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Anyone Def Yet?"
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Antler
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Post Anyone Def Yet?" Reply with quote
Def as in broadcasting in HD or high definition (aka digital)? I would really like to know about switching over to HD and what additional equipment would be necessary? BTW, we have several local "HD" commercial stations already.

See article on HD radio
Sat May 20, 2006 3:18 am View user's profile Send private message
Sir Nigel
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I don't think HD radio is going to take off yet. Many people don't want to go out to buy a new radio just to get the digital channels. Even then the quality isn't all that great from what I've heard.

However your question was about whether anyone was using the HD radio equipment, and given the high price to do so, I don' think it's going to be within reach for smaller broadcasters for some time.

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Sat May 20, 2006 5:23 pm View user's profile Send private message Visit poster's website
Antler
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I don't think HD radio is going to take off yet. Many people don't want to go out to buy a new radio just to get the digital channels. Even then the quality isn't all that great from what I've heard.

However your question was about whether anyone was using the HD radio equipment, and given the high price to do so, I don' think it's going to be within reach for smaller broadcasters for some time.


I can't comment on the quality as I haven't heard it yet... I am thinking of going out to look for the equipment this afternoon though. XM is offers dolby 5.1 on some of their channels and at the very least I will upgrade to that.. Dolby 5.1 is something I am interested in also.

My opinion is that digital radio will catch on really fast around here, especially with the AM stations, for people who live in the country as I do. Digital AM should be "killer" as there will be no more static.. I am so tired of trying to hear my usual shows through the static.

I do have a FM workaround, I would rather pick up the stations from the big cities a couple of hours away.
Sat May 20, 2006 5:38 pm View user's profile Send private message
cliffyk
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HD Radio (HDR) is a load of rubbish, part of a scam power-grab being bullied through by the NAB and a bunch of other people that think they can make bunch of money by exploiting the FM broadcast band.

For years the FCC prevented adjacent channels from being occupied, and the NAB supported this--this made sense 40 years ago when concumer grade electronics had poor selectivity, however over the last 20 years (digital tuners and better analog tuners) it has become just a reason for commecrcial broadcasters to restrict the competition (most markets would have twice as many slots overnight if adjacent channels were licensed)...

However, now that the commercial broadcasters are facing real competition from satellite and broadband sources (and now that they would like to broaden their "digital" revenues from pagers, etc) all of a sudden it's OK for them to transmit on adjacent channels (I.e. broaden their slice from 240 kHz to over 400 kHz)--and quite effectively removes every other slot on the FM band (and the competition that might fit there).

If you doubt this lookee here at the IBOC spectra of the NPR (National Public Radio) station up the street at 89.9 MHz--you can see quite clearly that it's 400 kHz wide (2 "slots") all the way out to the middle of what used to be the adjacent channels.



Here's what happens when you're in the middle of a HDR IBOC station and a bit further distant plain ol' stereo station (that you used to like to listen to)...



At 97.9 there's an "HD Radio" station to the north of me about 45 miles, to the south at about 65 miles there's a stereo station at 98.1--as you can see, the upper sideband of the HDR signal has invaded and obliterated what used to be a weak but quite listenable "not-all-that-distant" signal.

There are also, in addition to the political and spectrum based issues raised here, a number of technical realities that make the claims of "near-CD" and "superior fidelity" an even higher pile of BS...

The worst part is that there's a much better, non-invasive method for simultaneously broadcasting analog and digital signals (FMeXtra) that could easily handle 156+ kbps digital audio (HD Radio maxes out at 96 kbps*), with much better range potential than HDR's 12-20 miles. If the broadcasters were genuinely interested in audio quality (and iBiquity wasn't a baby of the mainstream broadcast conglomerates) FMeXtra would be a no brainer...

If you live in the US, call your congressmen and tell them to block the FCC's final approval of this crock of corporate crap!!!

--------------------------
* - However this can be split into up to 8 digital streams, most commercial stations will do this tand leave only 48 kbps of compressed, lossy, digital mush (good enough for the masses) for audio.

