I think you've done a nice job of layout and assembly. The microphonics can be reduced a lot by putting a small piece of sponge inside of the coil. Even a tiny piece of fabric will help, and drop a few drops of candle wax on it once you have the coil positioned right. Thanks for the video.
Hi there Raj. I’m still considering the doorbell option but I’ve been distracted by other projects, I’m just finishing off another FM transmitter circuit that I will put on CZcams sometime in the next few days (it’s now the 15th of July 2012) I’ve built the latest circuit so I can connect it to my TV set. Anyway, I may still get around to a wireless doorbell. Thanks for watching. Kind regards ... Andy
Hi there, you have a good point about the ground it would improve the range I'm sure but it will also ‘pull’ the frequency a little bit, not that matters too much. You might want to have a look at some of the other little transmitters I’ve built. I can definitely say that using a second or third transistor is well worth the effort but if this is your first transmitter then try building the single transistor version and progress from there. Good Luck! Kind Regards ... Andy
Hi there, I want to use the transmitter with several different domestic receivers. It’s understood that if you live in a built up environment you could easily cause interference with such a device but I figure that anyone who has the ability and desire to build such a device will have an appreciation of the regulations in their country. I remember being in QSO with a ham and there was a crash at his end, apparently if he caused TVI the neighbour threw a brick at the shack. Regards ... Andy
Hi there I picked up the basic circuit from a CZcamsr called ‘dazar03’ the item is under the heading of ‘How to build a SPY Bug.’ Please remember that if you cause interference to other members of the public or worse still with any service or emergency service with a transmitter you could get into a shed load of hassle. That shouldn’t happen, but you could easily cause local interference to a close neighbor. All the best ... Andy
I certainly did! I'm a third-year EE student and have been wanting to build a digital transmitter/receiver pair since the day I got in uni. The thing is I really dislike building stuff I do not understand. Otherwise, I could have built it years ago. So, I'm trying my best to understand what I'm doing before I do it. Thanks for your response!
Hi Rick, your right I’ve had a lot of fun with the FM-TX, I haven’t pulled the tank down on this circuit but I have built another with a Hartley oscillator ~150/250 kHz but I seem to have redefined the laws of resonance as it works but not how I anticipated. Thanks for your original posting, man, so long as I’ve got a soldering iron and the gumption to use it I’ll never get bored! 73’s ... Andy
Hi, well done on building the transmitter. The brighter the light the more power is being sent out. It’s an indication of SWR but I’d say not a replacement for a meter. A meter will give you a definite reading whereas a light will only give you a ‘better-or-worse’ indication but gives no actual numeric reading. One of my old mates (G4PDQ) talks about ‘Tuning-for-maximum-smoke’ that means minimum SWR or maximum brightness. Kind Regards ... Andy GWØJXM
hey andy, wow, my new favorite circuit youtuber. i love all your radio experiments, and your copper clad land drilling technique is SO clean! how would you feel about posting schematics for some of these circuits for download? best daniel
Hey Andy, Nice FM transmitter and they are fun. Just a few parts and a little time, and they work amazingly well. It looks like to me that if you change the tank down in the AM/BC band, it should work as an AM transmitter also, maybe not as efficient. Really nice job building and demo. Regards Rick
Hi, OK on Mission Impossible whenever I hear the theme music is stirs memories for me. This little transmitter is really quite large when compared with some of the very small ones, but it’s really quite amassing just how sensitive they can be. With a very cheap crystal mic I was surprised that on a radio could pick up the sound of an ordinary domestic clock ticking 20 foot away from the microphone, and it could very easily pick up a whispered conversation. Regards ... Andy
Hi Daniel, thanks. I haven’t got a web site to post any circuits but where I do give a circuit diagram you could always copy it from the screen. I'm sure you know already but if you have your printer switched off and press the Prt Scrn (Print Screen) button and then you can paste the screen shot into a word document or as an image in some program. If you press Alt & Prt Scrn you just take an image of the application. Most of my stuff is in HD so have it full screen. All the best ... Andy
Hi Carl, you have to have a bit of fun. I’m having a rest from the house work, when I say ‘house work’ I mean I’ve just finished rebuilding the chimney with all of the lead work and retendering/pebble-dashing the south wall of the house. Mind you, while I had the scaffold up I did think about putting an aerial up on it. Thanks for watching. Kind regards ... Andy . gw0jxm
BC338 is an NPN general Purpose bipolar transistor. You can also use the common 2N2222 transistor or an actual RF transistor to get more power. Running the voltage up will result in power increase also but mind the capacitor voltages and the CL resistor. As for the coil you could use a tunable type coil which can be made or salvaged from an old CB radio and tune it with a non metallic tuner tool Also you can tap the coil and attach an antenna lead.
