Somebody, quite some time ago it seems, made this test load for a 1 KW AM transmitter. It is very nice, carbon ceramic resistors, 50 ohms and surprisingly little reactance. Then they attached it to this piece of plywood. As one can surmise, the load gets quite hot under full power, full modulation conditions. We remounted this in a cage type enclosure and bolted it to the cinder block wall.

Scala PR-950U cross polarized

Scala PR-950U cross polarized

The client at this station is complaining of intermittent STL drop outs and low signal strength at the receive end. Found this Scala PR-950U antenna mounted for vertical polarization, but the antenna element is horizontally mounted. We’ll call it “vorizontal.”

Ribbon cable from a Cummins 135 KW generator

Ribbon cable from a Cummins 135 KW generator

This was discovered during routine maintenance and thankfully not during a power outage. Mice got into the control box of a newish Cummins 135 KW generator and chewed through what looks like a data buss cable. The generator would not run and the cable and control board needed to be replaced.

Bulging capacitors

Bulging capacitors

There is more bulging capacitors removed from flat panels monitors.

And so on…

Transmitter site re-hab

One of the reasons for the recent lack of posts; I have been busy rehabilitating several transmitter sites for various broadcasting companies. These are mostly FM transmitter sites and vary in power from one kilowatt to twenty six kilowatts ERP.  I enjoy project work, but I have been driving hither and yon, racking up 27,000 miles on my new car since last August.

Subaru Crosstrek XV at remote transmitter site, somewhere in rural New York

Subaru Crosstrek XV at remote transmitter site, somewhere in rural New York

So, here is one transmitter site that I just finished; WFLY, Albany, New York.  Removed Collins 831F2 transmitter which was functioning as a backup and installed new Broadcast Electronics FM20S.  The Continental 816R2 is becoming a little bit long in the tooth for a main transmitter, being new in 1986.  Thus, it was time to install a new unit, and I like the Broadcast Electronics solid state and tube designs.  With the BE AM and FM solid state units, their simplicity is their beauty.  We service many BE transmitters, some are thirty years old and are still supported by the manufacturer.

WFLY transmitter building, New Scotland, NY

WFLY transmitter building, New Scotland, NY

The BE FM20S transmitter is actually two FM10S cabinets combined with one controller.  Each cabinet requires a 100 amp three phase mains connection.  This station’s TPO is 11.5 KW, so there is plenty of head room in case the owner’s ever want to install HD Radio or replace the three bay antenna with a two bay unit.

WFLY main transmitter, Broadcast Electronics FM20S

WFLY main transmitter, Broadcast Electronics FM20S

In transmitter cabinet two, above the exciter is room for HD equipment.

BE FM20S exciter housing

BE FM20S exciter housing

I also reworked the coax switches to provide easier implementation of the backup transmitter.  Basically, the main transmitter is on the main antenna, the backup transmitter is on the backup antenna.  We can move the second coax switch to test the backup into the dummy load.  We can move the first coax switch to change antenna feeds.

WFLY backup and main transmitters

WFLY backup and main transmitters

Pretty standard setup.

WFLY RF path diagram

WFLY RF path diagram

We moved the Collins 831F2 from Albany to here to replace another, dead Collins unit at WKXZ in Norwich, New York.  This transmitter is forty years old, but still runs reliably.  Of course, doing this work in the dead of winter added a degree of difficulty to the job, as the roads to both the WFLY and the WKXZ transmitter sites needed work to make them passable for a moving truck.  In the end, we used a skid steer with forks on it to get the transmitter up the final hill and into the small WKXZ transmitter building.

Collins 831F2 transmitter, WKXZ, Norwich NY

Collins 831F2 transmitter, WKXZ, Norwich NY

Collins 831F2 transmitter

Collins 831F2 transmitter

The WKXZ transmitter building interior is floor space challenged. It is located next to a former TELCO microwave site which has a guyed tower.

Drone footage of tower demolition

Watching a tower drop from a different perspective:

Looks like a World Tower Utility 80.

The IP enabled transmitter site

This is a project that we have been working on, weather permitting, for the last month. Basically, it called for installing this Nautel VS2.5 transmitter, mod monitor, remote control and audio processor:

WEXT Nautel VS2.5, Amsterdam, NY

WEXT Nautel VS2.5, Amsterdam, NY

The common thread here; each piece of new equipment has a web interface.  More and more, HTTP is being used to monitor and control transmitters, audio processors, STL’s, consoles, satellite receivers, etc.  Port 80 services (HTTP) are nice, but I think I would prefer port 443 (HTTPS).  Secure HTTP has a whole set of additional requirements, so it is understandable why manufactures do not use it.  However, it is only a matter of time until some problem arises…

Nautel VS2.5 Web AUI

Nautel VS2.5 Web AUI

Burk ARC Plus web interface

Burk ARC Plus web interface

Telos Omnia One web interface

Telos Omnia One web interface

I like the Nautel AUI, especially for any station running HD Radio.  In this setup, there are multiple control and monitoring points available via the LAN at the studio.  The Omnia One is set up to take the AES input from the Harris IP Link as the main feed and fail over to the analog output from the Inno Tuner as a backup.  The Inno is set to WMHT-FM which broadcasts the WEXT format on the HD-2 channel.

