DADDY TROY: Welcome back to Gear Daddy. I’m your host, Daddy Troy, and this whole week
at DadLabs we’ve been talking about baby monitors. Today in particular we’re going
to be talking about issues that affect privacy and interference. It’s time to put your
geek hat on because it’s time to talk about bandwidth behemoths and modulation mixups.
When I tune the radio in my car, in this case 107.1 that number means something. 107.1 megahertz
(Mhz). It stands for the frequency that the radio station broadcasts at. It is reserved
by the FCC for radio stations and in this town it is reserved for just one radio station.
Most baby monitors use a system that’s similar to FM radio stations. It’s called “frequency
modulation.” But the biggest difference here is that baby monitors don’t have they’re
own set of reserved frequencies. Instead they have to share a set of frequencies with other
devices. These frequency bands are called ISM – Industrial, Scientific, Medical. They’re
pretty crowded with other devices such as cordless phones, wireless routers, and even
microwave ovens.
Any of these might interfere with a baby monitor depending on the frequency of the monitor
and the other device. Before you go out and purchase a baby monitor check around your
home and see what frequencies your other wireless devices are using.
Cordless phones use the frequencies 900 Mhz, 2.4 Ghz and 5.8 Ghz.
Wireless routers use 2.4 Ghz and so do microwave ovens.
Baby monitors most commonly come in the following frequencies – 49 Mhz, 900 Mhz, 2.4 Ghz,
and 5.8 Ghz.
So if all this talk of megahertz and gigahertz has you confused don’t worry about it. Just
go to the user manual or look at the device itself and look at the numbers. This one has
a 5.8 Ghz and this one right here has a 900 Mhz. The two don’t match so they’re less
likely to interfere.
A lot of wireless devices can transmit over hundreds of feet so that means sometimes interference
you here on your baby monitor is coming from the neighbors next door. This can be especially
problematic if they are using a baby monitor with the same frequency as you. The way around
this is that many monitors have this little A-B switch on them, which allows you to switch
between two channels.
If privacy is super important to you, realize that a lot of baby monitor manufacturers will
put “private” or “privacy” on their box. What that really means is they have multiple
channels that allows you to switch among them and have more privacy.
So far I’ve been talking about analog monitors. If you’re really concerned about interference
and privacy it’s best to go with a digital monitor. You’re going to have to pay for
this added feature but it might be worth it to you. Digital monitors are less susceptible
to interference and they make it easier for the engineer who designed it to code the information
so that it can be truly private.
There’s one kind of baby monitor I haven’t talked about yet and that’s the one that
uses the 1.9 Ghz range of the electro magnetic spectrum. It’s a band that has been recently
opened up by the FCC so it’s not very crowded yet and not a whole lot of devices yet have
been developed to occupy it so you don’t get a whole lot of interference and more importantly
it’s also designed specifically for voice communications so you don’t get many other
applications in that range.
Devices that use this frequency like this Phillips model are often labeled with the
acronym DECT – Digital Enhanced Cordless Telecommunications. Don’t be confused if
you see DECT 6.0. The device still uses 1.9 Ghz. This actually means between 1.92 and
1.93 Ghz which gives monitors a lot of range.
A DECT monitor determines if a certain frequency within this range is being used and if it
is it automatically switches to a new frequency within that range while at the same time encoding
all that information for privacy.
There are a lot of things that I didn’t go into today that can affect interference
on a baby monitor such as the type of antenna, diffraction due to wavelength, absorption,
reemission of certain materials in your home. The list goes on and on. If all this seems
a little complicated or if you just want some friendly advice go to DadLabs.com. There’s
a thriving community of dads there. Most of them have already bought baby monitors so
they can give you some advice as to which ones worked for them and which ones didn’t.
Thanks for tuning in. We’ll see you next time on Gear Daddy and all week long at DadLabs.com.