HD Interference Case #1 (FM)

[audiophile.]

Each pixel represents a cell of approximately one square kilometer, so the interference is blocking WHMI-FM’s signal to a large number of homes in WHMI-FM’s core service area. Livingston’s President has advised me that the interference is real as well as theoretical. It varies from day to day based on weather conditions; and based on analog experience over many years, the digital interference problem is likely to be magnified significantly as the weather warms, during temperature inversions that occur frequently in the Livingston County area.

These are PDF documents which have much more info:

http://gullfoss2.fcc.gov/prod/ecfs/retrieve.cgi?native_or_pdf=pdf&id_document=6518313944
(See page 4 for interference map)

http://gullfoss2.fcc.gov/prod/ecfs/retrieve.cgi?native_or_pdf=pdf&id_document=6517614999

http://gullfoss2.fcc.gov/prod/ecfs/retrieve.cgi?native_or_pdf=pdf&id_document=6516753033

http://gullfoss2.fcc.gov/prod/ecfs/retrieve.cgi?native_or_pdf=pdf&id_document=6516483296

 

[autopaint-1]

I think the answer will be that WBCT is grandfathered and that while WHMI may get some intereference with it being shoe-horned in as a class A, WBCT is operating legally and affords WHMI limited protection. I'll bet that WHMI is the one who has to protect WBCT in this case. The other alternative of course is for WBCT to go directional. Trust me, the local station which covers out county went Polish a few years back and we've tried to have a local 500 watt directional doesn't cover the entire county (whic is geographically small) because of its 3 tower directional pattern. The FCC told us that our oocal station now comes from across the river and about 30 miles to the north east. It doesn't really cover our county news wise but that's what we're stuck with. Welcome to the modern world.

 

[audiophile.]

Actually WHMI is clear from WBCT by 18.1 km. WBCT is allowed to run 3.2 kw digital toward toward WHMI under the 20 dB down rule. The 20 dB down rule doesn't address every situation properly, as in this case.

Why should WHMI have to protect WBCT? WHMI doesn't cause interference TO WBCT!


Searching Channel 228A6 (93.5 MHz), from the site of WHMI:
CALL CITY ST CHN CL S DIST SEPN BRNG CLEARANCE
WJZL GRAND LEDGE MI 225 A C 50.9 31.0 278.8ø 19.9
WDRQ DETROIT MI 226 B L 64.3 69.0 109.4ø -4.7
WKQZ MIDLAND MI 227 C2 L 132.0 106.0 354.6ø 26.0
WRQN BOWLING GREEN OH 228 A L 135.9 115.0 170.2ø 20.9
WBCT GRAND RAPIDS MI 229 B L 131.1 113.0 268.5ø 18.1
WRCL FRANKENMUTH MI 229 A L 78.0 72.0 23.9ø 6.0
WVIC JACKSON MI 231 B L 66.9 69.0 243.3ø -2.1

Welcome to the modern world??? If we use our brain we can solve most of these issues. Blowing them off won't solve anything.

 

[autopaint-1]

Because WBCT has been grandfathered. You're talkinng about odd cases here and there amongst many thousand radio stations. Even if this case can't be worked out (and I'll bet it can) you don't get rid of otherwise usefull technology because of a Class A in Michigan. As david and others have stated properly, the odd case willl be dealt with and some of these stations should never have been licensed in the first place.

 

[1q2w3e]

Actually WHMI is clear from WBCT by 18.1 km. WBCT is allowed to run 3.2 kw digital toward toward WHMI under the 20 dB down rule. The 20 dB down rule doesn't address every situation properly, as in this case.

Why should WHMI have to protect WBCT? WHMI doesn't cause interference TO WBCT!


Searching Channel 228A6 (93.5 MHz), from the site of WHMI:
CALL CITY ST CHN CL S DIST SEPN BRNG CLEARANCE
WJZL GRAND LEDGE MI 225 A C 50.9 31.0 278.8ø 19.9
WDRQ DETROIT MI 226 B L 64.3 69.0 109.4ø -4.7
WKQZ MIDLAND MI 227 C2 L 132.0 106.0 354.6ø 26.0
WRQN BOWLING GREEN OH 228 A L 135.9 115.0 170.2ø 20.9
WBCT GRAND RAPIDS MI 229 B L 131.1 113.0 268.5ø 18.1
WRCL FRANKENMUTH MI 229 A L 78.0 72.0 23.9ø 6.0
WVIC JACKSON MI 231 B L 66.9 69.0 243.3ø -2.1

Welcome to the modern world??? If we use our brain we can solve most of these issues. Blowing them off won't solve anything.

