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Why are AM and FM presets separted?


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#1 of 15 OFFLINE   Hunter P

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Posted January 19 2006 - 10:07 AM

I posted this question in the Car Audio/Video section but got no response so I'm trying again in the AHL where all the cool people hang.Posted Image

Every car radio (to my knowledge) has their AM and FM presets separated and I would like to know why. I listen to a few FM stations and one AM station when I'm flipping through channels. It is such a hassle to switch over to AM before getting to that memorized station. Why can't the radio save favorite stations on the same set of presets regardless of AM or FM? Haven't we advanced as a race to be able to do this?
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#2 of 15 OFFLINE   Ken Chan

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Posted January 19 2006 - 10:50 AM

If you have six buttons, with separate AM and FM presets, you can have -- and advertise -- twelve presets. Some have even more, by using AM, FM1, and FM2.

So which way is better depends on how many presets you use. Given how fancy radios are nowadays, they should have an option to work either way.

#3 of 15 OFFLINE   Henry Gale

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Posted January 19 2006 - 11:43 AM

Oh get a life Hunter! Posted Image
I've got REAL problems. Why don't VCRs have a "Record Tuesday thru Saturday" setting so I can record programs that come on after midnight on weekdays?
Maybe TIVO has solved this problem, but I've slipped behind on technology. Posted Image

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#4 of 15 OFFLINE   Joseph DeMartino

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Posted January 19 2006 - 11:48 AM

Techno-lag. It is a common thing for technology to retain elements of earlier technology that it was based on, even when those things no longer seem to make a great deal of sense. Sort of like junk DNA or the human appendix. Posted Image

All radios have separate tuners for the two frequency bands. With the early electro-mechanical radios, it clearly made the most sense to switch to the proper band first, then tune to specific station. Early presets were mechnical button and pin arrangements, somewhat like tabulation stops on a mechanical typewriter. When these things were gradually replaced with electronic versions, they retained the look and feel of their predecessors.

It is true that modern electronic systems could store both the band and the channel information, and switch both band and channel in one operation, but nobody thought to do this because - well, nobody thought to do it and probably nobody asked for it. (And with multiple "pages" of presets the car companies could still advertise those 12 channels even if you could mix and match.)

Chances are the system response would be slower with such an arrangement - which raises the possibility that somebody did experiment with the idea at some point but that focus-group research killed it. (There would have to be a lag in switching bands before switching to a channel, and people are used to instantly hearing different music when they mash a button. I can actually see this being something people would complain about. Posted Image)

But there are all sorts of design elements like this that just persist in products until and unless somebody asks, "why are we doing it this way?" and nobody in the room can give him an answer.

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Joe

#5 of 15 Guest_Eric Kahn_*

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Posted January 19 2006 - 12:30 PM

the question should be, why do we even have AM radio any more
for some reason, AM does not seem to work as well with digital tuners as it did with analog tuners, it never sounds as good

#6 of 15 OFFLINE   Kirk Gunn

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Posted January 19 2006 - 12:39 PM

Early presets were mechnical button and pin arrangements


Too funny..... and my 8-track was right underneath. Posted Image

#7 of 15 OFFLINE   Jeff_CusBlues

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Posted January 20 2006 - 12:32 AM

Quote:
the question should be, why do we even have AM radio any more, AM does not seem to work as well with digital tuners as it did with analog tuners, it never sounds as good


Lots of people listen to talk radio on AM. I don't personally like it, but all I have to do is walk around the place where I work and a lot of radios are tuned into talk radio on AM. Also, I don't think the problem is with digital tuners, but AM tuners in general. With AM now being mostly talk or sports, fidelity is not an issue with most people. The development money is spent on the FM side. Personally, I've gone to XM.

#8 of 15 OFFLINE   Dave Poehlman

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Posted January 20 2006 - 02:34 AM

Why, if flipping through channels consecutively on my TV and I hit the "last channel" button, it takes me back one channel!?? Posted Image

I used to have a cable box that remembered the last number you entered rather than the last channel you flipped through. So, you could flip all over the place and hit "last channel" and it would take you back to where you wanted to go.

#9 of 15 OFFLINE   Kirk Gunn

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Posted January 20 2006 - 04:03 AM

Why, if flipping through channels consecutively on my TV and I hit the "last channel" button, it takes me back one channel!??


Anyone know of a third-party remote that does NOT do this ? Please let us know !

#10 of 15 OFFLINE   Robert_J

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Posted January 20 2006 - 06:37 AM

Quote:
I've got REAL problems. Why don't VCRs have a "Record Tuesday thru Saturday" setting so I can record programs that come on after midnight on weekdays?
Maybe TIVO has solved this problem, but I've slipped behind on technology.
Tivo has solved this problem.Posted Image It doesn't care when the show comes on, it records it based on the show's name.

Back to the original question, I have an '04 Maxima with a factory Bose (no other option) radio. It has 3 sets of 6 presets which can be any combination of AM, FM or XM.

-Robert

#11 of 15 OFFLINE   Grant B

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Posted January 20 2006 - 07:44 AM

Quote:
the question should be, why do we even have AM radio any more

Distance mainly. When I was working down in LA, I could go to the top of the 7 story parking garage and pick up Giant Broadcasts from San Francisco 400 miles away.
FM Might get 60 /70 miles at the most.


Quote:
AM does not seem to work as well with digital tuners as it did with analog tuners

True my tube radios from the 50s sound better than any non tube radio for Baseball games
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#12 of 15 OFFLINE   MarkHastings

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Posted January 20 2006 - 07:50 AM

Probably the same reason DVD studios don't like you switching audio tracks on the fly Posted Image

According to a quick bit of research, it appears that AM and FM signals are processed differently.

According to How Stuff Works.com...
Link

AM:
Quote:
The tuner causes the radio to receive just one sine wave frequency (in this case, 680,000 hertz). Now the radio has to extract the DJ's voice out of that sine wave. This is done with a part of the radio called a detector or demodulator. In the case of an AM radio, the detector is made with an electronic component called a diode
FM:
Quote:
In an FM radio, the detector is different, but everything else is the same. In FM, the detector turns the changes in frequency into sound, but the antenna, tuner and amplifier are largely the same.
It looks like a somewhat complicated process. Even though they could probably do it, I agree with Joseph that no one decided to change what's already been put in place.

It's the old "If it ain't broke, don't fix it" routine.

#13 of 15 Guest_Eric Kahn_*

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Posted January 20 2006 - 08:15 AM

AM is Amplitude modulation, they vary the power of the signal but the frequency stays the same at all times, the tuner decodes this power change for an audible signal

FM is frequency modulation, they modulate the frequency but the signal strength stays the same, to get any deeper into how they do this, ask someone else, I am not sure

#14 of 15 OFFLINE   Hunter P

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Posted January 20 2006 - 09:19 AM

Back to the original question, I have an '04 Maxima with a factory Bose (no other option) radio. It has 3 sets of 6 presets which can be any combination of AM, FM or XM.

So it does finally exist!!! Finally we have moved beyond knuckle dragging apes.


Tivo has solved this problem. Posted Image It doesn't care when the show comes on, it records it based on the show's name.
You can also set it to record a channel at a certain block of time, like Tues-Sun from 12am-2am.
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MONKEY!
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#15 of 15 OFFLINE   Ken Chan

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Posted January 21 2006 - 08:40 AM

Quote:
Why don't VCRs have a "Record Tuesday thru Saturday" setting so I can record programs that come on after midnight on weekdays?
I recall my old ProScan VCR could do this. It also had Commercial Advance.


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