Maybe it's just because I'm old, but even though Spotify, podcasts, and other
forms of audio streaming seem to rule the day, there's just something
comforting about the simplicity of turning a knob on the radio and
listening to what's happening on the airwaves. Even in the digital age, radio
has maintained a fair amount of popularity since the first public
broadcasts in the early 20th century.
But since radio has been around since
long before we had things like digital decoders that turn electrical impulses
into music, how the heck do simple cheap
radios know how to convert an electromagnetic radio signal into a I
don't know, let's say a basketball game or a weather report or a you know Justin
Bieber's greatest who put that crap in my script. Anyway, AM radio broadcasts
showed up before FM. So, we'll start with those. An AM station will broadcast
a signal at a constant frequency, but
will add the soundwave representing the actual audio to that base signal. It's
also called a carrier wave, resulting in the height or amplitude of the wave
changing accordingly. This is where the term AM comes from, as it stands for
amplitude modulation. You can get your radio to play back this signal as actual
music or dialogue by tuning it to
whatever frequency the station that you're looking for broadcasts at. This
makes your antenna resonate at the frequency and ignore everything else in
the air. So, very simple radio tuners are actually little more than coils of
wire. How many turns of the wire will determine what frequency you're picking
up. Cool, right? The antenna actually creates an electrical current that
corresponds to the radio signal. This current is sent to other parts of your
radio that filter out the irrelevant parts of the signal and send it to your
speakers or your headphones as changes in voltage which drive those speakers
and produce sound. It's actually pretty remarkable that this is all done without
any digital decoding by something like a a CPU. It's a completely analog process
that made it possible for news, music, and entertainment to stream into homes
decades before the internet or even TV.
FM broadcasting works somewhat similarly, though with FM, it's the
frequency of the signal that gets changed, hence the F in FM. FM radios
have a special transformer inside them that basically sits idle as long as
exactly whatever frequency you're tuned to hits your antenna. But once it
detects a small change in that frequency, it outputs a voltage that
makes your speakers emit a certain sound. So let's say you're tuned to 99.5
FM on your dial. Since FM works by using
very small changes in frequency to carry a signal, you are actually tuned to
signals just above and below 99.5 MHz,
which makes that transformer send the voltage to your speakers. Now, although
this process makes FM more complicated to engineer than AM, you often get a
much clearer, higher quality signal. FM
is less susceptible to interference as well because interference often
manifests as amplitude spikes. An AM
radio would see these spikes as actual
sound to produce and it would end up coming out of your speakers while FM
cares about variations in frequency rather than amplitude. So an FM radio
can just ignore that type of interference and the death metal you're
listening to will come out sounding just as clear and angry as ever. FM also has
the advantage of having much higher bandwidth than AM due to the
mathematical properties of frequency modulation. This allows for lots of
wiggle room in the signal to create more sounds more accurately, making FM the
clear choice for music, while AM is often just fine for stuff where
highfidelity isn't a big deal, such as talk radio. But if FM is so superior,
then why do AM stations seem to have so
much better range? Well, it's because AM
wavelengths are much longer, meaning that they can move more effectively
following even the curvature of the Earth and deal with obstacles like
buildings, whereas you can quickly lose highfrequency FM signals if you start
putting stuff in the way. AM frequencies also allow signals to cause free
electrons in the ionosphere to oscillate at the same frequency as the radio wave
that hits them. Meaning that AM signals can actually reflect off the upper
atmosphere. At night, there are more free electrons hanging out in the sky,
which is why you can sometimes hear AM stations from hundreds of miles away
after the sun goes down, as opposed to FM, which tends to go right through the
atmosphere. Of course, this may not seem impressive when the internet allows you
to listen to highquality digital broadcasts from the other side of the
world, no problem. But good old analog radio still has the distinct advantage
of only requiring a $10 receiver with no
subscription fees and very high ease of use, especially for people who might not
be terribly tech-savvy. And of course, your radio will keep working even if
your finicky internet connection goes out. Sometimes simpler is indeed better.
Speaking of keeping things simple, FreshBooks. Freshbooks is the
cloud-based accounting solution that helps you, you small business owner, you
keep organized, get more work done, and ultimately, well, make more money.
Because what FreshBooks does is it lets you track your expenses by taking
pictures of your receipts, track your hours on particular jobs through the
cloud interface, send bills to your customers through the app itself, and
even take payments from your customers via credit card directly through
FreshBooks. With all that stuff in one place, whether you're a plumber or a
small-time computer repair operator or you do, I don't know, TV installations,
whatever it is you're doing, it allows you to spend your time doing that
instead of staring at complicated accounting software at the end of every
day when your brain is tired because you were working on other stuff and you just
don't feel up to it. The best part is you can try FreshBooks for free for 30
days by going to freshbooks.com/tequicky which is linked in the video description
and entering techquicki in the how did you hear about us section. So thanks for
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