“pirate radio transmitter” let me quess it is illegal in hour country? (or require ridiculous certification) … Well sometimes I wish we had like frequency range where you can just emmit whatever you want but I know that it isn’t that simple.
The first thing that got me into electronics was making something like this. At work when I was young, we listened to an FM radio that got two channels: an “oldies” station, and some godawful country station. We had listened to oldies and otherwise enjoyed it (six of us for like seven years, like they would legit take and play our requests during the lunch hour), but a new hire at one point decided to change the channel and would put the country station on. I was having none of that, but this was the boss’s brother-in-law, hired under duress at the request of his wife (another story entirely).
I made a tiny little FM transmitter that broadcast noise on everything from 100MHz up (where the country station was – didn’t need to nail the frequency exactly… noob here working with stock capacitor values, and I couldn’t find a variable capacitor to save my life).
It was a tiny thing with the range of maybe a few feet taped to the side of a 9v battery. The radio itself was like a full receiver set on the top shelf of a wall. I set it up next to the radio on the side, behind some bric-a-brac, powered it on, and lived happily ever after.
For those wondering about licensing, legality, power, and such:
In the US, at least, the frequency on which this module operates falls in one of the [ISM Bands](https://en.wikipedia.org/wiki/ISM_radio_band), which is a small part of the 900MHz band set aside for unlicensed low-power operation, and there’s nothing particularly “pirate” about this, it’s completely legal. The company that manufactured the module OP is using wouldn’t be able to stay in business if it wasn’t.
In fact, Radio Shack and other companies used to sell “wireless headphones” 20 or 25 years ago that worked by transmitting two mono FM signals, one for each ear, in this band, and the power was enough to use them all throughout your house and into your yard. I could get 300 feet in every direction most of the time, and the dual-mono nature of the signal meant that it wasn’t prone to “stereo fading” effects like FM stereo broadcasts, which use a subcarrier above baseband to carry the stereo part of the signal, and would be the first part of the signal to get weak at the fringes of reception range. Cordless phones, baby monitors, and other consumer products that transmitted analog RF in the 2000s and 2010s frequently used the ISM band.
Contrast this with your average “iPod FM Transmitter” for your car, which barely worked when it was six inches from your car radio. Unlicensed transmitters in those parts of the frequency spectrum were very heavily regulated in terms of how much power they could emit, to the point where they were practically unusable, and any significant power *would* be “illegal” or considered “pirate radio.”
One of the other ISM bands is 2.54GHz. You might think this is so your Wi-Fi router doesn’t need a license. No. It’s because your microwave oven throws off so much RF when you use it that you can’t reliably put any fixed-frequency services anywhere in that band, or they’d be useless anytime someone nearby nuked their leftovers. Most Wi-Fi systems that still use 2.4 GHz automatically frequency-hop between 11 different channels when interference is detected, so they keep working. My Bluetooth earbuds aren’t so intelligent, however. Come to think of it, I used to have a cordless phone that boasted it used 2.4GHz for superior performance… and every time my phone rang back then, my Wi-Fi would cut out. So yeah, no power regulation in the ISM bands. It’s sort of the wild west.
Despite the clickbaity title, OP is well within the law here, has nothing to worry about, and isn’t going to disturb any of his neighbors… unless they’re playing with the exact same module or they have a very, very old cordless phone on their landline that can’t automatically change to an unused frequency.
Cool. How did you make it?
“pirate radio transmitter” let me quess it is illegal in hour country? (or require ridiculous certification)
… Well sometimes I wish we had like frequency range where you can just emmit whatever you want but I know that it isn’t that simple.
That’s pretty cool. Why did you choose the lipo cell?
Wow, so that little transmitter module is all it takes? That is cool
I see u have a 3d printer cool
the blue side cuter is the giveaway
The first thing that got me into electronics was making something like this. At work when I was young, we listened to an FM radio that got two channels: an “oldies” station, and some godawful country station. We had listened to oldies and otherwise enjoyed it (six of us for like seven years, like they would legit take and play our requests during the lunch hour), but a new hire at one point decided to change the channel and would put the country station on. I was having none of that, but this was the boss’s brother-in-law, hired under duress at the request of his wife (another story entirely).
I made a tiny little FM transmitter that broadcast noise on everything from 100MHz up (where the country station was – didn’t need to nail the frequency exactly… noob here working with stock capacitor values, and I couldn’t find a variable capacitor to save my life).
It was a tiny thing with the range of maybe a few feet taped to the side of a 9v battery. The radio itself was like a full receiver set on the top shelf of a wall. I set it up next to the radio on the side, behind some bric-a-brac, powered it on, and lived happily ever after.
Are you stateside? The SDR for testing?
this is mega cool
Kind of adorable
For those wondering about licensing, legality, power, and such:
In the US, at least, the frequency on which this module operates falls in one of the [ISM Bands](https://en.wikipedia.org/wiki/ISM_radio_band), which is a small part of the 900MHz band set aside for unlicensed low-power operation, and there’s nothing particularly “pirate” about this, it’s completely legal. The company that manufactured the module OP is using wouldn’t be able to stay in business if it wasn’t.
In fact, Radio Shack and other companies used to sell “wireless headphones” 20 or 25 years ago that worked by transmitting two mono FM signals, one for each ear, in this band, and the power was enough to use them all throughout your house and into your yard. I could get 300 feet in every direction most of the time, and the dual-mono nature of the signal meant that it wasn’t prone to “stereo fading” effects like FM stereo broadcasts, which use a subcarrier above baseband to carry the stereo part of the signal, and would be the first part of the signal to get weak at the fringes of reception range. Cordless phones, baby monitors, and other consumer products that transmitted analog RF in the 2000s and 2010s frequently used the ISM band.
Contrast this with your average “iPod FM Transmitter” for your car, which barely worked when it was six inches from your car radio. Unlicensed transmitters in those parts of the frequency spectrum were very heavily regulated in terms of how much power they could emit, to the point where they were practically unusable, and any significant power *would* be “illegal” or considered “pirate radio.”
One of the other ISM bands is 2.54GHz. You might think this is so your Wi-Fi router doesn’t need a license. No. It’s because your microwave oven throws off so much RF when you use it that you can’t reliably put any fixed-frequency services anywhere in that band, or they’d be useless anytime someone nearby nuked their leftovers. Most Wi-Fi systems that still use 2.4 GHz automatically frequency-hop between 11 different channels when interference is detected, so they keep working. My Bluetooth earbuds aren’t so intelligent, however. Come to think of it, I used to have a cordless phone that boasted it used 2.4GHz for superior performance… and every time my phone rang back then, my Wi-Fi would cut out. So yeah, no power regulation in the ISM bands. It’s sort of the wild west.
Despite the clickbaity title, OP is well within the law here, has nothing to worry about, and isn’t going to disturb any of his neighbors… unless they’re playing with the exact same module or they have a very, very old cordless phone on their landline that can’t automatically change to an unused frequency.
My first thought was that at 900MHz my best hope would be to try to listen on my indoor-outdoor thermometer.