What is the most crowded FM frequency?

[davideduardo]

For historical information on channel use, you could look at Vane Jones Log, White's Radio Log, and The FM Atlas, on David's wonderful Archive, americanradiohistory.com. The Broadcasting Yearbook is another source of these lists. Often, you can spot the crowded channels and lesser used channels by looking at the column lengths of various frequencies.

Also very worth checking are the M Street Directory issues, the last of which was only 4 years ago... there are frequency by frequency lists.

http://www.americanradiohistory.com/M_Street_Directory_Page.htm

All 19 editions from 1989 to 2010 are there.

 

[K6JHU]

Checked the latest issue. Thanks David. Sound in 2010-2011 the FM counts were as follows. 88.1 is still the clear winner.

Freq Count
88.1 265
88.3 189
88.5 178
88.7 158
88.9 168
89.1 138
89.3 164
89.5 159
89.7 158
89.9 164
90.1 159
90.3 160
90.5 176
90.7 159
90.9 159
91.1 177
91.3 179
91.5 182
91.7 202
91.9 195
92.1 147
92.3 88
92.5 96
92.7 116
92.9 94
93.1 69
93.3 86
93.5 105
93.7 95
93.9 78
94.1 85
94.3 96
94.5 91
94.7 75
94.9 75
95.1 88
95.3 111
95.5 79
95.7 84
95.9 112
96.1 98
96.3 67
96.5 81
96.7 109
96.9 86
97.1 65
97.3 76
97.5 86
97.7 106
97.9 86
98.1 81
98.3 104
98.5 85
98.7 77
98.9 74
99.1 90
99.3 97
99.5 97
99.7 58
99.9 98
100.1 90
100.3 92
100.5 70
100.7 96
100.9 83
101.1 93
101.3 67
101.5 94
101.7 101
101.9 85
102.1 90
102.3 121
102.5 82
102.7 76
102.9 91
103.1 105
103.3 78
103.5 68
103.7 83
103.9 112
104.1 88
104.3 85
104.5 76
104.7 97
104.9 123
105.1 90
105.3 94
105.5 135
105.7 90
105.9 82
106.1 95
106.3 11
106.5 84
106.7 84
106.9 88
107.1 113
107.3 82
107.5 80
107.7 72
107.9 97

 

[CalebC]

Checked the latest issue. Thanks David. Sound in 2010-2011 the FM counts were as follows. 88.1 is still the clear winner.

Freq Count
88.1 265
88.3 189
88.5 178
88.7 158
88.9 168
89.1 138
89.3 164
89.5 159
89.7 158
89.9 164
90.1 159
90.3 160
90.5 176
90.7 159
90.9 159
91.1 177
91.3 179
91.5 182
91.7 202
91.9 195
92.1 147
92.3 88
92.5 96
92.7 116
92.9 94
93.1 69
93.3 86
93.5 105
93.7 95
93.9 78
94.1 85
94.3 96
94.5 91
94.7 75
94.9 75
95.1 88
95.3 111
95.5 79
95.7 84
95.9 112
96.1 98
96.3 67
96.5 81
96.7 109
96.9 86
97.1 65
97.3 76
97.5 86
97.7 106
97.9 86
98.1 81
98.3 104
98.5 85
98.7 77
98.9 74
99.1 90
99.3 97
99.5 97
99.7 58
99.9 98
100.1 90
100.3 92
100.5 70
100.7 96
100.9 83
101.1 93
101.3 67
101.5 94
101.7 101
101.9 85
102.1 90
102.3 121
102.5 82
102.7 76
102.9 91
103.1 105
103.3 78
103.5 68
103.7 83
103.9 112
104.1 88
104.3 85
104.5 76
104.7 97
104.9 123
105.1 90
105.3 94
105.5 135
105.7 90
105.9 82
106.1 95
106.3 11
106.5 84
106.7 84
106.9 88
107.1 113
107.3 82
107.5 80
107.7 72
107.9 97

Forgive me, as it is 2:30 in the morning my time, so I may not have grasped the overall concept of this post, but you mean to tell me in ALL of the U.S., there are only 11 stations broadcasting on 106.3?

 

[K6JHU]

But then there is no guarantee that I didn't do the list at 2:30 either

Correct answer for 106.3 is 111.

BTW, the data is for 2010-2011. I suspect all that has changed since then is infilling (e.g. LPFM and Translators).

 

[kenglish]

For historical information on channel use, you could look at Vane Jones Log, White's Radio Log, and The FM Atlas, on David's wonderful Archive, americanradiohistory.com. The Broadcasting Yearbook is another source of these lists. Often, you can spot the crowded channels and lesser used channels by looking at the column lengths of various frequencies.