I built something like this about 30 years ago, hung it in a tree on a hill with a tuned aerial. It drew about 14ma@12V and due to the high location had a range of over 6 miles. I got caught by the GPO back then and it was a prison sentence, they let me off due to my young age 14 at the time, so be very careful in the UK.
Hi well I guess the short answer is, ‘it won’t work’ Sometimes extra components simply add ‘Refinement’ bit like asking what would happen if I cut my thumb off. But if you removed the 10nf cap from the +ve rail to ground it’d probably still work, depending on where the AF signal is coming from you, could possibly do without the 1uf cap on the AF input line. At a pinch you might even get away without the 0.01uf from the base to ground but everything you change will have some affect on the circuit
I noticed that in the schematic at the end you showed the capacitor from collector to emitter as 0.01 uF. In the beginning your schematic shows it as 10 pF, which is the correct value. Using a 0.01 uF is much too high and it won't oscillate. Over the years I think I've built over a dozen of these. I used to tell if the coil had too many turns by watching TV channel 6, which was right below the FM band here in the U.S. But the changeover to digital TV in 2009 has changed all that. Thanks.
Hi, very interesting your video. I would watch mission impossible when I was a child and I got surprised when they did this kind of things to spy their enemies. I hard believe that is so easy to do it. Thanks for this video and explanation!!
Hi, a ferrite core doesn’t necessarily make a ‘better’ inductor. If you have an inductor and you introduce a ferrite core into it, it will increase the inductance. The technicalities of cores and core material are quite complicated as you will find the deeper you delve into it. Good luck with your project, it sounds like you’ve kind of thrown yourself in at the deep end there. Kind Regards ... Andy
Hi Raj, no I haven’t done any more with the doorbell yet, I’ve been distracted by having to build some fitted wardrobes and I’ve been busy knocking the house about and building sets of draws to be fitted into our little house, and that’s just for starters. I need to build the time machine next, then I’ll have all the time I need to do everything I want to do as well as all the things I must do. All the best to you and your family Raj. Kind Regards ... Andy
Have you tried connecting the ground on the board to the house earth? A radiator or water pipe may do. Could increase the range. I'm inspired to build one ! Thanks.
Hi Ted the wire diameter 0.6 mm diameter (0.236”) but the size really isn’t important. The variation in layout will have a bigger influence over inductance than wire diameter plus you may find you have to stretch or squeeze the coil to find the frequency. The coil DIAMETER and NUMBER of TURNS (and any core material) all have a much bigger effect on ‘L’ than wire size. Remember L is tuned against C but finding the frequency will be the hardest part of the project. Good Luck. Regards ... Andy
Thank you, it’s all been done before by others but I hope my take on things might just be of help and interest to someone just starting out on construction. Kind Regards ... Andy
Hi Raj, how are you doing? Well I have to say I haven’t done anything with the doorbell project. I’ve had a lot of renovation work to get on with and I’ve also been very distracted by the production of HHO gas (making gas from water) as I guess you know it’s possible to run a car on ‘water gas,’ the problem is we don’t know how to do it economically and I'm looking to see if I can help find an answer. It’s a bit of fun and I think one day we’ll find the way. All the very best to you ...Andy
Thanks, I used a Spherical Camera mount that I made for the opening shots. I show how I made it in a video with the title Camera mount for Special Effects video (Spherical) I followed that up with a modification to the mount. There’s a link from the first video to the second in the description of the first video. Kind Regards .... Andy
Hi there, if you look at one of my latter videos About radio 41 you’ll see that it’s based on a circuit referred to as a ‘quality audio FM transmitter’ published in everyday electronics. Goggle ‘quality audio FM transmitter’ and you should find several items describing how that circuit works and that may help you. Kind Regards ... Andy
Hi Andy, . Found this video interesting and wanted to ask you a question. I have a rooftop terrace and have been thinking about doing something so that while we are in the terrace we can hear the video door bell. Was wondering if building something like this and connecting it to the video doorr bell, would then allow me to use it to transmit to a receiver on the terrace. If so would you know of where I could find a cuircuit.
