durable AM/FM radio

[SiRbossR]

Yup it is actually. That may also be the reason why it is still in use today. Simple setup and efficient transmission.

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[badkuk]

sirs bakit nga ba AM ang madalas ginagamit for emergency facilities? Even the US uses AM for its NOAH system. Isn't FM supposed to be immune to signal attenuation?

Is it really just a matter of not wanting to upgrade the current AM radio infra? Or baka wala na ring available FM frequencies? While everyone was wondering when the power would come back during Glenda, panay tugtog pa rin ng mga kanta sa FM stations. Even 92.3 wasn't that informative. Maddening.

[oj88]

Just found out why AM is still being used. AM (amplitude modulation) is not susceptible to "capture effect". Capture effect is a phenomenon when a stronger transmitting station blankets weaker stations. FM has this problem.

Capture effect - Wikipedia, the free encyclopedia

[dr. d]

theoretically, am has better useful range..
am, under certain conditions, can be reflected by our atmosphere. can you hear those chinese am stations at night?
fm is line-of-sight. our formerly superb TV signals became impossible, once the ayala buildings arose..

[crosswind]

yup
AM can work anywhere unlike
FM when in the province or basement it wont work

[dr. d]

yup
AM can work anywhere unlike
FM when in the province or basement it wont work

surprisingly, walang dzmm (am) sa ayala tunnel, while i can still get some fm...

[remzam]

the higher the frequency, the better it is with penetrating walls in sending the signals. however, vhf and beyond are mainly line of sight. our radio fm stations belong to vhf (very high frequency)

our am stations can send signals farther simply because our am station, about 500khz-1300khz, falls under the category of HF (high frequency). compared to vhf, hf signals can bounce on our atmosphere thus being able to reach longer distances. that's why in the provinces, especially far flung areas, am is still the king. am requires very little resources to send signal to a certain distance compared to fm. however fm has better sound quality than am. thus many am stations traditionally use it for voice while fm stations use the frequency for music.

if you do swl (short wave listening), a basic sw radio can receive signals from Taiwan, China, and nearby countries. With a good antenna set up, you can even listen to stations from Europe, Africe, or even US. This is what old folks do before tv cable, and even internet.

the reason why it's hard to hear am signals like dzmm inside the ayala tunnel is because it can not penetrate the concrete wall while fm can.

[remzam]

...

OT: This thread sorta revived my interest on amateur radio. I operated on the 2-meter ham band (144-148MHz) back in the day. Ham radio has become less relevant now mainly because of the Internet, but it has been proven crucial in the coordination of relief during calamities, like in the weeks after Yolanda struck.

73 OJ88 de DV1UAR! hi-hi!
--... ...--

[badkuk]

Very informative sirs, akala ko pa naman pawala na ang AM ^_^

Now if only smartphone makers could add AM in their phones..

[badkuk]

Very informative sirs, akala ko pa naman pawala na ang AM ^_^

Now if only smartphone makers could add AM in their phones..

[oj88]

Very informative sirs, akala ko pa naman pawala na ang AM ^_^

Now if only smartphone makers could add AM in their phones..

Three words: Ferrite core antenna

AM receivers requires a significantly long antenna (the lower the resonant frequency, the longer the wavelength). In short, AM receivers uses a very long wire coiled around a ferrite core/bar. Modern smartphones are jam-packed with parts and the last thing manufacturers need is an AM antenna eating up maybe 1/10 to 1/5 the space.

FM radio, which works on a higher frequency (VHF), are able to receive signals with a significantly shorter antenna, typically a telescopic one or by utilizing the headphone/handsfree wires (to get rid of the still bulky, telescopic antenna).

[badkuk]

Three words: Ferrite core antenna

AM receivers requires a significantly long antenna (the lower the resonant frequency, the longer the wavelength). In short, AM receivers uses a very long wire coiled around a ferrite core/bar. Modern smartphones are jam-packed with parts and the last thing manufacturers need is an AM antenna eating up maybe 1/10 to 1/5 the space.

FM radio, which works on a higher frequency (VHF), are able to receive signals with a significantly shorter antenna, typically a telescopic one or by utilizing the headphone/handsfree wires (to get rid of the still bulky, telescopic antenna).

hmm, baka pwede na po earphones as antenna? :D

Seriously though, the GE clock radio i have doesn't have a physical(or at least, visible) antenna, but the reception is pretty good at ground floor, lots of buildings but relatively lots of open space.

[dr. d]

Very informative sirs, akala ko pa naman pawala na ang AM ^_^

Now if only smartphone makers could add AM in their phones..

sony did, some time back.. i think only two (me and my officemate) bought it.. i don't see the model anymore.
wala siguro ibang bumili..

i was told, the EM signals generated by the cellphone circuitry, interfered with the AM signals, requiring good shielding.. i am not sure if this is true.

besides, sosyal na sosyal ka't naka-cellphone ka na nga.. tapos makikinig ka kay kabayan at ted failon?
heh heh.

(don't get me wrong... my talapihitan is superglued to their station.)