As a matter of fact, I have been through the area. WBCTs HD signal drops well before hiway 50. The analog drops well before Ann Arbor. WBCTs 54dBu is short of hiway 50 along I-94. I would anticipate WBCTs HD signal to be about where the 54dBu line is.

I have driven past WHMI, camped at the State park close by, had lunch at the Irish pub downtown Howell, and never heard any troubles with WHMIs signal.

As the previous posted said, WHMI has to protect WBCT due to WBCT being there first, and is grandfathered. WHMI was shoe horned in, and as part of their license (I believe) they have to protect WBCT. I have had a few FMs that specifically say that a certain station needs to be protected, and that any cross over must be tolerated.

 

[audiophile.]

You're talkinng about odd cases here and there amongst many thousand radio stations. Even if this case can't be worked out (and I'll bet it can) you don't get rid of otherwise usefull technology because of a Class A in Michigan.

Unfortunately this isn't an "odd" case, if it was, I wouldn't be wasting your time! There are 173 'VICTIM' first adjacent FM stations (there even more second adjacents...more come on that later). This is not a trival matter. How would you feel is this was your class A Michigan station? As Harry Truman would say: You'd be mad as hell (actually the name town near WHMI)!

WHMI is full spaced to WBCT and has peacefully existed until now... There is nothing on their license (or Application, CP) about accepting interference from WBCT. http://svartifoss2.fcc.gov/prod/cdbs/pubacc/Auth_Files/273830.pdf

Read and weap the list of 173 I-BLOC'd FM stations:

 

[audiophile.]

173 stations part 1:

FIRST ADJACENT VICTIMS OF GSS 10% STATION PREDICTED ANALOG AND IBOC INTERFERENCE
Victim Station FacID Channel First-Adjacent Grandfathered Superpowered FM Station FacID of GSS FM Station
Channel Distance (km) Analog Interfering Contour Overlap (%) IBOC Interfering Contour Overlap (%)
KPSL-F 35108 221A KHHT 35022 222 158.7 0.0 22.3
KSOQ-F 49206 221A KHHT 35022 222 149.9 50.5 98.9
WBST 3645 221A WTTS 59141 222 107.1 9.5 68.3
WZDM 66214 221A WTTS 59141 222 137.4 0.0 14.8
WWHC 49936 222A WINC-F 41810 223 140.8 0.0 17.0
WERQ-F 68827 222B WINC-F 41810 223 124.8 25.2 47.9
KMYX-F 21209 223A KHHT 35022 222 122.6 12.3 49.9
WZWZ 41850 223A WTTS 59141 222 118.2 0.0 38.8
WOFX-F 51725 223B WTTS 59141 222 145.7 15.5 32.6
WBZS-F 43277 224A WINC-F 41810 223 128.1 7.2 50.1
WCCR 11661 224A WLTJ 73889 225 105.0 21.4 59.7
WJSM-F 40503 224A WINC-F 41810 223 149.9 0.0 12.6
WUVA 74161 224A WINC-F 41810 223 114.8 7.0 47.1
KJEE 43589 225A KCBS-F 9612 226 150.0 24.3 62.4
KXFG 63912 225A KCBS-F 9612 226 111.0 93.9 100.0
WMGS 70880 225B WNTQ 50514 226 196.4 0.0 2.9
KRFR 35953 226A KZOZ 36025 227 148.4 0.0 1.1
WBVQ 21170 226A WLTJ 73889 225 116.6 10.4 36.5
WZAK 74465 226B WLTJ 73889 225 160.9 6.4 28.9
WQYX 11981 226B1 WLTJ 73889 225 141.8 0.0 23.6
KBHR 51566 227A KCBS-F 9612 226 118.0 55.3 92.0
WBBF-F 37824 227A WNTQ 50514 226 121.1 5.6 48.0
WCAN 70503 227A WNTQ 50514 226 116.8 9.9 47.0
WCIZ-F 153 227A WNTQ 50514 226 113.1 20.7 75.7
KHTS-F 20697 227B KCBS-F 9612 226 190.2 29.0 61.7
KKBN 11977 228A KSKS 26924 229 132.0 67.1 100.0
WHMI-F 65917 228A WBCT 73606 229 131.1 26.3 87.4
KCLB-F 12131 229B KZLA-F 59987 230 177.2 9.1 22.7
KDB 51169 229B KZLA-F 59987 230 150.0 36.4 56.8
KEJC 43335 230A KSKS 26924 229 154.5 24.5 66.5
KEJC 43335 230A KPFA 51246 231 108.1 24.0 66.5
KZLA-F 59987 230B KMYI 58821 231 172.3 19.7 41.5
WLIT-F 70042 230B WBCT 73606 229 192.3 11.3 39.7
KHDV 67104 230B1 KSKS 26924 229 177.0 14.4 35.5
KHDV 67104 230B1 KPFA 51246 231 187.4 0.0 4.6
KISV 18060 231B KZLA-F 59987 230 147.1 7.1 23.3
KMYI 58821 231B KZLA-F 59987 230 172.3 16.4 30.0
KEBN 50513 232A KMYI 58821 231 120.4 9.8 69.0
WBRX 33971 232A WWSW-F 59968 233 114.5 13.2 47.7
WHUZ 12918 232A WWSW-F 59968 233 130.5 0.0 10.6
WJIJ 1208 232A WRVQ 11963 233 127.5 0.0 41.9
WLVY 52122 232A WYYY 48725 233 106.1 1.3 48.3
WRLF 20460 232A WWSW-F 59968 233 110.7 8.1 44.5
KOSL 24464 232B1 KPFA 51246 231 149.7 25.5 59.9
KMYT 2910 233A KTWV 25437 234 116.0 100.0 100.0
KSPE-F 61058 233B KTWV 25437 234 177.4 21.5 53.8
WLRW 58542 233B WFBQ 59590 234 180.2 0.0 13.8
WBXQ 60909 234A WWSW-F 59968 233 125.6 0.0 6.6
WFGO 52144 234A WNED-F 27669 233 126.0 0.1 40.3
WIYN 16441 234A WYYY 48725 233 114.9 0.0 25.0