@andydaviesbythesea I have just made a new fm transmitter and I put a lightbulb in series with the antenna. when I turn the tank capacitor the light intensity changes. is the transmitter putting out the most power when the light is brightest or dimest? and how can i use the light to check swr?
Hi, well I guess when you say FM (Frequency Modulated) you’re implying VHF (Very High Frequency) as the two are taken to be pretty well synonymous. You can build a vhf circuit on a proper breadboard that is to say a piece of wood with nails knocked in it. At VHF you’re more likely to have problems with stray inductance rather than capacitance, you simply have to be aware of the issue. Have a look at radiofun232 and Stefan0719 they have some interesting breadboards Kind Regards ...Andy GWØJXM
Hi, you might take a look at ‘About Radio part 41 Quality Audio FM Transmitter’ It’s more complicated but it has better performance, and if tyou look in the ‘show more’ box of that video you’ll find a link to how I cut the pads that the components are mounted on. if it’s your first project I’d say start with the single transistor and see how you get on. Kind Regards ... Andy
Hi this ids a second reply, I’ve just put the link to ‘About Radio part 41 Quality Audio FM Transmitter’ at the bottom of the show more box of this video. If you look in the ‘show more’ box of the part 41 video you’ll find a link to how I cut the pads that the components are mounted on. Good Luck ... Andy
as an input do I have to have a sine wave from somewhere (like microphone or sine wave generator) or I can just put a switch like on/off to make a simple remote switch or something like that? I have already maden similar thing but with Infra-red transmitter and reciever and it worked quite good (specially with some extra encoder/decoder chips) but this is the time for something more practical (because IR remote control loose its signal quite often so it would be quite difficult to control a relay or something (through a transistor of course etc.)
How would the inductor behave if it had a ferrite core? From what I know, a ferrite core allows for a much higher inductance at the same size and better operation at higher frequencies. I'm currently struggling to build a digital transmitter but trying to build an AM/FM transmitter/receiver pair first to understand RF engineering better.
Hi Carl, yes that’ll be great, when are you going to start it. But seriously making these videos can real cramp your style, today I’ve been building and videoing a medium wave transmitter and I’m working without a final design in place, I’ve got it working but not quite how I intended. The idea is for folk who may have a vintage radio, the new transmitter I’m working on allow them to play their MP3 through an old radio(s) without having to make an electrical connection. 73 ... Andy
Hi, I haven't seen you do an FM circuit on a breadboard. Are they unsuitable at FM frequencies due to capacitance? Would be great to see you do one, any chance?
Excellent video: I've just subscribed (: Does anybody here know where I can find a circuit analysis? I'd love to know more in detail how the thing works!
I couldn’t respond to your last comment for some reason it’s not in the public domain but just remember... if it were easy everyone would be doing it. All the best and good luck Kind Regards ... Andy
Hi, in the United Kingdom we can buy a 9 Volt Duracell plus battery for £1.99 including tax. If you want to see over prices go to BatteryStation .co .uk Kind Regards ... Andy
I think you've done a nice job of layout and assembly. The microphonics can be reduced a lot by putting a small piece of sponge inside of the coil. Even a tiny piece of fabric will help, and drop a few drops of candle wax on it once you have the coil positioned right. Thanks for the video.
Hi there Raj.
I’m still considering the doorbell option but I’ve been distracted by other projects, I’m just finishing off another FM transmitter circuit that I will put on CZcams sometime in the next few days (it’s now the 15th of July 2012) I’ve built the latest circuit so I can connect it to my TV set. Anyway, I may still get around to a wireless doorbell.
Thanks for watching.
Kind regards ... Andy
I really liked the shots you got at the beginning. Also, this is a very clean job you've done. Nice and neat configuration. Great job.
Hi there, you have a good point about the ground it would improve the range I'm sure but it will also ‘pull’ the frequency a little bit, not that matters too much. You might want to have a look at some of the other little transmitters I’ve built. I can definitely say that using a second or third transistor is well worth the effort but if this is your first transmitter then try building the single transistor version and progress from there.
Good Luck!
Kind Regards ... Andy
Hi there, I want to use the transmitter with several different domestic receivers. It’s understood that if you live in a built up environment you could easily cause interference with such a device but I figure that anyone who has the ability and desire to build such a device will have an appreciation of the regulations in their country. I remember being in QSO with a ham and there was a crash at his end, apparently if he caused TVI the neighbour threw a brick at the shack. Regards ... Andy
Hi there I picked up the basic circuit from a CZcamsr called ‘dazar03’ the item is under the heading of ‘How to build a SPY Bug.’
