AMband.org

From CGC Communicator – The new KSON(AM) tower was
completed and activated today at about 4:30 p.m. according
to Joel Saxberg who performed the RF matching. The tower is
grounded at its base and skirted to permit RF to be induced
onto the structure.
(more…)

Tower Lighting

The FCC has issued waivers of the requirement to visually check tower lights annually instead of every three months when using a high tech monitoring system. Flash Technology’s ArgusON monitors have won the confidence of regulators to let broadcasters cut back on these visual inspections.

This is partcularly valuable when the tower site is remote, or difficult to reach during winter.

Consultants and Station Owners have been asking for twenty years for relief on burdensome rules to prove the performance of directional antennas for AM stations.

Last week the shoe finally dropped, and the Commission approved as a notice of proposed rulemaking, the analysis of directional antennas using Method-Of-Moments and rigorous monitoring standards to verify that AM antennas actually perform as they should.  The new rules only apply to series fed, non-toploaded, non sectionalized towers.

For stations meeting the specifications, it means a substantial decrease in cost to commission or rebuild an AM directional array.  The labor intensive and sometimes dangerous and always problematic field measurements may be dispensed with.

For those who choose, the old way remains available.  Several safeguards have been added – regular calibration of the entire sample system, and external measurement reference points.  The good thing about this is that it all encourages regular rational maintenance of antenna systems, instead of inhibiting repairs to ailing systems.

Stations with series fed simple radiators and solid sampling systems may want to consider going through the effort of changing over to the new regulatory scheme, especially if the system needs a good cleanup.

The complete Report and Order is available at the FCC website. This is now at the Notice of Proposed Rulemaking stage, with a comment and reply comment period, and publication period before the final rules are in place. There could still be a hitch if someone files comments that cause serious reconsideration.

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.”

Crawford Broadcasting has started a forum to investigate means of combating the rash of copper thefts from ground systems. You can look for ideas and add your two cents at The Copper Capers forum.  If you have a theft, please post the details here so that we can understand the risks.

The historic KFI tower fell in December 2004 when a private aircraft hit the tower.  After three years of seeking approval to rebuild the  684 foot structure, the new tower construction was underway Tuesday, 19 March 2008 when the partially constructed tower collapsed.  For a full story see Dino’s Website with pictures of the falling tower.

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.