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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.

Winter! Is upon us….

What better time to take the gondola to K-1? None, none at all.  We do work for the two radio stations that are on the peak of Mount Killington, near Rutland, Vermont.  In the summer, usually we can drive up there in a four wheel drive truck.  In the winter, the gondola is the way to go.  On this day, there was a 48-56 inch base, light north winds and air temperature around 10° F (-12° C) .

This is not my video, I did not have enough memory on my SIM card to film a video and I didn’t bring my expensive camera. However, this is a good example of the ride:

Not a bad way to get to a transmitter site, all things considered.

Ride up to Killington Peak

Ride up to Killington Peak

View from Killington Peak

View from Killington Peak

View from Killington Peak

Transmitter buildings on Killington Peak

View from Killington Peak

View from Killington Peak

View from Killington Peak

Tower from Killington Peak

Killington STL dishes

Killington STL dishes

ERI antenna, WZRT/WJJR Killington VT

ERI antenna, WZRT/WJJR Killington VT

The reason for the trip today; repair work on the Nautel VS2.5 transmitter. All three power supplies and the power supply summing board needed to be replaced.

MPX over IP

In the progression from Circuit Switched Data to Packet Switched Data, I can think of many different applications for something like this:

FMC01 MPX to IP CODEC

FMC01 MPX to IP CODEC

The FMC01 MPX to IP encoder can be used for multi-point distribution (multi frequency or same frequency network) of FM Composite audio, or as a backup solution over a LAN bridge, LAN extension, or public network.  I can think of several advantages of using this for a backup when composite analog STL’s are in use.  There are many compelling reasons to extend the LAN to the transmitter site these days; Transmitter control and monitoring, security cameras, office phone system extensions, internet access, backup audio, etc.  I would think, any type of critical infrastructure (e.g. STL) over a wireless IP LAN extension should be over a licensed system.  In the United States, the 3.6 GHz WLAN (802.11y) requires coordination and licensing, however, the way the rules are set up, the license process is greatly simplified over FCC Part 74 or 101 applications.

Another similar CODEC is the Sigmacom Broadcast EtherMPX.

Sigmacom Broadcast EtherMPX CODEC

Sigmacom Broadcast EtherMPX CODEC

Features include:
• Transparent Analog or Digital MPX (MPX over AES), or two discrete L/R channels (analog or AES).
• Built-in MPX SFN support with PTP sync (up to 6.000km in basic version). No GPS receivers!
• Unicast or Multicast operation to feed unlimited number of FM transmitters with MPX from one encoder.
• Linear uncompressed PCM 24-bit audio.
• Very low audio latency: 2,5mS in MPX mode.
• Perfect match with Sigmacom DDS-30 Exciter with Digital MPX input.
• Can be used with high quality 802.11a/n Ethernet links.
• DC coupled, balanced Analog inputs & outputs with -130dBc noise floor.
• No modulation overshoots due compression or AC capacitor coupling.
• Decoder provides simultaneously Analog & Digital output for transmitter redundancy.
• Aux RS232 serial transparent link, Studio to Transmitter.
• Auto switchover to Analog input when Digital signal is lost.
• Centralized remote control & management software

One last thought; separating the CODEC from the radio seems to be a good idea. It allows for greater flexibility and redundancy. Using an MPX type STL allows sensitive air chain processing equipment to be installed at the studio instead of the transmitter site.

Well, crap

Radio Shack Store, Courtesy of Wikipedia

Radio Shack Store, Courtesy of Wikipedia

Radio Shack (AKA, RadioShack, The Shack, Tandy Corporation, Realistic, Optimus, etc) appears to be filing for Bankruptcy if the Wall Street Journal and Reuters is to be believed.  I see the words “private equity firm” in the article, that does not bode well.

Radio Shack of late has become a glorified cell phone store.  It used to be one could get some emergency repair parts, an FM antenna or a CB radio as the need arose.  As a young lad, it was fun to poke around and look at the various radio kits and other assorted fun things.  My first shortwave radio was a kit from Radio Shack; assembly finished just in time to hear the Vatican Radio’s announcement that Pope Paul IV had died.

What happened to Radio Shack is fairly typical; what was once a niche market for hobbyists and experimenters tried to go main stream and lost their core customers.  There are still plenty of electronics hobbyists out there, look at the Amateur Radio community as an example.  Yet, that market was abandoned for the more lucrative general consumer electronics market.  Unfortunately, Radio Shack never produced high quality stuff, so their reputation in the consumer electronics market was not that great.  Thus, not being known for anything, they slowly slipped into irrelevance.

Don’t try this at home, kids

Happy New Year, and stuff.

I found this interesting little video on Youtube recently:

That has to be a fairly high powered AM radio station to have that effect. According to the video, this is in Ukraine.

Other than generating RF burns to the hands, there is also the issue of exposure to non-ionizing radiation causing body tissue heating. Then there is the potential broadband RF interference from the arcing plant matter. This can cause interference to STL’s and other receivers.

Axiom


A pessimist sees the glass as half empty. An optimist sees the glass as half full. The engineer sees the glass as twice the size it needs to be.

Congress shall make no law respecting an establishment of religion, or prohibiting the free exercise thereof; or abridging the freedom of speech, or of the press; or the right of the people peaceably to assemble, and to petition the Government for a redress of grievances.
~1st amendment to the United States Constitution

Any society that would give up a little liberty to gain a little security will deserve neither and lose both.
~Benjamin Franklin

The individual has always had to struggle to keep from being overwhelmed by the tribe. To be your own man is hard business. If you try it, you will be lonely often, and sometimes frightened. But no price is too high to pay for the privilege of owning yourself.
~Rudyard Kipling

Everyone has the right to freedom of opinion and expression; this right includes the freedom to hold opinions without interference and to seek, receive and impart information and ideas through any media and regardless of frontiers
~Universal Declaration Of Human Rights, Article 19

...radio was discovered, and not invented, and that these frequencies and principles were always in existence long before man was aware of them. Therefore, no one owns them. They are there as free as sunlight, which is a higher frequency form of the same energy.
~Alan Weiner

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