I don't even have to do that...I just grab the "latest" (many years old) copy off my desk. God, I sure loved those old books....still refer to them, even today.

 

[fordranger797]

Wow! Thanks for the lists. Its further reiteration of why its so rare to hear silence on the FM dial.

 

[davideduardo]

But then there is no guarantee that I didn't do the list at 2:30 either

Correct answer for 106.3 is 111.

BTW, the data is for 2010-2011. I suspect all that has changed since then is infilling (e.g. LPFM and Translators).

I searched 106.3 in a database and included CPs, LPFMs, translators, etc. The total for the US is 218. I get 111 for "regular" commercial stations and the 3 non-coms on the channel.

 

[K6JHU]

I don't have access to a computerized data base except for Wikipedia and the FCC data base. I have doubts about Wikipedia. The FCC data base requires too much processing on my part for a casual query. For the FCC data base I would have to eliminate Use, App, Canadian, Mexican, and may a couple of other things. My SQL is very rusty. But absolute accuracy is not the question. The question is 'which frequency has the most number of stations'. Using proportionality of other than listed stations in the guide, the answer still appears to be 88.1.

 

[K6JHU]

Nobody has asked the same question about AM

1230, 1240, 1450. Take your pick.

 

[Schroedingers Cat]

I always heard that the Local Channels had about 175-200 stations. It was always kind of a steady state in fairly recent years, with stations moving to Regionals and Clears offsetting new stations on the Local Channels. However, when they went to 1000 watts night, the managers and attorneys couldn't see the advantage of moving to Regional Channels and Clear Channels. Managers and attorneys don't understand NIFs, unless they are AM engineering geeks or consultants.

 

[dxtrfn80]

In the Atlantic City area they have 5 graveyard frequencies in a short radius 1230 1340 1400 1450 and 1490 which makes dxing in the 1400s impossible.

 

[cyberdad]

Nobody has asked the same question about AM

1230, 1240, 1450. Take your pick.

Without looking anything up, I'm going to guess that it's either 1230 or 1490. If I'm correct, it wouldn't be by a very wide margin. My thinking being that these two might have an ever-so-slight edge is because each has a first adjacent that was formerly a "clear" channel (1220 and 1500). Perhaps that might have enabled a few more "graveyard" allocations to get squeezed in.

 

[Schroedingers Cat]

In the mid 1960s there was a GM Information Rack Service publication about FM Radio, a relatively new addition to the Delco Radio line. Because of the polarization of most stations being horizontal only and most car radio antennas being vertical only, the range was limited, quoted as 20 or 30 miles. By the late 1970s, they had improved both the receivers and antennas greatly, and the circular or added separate vertical station polarizations greatly improved the situation also. So the FM part caught up with the superior AM radio section. Some continued to believe that sound quality was more important, but the RF portion couldn't be matched by any after market radio I ever heard. But the reason I brought this up is that the publication had a bar graph of every AM frequency and the number of stations in 1941, and the publication date, which I think was 1962. 1340 was the most used frequency on the bar graph. The publication also discussed FM propagation situations and the capture effect. I thought it might have been a mock up, but the drawing showed the marquis with the call letters WIBC, which compared to Kokomo where Delco was based, wasn't that far away in Indianapolis. I think the frequency was right too, for WIBC-FM, it was indeed 93.1 then and now. The capture station was 94.7, indicating that the selectivity and AFC was quite wide. An amazing publication. If I can find it, I'll see if David can scan it without destroying it's value as a collectors item, for americanradiohistory.com. I refrerred to that bar graph again and again over the years. 1200 was the least used frequency, with one station in 1941 and 1962, which was WOAI.

 

[fordranger797]

In the mid 1960s there was a GM Information Rack Service publication about FM Radio, a relatively new addition to the Delco Radio line. Because of the polarization of most stations being horizontal only and most car radio antennas being vertical only, the range was limited, quoted as 20 or 30 miles. By the late 1970s, they had improved both the receivers and antennas greatly, and the circular or added separate vertical station polarizations greatly improved the situation also. So the FM part caught up with the superior AM radio section. Some continued to believe that sound quality was more important, but the RF portion couldn't be matched by any after market radio I ever heard. But the reason I brought this up is that the publication had a bar graph of every AM frequency and the number of stations in 1941, and the publication date, which I think was 1962. 1340 was the most used frequency on the bar graph. The publication also discussed FM propagation situations and the capture effect. I thought it might have been a mock up, but the drawing showed the marquis with the call letters WIBC, which compared to Kokomo where Delco was based, wasn't that far away in Indianapolis. I think the frequency was right too, for WIBC-FM, it was indeed 93.1 then and now. The capture station was 94.7, indicating that the selectivity and AFC was quite wide. An amazing publication. If I can find it, I'll see if David can scan it without destroying it's value as a collectors item, for americanradiohistory.com. I refrerred to that bar graph again and again over the years. 1200 was the least used frequency, with one station in 1941 and 1962, which was WOAI.

