Looks like an increase is coming...

IBOC, HD Radio, FM eXtra, DRM, Importers, Exporters, Exgines...digital radio spoken here!
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RFWarrior
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Looks like an increase is coming...

Post by RFWarrior » Tue Jul 14, 2009 6:25 am

From today's Radio World News Bytes, three of the first five headlines were:
Radio World wrote:
Best Buy Releases First Portable HD Radio Receiver
Armband unit made by KRI is sold as part of Best Buy’s Insignia line

NPR Supports Immediate Interim Digital Power Increase But in a Different Form
Says FMs could be allowed to go up to 10 dB but with protections in place

IBiquity Seeks Interim FM IBOC Power Increase
The company asked the FCC to allow a 6 dB hike
So, it's a fairly safe bet something is going to happen and soon - the question then becomes what :)

Best,

Jeff
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Re: Looks like an increase is coming...

Post by Deep Thought » Tue Jul 14, 2009 9:07 am

What = analog interference increases by 6 dB, more people lose analog reception meaning fewer people using radio, and all four of the "HD" radios out there work better inside a couple more buildings.

All in all it's just another brick in the wall.

added: And then there is this...
Greater Media and iBiquity conducted indoor elevated power reception tests using WKLB(FM), Waltham, Mass, as well. They took measurements at six locations with buildings chosen to represent different types of construction. This test is noteworthy because it used several buildings and multiple radios within the buildings, and because it involved a station whose signal covers an entire metro.

The first three locations in downtown Boston are within 8 to 10 miles of the WKLB transmission facility in Needham, Mass. They are the Greater Media studio building, a low-rise, two-story structure built with masonry, steel and glass; The Caning Shop, a single-story building of wood and masonry construction; and the Prudential Tower, a high-rise skyscraper of steel, aluminum and glass construction.

The other points where measurements were taken were farther out in the Boston Metro. They are a two-story, split-level home in Andover, of wood frame construction; the Comrex Corp. headquarters, a two-story steel framed, wood building in Devens; and a three-story apartment building of poured concrete (with rebar) construction in North Attleboro. These locations are at approximately the edge of digital coverage assuming the currently authorized –20 dB power level.

Up to four receivers, operated with manufacturer supplied antennas, were used simultaneously in each location to characterize reception at various points within each building. Generally, the closer testers were to the core of each building, the worse the digital reception was. Digital power was increased in 2 dB steps from –20 dB to –10 dB until the radio solidly locked onto the digital signal.

Testers concluded that in many types of buildings, digital reception is "simply impossible" on IBOC table radios and "nonexistent" on the new class of portable receivers about to be introduced into the market. An interim power level increase may partially mitigate the problem in some fixed locations, they concluded, however only the full 10 dB increase will permit reliable service to portable IBOC receivers and come close to replicating analog coverage.

As I noted, it's striking for advocates of HD Radio to state publicly that "digital reception is simply impossible in many types of buildings" and this says a lot about the HD Radio rollout. In pushing for an increase, the proponents are reiterating that they intentionally asked for a certain power level to be low enough so as not to cause analog interference to those stations nearby as well as those not yet digital. Engineers have said to me recently concerning the power issue that the NRSC, a largely volunteer effort, did what testing it could given the time and resources it had.
(My emphasis)

This test, by two of the biggest IBOC proponents, is some bad news for any 'fixed location' format and even worse news for side channels with no analog to fall back on.
Mark Mueller • Mueller Broadcast Design • La Grange, IL • http://www.muellerbroadcastdesign.com

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Re: Looks like an increase is coming...

Post by w9wi » Wed Jul 15, 2009 7:41 am

this...
An interim power level increase may partially mitigate the problem in some fixed locations, they concluded, however only the full 10 dB increase will permit reliable service to portable IBOC receivers and come close to replicating analog coverage.
Increasing power 4dB is going to make the difference between "simply impossible" and reliable reception?
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Doug Smith W9WI
Pleasant View, TN EM66

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Re: Looks like an increase is coming...

Post by RFWarrior » Wed Jul 15, 2009 6:32 pm

Deep Thought wrote:Testers concluded that in many types of buildings, digital reception is "simply impossible" on IBOC table radios and "nonexistent" on the new class of portable receivers about to be introduced into the market. An interim power level increase may partially mitigate the problem in some fixed locations, they concluded, however only the full 10 dB increase will permit reliable service to portable IBOC receivers and come close to replicating analog coverage.
The thing that intrigues me is that the two people I know of who have done any amount of listening tests with the new portable indicate that it receives much better than any tabletop they have seen, even when the tabletop has a tuned dipole on it (see Kirk Harnack's facebook post for more info). That is totally counter to what is written above, but I'll take real world results over calculated numbers any day - no matter how much I know something "should" work, I've seen too many times where it doesn't.

Doc, have you had a chance to do any sensitivity testing with your Insignia, compared to any of the tabletops on the market?

Oh, and Doug - the interim increase that was requested by iBiquity is an increase of 6dB to -14dB, not 4dB.... Even so, I agree it probably won't solve all the problems of the world - the ultimate issue as I see it is that broadcasters insisted on a hybrid system instead of using new spectrum or slowly migrating to digital, and they got exactly what they demanded. Isn't the definition of compromise a solution that makes nobody happy? But that is a whole 'nother topic :)

Best,

Jeff
Jeff Welton
Regional Sales Manager - Central U.S.
Nautel
Toll free: 1-877-662-8835, ext. 5127
Halifax Number: 902-823-5127
Quincy Number: 217-919-0189
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jwelton@nautel.com

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Re: Looks like an increase is coming...

Post by w9wi » Wed Jul 15, 2009 6:50 pm

RFWarrior wrote: Oh, and Doug - the interim increase that was requested by iBiquity is an increase of 6dB to -14dB, not 4dB.... Even so, I agree it probably won't solve all the problems of the world - the ultimate issue as I see it is that broadcasters insisted on a hybrid system instead of using new spectrum or slowly migrating to digital, and they got exactly what they demanded. Isn't the definition of compromise a solution that makes nobody happy? But that is a whole 'nother topic :)
That'll teach me to compose messages as I'm getting ready for work :)

By 4dB, I meant the difference between the 6dB increase (to -14) in the Massachusetts test and the 10dB increase (to -10) that the testers "...concluded, however only the full 10dB increase will permit reliable service to portable IBOC receivers..."

BTW, I acquired a Sony XDR-F1HD on Monday. The selectivity of this thing is simply amazing. (that from someone who already has a Boston Acoustics HD receiver & thought *that* set had excellent selectivity) Haven't had time to swing the antenna around & determine how the HD performance compares to the Boston Acoustics. I'm afraid it is just as bad as the BA about generating self-interference on AM.
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Doug Smith W9WI
Pleasant View, TN EM66

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