KFXR with 12 night towers and 4 day towers

[davideduardo]

True, dat. Another factor that affected KLIF was the consolidation of the Dallas and Ft Worth Arbitron ratings. The MSA grew to double digit counties and only three AM's could provide a listenable nighttime signal. The Mighty 11~Ninety was NOT one of them.

570, 1080 and, of course, 820.

Few realize that the "death of AM" had more to do with coverage than nearly anything else. Few markets even have three full-market day and night signals. Some have just one or two. The top 100 markets have a total of just over 180 stations with usable day and night signals in at least 80% of the market.

And as noise levels increase, the usable coverage today is even less.

But back to the 70's (DeLorean optional): Many FMs entered the decade with less than full class-maximum power: that was rather quickly resolved. Many FMs ran fewer commercials than successful AM; that changed by the end of the decade. Many people had no FM radio; that resolved itself in that same decade.

Yet many insist that the reason FM "won" was stereo audio and better quality. I think that those benefits were secondary to better signals and static free reception.

It had, however, no relationship with the 1970 introduction of the Gremlin.

 

[briancraig]

DFW and Washington DC seem to be the first larger two markets where FM really dominated. Doesn’t DC really only have one full market AM, 630? I’m not sure 50Kw 1500 covers the whole area.

AM appears to have been dominant in a market like Chicago for much longer, where you had 6 signals that had adequate coverage. 560, 670, 720, 780, 890, 1000. Also of course in SF, where terrain kept AM going longer. But you also had 560, 610, 680, 740 and 810 and maybe one or two more good AM signals.

 

[davideduardo]

570, 1080 and, of course, 820.

Few realize that the "death of AM" had more to do with coverage than nearly anything else. Few markets even have three full-market day and night signals. Some have just one or two. The top 100 markets have a total of just over 180 stations with usable day and night signals in at least 80% of the market.

And as noise levels increase, the usable coverage today is even less.

But back to the 70's (DeLorean optional): Many FMs entered the decade with less than full class-maximum power: that was rather quickly resolved. Many FMs ran fewer commercials than successful AM; that changed by the end of the decade. Many people had no FM radio; that resolved itself in that same decade.

Yet many insist that the reason FM "won" was stereo audio and better quality. I think that those benefits were secondary to better signals and static free reception.

It had, however, no relationship with the 1970 introduction of the Gremlin.

Follow up: By the earlier 70's, Arbitron was becoming the standard at ad agencies. Because they use a mailed diary, they could survey the whole metro area, not just the "inner city zone" where phone calls were toll free. So stations on lesser signals that had done very well in Pulse and Hooper, like WEAM in DC, collapsed against bigger AM signals and FMs (WPGC in that case).

 

[davideduardo]

DFW and Washington DC seem to be the first larger two markets where FM really dominated. Doesn’t DC really only have one full market AM, 630? I’m not sure 50Kw 1500 covers the whole area.

630 is not a full market signal, particularly after it moved so they could cash in on the land the old site was on. 1500 misses a huge part of the market

AM appears to have been dominant in a market like Chicago for much longer, where you had 6 signals that had adequate coverage. 560, 670, 720, 780, 890, 1000. Also of course in SF, where terrain kept AM going longer. But you also had 560, 610, 680, 740 and 810 and maybe one or two more good AM signals.

Then you have Phoenix with none, LA with just 3, Cleveland with 1, Richmond with 1 (but part of market is in night nulls), Tidewater with none, Miami with none, Atlanta with 1, Mobile, Birmingham and Montgomery with none... and so on.

The most amazing "FM killed AM" story was Phoenix, where three of the top stations, all Top 40, were 500 watt KUPD, 5kw / 500 watt KRUX and 1kw/250 watt KRIZ. When KUPD built out its FM on the mountain, it was over for all of them very soon.