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simple HF Signal

Hello all.
I'm learning how HF signals work.
I just want an emitter who sends a wave (30mhz)to a receiver.
So I wanted to know if my schema is right.
And how to make the receiver part please?.
Thank you all.
 

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davenn

Moderator
hi

welcome to EP :)

without knowing the model of the ceramic resonator, I cannot guarantee that that's the way it can be connected
Do you have the part number for it ?

cheers
Dave
 
Dear Dave.
Someone just told me it won't work with it.
I just found out this,I will build it.
Apparently it's a 90MHz transmitter.
But I can't find any 90MHz receiver.
Can you help me please.
Thanks.
 

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davenn

Moderator
90MHz receiver ..... your FM band receiver they all go from 88 - 108MHz ;)

if you haven't got ... go buy a $5 AM/FM radio
a lot of mobile phones also have a FM band receiver

Dave
 
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davenn

Moderator
just as a side thing for you to learn ....

If you are going to start playing with electronics ... its important to get your designations correct
note how I corrected your post :)

MHz not mhz

just one of many things for you to learn .... it saves confusion

M for Mega ..... m for milli
Hz for Hertz .... as it was named after Mr Hertz

cheers
Dave
 
Dear Dave.
You are right!..interferences.I need less than 90.
"The frequency is determined by the 6 turn coil. By moving the turns together, the frequency will decrease. The circuit transmits at 90Mhz. It has a very poor range and consumes 16mA".
Now I need to build a receiver,maybe a 80 or 70Mhz.
Thanks.
 

davenn

Moderator
I don't think you understood

If its supposed to work at around 90MHz, leave it there.
you can tweek the coil a bit if there is a local FM radio station at around 90MHz

did you not read this bit ?.....
BUY a $5 AM/FM radio for your receiver

cheers
Dave
 

KrisBlueNZ

Sadly passed away in 2015
90 MHz is just an approximate frequency. You can tune your receiver to somewhere where there's nothing transmitting, then tune your transmitter to match.

Is your transmitter an FM transmitter? If it's AM, an FM radio won't receive it very well.
 
Dear friends.
I built it,took my radio switched to 90Mhz.But nothing happened.
I think I have an issue with the size/diameter of the coil.
"then tune your transmitter to match."
Where I do that? reducing the 6turn coil?how much I need?.
Thanks.
 

davenn

Moderator
it may not be exactly 90MHz you need to tune around on the radio carefully to find where the background hiss gets quieter
(assuming that the oscillator is resonating somewhere in the 88-108MHz band)

if you do find where the hiss gets quieter, then switch off the transmitter and see if the hiss comes back

( when I want to find what freq a transmitter if on, I use a frequency counter. Else it is VERY difficult to know what is happening)

cheers
Dave
 
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