FIRST ADJACENT VICTIMS OF GSS 10% STATION PREDICTED ANALOG AND IBOC INTERFERENCE
Victim Station FacID Channel First-Adjacent Grandfathered Superpowered FM Station FacID of GSS FM
Station Channel Distance (km) Analog Interfering Contour Overlap (%) IBOC Interfering Contour Overlap (%)

WMHI 40435 234A WYYY 48725 233 126.3 16.6 68.4
WARW 9619 234B WRVQ 11963 233 174.1 4.0 32.3
KSSJ 6810 234B1 KYLD 59989 235 145.9 7.8 37.5
WELK 19369 234B1 WWSW-F 59968 233 173.2 0.0 0.1
WMTT 19858 234B1 WNED-F 27669 233 132.4 2.0 34.0
WMTT 19858 234B1 WYYY 48725 233 141.7 11.0 38.7
WOFM 43881 234C2 WOLX-F 60236 235 175.5 0.0 2.8
WRHK 57465 235A WFBQ 59590 234 113.7 7.9 49.2
KBZT 58816 235B KTWV 25437 234 171.4 60.1 84.3
WMOJ 73369 235B WFBQ 59590 234 163.6 9.3 27.9
KHOP 52528 236B KYLD 59989 235 169.4 17.0 38.1
WIIL 28473 236B WOLX-F 60236 235 173.4 8.9 26.3
WJPA-F 70944 237A WKYE 72965 238 108.3 69.0 100.0
WZWW 64572 237A WKYE 72965 238 111.0 22.5 57.9
KLLY 7709 237B1 KLOS 35078 238 162.2 26.3 49.7
WKYE 72965 238B WPIG 2864 239 190.2 0.0 11.2
WPWZ 74222 238C3 WVKL 4672 239 144.2 0.0 6.6
WMRF-F 42131 239A WKYE 72965 238 121.9 21.3 41.9
KUSS 67664 239B KLOS 35078 238 171.6 67.0 96.8
WPIG 2864 239B WKYE 72965 238 190.2 3.8 15.2
WVKF 50150 239B1 WKYE 72965 238 154.6 6.4 29.6
WPNC-F 52737 240A WVKL 4672 239 110.6 18.9 44.8
KUBB 7707 242B KOIT-F 6380 243 215.2 0.0 4.2
KMRQ 12963 244A KOIT-F 6380 243 116.9 12.4 85.9
KMRQ 12963 244A KWAV 7714 245 139.6 33.0 62.3
KNOB 79003 244A KOIT-F 6380 243 114.2 47.0 74.8
KEZL 2097 244B1 KWAV 7714 245 169.8 10.6 36.6
KTSE-F 29542 246A KWAV 7714 245 112.0 60.9 100.0
KTSE-F 29542 246A KLLC 9624 247 119.1 18.8 65.0
KULV 85173 246A KLLC 9624 247 150.7 0.0 0.1
KLRM 11622 246B1 KWAV 7714 245 156.7 0.0 1.2
KSON-F 30832 247B KLSX 25075 246 191.0 0.0 19.1
KSON-F 30832 247B KLYY 58809 248 168.1 51.4 80.6
KABX-F 41173 248B KLLC 9624 247 212.6 0.0 13.9
KRCK-F 52808 249A KLYY 58809 248 124.4 16.5 48.0
KSMJ 8109 249A KMGQ 3159 248 134.4 46.1 90.0
KVVS 2320 249A KLYY 58809 248 125.3 17.6 58.3
WAXZ 56222 249A WNCI 47741 250 140.8 0.0 11.5
WCJO 29684 249A WNCI 47741 250 110.1 13.9 71.3
WILE-F 13982 249A WNCI 47741 250 116.0 0.0 8.5
WTGN 3037 249A WNCI 47741 250 129.8 0.0 23.9
KEBV 15197 250A KISQ 59964 251 156.7 0.0 11.3
KTTA 51221 250A KISQ 59964 251 114.5 34.7 79.2
WYTT 17568 250A WTVR-F 54387 251 123.0 0.0 16.6
WDFM 73393 251B WNCI 47741 250 196.0 0.0 9.9
WKDD 43863 251B WNCI 47741 250 179.6 0.0 8.2
KWNN 60427 252A KISQ 59964 251 148.6 0.0 16.3
KXBX-F 49198 252A KISQ 59964 251 135.0 6.6 38.7
WDLZ 56667 252A WTVR-F 54387 251 128.7 0.0 21.3
WOGI 21214 252A WFGY 38265 251 132.0 0.0 0.1

