POLL: Analog FM Scanning & HD

[radiodial]

1) Does your analog FM car radio, when scanning channels, pause/stop on the HD channels?

2) If so, is there sound/nosie/hiss?

 

[JM_pstar]

> 1) Does your analog FM car radio, when scanning channels,
> pause/stop on the HD channels?
>
> 2) If so, is there sound/nosie/hiss?
>

No, I have not noticed this when I am in the closest market with HD stations. However, there is some different noise on the adjacent stations...but it doesn't interfere with any other stations and my car radio does not stop on them when scanning, so it does not bother me at all.
<P ID="signature">______________
16-year-old radio geek.</P>

 

[radiodial]

> > 1) Does your analog FM car radio, when scanning channels,
> > pause/stop on the HD channels?
> >
> > 2) If so, is there sound/nosie/hiss?
> >
>
> No, I have not noticed this when I am in the closest market
> with HD stations. However, there is some different noise on
> the adjacent stations...


That's what I am talking about... the adjacent channels - HD1, HD2.

> but it doesn't interfere with any
> other stations


I am not talking about interference whatsoever. I have never brought up the subject of interference.

> and my car radio does not stop on them when
> scanning, so it does not bother me at all.
>

In your first sentence you said you did notice the noise on the HD channels. How did you stop on those channels if not by scanning? Manually?

I am curious.

 

[JM_pstar]

> > but it doesn't interfere with any
> > other stations
>
>
> I am not talking about interference whatsoever. I have
> never brought up the subject of interference.

I know that you haven't. I just wanted to bring it up.


> > and my car radio does not stop on them when
> > scanning, so it does not bother me at all.
> >
>
> In your first sentence you said you did notice the noise on
> the HD channels. How did you stop on those channels if not
> by scanning? Manually?
>
> I am curious.
>

Yes, you are correct. I decided to tune in manually to the adjacent channels of stations running HD when I was recently in the nearest market running HD after hearing about the so-called "hiss" associated with them. Lo and behold, it was there...but, as I mentioned, my car radio does not stop on them when scanning and it causes no interference or other ill effects, so it doesn't bother me at all.
<P ID="signature">______________
16-year-old radio geek.</P>

 

[radiodial]

>
> Yes, you are correct. I decided to tune in manually to the
> adjacent channels of stations running HD when I was recently
> in the nearest market running HD after hearing about the
> so-called "hiss" associated with them. Lo and behold, it was
> there...but, as I mentioned, my car radio does not stop on
> them when scanning and it causes no interference or other
> ill effects, so it doesn't bother me at all.
>

Thanks for the reply. That helps me a lot. So I am guessing that some analog radios while scanning will stop on the HD channels while others will not. That's interesting. Again, thanks for the info.

 

[DFWRadioJock]

> Thanks for the reply. That helps me a lot. So I am
> guessing that some analog radios while scanning will stop on
> the HD channels while others will not. That's interesting.
> Again, thanks for the info.

EXACTLY!!! Now you get it, finally. This is what we've been trying to tell you all along.

 

[BrokeEngineer]

> 1) Does your analog FM car radio, when scanning channels,
> pause/stop on the HD channels?

Does not stop on the HD channels.......2 cars were used for this study.


>
> 2) If so, is there sound/nosie/hiss?

Manually tuned to 1st adj. and no noice to speak of, one I actually get a pilot lock on for another station....92.3 (has HD) and 92.5. (does not)

 

[HD_Ready]

> 1) Does your analog FM car radio, when scanning channels,
> pause/stop on the HD channels?
>
> 2) If so, is there sound/nosie/hiss?
>


My analog Ford factory radio stops on All stations, even the HD ones, I hear what ever programming is on them. I only hear static if the station is weak.

 

[HD_Ready]

> > Thanks for the reply. That helps me a lot. So I am
> > guessing that some analog radios while scanning will stop
> on
> > the HD channels while others will not. That's
> interesting.
> > Again, thanks for the info.
>
> EXACTLY!!! Now you get it, finally. This is what we've
> been trying to tell you all along.
>
They should all be stopping on the HD stations, broadcasters would be shooting themselves in the foot if installing digital caused old radios to skip over them.

