@hecanet hey friend...thanx a lot for this video.i built this fm transmitter by doing very small hard work. i used small AM GANG capacitor and it worked very well for me.also i need to mention one thing that i placed antenna above the tank circuit at collector because it was not working at emitter. thanx a lot again because i was trying to build simple Fm transmitter for last 2 months. and one question please..how can i increase range of my transmitter?
@90asadali Hello Friend...to increase the range, you need a higher power supply & add an output RF amplifier.
Use 9 to 12 Volts power supply. Look at the pre-amp in one of our videos & adopt it for the output RF amp. You will need some tuning if you want it to be near perfect.
To avoid repeating efforts, use 1.5 to 3Volts zener diode as a voltage regulator for the transmitter portion. This ensures the frequency does not shift as long as the voltage supply remains above this value.
@hecanet hi friend..i have made the fm transmitter with the help of your video and now i am trying to build FM receiver but it is not working for me.i put the pre amplification stage after the receiver as shown by you and then took output from speaker but it is not working..should i use another amplification stage after pre amplification?
and for amplification what should i use?? LM 741 or LM 324 or something else??
@90asadali Build ur amplifier & test it separately first. Make sure it works. Use a simple microphone as the input. Then connect the pre-amplifier to it & make sure it works
After those 2, then you are ready to try the FM rcvr
LM741 might not work well. So, try LM 324, 380, 386 or any other amplifier (from 0.5 watts and above)
The idea is to make sure that each stage works on its own before cascading other stages. U might have to tweak the coil & gang to get reception
@hecanet hey friend i have built the receiver but voice is very low what should i do. i have used amplification stage only. what should i do if my amplification stage does not make a good combo with the pre amp stage shown in your video?
@90asadali Hello Friend...am glad you got it working. That is the first and most important step. Now, you have to play around with your amplifier. Try your amplifier on other signals to make sure the amplifer is working great. If that is confirmed, then try a different pre-amp. I have not had time to work on new pre-amps but I can definitely take a look and recommend some designs later.
@hecanet Ok.i got it.now i will try using a simple mic and will tell you if it works or not.one more question please...if i build this circuit on bread board,will it work?. or i have to make it on a vero board as you did?
@90asadali Hey Friend...any mic works. I used a crystal here. But I have used condenser & dynamic microphones before (a small speaker works as well). I have also used carbon microphone (in my second year at the secondary school I made a simple carbon microphone and it worked for me). You might have to tweak the biasing of the input circuit, though. I can make a video of the carbon microphone (from carbon rod of dead alkaline batteries) if time permits so you can see how easy it is.
@srgpip The trimmer was from an old radio receiver. The value was not specified but any range from 5p to 30p air trimmer would just be good enough.
You can also try small AM gang (variable capacitor). If you want to use this, make use of the middle terminal and one of the other two terminals (leave out the remaining third terminal). This should work great as well.
What's the value of the capacitor attached to the antenna?
7419635841635 4 weeks ago in playlist Favorite videos
@7419635841635 Hey there, use 104 (100nF)...I experimented with various values as well. (10 * 10^4 * 10^-12 = 10 * 10^-8 = 100nF)
hecanet 4 weeks ago
@hecanet hey friend...thanx a lot for this video.i built this fm transmitter by doing very small hard work. i used small AM GANG capacitor and it worked very well for me.also i need to mention one thing that i placed antenna above the tank circuit at collector because it was not working at emitter. thanx a lot again because i was trying to build simple Fm transmitter for last 2 months. and one question please..how can i increase range of my transmitter?
90asadali 1 month ago
@90asadali Hello Friend...to increase the range, you need a higher power supply & add an output RF amplifier.
Use 9 to 12 Volts power supply. Look at the pre-amp in one of our videos & adopt it for the output RF amp. You will need some tuning if you want it to be near perfect.
To avoid repeating efforts, use 1.5 to 3Volts zener diode as a voltage regulator for the transmitter portion. This ensures the frequency does not shift as long as the voltage supply remains above this value.
hecanet 1 month ago
@hecanet hi friend..i have made the fm transmitter with the help of your video and now i am trying to build FM receiver but it is not working for me.i put the pre amplification stage after the receiver as shown by you and then took output from speaker but it is not working..should i use another amplification stage after pre amplification?
and for amplification what should i use?? LM 741 or LM 324 or something else??
kindly explain. thanx alot
90asadali 1 month ago
@90asadali Build ur amplifier & test it separately first. Make sure it works. Use a simple microphone as the input. Then connect the pre-amplifier to it & make sure it works
After those 2, then you are ready to try the FM rcvr
LM741 might not work well. So, try LM 324, 380, 386 or any other amplifier (from 0.5 watts and above)
The idea is to make sure that each stage works on its own before cascading other stages. U might have to tweak the coil & gang to get reception
Grace & Peace!
hecanet 1 month ago
@hecanet hey friend i have built the receiver but voice is very low what should i do. i have used amplification stage only. what should i do if my amplification stage does not make a good combo with the pre amp stage shown in your video?
90asadali 3 weeks ago
@90asadali Hello Friend...am glad you got it working. That is the first and most important step. Now, you have to play around with your amplifier. Try your amplifier on other signals to make sure the amplifer is working great. If that is confirmed, then try a different pre-amp. I have not had time to work on new pre-amps but I can definitely take a look and recommend some designs later.
hecanet 3 weeks ago
@hecanet one more thing.i am anxiously waiting for your video on walkie talkie using this circuit.when will you upload it??
90asadali 3 weeks ago
@hecanet Ok.i got it.now i will try using a simple mic and will tell you if it works or not.one more question please...if i build this circuit on bread board,will it work?. or i have to make it on a vero board as you did?
90asadali 1 month ago in playlist More videos from hecanet
@90asadali Hello Friend...Yes, it works on bread board. Try to keep your wires short to minimize stray capacitances.
hecanet 1 month ago
hi hecanet,
please tell me if i can use a simple mic instead of crystal mic because i cannot find a crystal mic,i searched a lot.will a simple mic work??
90asadali 1 month ago in playlist More videos from hecanet
@90asadali Hey Friend...any mic works. I used a crystal here. But I have used condenser & dynamic microphones before (a small speaker works as well). I have also used carbon microphone (in my second year at the secondary school I made a simple carbon microphone and it worked for me). You might have to tweak the biasing of the input circuit, though. I can make a video of the carbon microphone (from carbon rod of dead alkaline batteries) if time permits so you can see how easy it is.
hecanet 1 month ago
Thanks for the upload! BTW what trimmer value did you use?
srgpip 6 months ago
@srgpip The trimmer was from an old radio receiver. The value was not specified but any range from 5p to 30p air trimmer would just be good enough.
You can also try small AM gang (variable capacitor). If you want to use this, make use of the middle terminal and one of the other two terminals (leave out the remaining third terminal). This should work great as well.
Let me know how you if this helps you.
hecanet 6 months ago
@hecanet what if i dont want to use ANY of the variable or trimmer caps?
7419635841635 3 months ago