 

[audiophile.]

173 stations part 2:

[size=6pt]FIRST ADJACENT VICTIMS OF GSS 10% STATION PREDICTED ANALOG AND IBOC INTERFERENCE
Victim Station FacID Channel First-Adjacent Grandfathered Superpowered FM Station FacID of GSS FM
Station Channel Distance (km) Analog Interfering Contour Overlap (%) IBOC Interfering Contour Overlap (%)

WSMD-F 60776 252A WTVR-F 54387 251 112.4 7.9 45.7
WWBE 40424 252A WFGY 38265 251 127.2 0.0 43.5
KWXY-F 24253 253B KYSR 36019 254 182.9 11.3 35.3
KDFO-F 64607 253B1 KYSR 36019 254 166.5 0.0 21.2
WNNS 38347 254B WHTS 8590 255 187.8 0.0 7.7
WXMG 73972 255A WHKO 14245 256 107.7 22.5 72.8
WBYR 55659 255B WHKO 14245 256 145.9 21.8 45.5
WZKF 60706 255B WHKO 14245 256 213.6 0.0 1.0
WSCH 16256 257A WHKO 14245 256 104.5 8.0 65.0
WOXX 49789 257B1 WDCX 34820 258 163.9 0.0 16.6
KLOK-F 49100 258B KFRC-F 1084 259 169.3 14.9 30.2
KNTI 20025 258B KFRC-F 1084 259 169.7 8.1 26.0
WZXV 51353 259A WDCX 34820 258 118.7 0.0 32.1
KCIV 6504 260B KFRC-F 1084 259 213.5 0.0 7.0
KRCX-F 56513 260B KFRC-F 1084 259 176.9 9.8 25.5
KKZQ 85024 261A KOLA 55240 260 158.0 0.0 29.4
KKZQ 85024 261A KKBT 70038 262 98.1 33.5 83.3
KLVJ 49854 261A KOLA 55240 260 109.2 48.6 95.8
KQOD 9134 261A KBRG 68839 262 112.5 64.9 100.0
KZST 55430 261A KBRG 68839 262 162.6 0.0 7.6
KHWZ 34557 261B1 KOLA 55240 260 133.2 2.2 26.5
KMEN 88205 263A KBRG 68839 262 142.7 0.0 32.6
KZZO 65481 263B KBRG 68839 262 182.3 24.2 51.2
KMQA 3395 263B1 KHAY 35848 264 181.8 0.0 4.0
KPSI-F 35497 263B1 KKBT 70038 262 156.1 15.6 25.2
KRAJ 84860 265B1 KRTH-F 28631 266 142.8 22.1 74.7
KHYL 10144 266B KIOI 34930 267 178.9 26.0 56.6
KATY-F 33611 267A KRTH-F 28631 266 133.9 91.0 100.0
KAMB 34427 268B KIOI 34930 267 213.3 0.0 4.9
KSBL 35592 269A KSCA 24548 270 150.9 0.0 8.4
KXSB 43999 269A KSCA 24548 270 110.2 31.6 78.3
KCCL-F 50302 270B KDFC-F 65486 271 175.9 11.2 35.1
KPRI 51503 271B KSCA 24548 270 147.0 40.0 63.0
KJSN 12960 272A KDON-F 26930 273 114.7 59.1 100.0
KJSN 12960 272A KDFC-F 65486 271 139.9 0.0 19.7
WGRT 53033 272A WIOG 22675 273 119.5 0.0 44.0
WISY 8505 272A WTSS 34382 273 109.0 52.6 100.0
WQHZ 65748 272A WTSS 34382 273 137.4 10.5 48.1
KYOE 16414 272B1 KDFC-F 65486 271 147.6 0.0 5.5
WFBY 71690 272B1 WDVE 59588 273 165.2 0.0 7.3
WYBR 71629 272C3 WIOG 22675 273 142.3 0.0 21.4
WRFY-F 69562 273B WKSB 15326 274 133.1 27.2 52.5
WTSS 34382 273B WKSB 15326 274 212.8 2.2 10.1
WGYE 32202 274A WDVE 59588 273 115.1 7.5 42.2
WRCI 34818 274A WTSS 34382 273 96.3 82.7 100.0
KALZ 48777 274B KDON-F 26930 273 178.0 15.3 32.3
WDMK 54915 274B WIOG 22675 273 128.7 36.6 72.1
WKSB 15326 274B WTSS 34382 273 212.8 4.7 18.1
KXLM 34349 275A KIIS-F 19218 274 104.8 57.8 94.6
WOKW 55251 275A WKSB 15326 274 130.9 0.0 11.7