 

[radiodial]

> > Thanks for the reply. That helps me a lot. So I am
> > guessing that some analog radios while scanning will stop
> > on the HD channels while others will not. That's
> > interesting. Again, thanks for the info.
>
> EXACTLY!!! Now you get it, finally. This is what we've
> been trying to tell you all along.
>

No. You have always talked about interference to which I had not brought up. This is why I started this thread to make clear the issue was not one of interference.

But his does become interesting. Why would a car radio pick up the HD channel while others do not?

 

[DFWRadioJock]

HD Noise: Main vs. Adjacent

At the present time, there are 17 FM stations in the Dallas market running HD, according to the Ibiquity website. They will be referred to as “main” channels. Those frequencies are as follows:

88.1
90.1
92.5
93.3
94.5
96.7
97.1
100.3
101.1
102.1
102.9
103.3
104.1
105.3
106.1
107.5
107.9

Since I had absolutely nothing better to do today…

I used the scanning mode on one of my analog FM radios to see which frequencies it would stop on and what could be heard, and I also tested to see if the scans would stop on any adjacent frequencies. I ran this test twice, and in both cases the only adjacent channels the radio stopped on were 96.0, 99.2 and 107.2.

As you can clearly see, the only adjacent channel the radio stopped on near an HD broadcast for a station licensed to this market, was 107.2. When my radio stopped on all the main frequencies of all 17 stations, the audio was not “noisy”.

I also recorded and studied the graphic image file of WRR 101.1 FM, which is a lightly processed classical music station. There was absolutely no extraneous noise whatsoever on this frequency, during the silent passages found in many classical music pieces.

Based on my tests, I have shown HD main channels are not noisy, and any possible IBOC noise that might be present on the HD station adjacent channels is skipped over by my radio while it is scanning. I would suspect most other FM radios would perform similarly. This does not lead me to believe the FM dial is now cluttered with IBOC noise on the FM dial, at least not on the main channels.

I would now like to challenge you to identify what market you are in, and to run this exact same test that I did. Tell us exactly what HD main channels your radio stops on are noisy. If your radio stops on an HD main channel and you hear noise, then my original conclusion of interference or a faulty radio likely still stands. I’d try another radio with a scanning mode to see if it exhibits the same effect. If your radio is stopping on adjacent channels of an HD station’s main frequency, it probably isn’t capable of rejecting them or there is some other issue.

I would be interested in hearing from anyone else in the Dallas market that has run similar tests to mine, and what the results were.

The full list of AM and FM stations in the Dallas market running HD can be found here:

<a target="_blank" href=http://www.ibiquity.com/cgi-bin/liststations?state=TX>http://www.ibiquity.com/cgi-bin/liststations?state=TX</a>
<P ID="edit"><FONT class="small">Edited by randrewsIII on 02/16/06 06:06 PM.</FONT></P>

 

[radiodial]

Re: HD Noise: Main vs. Adjacent

> I would now like to challenge you to identify what market
> you are in, and to run this exact same test that I did.
> Tell us exactly what HD main channels your radio stops on
> are noisy.


I never argued that the main channels are noisy. I only said that while scanning, my analog radio stops on the adjacent channels which are noisy.


> If your radio stops on an HD main channel and
> you hear noise, then my original conclusion of interference
> or a faulty radio likely still stands.


I never argued that the main channels are noisy. I only said that while scanning, my analog radio stops on the adjacent channels which are noisy.