Please remember that if you cause interference to other members of the public or worse still with any service or emergency service with a transmitter you could get into a shed load of hassle. That shouldn’t happen, but you could easily cause local interference to a close neighbor.
All the best ... Andy
I certainly did! I'm a third-year EE student and have been wanting to build a digital transmitter/receiver pair since the day I got in uni. The thing is I really dislike building stuff I do not understand. Otherwise, I could have built it years ago. So, I'm trying my best to understand what I'm doing before I do it.
Thanks for your response!
Megépitettem és szuperul működik.Átalakitottam,hogy tudja fogadni a PC hang kimenetet.
Sok sikert a továbbiakban.
Üdvözlöm
András
Hungary
Hi Rick, your right I’ve had a lot of fun with the FM-TX, I haven’t pulled the tank down on this circuit but I have built another with a Hartley oscillator ~150/250 kHz but I seem to have redefined the laws of resonance as it works but not how I anticipated. Thanks for your original posting, man, so long as I’ve got a soldering iron and the gumption to use it I’ll never get bored!
73’s ... Andy
Hi, well done on building the transmitter. The brighter the light the more power is being sent out.
It’s an indication of SWR but I’d say not a replacement for a meter.
A meter will give you a definite reading whereas a light will only give you a ‘better-or-worse’ indication but gives no actual numeric reading.
One of my old mates (G4PDQ) talks about ‘Tuning-for-maximum-smoke’ that means minimum SWR or maximum brightness.
Kind Regards ... Andy
GWØJXM
hey andy,
wow, my new favorite circuit youtuber. i love all your radio experiments, and your copper clad land drilling technique is SO clean! how would you feel about posting schematics for some of these circuits for download?
best
daniel
Very nice. I love the bit about using a socket for the coil. Very clever.
Hey Andy,
Nice FM transmitter and they are fun. Just a few parts and a little time, and they work amazingly well. It looks like to me that if you change the tank down in the AM/BC band, it should work as an AM transmitter also, maybe not as efficient. Really nice job building and demo.
Regards
Rick
Try this, use 2N2222 Transistors and change R 470 to 250 ohm and use 9 volt you should be able to go where no man has gone before :))
This is fun stuff. Thanks as always Andy.
73
Hi, OK on Mission Impossible whenever I hear the theme music is stirs memories for me. This little transmitter is really quite large when compared with some of the very small ones, but it’s really quite amassing just how sensitive they can be. With a very cheap crystal mic I was surprised that on a radio could pick up the sound of an ordinary domestic clock ticking 20 foot away from the microphone, and it could very easily pick up a whispered conversation.
Regards ... Andy
Hi Daniel, thanks. I haven’t got a web site to post any circuits but where I do give a circuit diagram you could always copy it from the screen. I'm sure you know already but if you have your printer switched off and press the Prt Scrn (Print Screen) button and then you can paste the screen shot into a word document or as an image in some program. If you press Alt & Prt Scrn you just take an image of the application. Most of my stuff is in HD so have it full screen.
All the best ... Andy
Hi Carl, you have to have a bit of fun. I’m having a rest from the house work, when I say ‘house work’ I mean I’ve just finished rebuilding the chimney with all of the lead work and retendering/pebble-dashing the south wall of the house. Mind you, while I had the scaffold up I did think about putting an aerial up on it.
Thanks for watching.
Kind regards ... Andy
. gw0jxm
BC338 is an NPN general Purpose bipolar transistor. You can also use the common 2N2222 transistor or an actual RF transistor to get more power. Running the voltage up will result in power increase also but mind the capacitor voltages and the CL resistor.
As for the coil you could use a tunable type coil which can be made or salvaged from an old CB radio and tune it with a non metallic tuner tool
Also you can tap the coil and attach an antenna lead.
I built something like this about 30 years ago, hung it in a tree on a hill with a tuned aerial. It drew about 14ma@12V and due to the high location had a range of over 6 miles. I got caught by the GPO back then and it was a prison sentence, they let me off due to my young age 14 at the time, so be very careful in the UK.
How did they notice your device?
They tracked me because i was selling them in the Exchange and Mart magazine, simple as that.