FIRST ADJACENT VICTIMS OF GSS 10% STATION PREDICTED ANALOG AND IBOC INTERFERENCE
Victim Station FacID Channel First-Adjacent Grandfathered Superpowered FM Station FacID of GSS FM
Station Channel Distance (km) Analog Interfering Contour Overlap (%) IBOC Interfering Contour Overlap (%)

KLQV 51164 275B KIIS-F 19218 274 171.5 25.9 52.7
WMGK 25094 275B WKSB 15326 274 195.2 3.7 20.3
WMHR 40432 275B WKSB 15326 274 207.8 0.0 3.2
KDLD 33902 276A KRUZ 8853 277 156.0 21.6 76.5
KLUN 2243 276A KRUZ 8853 277 143.2 71.8 100.0
KTPI-F 66228 276A KRUZ 8853 277 157.8 15.1 63.6
KGBB 85012 277A KOST 34424 278 116.1 72.7 100.0
KRUZ 8853 277B KOST 34424 278 177.4 21.5 33.9
KTEA 77773 278A KRUZ 8853 277 160.4 39.2 85.2
KOST 34424 278B KRUZ 8853 277 177.4 42.9 57.8
KIQQ-F 79388 279A KOST 34424 278 129.8 0.0 22.3
KMLA 55273 279A KOST 34424 278 107.5 70.2 100.0
KPLN 59816 279B KOST 34424 278 171.4 32.4 55.5
WRBR-F 27145 280A WVGR 66309 281 122.1 0.0 43.0
WRSR 41681 280A WVGR 66309 281 128.7 0.0 29.9
WWYL 7663 281A WFRG-F 50362 282 119.4 0.0 9.5
WQAL 72889 281B WOMC 28623 282 167.5 9.8 38.2
WVGR 66309 281B WOMC 28623 282 198.1 0.0 15.0
WCZY-F 9920 282A WVGR 66309 281 115.2 6.3 45.1
WJMK 28621 282B WVGR 66309 281 197.0 0.0 8.1
WOMC 28623 282B WVGR 66309 281 198.1 0.0 11.7
KBTW 81804 283A KBIG-F 6360 282 125.3 45.1 96.9
KVLI-F 35856 283A KBIG-F 6360 282 158.5 0.0 25.8
WABT 22004 283A WFRG-F 50362 282 128.4 0.0 6.4
WILZ 58578 283A WOMC 28623 282 122.0 0.0 39.0
KLOA-F 458 285B1 KMZT-F 43939 286 142.6 9.7 24.6
KOCN 8082 286A KITS 18510 287 138.6 0.0 12.6
KNCI 20353 286B KITS 18510 287 158.4 15.9 36.8
KIOZ 13504 287B KMZT-F 43939 286 171.9 36.9 63.3
KKDJ 37774 287B KMZT-F 43939 286 169.1 11.2 29.7
KRSX-F 2316 287B1 KMZT-F 43939 286 141.3 9.0 27.8
WTHD 36274 288A WOOD-F 73605 289 115.9 59.7 100.0
KKFS 51220 288B1 KITS 18510 287 125.2 2.5 30.5
WWCK-F 39678 288B1 WOOD-F 73605 289 156.1 18.2 65.5
KXRS 36829 289A KPWR 35498 290 121.3 17.2 75.9
KQPM 65249 290B KMEL 35121 291 169.4 11.0 38.6
WCKG 71283 290B WOOD-F 73605 289 197.0 9.3 32.9
WDTJ 4597 290B WOOD-F 73605 289 191.1 6.9 34.8
KPLM 54360 291B KPWR 35498 290 174.4 16.0 29.3
KRAB 17359 291B1 KPWR 35498 290 139.4 0.0 7.2
KSES-F 3155 296A KEAR 20897 295 157.3 0.0 19.0
KSES-F 3155 296A KSTN-F 69685 297 140.8 0.0 10.5
KSRT 52879 296A KEAR 20897 295 116.8 33.7 77.2
KIXW-F 68413 297A KLVE 35086 298 125.2 18.7 55.8
KPIG 54745 298A KSTN-F 69685 297 109.7 8.9 32.2
KQPT 51638 298B KSTN-F 69685 297 169.8 7.1 20.6
KCDZ 43811 299B1 KLVE 35086 298 172.6 4.6 22.7
KIST-F 31434 299B1 KLVE 35086 298 166.7 13.4 41.3

