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2 watt max FM transmitter circuit

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JohnnBlade

New Member
audioguru

Greets, and cools to meet you, have been reading yr posts for years, but never had any questions.

Untill now,

Just yr advice, if i wanted to build a 3 stage or 4 stage fm transmitter of about 1.5 to 2 watt

Can i acomplish this using. 12v 3a power supply, and the only transistors i have available are the
Bc548, bc549, bc547, 2n222a, 2n2219a, 2n3866,
Can i reach the wattage im looking for with the transistors?



If so, which ones do you think are best for certain stages of the circuit to get max 1.8, 2 watts transmitter?


Thnx for yr time

Regards,

JB
 

audioguru

Well-Known Member
Most Helpful Member
Anything more than about 0.05W is illegal because it will probably interfere with REAL radio stations.
My FM transmitter has a range of 2km to a very sensitive receiver with nothing in between. Another member made it and saw the RF cops (with their antenna on top of their truck) slowly driving down his street the day after he tested it. They were probably looking for me!
I used my FM transmitter for no more than 1 hour.

Here is a powerful FM transmitter from another site: https://www.electronics-lab.com/projects/rf/016/index.html
 

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JohnnBlade

New Member
Btw im already reaching 1.2 km circle diameter, on usb powered transmitter, using 3 stages all 2n3904
Using about 25mA

Im gonna make a new one but this time tune it carefully for 50 ohm impedance, and almost no disturbance, i also got my own free clean fm channel not interfering with other stations.
 

JohnnBlade

New Member
I have the bf90 and bf91a also but i dont wanna waist these on low frequencies as the can reach ghz, or could the be useful

In reaching 1.8 watt
 

audioguru

Well-Known Member
Most Helpful Member
I do not want to get involved with recommending an illegal radio transmitter. These simple ones do not have accurate crystal frequency control so their frequency will drift which might cause interference. Also their harmonics can interfere with other communications.
 

alec_t

Well-Known Member
Most Helpful Member
I know its illegal, but we all gota build stuff anyways. Tools make da man
Why do you want to interfere with other people's legitimate use of FM broadcasts?
 

4pyros

Well-Known Member
Most Helpful Member
I dont think there is a legitimate use for a home made 2 watt transmiter.
 

audioguru

Well-Known Member
Most Helpful Member
If you use good antennas and a high quality very sensitive receiver (home hi-fi or car radio) then you will have good range without using high power.
But the FM "radio" available at The Dollar Store has terrible sensitivity and selectivity.
 

JohnnBlade

New Member
Thnx, found this circuit

https://fahriemjeblog.wordpress.com...mitter-88-108-with-independent-vhf-amplifier/

Since the 2n3866 needs about 500mw in, i will build the tx500, and then add the 2n3866 as extra final stage

That should do it right?

I have all the parts, inc rf shield box, rfc, and i will be using an laptop adapter for power supply

Any suggestion?

Yes i know its illegal, but i still want to build, i take all responsebility for whatever may happen.

Please only technical replies
 

JohnnBlade

New Member
Anything more than about 0.05W is illegal because it will probably interfere with REAL radio stations.
My FM transmitter has a range of 2km to a very sensitive receiver with nothing in between. Another member made it and saw the RF cops (with their antenna on top of their truck) slowly driving down his street the day after he tested it. They were probably looking for me!
I used my FM transmitter for no more than 1 hour.

Here is a powerful FM transmitter from another site: https://www.electronics-lab.com/projects/rf/016/index.html



Could i add the 2n3866 as rf amplifier aat antenna output?
 

JohnnBlade

New Member
And to measure the output watts of a transitor, do i take emitter amps, times power supply?

Or is there a diff formula for that?

Thnx
 

MikeMl

Well-Known Member
Most Helpful Member
...
I know its illegal, but we all gota build stuff anyways. Tools make da man...

Is there anybody else that is not at risk, who can give some pointers

The silence is deafening...

With your attitude, we are just waiting for you to get lost...
 

JohnnBlade

New Member
I live in an area where there is no one for miles, thats why i want to build this transmitter.
It isnot going to disturb or harm anyone.

I just love to build rf and other stuff

Its just for practice, cause in the end i need to transmitt on 10.184ghz

To understand why, see here where we work on the life ray with John Hutchison, Me, and others
**broken link removed**
 

4pyros

Well-Known Member
Most Helpful Member
To understand why, see here where we work on the life ray with John Hutchison, Me, and others
**broken link removed**
Now we know whats up.
 

JohnnBlade

New Member
So there is more to this, its not just playing a pirate at FM, its about fukushima

See some more info, so that yall know where im going to, and if you have mad Rf skills you are welcome to join the group to
John has the biggest ray gun of all, and is being tested as we speak, and that one has allot more watts then what im looking for. We are building the smaller version of this



is anybody willing to give some pointers, instead of trolling.

And all of you here are also RF lovers, so just try to think out the box, i know that i may have sounded a bit reckless, but its not wat im doing.







The silence is deafening...

With your attitude, we are just waiting for you to get lost...


So there is more to this, its not just playing a pirate at FM, its about fukushima

See some more info, so that yall know where im going to, and if you have mad Rf skills you are welcome to join the group to
John has the biggest ray gun of all, and is being tested as we speak, and that one has allot more watts then what im looking for. We are building the smaller version of this



is anybody willing to give some pointers, instead of trolling.

And all of you here are also RF lovers, so just try to think out the box, i know that i may have sounded a bit reckless, but its not wat im doing.
 
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