Thanks Dennis, I hope the video helps novices to get an appreciation how mechanically unstable these things are.
Kind Regards ... Andy
Hi well I guess the short answer is, ‘it won’t work’ Sometimes extra components simply add ‘Refinement’ bit like asking what would happen if I cut my thumb off. But if you removed the 10nf cap from the +ve rail to ground it’d probably still work, depending on where the AF signal is coming from you, could possibly do without the 1uf cap on the AF input line. At a pinch you might even get away without the 0.01uf from the base to ground but everything you change will have some affect on the circuit
I noticed that in the schematic at the end you showed the capacitor from collector to emitter as 0.01 uF. In the beginning your schematic shows it as 10 pF, which is the correct value. Using a 0.01 uF is much too high and it won't oscillate.
Over the years I think I've built over a dozen of these. I used to tell if the coil had too many turns by watching TV channel 6, which was right below the FM band here in the U.S. But the changeover to digital TV in 2009 has changed all that. Thanks.
I made American 5s MOSFET transmitter and straight away it blanked out my digital TV, turned it off quick😄👍❤️
Hi, very interesting your video. I would watch mission impossible when I was a child and I got surprised when they did this kind of things to spy their enemies. I hard believe that is so easy to do it. Thanks for this video and explanation!!
Hi, a ferrite core doesn’t necessarily make a ‘better’ inductor. If you have an inductor and you introduce a ferrite core into it, it will increase the inductance. The technicalities of cores and core material are quite complicated as you will find the deeper you delve into it.
Good luck with your project, it sounds like you’ve kind of thrown yourself in at the deep end there.
Kind Regards ... Andy
Thank you very much. For the reply and and the information. I look into it. You take care. Tec
Hi Raj, no I haven’t done any more with the doorbell yet, I’ve been distracted by having to build some fitted wardrobes and I’ve been busy knocking the house about and building sets of draws to be fitted into our little house, and that’s just for starters. I need to build the time machine next, then I’ll have all the time I need to do everything I want to do as well as all the things I must do.
All the best to you and your family Raj.
Kind Regards ... Andy
Have you tried connecting the ground on the board to the house earth? A radiator or water pipe may do. Could increase the range. I'm inspired to build one ! Thanks.
Thank you for sharing. Take care. Tec
Hi Ted the wire diameter 0.6 mm diameter (0.236”) but the size really isn’t important. The variation in layout will have a bigger influence over inductance than wire diameter plus you may find you have to stretch or squeeze the coil to find the frequency. The coil DIAMETER and NUMBER of TURNS (and any core material) all have a much bigger effect on ‘L’ than wire size. Remember L is tuned against C but finding the frequency will be the hardest part of the project.
Good Luck.
Regards ... Andy
you vary cool thanks from baghdad iraq
great information
Andy, don't you think a series on antenna theory would be fun? Ha ha don't want to get
you nuts ;).
Carl
KD8SKG
Thank you, it’s all been done before by others but I hope my take on things might just be of help and interest to someone just starting out on construction.
Kind Regards ... Andy
Hi Raj, how are you doing? Well I have to say I haven’t done anything with the doorbell project. I’ve had a lot of renovation work to get on with and I’ve also been very distracted by the production of HHO gas (making gas from water) as I guess you know it’s possible to run a car on ‘water gas,’ the problem is we don’t know how to do it economically and I'm looking to see if I can help find an answer. It’s a bit of fun and I think one day we’ll find the way.
All the very best to you
...Andy
Thank you.
Regards ... Andy
Thanks, I used a Spherical Camera mount that I made for the opening shots. I show how I made it in a video with the title
Camera mount for Special Effects video (Spherical)
I followed that up with a modification to the mount. There’s a link from the first video to the second in the description of the first video.
Kind Regards .... Andy
Hi there, if you look at one of my latter videos About radio 41 you’ll see that it’s based on a circuit referred to as a ‘quality audio FM transmitter’ published in everyday electronics. Goggle ‘quality audio FM transmitter’ and you should find several items describing how that circuit works and that may help you.
Kind Regards ... Andy
Hi Andy, . Found this video interesting and wanted to ask you a question. I have a rooftop terrace and have been thinking about doing something so that while we are in the terrace we can hear the video door bell. Was wondering if building something like this and connecting it to the video doorr bell, would then allow me to use it to transmit to a receiver on the terrace. If so would you know of where I could find a cuircuit.
thanks for the quick response, i have a crummy vid of it on my channel
This is really neat. Could you explain how it works and what each part does?
