R
rbrucecarter5
Guest
https://media.ford.com/content/ford...usion-and-escape-dual-fm-radio-receivers.html
It sounded like a scholarly article. Until I read further.
First problem I have with it are the statements about receiving two stations at once. The capture ratio of FM radios precludes that. The closest I have ever come is with a Delco that had an early ceramic filter in the FM IF, and allowed two frequencies - not two stations - to come in at once. Assuming that they mean a rapid switching between two weak stations - it is either all one, or all the other. In those circumstances, HD reception would be impossible anyway - due to the long lock times.
Where they really lost me was their example of a drive from Chicago to Detroit, and how a Chicago station would swap with a Detroit on the same frequency. I used to live in Jackson, Michigan - this example is total, complete fabrication! There is not a single Chicago or Detroit station that has the range to swap with its counterpart. The FM band is so packed, it would be impossible for this scenario to unfold.
There is a real world example of stations rapidly switching. A trip to Austin, TX and anywhere 40 to 50 miles NE of there, you have Dallas, Houston, and San Antonio stations fighting it out. A good example is 101.1. You would think that KONO would dominate in North Auston, but it is actually WRR, with frequent intrusions from KLOL. Classical to oldies to Spanish language - now THAT is enough to be annoying to anybody! If diversity receivers could alleviate the problem somewhat, they might have something. But I doubt it. It might stop the quickest transitions, but most of them are hundreds of yards and many seconds wide, not the width of a car.
It sounded like a scholarly article. Until I read further.
First problem I have with it are the statements about receiving two stations at once. The capture ratio of FM radios precludes that. The closest I have ever come is with a Delco that had an early ceramic filter in the FM IF, and allowed two frequencies - not two stations - to come in at once. Assuming that they mean a rapid switching between two weak stations - it is either all one, or all the other. In those circumstances, HD reception would be impossible anyway - due to the long lock times.
Where they really lost me was their example of a drive from Chicago to Detroit, and how a Chicago station would swap with a Detroit on the same frequency. I used to live in Jackson, Michigan - this example is total, complete fabrication! There is not a single Chicago or Detroit station that has the range to swap with its counterpart. The FM band is so packed, it would be impossible for this scenario to unfold.
There is a real world example of stations rapidly switching. A trip to Austin, TX and anywhere 40 to 50 miles NE of there, you have Dallas, Houston, and San Antonio stations fighting it out. A good example is 101.1. You would think that KONO would dominate in North Auston, but it is actually WRR, with frequent intrusions from KLOL. Classical to oldies to Spanish language - now THAT is enough to be annoying to anybody! If diversity receivers could alleviate the problem somewhat, they might have something. But I doubt it. It might stop the quickest transitions, but most of them are hundreds of yards and many seconds wide, not the width of a car.
