433MHz RF wireless modules from eBay (transmitter and receiver)

"When DATA is spelled ATAD, you know you are getting the best" - gave me a chuckle! 😁

May YouTube never run out of valuable educational channels like this one!

if you have your project ready (transmitter sending data and receiver actually receiving the data and added a 17.3cm copper wire antenna to both) you can connect a small temporary speaker to the output of tye receiver. than move the receiver away from the transmitter for about 30 meters and fine tune the coil of the receiver with a plastic screw driver. you will hear the sound increase and decrease if you slowly rotate the coil, a louder setting will significantly extend the range. than remove the speaker from the receiver and the two are adjusted optimally. this worked perfectly for me!

Transmitter to improve the fall time you can put a 20k resistor from Vcc to the collector of the switching transistor, to provide a discharge path for the oscillator side. Increases power draw a little, but should reduce that switch off time. input can also be improved by a ceramic capacitor across the supply pins, any value from 10n up chip ceramic, to make the impedance of the supply lower at RF.

3:00 dBm is not decibel meters, but a shorthand for dBmW (dB relative to 1 mW)

I am using the same module on my thermometer. Now, I finally learned how it works and that I am supposed to send data in reverse order.

As mentioned on this video, these modules have been same for the past 10 years or more. Its pure analog output, you make your own protocol to have effective communication. You have to do your own preamble (send like 10101010 sequence), form packet and add CRC. This band is crowded and combined with the automatic gain control of the receiver, the output will be very noisy. But even with all these checks and corrections, there is no way for transmitter to know if the receiver has really received the data. So this module is not good for digital data communication.

One advice on the Transmitter module: Don‘t use it without a proper low pass filter to cut off frequencies above 433 MHz. Otherwise you produce a lot of out of band emissions.

dBm I think is decibel- mw into a 50 ohm load? 0dBm is 1mw into a 50ohm impedance (or 600 ohm for video)

Hey DGW, if you're open to video ideas, I'd be interested in learning about how to design circuitry to drive recycled VFDs from scrap VCRs, microwaves, ect using a microcontroller

You've covered VFDs from clocks a few times and they've been really informative videos, a video dedicated to running them would be really cool

What Is a decibel Meter? Questionable unit :D
dBm means decibel milliwatt!

I'm addicted to your videos. I like good amount of depth your explanations has & also the way you speak is very rhythmic(singing) :)

Excellent. I'm still exploring these modules after two years. They work!

I like that , you are also covering the RF Electronic.

I was experimenting with these modules last year because I wanted to transmit on/off commands to the thermostatic switch plug that controls the fan heater in my room - the supplied thermostat was innacurate and ate batteries so quickly. I bought some reciever/transmitter pairs off ebay and the receivers were so noisy they were unusable. I bought another from Amazon that was more expensive and was surprised that I could recieve the signals from the tyre sensors of cars driving past on the road 20-25m away! So performance is very variable, and its not always possible to know which receivers are best.

Yes please DGW, more information regarding the wireless thermometer circuit would be good. I'm thinking of building one.

Interesting video, I have never looked at transmitters & receivers in any detail.

Man I love your voice, I wish you were my physics teacher

I have had 4 pairs of those sitting over here and didn't have a chance to toy with them yet. I appreciate the info about the poor sensitivity and the good receiver. I'm looking forward to more videos about how to get the best out of them!

Super cool!! I have just started experimenting and building wireless networks with these things....