@andydaviesbythesea I have just made a new fm transmitter and I put a lightbulb in series with the antenna. when I turn the tank capacitor the light intensity changes. is the transmitter putting out the most power when the light is brightest or dimest? and how can i use the light to check swr?
Nice demo! What size wire is "L"? For those of us that are Digital and NOT RF, that info would help.
I enjoy your videos. do you have anything on wiper delay circuit for ? thanks
Hi, well I guess when you say FM (Frequency Modulated) you’re implying VHF (Very High Frequency) as the two are taken to be pretty well synonymous. You can build a vhf circuit on a proper breadboard that is to say a piece of wood with nails knocked in it. At VHF you’re more likely to have problems with stray inductance rather than capacitance, you simply have to be aware of the issue. Have a look at radiofun232 and Stefan0719 they have some interesting breadboards
Kind Regards ...Andy
GWØJXM
Hi, you might take a look at ‘About Radio part 41 Quality Audio FM Transmitter’
It’s more complicated but it has better performance, and if tyou look in the ‘show more’ box of that video you’ll find a link to how I cut the pads that the components are mounted on. if it’s your first project I’d say start with the single transistor and see how you get on.
Kind Regards ... Andy
Hi this ids a second reply, I’ve just put the link to
‘About Radio part 41 Quality Audio FM Transmitter’ at the bottom of the show more box of this video.
If you look in the ‘show more’ box of the part 41 video you’ll find a link to how I cut the pads that the components are mounted on.
Good Luck ... Andy
as an input do I have to have a sine wave from somewhere (like microphone or sine wave generator) or I can just put a switch like on/off to make a simple remote switch or something like that? I have already maden similar thing but with Infra-red transmitter and reciever and it worked quite good (specially with some extra encoder/decoder chips) but this is the time for something more practical (because IR remote control loose its signal quite often so it would be quite difficult to control a relay or something (through a transistor of course etc.)
Hi there, yep there’ll be 2222 and it’ll be next to a 555 timer.
All the best ... Andy
How would the inductor behave if it had a ferrite core? From what I know, a ferrite core allows for a much higher inductance at the same size and better operation at higher frequencies.
I'm currently struggling to build a digital transmitter but trying to build an AM/FM transmitter/receiver pair first to understand RF engineering better.
hi, thx for sharing. i was wondering how you know which operating frequency you have to seek in on your radio receicer ?
Hi Carl, yes that’ll be great, when are you going to start it.
But seriously making these videos can real cramp your style, today I’ve been building and videoing a medium wave transmitter and I’m working without a final design in place, I’ve got it working but not quite how I intended. The idea is for folk who may have a vintage radio, the new transmitter I’m working on allow them to play their MP3 through an old radio(s) without having to make an electrical connection.
73 ... Andy
how can I make one for this transmitter? it look like simple , but very fun.
Why not experiment on the frequency of 27MHz? This allowed the band.
Would you recommend obtaining a HAM radio licence before building this transmitter?
its a nice project...
Hi, I haven't seen you do an FM circuit on a breadboard. Are they unsuitable at FM frequencies due to capacitance? Would be great to see you do one, any chance?
Excellent video: I've just subscribed (:
Does anybody here know where I can find a circuit analysis? I'd love to know more in detail how the thing works!
thanks
I couldn’t respond to your last comment for some reason it’s not in the public domain but just remember... if it were easy everyone would be doing it.
All the best and good luck
Kind Regards ... Andy
All FM coils work ranging from 5 to 8 turns, 4mm to 8mm Dia. Doesn't make any difference. I've tried them all.
How do I switch on an FM transmitter using a 3V relay? In theory it should work, but it does NOT!!! The question is....Why not?
How much battery of 9v duracell in your coutry?
coud you use a bc 548?
r they ceramic capacitor
0.001nf capacitor is written but where is that
what capacitors is that with the color on top? who makes it
Multi-Layer Ceramic Capacitors (MLCC) type . see "Multilayer Ceramic Capacitor Pack" here :
www.futurlec.com/ValuePacks.shtml
Faça um receiver l também
Hi, in the United Kingdom we can buy a 9 Volt Duracell plus battery for £1.99 including tax.
If you want to see over prices go to
BatteryStation .co .uk
Kind Regards ... Andy
circuit digram