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Radio Currents reports that the first two Mexican stations have started broadcasting in HD Radio.

XEEZ 970 Radio Palacios is broadcasting an AM HD Radio signal from the U.S./Mexico border town of Caborca, Sonora, using a Broadcast Electronics transmission system.

XHTY-FM 94.5 in Tijuana on the FM Side has installed a Nautel V10 HD Radio transmitter. The station is operated by Uniradio.

I have received a lot of questions about the contours shown on the Radio-Locator maps. For AM they are:

• Red – 3.0 mV/m – Generally the Sellable area of the station
• Purple – 0.5 mV/m – Rural protected service area, but nobody would buy ads.
• Blue – 0.1 mV/m – You might still get it on a car radio

For FM they are:

• Red – 60 db/uV or 1.0 mV/m – Protected service area for Class A and C stations
• Purple – 50 db/uv or 0.316 mV/m – A pretty weak Signal, nobody would buy ads.
• Blue – 40 db/uv or 0.1 mV/m – You won’t pick it up, except in rural areas

I determined this by comparing the plots of sample stations in Radiosoft’s Comstudy with their Radio-Locator maps. Hopefully this clears a few things up!

The agency that regulates broadcasting in Mexico, CoFeTel has approved the use of HD Radio for both AM and FM stations withing 320 km of the US Border. The news reports did not mention whether night operation by AM stations was authorized.

Official statement (translated):

“Considering the extent of the development and implementation of the IBOC system in the United States of America, Mexico is required to take decisive action so that [the country's AM and FM radio stations] in the zone located within 320 kilometers of the northern border of Mexico can transmit at the same technological level so that they can provide the benefits of quality service to the radio listening public.”

According to Radio Magazine, the ITU gave the green light for DRM digital broadcasting in the tropical bands. Although not strictly an AMBand issue, it is creeping close, since the tropical bands are just above the high end of the US AM band. You can read the full article here.

The National Radio Systems Committee has issued two revised AM standards and deleted the NRSC-3 receiver specifications standard as obsolete on September 26. The revised standards are NRSC-1-A and NRSC-2-A. NRSC-1-A specifies the preemphasis and deemphasis curves and bandwidth limitations for AM transmission, while NRSC-2-A sets the standards for RF emissions from AM stations. The NRSC intends to publish the revised standards as soon as a procedural review is completed, in about four weeks.

The NRSC also adopted a guideline for recommended bandwidth for AM transmission. NRSC-G100 provides guidance for operators who would like to decrease first adjacent channel interference by operating with bandwidth narrower than the 10 kHz limit. Using the full 10 kHz bandwidth is lost on most receivers, as nearly all receiver IF filters limit audio response to much less than 10 kHz. Benefits from this technique are limited to cases where the licensees mutually agree to bandwidth reduction of stations that interfere with each other.

Our southern neighbors have formally communicated that they want the FCC to reconsider its order authorizing AM IBOC operations at night. A recent Radio World Online article outlines the objections. Leonard Kahn’s TheWrathofKahn.org site has a copy of the letter which objects to FM IBOC authorizations as well.

This is one more bump in the road for digital Medium Wave Broadcasting, but I think that our neighbors south of the border are probably just reserving their places at the table. I have heard that at least one Mexican station has begun broadcasting in IBOC.

The FCC has issued its Second Report and Order authorizing regular IBOC transmissions for AM and FM stations. The Report specifically authorized AM stations to operate during their regular night hours of operation with IBOC. There were a lot of additional issues covered, concerning FM, datacasting and multicasting. In the hybrid mode AM IBOC does not support multicasting, but limited rate datacasting can be accommodated.

Arbitron and Edison Media Research have conducted a study on the impact of alternate radio-like delivery methods, such as:  iPods, audio streaming, etc. You can download the report here.

• The report finds: Internet radio listening has increased 50% in the last year
• Internet radio reaches 19% of 18-34’s weekly
• Both XM and Sirius are recognized by more than 60% of the public
• Satellite listeners are an upscale audienc: 27% have incomes over $100k
• There is confusion between podcasting, internet radio and downloadable music
• More than half of those who have listened to podcasts are under 35, and 20% under 17
• Interest in HD radio is up: 8% very interested, and 27% more are somewhat interested
• Most people report the desired price point for an HD receiver at $50 to $100
• 77% of listeners report that they expect to listen to the same amount of AM and FM radio as they do now
• Digital radio users have not decreased the amount of time they spend listening to AM and FM radio

I wrote an article in Radio World concerning the full digital versions of IBOC.

The National Radio Systems Committee has released a study on the effects of reducing the bandwidth of AM transmissions from the present standard of 10 kHz.  The study used representative receivers to present transmissions of speech, sports, music and commercials with bandwidths of  5 kHz, 7 kHz and 10 kHz.  The study assumes that both the desired and undesired stations operate using the same standard.

The results showed that mutually reducing transmission bandwidth down to 5 kHz  is a big plus for speech.  There was either a benefit, or no change from the 10 kHz results when reducing the transmitted bandwidth to 7 kHz irrespective of format or first adjacent channel interference level. (more…)