 

[autopaint-1]

First of all, I wouldn't say that you can call the grandfatered stations "superpowered? I'd say that they are Class B full power operations which have been grandfathered due to their time in operation. the FCC has over populated the AM & FM broadcast bands by lowering interference and protection standards. That will have to be addressed. What I see here is a cleaning up of the broadcast bands and either repositoning or eleminating licenses which shouldn't have been granted in the first place. The commission has screwed up quite a bit. Allowing regional AM stations to run 50 Kw on otherwise regional frequencies. Odd power schemes (such as 800 watts on AM) to shoehorn in a station. Allowing a larger station to buy out another station so that they can go full time. In the North East they have two class B stations on the same frequency within 100 miles. Maybe it's time that some cleaning be done.

 

[audiophile.]

the FCC has over populated the AM & FM broadcast bands by lowering interference and protection standards.

I agree, in part. When the FCC changed to the mileage separation instead of coutour-based methodology is when the messes all started. The mileage separation "vitamin table" has been a complete disaster.

This is part of my concerns for IBOC. It doesn't take into account actual terrain and other issues, and is once again is creating new bigger mess, as you say, by "lowering interference and protection standards".

That will have to be addressed. What I see here is a cleaning up of the broadcast bands and either repositoning or eleminating licenses which shouldn't have been granted in the first place. The commission has screwed up quite a bit.

Eliminating? Whoa, that's pretty radical, and unconstitutional, without just compensation.

Odd power schemes (such as 800 watts on AM) to shoehorn in a station.

What's wrong with that? You should be able to run whatever power level works.

Allowing a larger station to buy out another station so that they can go full time.

Again, what's wrong with that?

In the North East they have two class B stations on the same frequency within 100 miles. Maybe it's time that some cleaning be done.

How do "clean" unless you open up 76-88 MHz after DTV transision period? What the about the co-channel AM's in Ohio that the Commission didn't realize were only one town apart. Oops!

100 miles is pretty tight. Likely this came about after rules changes affected the vitamin table (Vitamin B, LOL), and the FCC granted them a waiver to each go to class maximums.

 

[1q2w3e]

You're talkinng about odd cases here and there amongst many thousand radio stations. Even if this case can't be worked out (and I'll bet it can) you don't get rid of otherwise usefull technology because of a Class A in Michigan.

Unfortunately this isn't an "odd" case, if it was, I wouldn't be wasting your time! There are 173 'VICTIM' first adjacent FM stations (there even more second adjacents...more come on that later). This is not a trival matter. How would you feel is this was your class A Michigan station? As Harry Truman would say: You'd be mad as hell (actually the name town near WHMI)!

WHMI is full spaced to WBCT and has peacefully existed until now... There is nothing on their license (or Application, CP) about accepting interference from WBCT. http://svartifoss2.fcc.gov/prod/cdbs/pubacc/Auth_Files/273830.pdf

Read and weap the list of 173 I-BLOC'd FM stations:

OK as I said I have been there and listened to WHMI. I did not notice any problems. Where are these problems happening?

Also, is the FCC web site, the information is not listed off of the web site (using my past station as an example) though it is listed on the paper license.

