AM Radio?

[in-oblivian]

As we all know we can easily recieve FM radio, but sometimes it would be nice to have AM. I was just wondering why we dont have it? Is it that our radio tuner chip cannot recieve AM radio or something? I would love to have it... Would it be hard to implement?

[musichound]

Because it is a hardware component that the H3X0 series does not have.

[pmmagic]

Originally Posted by in-oblivian

As we all know we can easily recieve FM radio, but sometimes it would be nice to have AM. I was just wondering why we dont have it? Is it that our radio tuner chip cannot recieve AM radio or something? I would love to have it... Would it be hard to implement?

Yes, is a FM only device.

Also would need a very large antenna from what I have heared,if it did have a AM chipset.

Pmmagic

[Murkey]

I believe the antenna doesn't matter that much, as I have a portable AM radio that uses the earphone lead as the antenna, like the iRiver does with FM radio.

[LAB DESIGN]

Have you ever seen a AM antenna??
Looks like this: http://kitsrus.com/jpg/ferrite.jpg

It's a wound coil.. which the H300 don't have!

You should know better!

Simple.. it can't receive AM!

LD

[pez1234]

my car radio doesnt have all tht wound wire, just a standard antenna, same with portable radios which wouldnt have the room for all that wound wire, so i dont think the i-rivers use of the headfones as a antenna restricts it from being able to recieve AM

[Astec]

Yes it does. Go to maplins and take a look at the kits they sell for AM radio DIY kits. Your car radio has that in it.

[musichound]

Originally Posted by pez1234

my car radio doesnt have all tht wound wire, just a standard antenna, same with portable radios which wouldnt have the room for all that wound wire, so i dont think the i-rivers use of the headfones as a antenna restricts it from being able to recieve AM

But, it is missing the hardware components to make it an AM radio.
Make believe you are holding an AM only radio in you hand: Now let go of it. See? no AM radio in you hand. This is exactly what's missing in the H3X0 line.

[pez1234]

http://www.pogoproducts.com/radio_yourway.html - that looks like a smallish unit able to recieve am and fm and can play mp3s

[pez1234]

i was just saying that its not an aerial restricting the h3xx from playing am wether it could or not

[LAB DESIGN]

AM is received by the type of antenna that I've posted....

I don't give a hoot what you think about AM.. It's received with antennas of wound coils!

END OF!

LD

[Astec]

http://images.google.co.uk/imgres?im...icial%26sa%3DN
am radio kit

http://akamai.globalsources.com.edge...ach_id=1320323
am radio kit coil on bottom left

http://www.atatan.com/a/hard/ICradio2.jpg
AM radio completed design

As you can see AM needs this coiled wire to get the signals. End of, the H300 does not have this it will never have this and cannot have this in it. I have made plenty of AM radios in the past to know how it works.

[musichound]

I guess we can say thread I mean case closed?

[SnoopsterJ]

I have a question: you know for stereos and whatnot, why does the antenna have to be a plastic square thing?

[LAB DESIGN]

No idea.. it just is... thats how they work.

I guess you could pick up Am differently.... but I highly doubt it! It works best with coiled antennas.

LD

[musichound]

IIRC the curled antenna is used to tune into the stations. I think the more resistance on the coil the narrower the frequency, or something to that nature.

[Astec]

The plastic thing has coiled wires in it same idea as the sites and images I posted earlier. The external idea is that it can be moved to get a better signal.

[in-oblivian]

Thanks for clarifying guys, it's too bad though AM would've come in handy on some occasions.

[Alec]

If you plugged a coiled AM antenna into one of the input sockets (and obviously if Rockbox could handle AM) would that work? Or does the antenna need to be connected to something inside the player that's inaccessible from the sockets?

[Step666]

It would need to be connected up to an AM-compatable tuner, which the H300s don't have.
FM and AM tuners are different as they deal with substantially different wavelengths, so it would matter what sort of aerial you somehow connected up to your H300, you'd still only get FM.

We really can't put it any more simply - the H300s can't do AM. It's just impossible.

[02keilj]

ok
AM stands for Amplitude modulation
FM is fro frequency modulation
i believe that AM although it is a higher frequency works different to FM because the amplitude of the signal (strength) is much higher, this is why AM always seems to transmit further and clearer.
AM airials must be coiled so as to pick up this higher amplitude wave
FM airials just need to be a wire as it just needs to pick up the frequencey change not amplitude change.
this is what i THINK
im not saying THIS IS WHY
im just making a guess on the little knowledge i have
also the AM component required would have to be able to decode the higher frequency and be capable of working with higher amplitudes

[blatherskite]

Originally Posted by in-oblivian

As we all know we can easily recieve FM radio

can we? mine doesn't really work very well at all. (I'm in UK -- I can receive about 1 of the main stations and nothing else)

[DD]

I'm also in the UK and find the reception very bad on my iriver.

[rrryanc]

If you really wanted AM on your iRiver, the easiest way would be to build/buy some sort of AM tuner and plug it and an antenna into the line in. AM is a much lower frequency than FM (.6-1.4 MHz), but has much larger wavelengths, on the order of 300ft. This is why you need a longer antenna, preferably 150ft, which is why they are often coiled. Compare to FM, with a frequency range of 90ish - 110MHz and a wavelength of around 3ft, requiring an antenna around 1.5 ft long. However, the real reason the H300's can't do AM is because the radio signal is encoded on the AM waves differently than on the FM waves. For FM waves, the frequency of the carrier signal is changed according to the source signal(music, talk, etc.). For AM waves, the amplitude of the carrier signal is changed according to the source signal. So the hardware needed to decode each are different, and that's why the H#0's can't do AM. Hope that makes sense and is somewhat informative.

[Febs]

That's very informative. Since the original question is now well and truly answered, consider this thread closed.