i wanna make a fm transmitter..pls help me

[leoren_tm]

i wanna send a pulse using an fm transmitter,/..
maybe with just a 1000Hz ...wanna send a pulse trought fr tansmitter
plss help me do this

 

[IanP]

You have to make yourself more clear ..

To deal with pulses you need something like a pulse amplifier ..

FM transmitter (FM modulator + RF amplifier) outputs signals of certain amplitude regardless of the shape of the input signal => frequency modulation ..

Regards,
IanP

 

[leoren_tm]

huh?/
i wanna transmit a pulse with a specific frequeny value..
coz in the reciever ill be having a vey siff bandpass filtter...
pls ask me a specific question, for me to specify it..ty in advance

 

[IanP]

If ≈100MHz frequency is good for you here is an example of 250mW FM transmitter:
**broken link removed**

Regards,
IanP

 

[leoren_tm]

any paper available???
huh??
can i send a pulse???
ill be on a lowpower implementation,...maybe just a 12v DC....

Added after 1 minutes:

and also...ill be considering a lowcost implementation....

 

[Troela]

**broken link removed**

Easy to build

 

[leoren_tm]

i sot a problem on my transmitter.......
the range on my transmitter should be up the audio range..
but my fm receiver works only for below 20Khz...
but ill be on 30khz....
help me all
tnx in advance

 

[sinip]

i sot a problem on my transmitter.......
the range on my transmitter should be up the audio range..
but my fm receiver works only for below 20Khz...
but ill be on 30khz....
help me all
tnx in advance

I have no idea what you are talking about... Audio range is up to 20 kHz.

 

[loveangel4943291]

try this circuit and tell me what happened

 

[Nimer]

hi
first study the subject
look for otheres designes
design your own circuits
simulate them
identify your parts
test


dont trudt internet circuits

regards

 

[smxx]

hi
look at this

 

[okguy]

The previous rar file comes from here :
https://hem.passagen.se/communication/receiv.html

 

[leoren_tm]

i dont have a problem on my trnsmitter...
only on the reciever...
this is a low cost implimentation...
huh???
wat if i use AM???

 

[sinip]

i dont have a problem on my trnsmitter...
only on the reciever...
this is a low cost implimentation...
huh???
wat if i use AM???

What if you try to explain again what the actual problem is? What frequency your transmitter works on, and what kind of receiver you have? The thing is the more you write the more confusion you cause.

 

[VSMVDD]

you need to increase the audio bandwidth of the descriminator in the reciever
to do this you must change the second IF filter if it has one
dont know if its a pll controlled version
so it may or maynot use 450 or 455khz filter
if it does{usualy a small yellow or blue box with three or four legs }
this needs changed to a wider bandwidth

the first IF usualy 10.7 or so mhz
isnt so crytical

so modify the radio

30khz isnt so unachievable
you probably will also need to remove or alter the de-emphasis circuit in its audio section

what you need is the circuit for the radio rx your using.

 

[leoren_tm]

my realy BIG problem is making a wireless fire alrm.. using radio

 

[okguy]

Why don't you use DTMF frequencies codes :idea:
It is slow, but fire alarm don't requier high speed!

 

[leoren_tm]

ill be using radio, for low cost

 

[okguy]

Yes, I meant : send DTMF codes over FM.
Any simple FM transmitter as described above, and any simple receiver will take care of the transmission.
Any DTMF coder and decoder will take care of the digital modulation.
Add a CPU and you're done.

 

[leoren_tm]

:?::?::?::?::?:
i think that sugestion would complacate my design.....
but thank u...
i wanna make it portable...