The task of choosing which baby monitor to select can be a daunting one for dads. In this episode of Gear Daddy, Daddy Troy clears up the confusion and explains the science and technology behind baby monitors. What does Megahertz and Gigahertz mean? What about ISM and DECT? What wireless technology in your home do these baby products share frequencies with? Will a digital baby monitor provide more privacy and less interference? Gear Daddy has the answers to these and other questions about all kinds of baby gear. DadLabs Ep. 421.

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.