 

[SuperSound]

Re: HD Noise: Main vs. Adjacent

The even numbered decimal frequencies you listed are not 1st adjacent channels in the US as you claim, but part of the main channel. Your radio is stopping on the European main channel frequencies, which are even numbered decimals. The first adjacent channels on either side (above and below) are the next ODD NUMBERED decimal. For 92.5 (for example) the 1st adjacnts are are 92.3 (1st adjacent lower) and 92.7 (1st adjacent upper). Check the FCC rules, and you will find this to be true. On most FM radios the digital jamming interference on the real 1st adjacent channels (next odd decimal)is clearly audible, but can easily be mistaken for normal FM backround noise. The 1st adjacent hiss caused by digital has a more destructive raspy sound that tend to jam the main channels of stations located on the 1st adjacents.
[Code of Federal Regulations]
[Title 47, Volume 4]
[Revised as of October 1, 2004]
From the U.S. Government Printing Office via GPO Access
[CITE: 47CFR73.201]

[Page 76-77]

TITLE 47--TELECOMMUNICATION

CHAPTER I--FEDERAL COMMUNICATIONS
COMMISSION (CONTINUED)

PART 73_RADIO BROADCAST SERVICES--Table of Contents

Subpart B_FM Broadcast Stations

Sec. 73.201 Numerical designation of FM broadcast channels.


The FM broadcast band consists of that portion of the radio
frequency spectrum between 88 MHz and 108 MHz. It is divided into 100
channels of 200 kHz each. For convenience, the frequencies available for
FM broadcasting (including those assigned to noncommercial educational
broadcasting) are given numerical designations which are shown in the
table below:

------------------------------------------------------------------------
Channel
Frequency (Mc/s) No.
------------------------------------------------------------------------
88.1........................................................ 201
88.3........................................................ 202

[[Page 77]]


88.5........................................................ 203
88.7........................................................ 204
88.9........................................................ 205
89.1........................................................ 206
89.3........................................................ 207
89.5........................................................ 208
89.7........................................................ 209
89.9........................................................ 210
90.1........................................................ 211
90.3........................................................ 212
90.5........................................................ 213
90.7........................................................ 214
90.9........................................................ 215
91.1........................................................ 216
91.3........................................................ 217
91.5........................................................ 218
91.7........................................................ 219
91.9........................................................ 220
92.1........................................................ 221
92.3........................................................ 222
92.5........................................................ 223
92.7........................................................ 224
92.9........................................................ 225
93.1........................................................ 226
93.3........................................................ 227
93.5........................................................ 228
93.7........................................................ 229
93.9........................................................ 230
94.1........................................................ 231
94.3........................................................ 232
94.5........................................................ 233
94.7........................................................ 234
94.9........................................................ 235
95.1........................................................ 236
95.3........................................................ 237
95.5........................................................ 238
95.7........................................................ 239
95.9........................................................ 240
96.1........................................................ 241
96.3........................................................ 242
96.5........................................................ 243
96.7........................................................ 244
96.9........................................................ 245
97.1........................................................ 246
97.3........................................................ 247
97.5........................................................ 248
97.7........................................................ 249
97.9........................................................ 250
98.1........................................................ 251
98.3........................................................ 252
98.5........................................................ 253
98.7........................................................ 254
98.9........................................................ 255
99.1........................................................ 256
99.3........................................................ 257
99.5........................................................ 258
99.7........................................................ 259
99.9........................................................ 260
100.1....................................................... 261
100.3....................................................... 262
100.5....................................................... 263
100.7....................................................... 264
100.9....................................................... 265
101.1....................................................... 266
101.3....................................................... 267
101.5....................................................... 268
101.7....................................................... 269
101.9....................................................... 270
102.1....................................................... 271
102.3....................................................... 272
102.5....................................................... 273
102.7....................................................... 274
102.9....................................................... 275
103.1....................................................... 276
103.3....................................................... 277
103.5....................................................... 278
103.7....................................................... 279
103.9....................................................... 280
104.1....................................................... 281
104.3....................................................... 282
104.5....................................................... 283
104.7....................................................... 284
104.9....................................................... 285
105.1....................................................... 286
105.3....................................................... 287
105.5....................................................... 288
105.7....................................................... 289
105.9....................................................... 290
106.1....................................................... 291
106.3....................................................... 292
106.5....................................................... 293
106.7....................................................... 294
106.9....................................................... 295
107.1....................................................... 296
107.3....................................................... 297
107.5....................................................... 298
107.7....................................................... 299
107.9....................................................... 300
------------------------------------------------------------------------
Note: The frequency 108.0 MHz may be assigned to VOR test stations
subject to the condition that interference is not caused to the
reception of FM broadcasting stations, present or future.