 

[audiophile.]

The paper and FCC online version of recent licenses grants are indentical (except for signature). In WHMI's case it would be identical.

Take a look at this map. Note the blue "cubes"?

Each pixel represents a cell of approximately one square kilometer, so the interference is blocking WHMI-FM’s signal to a large number of homes in WHMI-FM’s core service area. Livingston’s President has advised me that the interference is real as well as theoretical. It varies from day to day based on weather conditions; and based on analog experience over many years, the digital interference problem is likely to be magnified significantly as the weather warms, during temperature inversions that occur frequently in the Livingston County area.

http://gullfoss2.fcc.gov/prod/ecfs/retrieve.cgi?native_or_pdf=pdf&id_document=6518313944
(See page 4 for interference map)

 

[1q2w3e]

The paper and FCC online version of recent licenses grants are indentical (except for signature). In WHMI's case it would be identical.

Take a look at this map. Note the blue "cubes"?

Each pixel represents a cell of approximately one square kilometer, so the interference is blocking WHMI-FM’s signal to a large number of homes in WHMI-FM’s core service area. Livingston’s President has advised me that the interference is real as well as theoretical. It varies from day to day based on weather conditions; and based on analog experience over many years, the digital interference problem is likely to be magnified significantly as the weather warms, during temperature inversions that occur frequently in the Livingston County area.

http://gullfoss2.fcc.gov/prod/ecfs/retrieve.cgi?native_or_pdf=pdf&id_document=6518313944
(See page 4 for interference map)

To me it sounds like attorneys looking to raise funds for their kids college.

The key words in the document are PREDICTED INTERFERENCE (in other words this is not measured!). According to their map, they are saying that WBCTs digital signal makes it all the way to Detroit. Um, no way Jose.

WHMIs 60dBu is the smaller circle. The lawyers are trying to suggest that the "extented coverage" of WHMI is being interfered with. This is not protected coverage!. There are a few blue squares within the protected coverage. I still find it very hard to believe that WBCT would still give WHMI troubles in those areas.

Also the attorneys are railing on WBCTs "Overpowered Signal". WBCT has been legally licensed at this power level before WHMI was even thought of. It is like people who move close to an airport yet complain about the jet noise. WHMI was fully aware of the WBCT signal when they applied for a license. There should be no surprise about the WBCT signal! Another quote: "Livingston continues to urge the Commission to address the SUPER POWER ISSUE....." Not even suggesting HD radio here, just the "super power" issue.

Continuing to quote....." It (the interfernce) varies from day to day based on weather conditions". Well YAAAAAA. Welcome to tropospheric ducting! One of my stations gets clobbered by a station 100 miles away within the protected contour. But we realize it is ducting that is causing it and not something being done illegally.

Their biggest complaint is for Brighton. Huh, I have family that lives in Brighton so I am very familiar with the situation there. I cannot get WBCT in Brighton! And I have not experienced and problems receiving WHMI.

It sounds like WHMI has a complaint with the weather (ducting).

 

[audiophile.]

How do you measure something that sounds and looks white noise at a distance? A FIM-71 is out. It's possible with spectrum analyzer but still difficult.

What is the actual advantage of measurements over using tech note 101? As you stated, measured ones would be subject to ducting at that distance. This would lead measurements that could show severe interference. Maybe that's what they should do!

I counted over 130 square kilometers of interference on the west side. This is not a small area.

The Brighton complaint is likely from WDRQ's IBOC signal.

Your airport analogy is invalid because WHMI was not complainting about analog interference from WBCT. This case would be like building a new airport, that should be subject to new standards that take into account the new interference (or noise) that it creates effectively as another co-channel to WHMI.

 

[1q2w3e]

How do you measure something that sounds and looks white noise at a distance? A FIM-71 is out. It's possible with spectrum analyzer but still difficult.

What is the actual advantage of measurements over using tech note 101? As you stated, measured ones would be subject to ducting at that distance. This would lead measurements that could show severe interference. Maybe that's what they should do!

I counted over 130 square kilometers of interference on the west side. This is not a small area.

The Brighton complaint is likely from WDRQ's IBOC signal.

Your airport analogy is invalid because WHMI was not complainting about analog interference from WBCT. This case would be like building a new airport, that should be subject to new standards that take into account the new interference (or noise) that it creates effectively as another co-channel to WHMI.

First of all, I want to thank you for this decent conversation. Though we may disagree, we are able to carry this conversation like adults! A tip of the hat to you!

Measuring HD is difficult. Even in the engineering corps that discussion is still going on.

