All Digital AM?

I have been reading, with interest, the saga of HD Radio on the AM (AKA Medium Wave) band. First question; if it goes all digital, will we still call it AM? Of course, there are other questions and concerns:

  • The proprietary nature of HD Radio, AKA MA3 or NRSC-5D as they are now calling it, is problematic. Xperi, the latest patent owner, currently (their word) has agreed to waive licensing fees for AM station owners who install their system. Is this a limited time deal for early adopters or in-perpetuity for all stations?
  • The NRSC-5D tests on WWFD, Fredrick, Maryland are hopeful, but as I pointed out before, it is one station with a well functioning antenna system. Many AM antenna systems are defective either in design or due to deterioration. Is the FCC going to start policing the AM band again to cure these self inflicted wounds?
  • Of course, the NAB wants zero oversight on the entire adventure. Under their proposal, small ownership AM stations would have a difficult time remediating interference issues from all digital co-channel stations be eliminating any required notification period, as proposed by the SBE.
  • The NAB also wants to nix a 1 Hz carrier frequency requirement, which would help with both the analog and digital interference issue, saying it would be too expensive. I disagree. In this day of universal GPS time keeping, it would be easy to implement this on all modern transmitters, especially if they were already installing an HD Radio exciter.
  • Denis Jackson’s Radio World Article states that reliable coverage can be had out to 0.1 mV/m. This seems very, very optimistic given that ambient electrical noise (non-broadcast related) on the AM band is at very high levels and still climbing. Further, once the all digital conversion starts, more and more co-channel digital interference will happen, likely cutting down that contour to a great extent. It works now, but may not work later. These types of statements seem naive or perhaps disingenuous. Again, WWFD is one digital signal in a vast ocean of analog carriers.

While I am skeptical of some of the statements made in various articles and comments before the FCC, I do believe that converting the Medium Frequency band to all digital will have benefits. The BBC DRM tests carried out in 2007 (The Plymouth DRM long term trial) show that digital on MF can work. DRM has been implemented in various countries with good results.

Getting rid of the hybrid IBOC/Analog is a step in the right direction.

My concerns are the small owners who are still making a go of it on AM. Those guys still doing community radio and serving the public interest. If they choose to wait, are they going to get buried under a digital dog pile and then have to pay the full license fee later? Something like that might be the end for them.

HD Radio in and of itself is not the panacea for the AM band. Other things have to happen to make it work right. The SBE speaks extensively about ambient noise on the MF band. They are entirely correct. In addition, there are many, many AM stations that do not have compliant antenna systems. There are stations operating a DA-2 system full time on the night pattern. There are stations operating a DA-2 full time on the daytime pattern and power. There are stations that are supposed to turn off at night, which stay on 24/7. There are stations not reducing power to night time levels. The list goes on. Simply putting digital carriers on everything will not reduce the station-to-station interference, especially at night.

I am cautiously hopeful that the FCC will look into the ambient noise problem, which simply cannot be over emphasized. They would also need to re-invigorating the Enforcement Bureau. Since they closed down most of their field offices, it has been kind of a free for all out here.

In this time of COVID-19

As most of you man know, I live in New York State (Hudson Valley region).  This is very close to the COVID-19 outbreak in Westchester County.  There has been one confirmed case in my town.  As such, we are experiencing the outbreak ahead of the curve from the rest of the country.  School has been cancelled for at least two weeks and perhaps indefinitely.   All public gathering places are closed; restaurants, bars, movie theaters, malls, churches, etc.  As a radio engineer, the COVID-19 virus has a several implications:

  • Things are still going to break and will need attention. The good news is that most transmitter sites are unmanned. The only social interaction my be during the travel phase (getting fuel, food, etc).
  • Many studios and offices are being abandoned as well. Over the last few days, we have set up DJ’s to operate from their houses.  Most sales and office staff have been told to work from home.
  • Broadcasters have been designated critical communications infrastructure, The Department of Homeland Security has issued letters that allow travel and procurement of fuel during the national emergency for critical personnel.
  • I managed, prior to the store shelves being emptied this weekend, procure some PPE.  I don’t know how effective it will be, but anything is better than nothing.
  • Since Hurricane Sandy, I have had in place many emergency supplies and equipment needed to restore service in the event of a long term interruption of basic services.

There are many long term economic implications. For commercial radio stations, the loss of income is going to be extreme.  As the virus has spread, businesses have cancelled pretty much all advertising.  During past disasters, radio was often the only means of getting information to the general population.  I am not sure if this is still the case.  How relevant is radio these days?

Automation Systems

Radio Automation Systems are nothing new under the sun. As Marconi tapped out his famous S, he was likely thinking “We should get a machine to do this…”

Broadcast stations have been installing different types of automation since the mid 1950’s and early 1960’s.  It was touted as a way to free up announcers so they could do more important things.