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Last edited by cliffyk on Wed May 24, 2006 12:15 am; edited 1 time in total
Tue May 23, 2006 7:46 pm View user's profile Send private message Visit poster's website
Antler
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cliffyk,

Your explanation of how digital is being implemented on the FM band is different than how I imagined. Apparently the digital signals on AM is different as the bandwidth is 10 kc.

I am familiar with some other digital broadcast where the carrier width on frequency is from between 1.8 and 2.3 kc wide (voice), I would have to check for the exact number... There are some digital signals where the carrier is limited to as little as .5 kc (data).

I will have to look into this for more info....


d'oh!
Tue May 23, 2006 9:22 pm View user's profile Send private message
cliffyk
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You are correct in pointing out that I should have qualified my comments as to their distinct relation to the FM implementation of HD Radio--the AM incarnation is quite innocuous and will I suspect be as much of a dud as C-Quam...

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Tue May 23, 2006 10:43 pm View user's profile Send private message Visit poster's website
cliffyk
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Oh, BTW, if the "masses gave a rat's backend about fidelity do you really think that nearly every commercial broadcaster would put out the compressed to 45 dB dynamic range, +20 dB bass boost, overmodulated crappy signal they do?

NO--they do this to be the LOUDEST signal on the "dial". I don't know what the digital equivalent of this is, but you can bet they'll figure it out.

My barely processed, flat audio chain from CD (OK, I boost the low end a couple dB), plain ol' analog L+R/L-R signal actually does have "near-CD" quality and if the aerial was at 100 ft. would easily beat HDR out to 20 miles at a lousy 7 Watts...

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Wed May 24, 2006 12:27 am View user's profile Send private message Visit poster's website
PhilJSmith67
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Post Reply with quote
cliffyk wrote:
You are correct in pointing out that I should have qualified my comments as to their distinct relation to the FM implementation of HD Radio--the AM incarnation is quite innocuous and will I suspect be as much of a dud as C-Quam...


If HD Radio splatter on FM were a bull in a china shop, HD Radio on AM would be a commercial oil tanker in your bathtub. First-adjacent channels (+/-10 kHz) are completely obliterated with a grinding loud hash, and there's no FM noise-immunity or capture-ratio to come to the rescue.

I used to get a station on 630 kHz that was receivable with some noise, only slightly weaker than a station on 620 that is 120 miles away. Since the station on 620 fired up HD Radio, 630 is toast. There is no trace whatsoever of AM 630, even on one of my receivers with IF bandwidth set to 2.5 kHz, not in AM or USB mode. The entire channel plus a little extra is covered, from 627 kHz through 638 kHz. Significantly stronger stations on 600 and 640 have a high-pitched hash noise in the background, except on receivers with very narrow bandwidth. On one of my cheaper "very wideband" receivers, even 620 itself has a shrill hash.

Coincidentally, the AM HD Radio system is such a technical distaster that it cannot be used after sunset.
Tue Jan 23, 2007 1:48 am View user's profile Send private message
pcs
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Thanks god they were smart enough to prohibit its use after sunset.

There's so much interference today on shortwave from everything,
cheap chinese digital gadgetry to broadband over powerline etc etc.

Add inductive heaters and long-range radars to the mix and you've got
yourself a SWL nightmare.

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Tue Jan 23, 2007 2:01 pm View user's profile Send private message Visit poster's website
Sir Nigel
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For the American market AM is dead when it comes to music, but that's no surprise (I'm not bad mouthing AM, just the state it's been in for years). I really wonder when a large enough percentage of cars will offer an HD radio for free so all these people will benefit from this disaster. Why couldn't they stick with AM stereo?

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Fri Feb 02, 2007 5:22 am View user's profile Send private message Visit poster's website
cliffyk
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OK 7-year old thread, however I just got a new spectrum analyzer (I.e. "toy") and in educating myself about its capabilities I recorded the spectra of one of the last surviving HD radio broadcasters in our area--a PBS station of course as they do not really have to worry about turning a profit--though I would share:

[/img]

The last images from way back were captured using an Instek DSP-810, the new toy is a Rigol DSA815-TG which among other neat things allows the dB per vertical division to be set to really "zoom in" on weak signals.

As far as I can tell there are only 4 "HD"broadcasters left withing 100 miles of here; reminds me of Quadrasonic sound, or maybe Facebook...

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