2 Pieces Digital FM Transmitter Module Stereo FM Transmitter DSP PLL 76.0-108.0MHz Stereo Frequency Modulation with LCD Display Line/USB/Mic Input, DC 3.0V - 5.0V

The two units came in anti-static bags. The only documentation is on this listing page. They work right out of the bag with micro USB power connected and no antenna. Adding an antenna is necessary for better range (reception over longer distances). There are volume and frequency up/down buttons as well as a mute ("pause") button. For the frequency buttons: If you long press, they will go up/down in 1 MHz units steadily (i.e., release button when you reach the value). Short presses increment/decrement in 0.1 MHz steps. USB to FM: Plugged into my Macbook Pro, it appears as a USB audio output device, and can broadcast system audio to the displayed FM frequency. This is handy, considering newer Mac's lack headphone outs. The device's microphone is not available as a sound input device via USB. Mic to FM: If I plugged the unit into a power supply, (either USB without a data connection, or the solder points) the microphone became active. The mic signal is actually excellent, with a clear and full response. Line Input to FM: With an external media player plugged into the line input, the mic is disabled. The line input's sound quality is also excellent. It has full frequency range, and the dynamic range is as good as can be expected from FM. A couple of times, I experienced some unexpected background noise, but I suspect it was unrelated to the transmitter. There's an option to connect a single-wire antenna with a thru-hole solder connection. The instructions recommend a 75 cm telescoping antenna. However, as my use is just around the house, and I wanted to keep the unit more portable, I just soldered a 12-inch length of 18 AWG solid copper wire. I can go around my house (away from the transmitter) and the signal strength is quite good. There are also two thru-holes for power, which are clearly labeled. It says 3.0-5.0v. I soldered a 3-AAA battery holder to those points and it works perfectly, even with rechargeables. The seller recommends disconnecting the external power source when connecting to USB (so it is not receiving power from both at the same time). I'm SUPER pleased with this purchase. Getting a two-pack makes this an unbelievably good deal. It's a truly excellent product at a great price. I bought another 2 pack. Though this transmitter does offer "campus" bands (additional frequencies below the standard range), I've never needed these, as I've always found some available frequency. UPDATE SEP 2024: Units are still going strong. Another review mentioned that USB did not work with their more recently purchased units. I also had purchased again more recently and find that the USB works as before, even with a recent Mac. I've been using one of these transmitters with a 12" wire antenna, along with a small MP3/FM player, for my in-ear monitoring system. When I arrive at the venue, I find a quiet, unused FM frequency on the MP3/FM player. Then I set the transmitter to that frequency. I feed my monitor signal into the FM transmitter. After setting correct levels, it just works. I've used it on 20+ gigs and never had an issue. Sounds fantastic.

These FM transmitter modules are fantastic if you don’t want to spend $100+ on a bulky, enclosed unit like the ones sold on Amazon. All you need to do is solder a fairly long wire to the antenna pad and plug it in. What’s really nice is that these modules can transmit audio through USB, so you can easily create a tiny, portable FM transmitter that plugs directly into your computer for music playback. I bought these for my Christmas light show. I connected the power pins to a 5V power supply that also powers my LEDs, and plugged the AUX port into a Raspberry Pi. I added a toggle switch so it wouldn’t stay on during testing, but it could just as easily be powered via a micro USB cable connected to the Pi. I 3D printed a small case for the transmitter, but while test-fitting it, I pressed too hard and cracked the LCD. The module still works, but half of the display is broken, as shown in one of the photos. These modules are a bit fragile—especially around the LCD corners—so handle them carefully. I’m not docking a star for this, since it was entirely my fault. Thankfully, they come in a two-pack! 😊 Also, these little guys are pretty hard to mount whether you are building a case for it or just attaching it to a piece of plywood. They are solid pcbs so they don’t have any mounting holes whatsoever. I have a picture of what I did to get around this. Probably not the best way, but it holds it in strong. Overall, these are great little modules and a perfect budget-friendly FM solution—especially for light shows or projects where you don’t want to spend a lot on a full transmitter. Just note that some simple soldering is required, but it’s very easy and nothing to worry about. One last note: I attached a long piece of solid-core copper wire (the kind used for doorbells) as the antenna, and I was able to get a clear signal from over 500 feet away in my car. Basically, any decent length of wire will give you a solid signal

