AM Radio might have 10 more years

[k8jd]

In LA, NYC, and Toronto AM will remain in use do to the fact that the FM spectrum is crowded and there is a significant Ethnic population in each city. In a city like Toledo for instance, I can see AM going away.

Add Chicago to that list. Probably a few others. Toronto has a need so great they are using LMAs for US stations like WTOR 770.

Even back in 1965-66, when I worked at the "Ethnic" AM station in Oak park, iL, on 1490 kHz, we barely reached the Downtown Loop area at night That was way before the "Expanded" AM band. AM must be exapnded from 500- 1790 kHz.

[Turkeytop]

Back then I was working and living in the small city of Waterloo ON. We had a local station on 1490. At night they would barely make it to the outskirts.

[Marcus]

In North America 1230 / 1240 / 1340 / 1400 / 1450 / 1490 kHz all have the worst night time interference in the AM band. 1450 from Port Huron drops quickly at night if you head east on the 402. That Kitchener area station on 1490 was CHYM and the programming moved over to 96.7 FM in 1992. In the late 1970's CHYM moved from 1490 to 570 AM and that signal is now home to the CityNews brand of Talk radio that Rogers owns.

[Turkeytop]

In North America 1230 / 1240 / 1340 / 1400 / 1450 / 1490 kHz all have the worst night time interference in the AM band. 1450 from Port Huron drops quickly at night if you head east on the 402. That Kitchener area station on 1490 was CHYM and the programming moved over to 96.7 FM in 1992. In the late 1970's CHYM moved from 1490 to 570 AM and that signal is now home to the CityNews brand of Talk radio that Rogers owns.

After CHYM vacated 1490 it was grabbed up by CFOS in Owen Sound. They set up a repeater in Port Elgin about 30 miles to the South West. The CFOS 560 signal had a null in that direction at night to protect a station in Monroe MI on 560. The 1490 transmitter helped them fill that gap in their night time pattern

[k8jd]

I believe the Canadians can go well above 1 kW on the US "local" channels . here limited to 1 kW ND, 24 hours, on 1230, 1240, 1340, 1400, 1450 and 1490.
Used to be a night hours limit of 250 W but that was changed a few decades ago.

[Marcus]

Right now there is a 1450 AM in Montreal which is 2,000 watts days.

[billmich88888]

In North America 1230 / 1240 / 1340 / 1400 / 1450 / 1490 kHz all have the worst night time interference in the AM band. 1450 from Port Huron drops quickly at night if you head east on the 402. That Kitchener area station on 1490 was CHYM and the programming moved over to 96.7 FM in 1992. In the late 1970's CHYM moved from 1490 to 570 AM and that signal is now home to the CityNews brand of Talk radio that Rogers owns.

After CHYM vacated 1490 it was grabbed up by CFOS in Owen Sound. They set up a repeater in Port Elgin about 30 miles to the South West. The CFOS 560 signal had a null in that direction at night to protect a station in Monroe MI on 560. The 1490 transmitter helped them fill that gap in their night time pattern

Why would CFOS have a null in its night pattern to protect a daytime only station in Monroe?

[Ben Zonia]

In North America 1230 / 1240 / 1340 / 1400 / 1450 / 1490 kHz all have the worst night time interference in the AM band. 1450 from Port Huron drops quickly at night if you head east on the 402. That Kitchener area station on 1490 was CHYM and the programming moved over to 96.7 FM in 1992. In the late 1970's CHYM moved from 1490 to 570 AM and that signal is now home to the CityNews brand of Talk radio that Rogers owns.

After CHYM vacated 1490 it was grabbed up by CFOS in Owen Sound. They set up a repeater in Port Elgin about 30 miles to the South West. The CFOS 560 signal had a null in that direction at night to protect a station in Monroe MI on 560. The 1490 transmitter helped them fill that gap in their night time pattern

Why would CFOS have a null in its night pattern to protect a daytime only station in Monroe?

That would be to protect WIND 560 Chicago at Night.

[Turkeytop]

They had and still have a null in that direction during the day too. They made several applications to CRTC to improve their signal in that direction. Their complaint was always "We are required to protect a station in Monroe MI."

[Ben Zonia]

CFOS is required to protect WRDT in the Daytime, but since WRDT is a Class D station, CFOS does not have to protect the WRDT Nighttime PSSA facility in the Royal Oak Township area.

Overlap over Lake Huron and service areas outside the country of origin are not protected for either station in the Daytime. But that probably precludes further increases by either, as it may cause interference within the country of origin. They are already closer than otherwise permitted because of Lake Huron and border agreements.

CFOS has to protect WIND at Night. There are two nulls in the Day pattern and one null at Night.

https://radio-locator.com/cgi-bin/pat?c ... AM&s=F&h=D

https://radio-locator.com/cgi-bin/pat?c ... ice=AM&h=D

[Turkeytop]

CFOS is required to protect WRDT in the Daytime, but since WRDT is a Class D station, CFOS does not have to protect the WRDT Nighttime PSSA facility in the Royal Oak Township area.

Overlap over Lake Huron and service areas outside the country of origin are not protected for either station in the Daytime. But that probably precludes further increases by either, as it may cause interference within the country of origin. They are already closer than otherwise permitted because of Lake Huron and border agreements.

CFOS has to protect WIND at Night. There are two nulls in the Day pattern and one null at Night.

https://radio-locator.com/cgi-bin/pat?c ... AM&s=F&h=D

https://radio-locator.com/cgi-bin/pat?c ... ice=AM&h=D

CFOS has resoled their problem by putting an FM transmitter at the Lake Huron town of Port Elgin.

[Marcus]

https://www.yahoo.com/news/future-fille ... 47763.html

Car makers don't intend on using the amount of RF shielding you would need just to make AM usable in electric cars, and the current owners of AM broadcasts see this as a threat. These cars simply omit the AM band.

[Turkeytop]

Shouldn't the makers of EVs be required to supress RF emissions from their vehicles?

If I'm driving a conventional vehicle and listening to AM radio, all the electric vehicles driving near me or passing me will be interfering with my radio.

[Marcus]

A Radioworld.com article mentions this and brings up the all digital AM mode, which is rarely used. Although many say that HD Radio is almost dead, Xperi hasn't given up on it yet. They are even talking about improving the signal of the FM side, which often simulcasts existing AM broadcasts.

https://www.lexology.com/library/detail ... 5a5b229243

https://www.radioworld.com/tag/electric-vehicles

[Turkeytop]

It may not have an effect on local AM but if I'm here in Lodon listening to AM from Toronto or Windsor there probably would be interference.