Public Broadcasters Want Digital Interference Examined

[SUPERCASTER]

"CPB has received reports that existing analog listeners have lost reception of their favorite public radio station when new HD signals have gone on the air."

This is one of HD Radio's dirty little secrets. In order to accommodate the simultaneous broadcast of both an analog and digital signal, all radio stations will effectively double their spectral footprints (AM stations triple their bandwidth when they broadcast in hybrid mode). Fattening the signals of every radio station is bound to cause interference between stations located near each other on the dial. ...
The broadcast industry got a proprietary DAB system it makes money from just by using; the listener, that "public" in "the public interest," gets "buzz saw" noises on FM and "frying bacon effect" hash on AM.

http://www.diymedia.net/archive/0506.htm#051206

 

[IBOCRocks]

"CPB has received reports that existing analog listeners have lost reception of their favorite public radio station when new HD signals have gone on the air."

This is one of HD Radio's dirty little secrets. In order to accommodate the simultaneous broadcast of both an analog and digital signal, all radio stations will effectively double their spectral footprints (AM stations triple their bandwidth when they broadcast in hybrid mode). Fattening the signals of every radio station is bound to cause interference between stations located near each other on the dial. ...
The broadcast industry got a proprietary DAB system it makes money from just by using; the listener, that "public" in "the public interest," gets "buzz saw" noises on FM and "frying bacon effect" hash on AM.

http://www.diymedia.net/archive/0506.htm#051206

Sounds like they're unsure of the potential of this and wish to do a study. Nothing to see here. Wake me when the results are in...

 

[audiophile.]

The interference is very real. I can show interference within the protected contour on hundreds of stations.

I'm not opposed to digital broadcasting but I am opposed to significant interference especially within the protected contour.

 

[I.B. Iquity]

Please show us these hundreds of stations who are being interfered with within their protected contour. That would be a real issue. You don't have to show 100, just give us say 10 examples and we'll take a look.

 

[1q2w3e]

The interference is very real. I can show interference within the protected contour on hundreds of stations.

I'm not opposed to digital broadcasting but I am opposed to significant interference especially within the protected contour.

I would very much like to see your examples.

I have traveled thousands of miles examining just this... are there issues WITHIN the protected contour where HD interfers with the analog signal. I have not run into one on the FM band, and very rare on the AM band. I am not saying that it couldnt happen. Most of the AM issues are with the HD station not having their antenna system set up properly and they get non-linearity. Once the station realizes what is happening, they are pretty quick to take care of it.

So bring on your HUNDREDS of examples and I hope you do provide engineering infomation as well. Not just-- Someone told me that they are getting interference from X station. I can provide you with examples of where it is working! Co channel examples!

 

[audiophile.]

I'll be happy to provide examples. It will take some time though.

I can provide you with examples of where it is working! Co channel examples!

Co-channel is not the problem at all! It's with first and second adjacents.

 

[autopaint-1]

NO real rush, go to it.

 

[1q2w3e]

I'll be happy to provide examples. It will take some time though.

I can provide you with examples of where it is working! Co channel examples!

Co-channel is not the problem at all! It's with first and second adjacents.

OOOPS! My bad.. I MEANT to say first adjacent. Sorry!

 

[audiophile.]

I'll be happy to provide examples. It will take some time though.

I can provide you with examples of where it is working! Co channel examples!

Co-channel is not the problem at all! It's with first and second adjacents.

OOOPS! My bad.. I MEANT to say first adjacent. Sorry!

Can you give the call letters? I want run it on the software.

 

[_Jim]

KTBB 2nd adjacent to KMKI.

Then there is the splatter from KMKI to KLBJ 3rd adjacent.

Seems whomever sets the levels (or maybe it is one of the audio processors themselves) into KMKI's new (well, 1 yr old Nautilus) xmtrs CAN'T seem to keep it clean even 35 dB down 30 some KHz away ...