What is the difference between horizontal and vertical polarization? Is that the same as what you see on radio locator? For example, you sometimes see see something like "98kw horizontal" and "94kw vertical" (note that I totally made that up). What does it mean though?

 

[Schroedingers Cat]

Electromagnetic (EM or TEM) waves of all types have a polarization in a single plane. If you draw a sine function representing a wave, the plane of the polarization is the plane of the paper you draw it on. This can be electrical or magnetic, and in all EM waves, these are perpendicular to each other. FM Broadcast Band (and all other wavelengths) antennas, both transmitting and receiving, have a physical orientation which normally is the same as the electrical component of the EM wave. There are also magnetic dipole antennas. Mixed polarization can be produced by separate horizontal and vertical antennas, or an oddly twisted antenna designed to approximate circular polarization. There is also a CW and CCW sense to the circular polarization, depending on whether the vertical component lags or leads the horizontal component by 90 degrees. This can be done by phasing separate antennas, or from the sense of the twisting of the antenna, CW or CCW.


There's a lot more to it than this, but this is about as simple and explanation as you can do and cover most aspects of polarization. Light waves are also EM/TEM waves. When circularly polarized light waves hit a horizontal reflecting surface at the correct angle, only the horizontally polarized component is reflected. Polarized sunglasses cut out this polarization orientation, resulting in reduced reflection and glare.

The separate H and V ERP represent the relative AMPLITUDE or height of an EM wave of each polarization. The amplitude of the wave is proportional to the SQUARE ROOT of the ERP. For example if a station is 100 kW H and 25 kW V, the V amplitude would be half of the H amplitude. SQRT 25/SQRT 100=5/10=1/2, or ONE HALF. If H and V ERP are the same the H and V amplitudes are the same. For example, SQRT 50/SQRT 50=1.

Sorry if this is confusing, but it takes a little Sheldon and Leonard language to explain it.

 

[davideduardo]

Without looking anything up, I'm going to guess that it's either 1230 or 1490. If I'm correct, it wouldn't be by a very wide margin. My thinking being that these two might have an ever-so-slight edge is because each has a first adjacent that was formerly a "clear" channel (1220 and 1500). Perhaps that might have enabled a few more "graveyard" allocations to get squeezed in.

Current Graveyard count

1230 162
1240 156
1340 166
1400 171
1450 177
1490 181

I think what favors the higher channels is the lesser coverage of the higher frequencies, making it possible to place stations closer together.

 

[Schroedingers Cat]

Another factor is the adjacency of 1230 and 1240, which has a preclusive affect in a single market. Somehow, they managed long ago to get them close together in many markets anyway, like WJOB 1230 and WSBC 1240. Interesting fact: The real Indiana house that "A Christmas Story's" real life Ralphie, Jean Shepherd, grew up in was just a half mile from WJOB's tower. A real life Ralphie would probably have had a Crystal Radio, on which he probably could have heard WIND and WJOB. What would you get on a Crystal Radio at the movie Christmas Story House in Cleveland, David?

 

[davideduardo]

What would you get on a Crystal Radio at the movie Christmas Story House in Cleveland, David?

Where I lived in the 50's, a mile or so from the corner of Cedar and Lee in Cleveland Heights, I would have received SRS 1490 which used a tower on the roof of the Ford dealer. In '59, they changed to WJMO and the format changed from "suburban shtick" to r&b and I managed to get employment there. I spent almost 5 years under the counterpoise.

 

[Schroedingers Cat]

Doesn't the present WJMO 1300 (WERE is 1490 now, a historical shame) blast Downtown Cleveland directionally?

 

[davideduardo]

Doesn't the present WJMO 1300 (WERE is 1490 now, a historical shame) blast Downtown Cleveland directionally?

It does OK on the west side and central zone of Cuyahoga County, but is pretty ratty nights east of Severance Center and definitely difficult daytime in the more eastern suburbs.

WJMO moved from Cleveland Heights to Euclid Avenue just a bit east of Case / Western Reserve in the early 60's. The tower, next to a rail line, had quite a few radials welded to the rails themselves. Somehow the New York Central crews never cut them loose.

Anything to improve the coverage of an old Class IV.