Any future updates will be below the Dislikes, under the === line. Dislikes: only complaint on one of the 2 I received, the leading one doesn't display, I use 107.1 and it displays as 07.1. Other than that I can't say how well they transmit yet. I would like both units to work the same, it just looks odd seeing only 07.1, when it should display 107.1 I'll post photo's later when I can get them both powered on at the same time to show this issue. ============================================ Upfdate 03/29/2024, I haven't gotten photos yet, but I was able to test both units out. I added 3 feet of actual antenna wire to the Ant pad, plugged a stereo audio cable to the transmitter line in jack, other end into my portable CD player. Turned xmtr on, set my receiver to 107.1FM, then plugged power to the xmtr. Reception on the miniature AM/FM/Digital Recorder I used was awesome. The xmtr was tested from inside my storage shed with door completely closed, my shed and its door are all metal, no windows. I walked to the end of my street, 4 houses to the East, and 4 to the West, xmtr worked perfectly, range was far better than I ever really expected.😮 I was very impressed with the range of this xmtr. No loss of clarity, music played crisp, clear and clean, no stray sounds heard. Didn't start losing the signal until I just got past the end of the block at each end. I tested BOTH transmitters, and BOTH operated exceptionally well. Again, my only complaint is one of the transmitters display shows 107.1 as 07.1, but still functioned 100% otherwise. Same results with both transmitters. If it weren't for the one not showing the leading # 1, I would have given these very tiny, but powerful xmtrs 5 stars. Now I'm just waiting on some project boxes to mount them in. I have a xmtr I bought years ago[in 2010] which cost me around $249.99 + accessories, and this little tiny transmitter is just as good as my original $250 transmitter!🫨 Which is also a humongous giant compared to this one. Can definitely recommend this to anyone looking for an FM transmitter for a Holiday Display, or any multitude of uses. You just need to know you'll have to figure out a mounting system for it, and an enclosure. And for the price, it sure beats paying $60 and up for one xmtr, when you can buy 14 for that $60 starting price tag, or the money you save buying 2 for the price sold for, less than $10 each, you can buy the extras you need, enclosure, antenna jack connector and build it up yourself for a lot less than that $60 price tag for a fully built-up one. ‐---------------- End Update for 03/29/2024 --------------- I just powered them up to make sure they would turn on, which they did. The microphone works, but haven't had a chance to test out the line in from the transmitter to the audio output from my audio player to see how far this unit will actually transmit, and whether I'll be able to utilize it for what I want to use it for. Will update this review after I can do more tests with them after I install an antenna bnc connector on the one with the full frequency display. This is so I can use one of my existing antennas to see how good or bad this transmitter is.

This transmitter is awesome! I set it up on one end of the house, and it reaches all the way to the opposite end with clear signal. My one and only complaint is that its mounting options are extremely limited, because of how packed the board is. I'm sure this keeps the cost down, though; a worth trade-off, with how well it transmits. It's very nice that it has frequency control buttons, though I haven't found any use for the volume/mute buttons. But, if I ever need them, they're there. Pros: - Transmission distance reaches throughout my whole house - Digital frequency control - Audio comes in clear Cons: - Mounting options are extremely limited

I used these tiny little FM transmitters to provide radio programming for electronic badges with built-in FM receivers at a geeky annual conference we put on. They worked absolutely perfectly, with just enough range to cover the hotel conference space so attendees could listen in on our transmissions. We did solder a short 3ft antenna wire to them to extend the range just a bit. We used these both as USB audio devices and with the audio input jack and they worked great any way we used them.

Lol, right out of the box I pranked my significant other by pirating her favorite (KQAM) station with this gadget playing California Dream in the middle of a Dan Bongino rant. I never been a DJ before... and she didn't have a clue... whisky tango foxtrot!! These work great. 1/4" thick and a bit larger than your thumb. Power it with a 3 to 5Vdc battery or micro-USB battery and you have a pocket pranker. 5Vdc or USB will give best transmitter range. Built-in microphone or, input from line level stereo audio. One or the other as input, but not both at same time. Pair this with a deep memory MP3 player and you got an instant private FM stereo station without the dadburn ads. Easy peasy to use. Flea power legal. No license required. The longer/higher the antenna -the greater the range. I haven't tested its range, but with a decent antenna >/= to bluetooth?

Reaches most of my house static free with only a 6 inch antenna. 4 stars because one of them arrived with a cracked screen and is unreadable. Not worth shipping costs to send one back. Probably the mailman's fault anyway. Not really a big deal since I plan to get it set and hide it out of sight in a cabinet.

Edit: How do you mount this? The 3 attached photos show a simple way to mount this transmitter. I first glued some wood strips to the board and then used nylon tiewraps to attach to a metal outlet box plate as shown in the photos. The wood acts as standoffs from the plate. The antenna lead is passed through a hole in the plate and connects to a whip antenna on stand offs and running through a notch in the outlet box. It’s a bit ugly but works. I’ve tried a lot of FM transmitters and have 2 operating continuously for over a year. The simplest is the Retekess FT11 that plays MP3s from a sd card. The other is a hard to get Ramsey 100b with low power output. This unit is almost as good as the above for a lot less $ but with one issue. For some reason, this transmitter is not picked up by my Yamaha RX-V475 shop receiver. My ear muff radios all pick it up and I get full area coverage but the Yamaha stays muted. All 3 transmitters with properly tuned antennas give full lot coverage and otherwise work well and sound good. With a tuned up dipole you only need .1 watts output to get good coverage for yourself while not blasting the neighborhood. This board transmitter has been working for about 2 weeks now. Without antenna it draws about 35ma. With antenna it draws about 85 ma. I’m guessing it has high swr detection (ie poor antenna) that limits it current. Once you get a good antenna connected it’s current draw will go up. For signal source, an Amazon echo works.