While cleaning out an old studio/transmitter building and getting things ready for demolition, I found a stash of old product brochures for various automation systems from the 60’s, 70’s and 80’s.  It looks like the previous owner used to go to the NAB every year.  How many radio guys got their start on the overnight shift changing out reels?  I know a few.

Gates automation system brochure, circa 1965
Gates automation system brochure, circa 1965

The Gates Radio Corporation had a fairly standard reel to reel system in three different configurations.  These systems were pretty pricey in their day.  According to the 1966 price list:

  • The Automate 244 cost $7,275.00 ($58,837.00 in 2020)
  • The Automate 484 cost $12,210.00 ($102,946.00 in 2020)
  • The Automate 1007 cost $17,150.00 ($138,799.00 in 2020)

Those are for stereo systems, mono systems cost about $500.00 less.  Each one of those systems ran one station.

Gates Automate 244 events thumb wheel
Gates Automate 244 events thumb wheel

The larger the system, the more events it could trigger.  I have never run into one of these in the wild.

Long form satellite shows began to surface in the early 1980’s. Things like all news formats and overnight talk shows.  I have had nightmares were everyone walks around saying “This is Larry King, you’re on…” while UFO’s fly overhead and next door neighbor, Jim Hightower, buries PCB’s in his back yard not more than 200 feet from his house.

Broadcast Electronics Control 16 radio automation system
Broadcast Electronics Control 16 radio automation system

Broadcast Electronics had the Control 16 system in the 1980’s that ran off of a very basic computer system that could handle 3,000 events with the standard RAM configuration and up to 9,999 events with additional RAM.  This was ideal for multiple program sources; music on reel machines, satellite syndicated talk or music formats, etc.  No longer were these machines simply running the overnights.

Schaffer 901 radio automation system
Schafer 90x radio automation system

Schafer is perhaps the most know analog tape automation, at least to me.  I know of several of these systems that were in operation through the mid 1990’s.  By this time, long form satellite music formats had become the rage.  However, there were still a few stations using reel to reel music services.

I particularly like this flyer from IGM:

IGM (International Good Music) brochure, circa 1971
IGM (International Good Music) brochure, circa 1971

By the mid 1990’s, these tired old dinosaurs where being removed.  Still, the mechanics of the operation were a thing to behold.  It was nice because you could hear the relays snap shut after decoding a 25/35 Hz tone or one of the Mutual Radio be-doops.  The cart-o-matic would chug through the break until the liner fired and then back to the bird.  If there were any issues, one simply needed to stand there and watch which part of the machine malfunctioned.

Schaffer logging system
Schafer logging system

Computer based systems like Computer Concepts DCS, Arrakis Digilink and Audio Vault came along, which got rid of the analog tape.  Instead they stored audio on hard drives.  Those early systems hard drive space was a premium, so usually at least 3:1 compression was needed to fit all the commercials onto the drive space available.

My first brush with Audio Vault was in 1994 at WGY in Schenectady, NY.   It was a pretty good system if you could understand the .ini files.  As the BE tech support guys used to say “You can program it to turn the coffee pot on if you wanted to.”

Nowadays, what used to be a studio location is more akin to a content distribution node.  This rack combines music and commercials stored locally on hard drives with out of town voice tracks and serves as the program source for eleven radio stations.

Radio Automation, 2020 style
Radio Automation, 2020 style

It works remarkably well, as long as the windows operating system stays functional.

Incandescent Indicating lamps

What is wrong with this picture?

WBNR equipment rack
WBNR equipment rack

It is a little bit blurry, but the real problem is that none of the indicator lamps on the phasor or antenna monitor are working.  Those little incandescent 387 bulbs burn out frequently.  It is difficult to tell, at a glance, whether the phasor is in daytime or night time mode.  One also cannot tell which tower or mode is selected on the antenna monitor.

It is a small job to replace them, but it does take some time.  They currently exist in older transmitters, studio consoles, meter back lighting, and other control indicators.  Since I began working in radio, I have replaced hundreds of these little lamps.  I would rather spend my time on more interesting projects.

The 387 bulbs cost about a dollar each and last less than a year, in most cases.  Fortunately, there is a solution to all this.  Enter the based LED replacement lamp.  These little guys have the long life of an LED (100,000+ hours) in a package that is a direct replacement for the Incandescent lamp.  They run about $5.31 each.

Dialight makes a very handy cross reference:

Dialight Incandescent to LED cross reference
Dialight Incandescent to LED cross reference

The entire cross reference section is three pages long and is a part of their PMI catalog.  The full cross reference .pdf can be found here.

Those Dialight LED lamps are available from Mouser, Allied and Newark Electronics.

Time is money.  There are much better things to be doing than going around replacing incandescent indicator bulbs in various pieces of equipment.  At the same time, it is important to know what the status of that equipment is at a glance, which is the reason for using any type of indicator in the first place.  Using drop in replacement LED indicating lamps with certainly save time and money in the long run.