I’ve played with kit of both high and low grade - and made a lot of fm/uhf transmitters my self (loved them as a kid) - these Chinese eBay ones are incredible for the price - £3/$3 each - small footprint using SMD parts - can run on 3v at 7mA can can be run from button cells / AA’s for a decent amount of time - and at this price they can be seen as disposable - build them into common household items and set at a frequency outside of normal FM range (50-80mhz is a golden range) and use a multi wave scanner to listen - great for pranks - I love how much random cool stuff you can buy from China!!
Try powering with two 9v batteries in series. The most important thing in such simple circuits is the output power which is propotional to the supply voltage.
This is a cheap device, however the "limited range" is about 30m with a 1/4 wave antenna (1.2m), and if you will try to adjust it to an empty spot in your FM radio, it will take you a very long time. Much professional ones are here, at www.petrutech.com. They are not cheap, but they are stable and easy to adjust.
Doubt someone looking at a vid of a £3 fm bug will be persuaded to blow £150+ on your kit - at that money you might as well pay a bit more and get the real pro stuff from Israel with all kinds of fancy burst transmission / encryption stuff going on - at £3 these Chinese ones are bloody incredibly
“His two plums and his banana” I see what you did there 🤣
Sat here with a brew watching this mate, ordered a load of the other ones for some experimentation. Got a little fm receiver kit too.
There great fun. Look forward to your video bud.
I’ve played with kit of both high and low grade - and made a lot of fm/uhf transmitters my self (loved them as a kid) - these Chinese eBay ones are incredible for the price - £3/$3 each - small footprint using SMD parts - can run on 3v at 7mA can can be run from button cells / AA’s for a decent amount of time - and at this price they can be seen as disposable - build them into common household items and set at a frequency outside of normal FM range (50-80mhz is a golden range) and use a multi wave scanner to listen - great for pranks - I love how much random cool stuff you can buy from China!!
UHF is much better for passing through objects. I am waiting for a VHF bug to get here now to perform similar tests.
great fun fred and your plums are belters....lol.
Try powering with two 9v batteries in series. The most important thing in such simple circuits is the output power which is propotional to the supply voltage.
two 9v batteries in series will fry it but good in parallel.
@@jmdds Yeah, after a second thought I suspect that too.
it is possible to set the FM frequency with a digital circuit such as MCU, I mean digitally change the variables of LC parameters
Iam not sure but i doubt it as there seems to be no connection.
The first one you tested seems much better?
Wouldn it be better range with more power? I dont know much about this but those button batteries arent very powerful right?
Not sure. Increasing the power might fry it.
bro can you help me?
I have the same module, but the trimpot is broken. is there another way to replace that component?
Prob not unless you can perform very good SM soldering.
Maybe try a 75cm wire antenna mate and a Poundland powerbank to give 5v. Could work a bit better :) great job anyway!!!
Yes antenna length is the key. The freq adjuster on this model was very sensitive.
Forgive me Fred but the banana and plums really do look a little suggestive. Lol
Cheers Paul. Glad someone spotted it. :-)
Yes, i thought they looked like a face as well ;+}
where i can find receiver ? simple one
Just buy a basic FM pocket radio and it will work.
This is a cheap device, however the "limited range" is about 30m with a 1/4 wave antenna (1.2m), and if you will try to adjust it to an empty spot in your FM radio, it will take you a very long time. Much professional ones are here, at www.petrutech.com. They are not cheap, but they are stable and easy to adjust.
*casual self promotion*
Doubt someone looking at a vid of a £3 fm bug will be persuaded to blow £150+ on your kit - at that money you might as well pay a bit more and get the real pro stuff from Israel with all kinds of fancy burst transmission / encryption stuff going on - at £3 these Chinese ones are bloody incredibly
totally invalid test. use the same antenna, and use an antenna of 72cm for midband 98MHz
I received mine two days ago and I put it in my mums house and I scared the life out of her I only live up the road from her
LOL. With a long wire antenna you can get amazing range.