This setup is pretty slick, especially in light of the equipment it is replacing:

Harris FM2.5H3, WEXT Amsterdam, New York

Harris FM2.5H3, WEXT Amsterdam, New York

Anyone feeling Nostalgic for a Harris FM2.5H3?

No?

I didn’t think so.

Brother, could you help a pirate out?

It is not news that the FCC has its hands full with the FM pirates in the NYC area, particularly Brooklyn. On any given night, as many as thirty unlicensed signals can be heard, jammed between the commercial and non-commercial broadcasters in the FM band.

I am quite sure that other parts of the country have similar pirate problems.  I do not see the FCC getting much more funding for enforcement purposes.

John Anderson asks; perhaps a pragmatic approach?

For most engineers, this will be a non-starter.  Engineers (and other technical people) tend to see things in binary; on/off, right/wrong, black/white, legal/illegal, working/broken, etc.  It is the nature of logic and dealing everyday operating status’ of technical equipment.  A transmitter that is halfway working is broken.  There is very little grey area in the interpretation of these things, nor is there very much human element.  One cannot reason with a broken piece of equipment; it is to be either repaired or replaced.

Helping a person engaged in what is ostensibly an illegal activity, no matter how pragmatic such help might be, or how just or helpful the illegal activity may be to the community, would not be something that most radio engineers that I know would want to take part in.

Truth be told, some good might come from helping pirate broadcasters clean up their act.  Over modulation, spurious emissions, poor quality transmitters all create bigger problems for everyone else.  The moral dilemma is what type of help to offer and can this or any technical advice then be used to make bigger and better pirates.

I don’t know, but it may be time to start thinking about things like this…

HD Radio development Stasis

I have been working on an HD Radio installation these last few days.  This particular installation was manufactured by Broadcast Electronics.  Some 13 years into the HD Radio development cycle and the implementation still seems like a kluge to me.  To get some idea; to transmit a digital HD Radio with added sub-channels, the following equipment is needed:

  • HD Data importer, off the shelf computer with a sound card and specific software from iBquity.  This is used to import the audio for the HD-2 and HD-3/4 channels.  Runs on Windows (Win 7), Linked to the exporter via IP ethernet
  • HD Radio exporter, another specialized computer with a sound card.  Frames the HD Radio data and adds PID, etc.  Runs on Mandrake Linux, communicates with the exciter via data connection.
  • HD Radio exciter; like other exciters, generates RF and modulates it.
  • HD Radio transmitter; essentially an FM transmitter designed to run as a linear amplifier.

The HD Transmitter part can come in several configurations, including low level combining, high level combining or using a separate antenna for digital and analog signals.

Broadcast Electronics HD Radio transmission system

Broadcast Electronics HD Radio transmission system

None of this is news, of course.  My point is, after ten years, there does not seem to be any further development in HD Radio technology.  In the mean time, competitors are not standing still.  The mobile wireless industry has evolved several times during the same time period; 3G, 4G and LTE have been successfully deployed and widely adopted by mobile phone users.  Truly, mobile data is the real competition to terrestrial broadcasting.

The HD Radio transmission process is an overly complicated patchwork of hardware and software.  The importer in particular seems substandard.  It’s function is to run a bunch of small programs, each doing some small part of the importing process.  The web-admin used Internet Explorer, who uses Internet Explorer anymore?

Since the HD Radio inception, little or no further development seems to have taken place.  There are features, such as album art, program data, traffic data, etc but the system interface is weak, the hardware clunky, the data paths fragile, the operating system outdated, the typical installation is a compromise between cost and available floor space at the transmitter site.

HD Radio is also expensive to deploy and proprietary.  There is little compelling reason to listen to HD-1 channels because the programming is identical to the main analog channel.  HD-2, 3 and 4 channels seem to be mostly used to generate translator feeds, which again, are available with an analog radio.  This use of HD Radio actually damages uptake because, If all the HD Radio sub channels are available on FM analog frequencies, then why even bother with an HD Radio receiver?

Thus the forces at work in the development of HD Radio seem to have reached equilibrium:

Consumer apathy + expensive deployment = 16% uptake on FM and 6% uptake on AM1

The digital radio roll out has been stuck at those levels for many years.  Unless something changes, FM HD Radio will be limited to translator program origination and distribution.  AM HD Radio will go the way of AM Stereo.

1: FCC data on HD Radio deployment; 1,803 of 10,727 FM stations and 299 of 4,708 AM stations have installed HD Radio as of December 31, 2014.