[28 FR 13623, Dec. 14, 1963, as amended at 30 FR 4480, Apr. 7, 1965; 52
FR 10570, Apr. 2, 1987]





> At the present time, there are 17 FM stations in the Dallas
> market running HD, according to the Ibiquity website. They
> will be referred to as “main” channels. Those frequencies
> are as follows:
>
> 88.1
> 90.1
> 92.5
> 93.3
> 94.5
> 96.7
> 97.1
> 100.3
> 101.1
> 102.1
> 102.9
> 103.3
> 104.1
> 105.3
> 106.1
> 107.5
> 107.9
>
> Since I had absolutely nothing better to do today…
>
> I used the scanning mode on one of my analog FM radios to
> see which frequencies it would stop on and what could be
> heard, and I also tested to see if the scans would stop on
> any adjacent frequencies. I ran this test twice, and in
> both cases the only adjacent channels the radio stopped on
> were 96.0, 99.2 and 107.2.
>
> As you can clearly see, the only adjacent channel the radio
> stopped on near an HD broadcast for a station licensed to
> this market, was 107.2. When my radio stopped on all the
> main frequencies of all 17 stations, the audio was not
> “noisy”.
>
> I also recorded and studied the graphic image file of WRR
> 101.1 FM, which is a lightly processed classical music
> station. There was absolutely no extraneous noise
> whatsoever on this frequency, during the silent passages
> found in many classical music pieces.
>
> Based on my tests, I have shown HD main channels are not
> noisy, and any possible IBOC noise that might be present on
> the HD station adjacent channels is skipped over by my radio
> while it is scanning. I would suspect most other FM radios
> would perform similarly. This does not lead me to believe
> the FM dial is now cluttered with IBOC noise on the FM dial,
> at least not on the main channels.
>
> I would now like to challenge you to identify what market
> you are in, and to run this exact same test that I did.
> Tell us exactly what HD main channels your radio stops on
> are noisy. If your radio stops on an HD main channel and
> you hear noise, then my original conclusion of interference
> or a faulty radio likely still stands. I’d try another
> radio with a scanning mode to see if it exhibits the same
> effect. If your radio is stopping on adjacent channels of
> an HD station’s main frequency, it probably isn’t capable of
> rejecting them or there is some other issue.
>
> I would be interested in hearing from anyone else in the
> Dallas market that has run similar tests to mine, and what
> the results were.
>
> The full list of AM and FM stations in the Dallas market
> running HD can be found here:
>
> http://www.ibiquity.com/cgi-bin/liststations?state=TX
>
<P ID="edit"><FONT class="small">Edited by SuperSound on 02/17/06 10:27 AM.</FONT></P>

 

[radiodial]

Re: HD Noise: Main vs. Adjacent

> The even numbered decimal frequencies you listed are not 1st
> adjacent channels in the US as you claim, but part of the
> main channel. Your radio is stopping on the European main
> channel frequencies, which are even numbered decimals. The
> first adjacent channels on either side (above and below) are
> the next ODD NUMBERED decimal. For 92.5 (for example) the
> 1st adjacnts are are 92.3 (1st adjacent lower) and 92.7 (1st
> adjacent upper). Check the FCC rules, and you will find this
> to be true. On most FM radios the digital jamming
> interference on the real 1st adjacent channels (next odd
> decimal)is clearly audible, but can easily be mistaken for
> normal FM backround noise. The 1st adjacent hiss caused by
> digital has a more destructive raspy sound that tend to jam
> the main channels of stations located on the 1st adjacents.
> [Code of Federal Regulations]
> [Title 47, Volume 4]
> [Revised as of October 1, 2004]
> From the U.S. Government Printing Office via GPO Access
> [CITE: 47CFR73.201]
>


Thanks SuperSound! You explained beautifully exactly what I have experienced. What you posted makes clear sense to me regarding when I do a scan across the FM band and come across the first adjacent channels.

Thanks!