Most of the legal document is complaining about the "super power" and really not so much about the HD signal. They mention that they ANTICIPATE having issues with the HD signal. Most the the interference they mention is outside of their protected coverage. In other words they are not offered protection. There are a few dots that they came up with. The document does speciicially mention the analog signal of WBCT.

In their document, they make mentio that even on the east side, THEY SAY that WBCT is interefering with them. Knowing the WBCT signal there that would be nearly impossible. They make no mention of another other station causing intereference. Just WBCT. But again, WBCT is operating within its license. If atmosperic conditions cause intereference, there is really nothing that can be done. This season in particular has been really nasty with tropo!

Hey if I get back up there, perhaps we could meet and compare notes and do a little listening! We could learn off of each other.

 

[Chuck]

I agree, in part. When the FCC changed to the mileage separation instead of coutour-based methodology is when the messes all started. The mileage separation "vitamin table" has been a complete disaster.

This is part of my concerns for IBOC. It doesn't take into account actual terrain and other issues, and is once again is creating new bigger mess, as you say, by "lowering interference and protection standards".

I'd just like to thank "audiofile" for taking he time to make those posts. They actually present new and useful information in a matter of fact sort of way. We don't have to all agree in something to be able to have a useful, informative and helpful discussion about the road that lies ahead. In fact, I appreciate helpful and informed points of view, even if they don't happen to be the same as mine. The whole idea of discussion boards like this is to actually learn something. Never forget old adage: "There are usually three sides to every argument, yours, mine and the facts."

Thanks for actually having an intelligent discussion for a change. It is refreshing.

 

[sbe1]

Just remember, only the analog signal of these superpowers is grandfathered. It is very possible that they will have to keep the digital to the level of class they truly are. That should get rid of the interference. Wont be popular with the superpowers but would be fair.

 

[1q2w3e]

Just remember, only the analog signal of these superpowers is grandfathered. It is very possible that they will have to keep the digital to the level of class they truly are. That should get rid of the interference. Wont be popular with the superpowers but would be fair.

I knew the regional VP for the station and they did set it up under their present license. I dont see how they could do otherwise as they are licensed to serve an area and would be expected to serve that same area with HD.

I am not arguing the point, just wondering what rule would come into play here.

 

[audiophile.]

Just remember, only the analog signal of these superpowers is grandfathered. It is very possible that they will have to keep the digital to the level of class they truly are. That should get rid of the interference. Wont be popular with the superpowers but would be fair.

Excellent post!

I think the owners of station like WHMI have a valid point. I don't think the global "20" dB down standard works for every scenario. It's simple, but it's incorrect. Some stations are cheated out of more ERP, and some receive potentially harmful interference. It's win-win, win-lose and lose-lose...

In reality the small stations next to big stations are the ones taking a 'hit' with IBOC. The interference contour from a large facility extends further than the opposite. It's rare (if not impossible) that interference contour from a small facility approaches the protected contour of large a station.

As mentioned earlier, there are 173 FM stations 'in this boat' so to speak. These are only first adjacent (co-channel IBOC) ones. Many more are second adjacent (first adjacent IBOC). I'll have more on that later...

 

[IBOCRocks]

Just remember, only the analog signal of these superpowers is grandfathered. It is very possible that they will have to keep the digital to the level of class they truly are. That should get rid of the interference. Wont be popular with the superpowers but would be fair.

Excellent post!

I think the owners of station like WHMI have a valid point. I don't think the global "20" dB down standard works for every scenario. It's simple, but it's incorrect. Some stations are cheated out of more ERP, and some receive potentially harmful interference. It's win-win, win-lose and lose-lose...

In reality the small stations next to big stations are the ones taking a 'hit' with IBOC. The interference contour from a large facility extends further than the opposite. It's rare (if not impossible) that interference contour from a small facility approaches the protected contour of large a station.

As mentioned earlier, there are 173 FM stations 'in this boat' so to speak. These are only first adjacent (co-channel IBOC) ones. Many more are second adjacent (first adjacent IBOC). I'll have more on that later...

I'm assuming that the assertion is that even with IBOC carriers within the mask, there is enough energy for the IBOC signal to cause interference in the protected contour of it's adjacent-channel neighbor?

If I understand what you are saying correctly, the opinion is that if there is a larger class station running IBOC the deck is stacked against the smaller classed adjacent-channel station because it's protected contour is, naturally, smaller than that the larger class. So has there been showings that an adjacent channel IBOC system has interfered with a stations protected contour, or that there has been an increase in interference in the stations secondary contour?

Sorry if this has been explained already...it was a little difficult to follow the thread...