FM Transmitter for sending the same thing through the whole house?


2017-08-05 12:57 am
Ocasionally I'd like to send the same thing to multiple rooms
throughout my house (background music, talking, etc.).

The easiest seems to use a small FM transmitter
and then just tune the receivers to that frequency.

I was curious as to how others have done this?

Thank you.
There are multiple ways of doing this with various home networking solutions. You can see one demoed in This Video

Fm Transmitters are old school (like me) but yes they certainly can work. Be aware there are some restrictions on their use that you should check out before going on-air. Mostly this applies to power and areas like Drive Ins where they use FM for the movie sound or Hospitals and Offices where FM is used for background music. But I've never heard of anyone actually running afoul of it... You can get a transmitter ... Here
I don't know about those bad reviews of that transmitter that Douglas pointed out.
Seems kinda schechy to me.

A few years ago I built (from a kit) the Ramsey FM25B, an FM stereo transmitter.
Ramsey stopped selling them, but some are still out there if you search around.
It's a great little unit, adjustable RF and audio levels, rock solid, no hum performance.
You can set it for any FM frequency (88-108Mhz) with DIP switches.

It broadcasts excellently all through my house and even outside with the included whip antenna.
I highly recommend it.


Paid Member
2015-12-31 4:57 pm
Most FM low-power home and car transmitters are now built with a microcontroller that does the modulation on software. As example, try the "DSP PLL 87-108 MHz FM transmitter" search keyword on a ecommerce site: this 4-10$ board is based on a low-power ST microcontroller with integrated 12 bit ADC. Quality of the modulation is of course worse than a transmitter with real RF section such as the Ramsey FM25B, so you will probably not get the same good results with today's low-cost portable FM transmitters with LCD display. If you need quality, either find a older device or use a Wi-Fi based digital streaming solution. I use the Amazon echo products, they have a line-out jack and are good for background music and paging.
Just want to point out that Bluetooth is the current favorite for local wireless audio. The quality of sound from older Bluetooth may be even worse than FM but the standard is evolving. You can buy Bluetooth blasters for cheap and carry it around with you, and your car stereo is probably ready to play in the garage. Waterproof Bluetooth speakers for the shower are a available. The point is to not re-invent the wheel will save you a lot of time and money.
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Paid Member
2003-06-12 7:04 pm
Maine USA
....I've never heard of anyone actually running afoul of it... ....

There have been several cases in recent decades where pirate radio broadcasters got in deep trouble. Most that I recall were running a LOT more than 0.5W, covering a whole metro area, and also ignoring initial citations. Arrogant violators can lose their gear and be fined heavily.

0.5W seems a lot more than needed to cover most houses.

It would be "OK" here because houses are far apart (few neighbors to annoy), and our FM band has gobs of empty space.

That is assuming the transmitter does not incidentally step-on the Aviation band just above the FM band. We are under the glide-path for the local airport. Confusion between pilots could bring a plane down on our house. (And that Waco is big, the Fokker"DC3" is a bit bigger.)