How would I increase the power in an RF signal?

[Resistanceisfutile]

Using a crystal oscillator and some other components I made a weak AM transmitter. I'm interested in trying to increase the power in the signal so that I can transmit further. Before anyone asks, I'm nowhere near the legal power limit in my country for this frequency so am not breaking any laws.

I was just wondering if anyone could suggest what I do next, 1. as I said I'm looking to improve the power but it doesn't need to be a particularly long range (although I'm assuming power dictates the range it can transmit at?). I'm also keen to get it to work with a crude crystal radio circuit (just a diode, antenna and a crystal earphone)
2. is there anything I can do to my transmitter circuit to make it easier for a signal to be induced in the antenna - (it doesn't matter if it only works from across the room, so long as the signal is strong enough to induce RF in the antenna)?

 

[RMMK]

you may find these threads as helpful:
https://www.edaboard.com/threads/320829/

And

https://www.edaboard.com/threads/319685/

 

[Resistanceisfutile]

Why thank you!
I wish you many Joules in your coulombs!

 

[jiripolivka]

Using a crystal oscillator and some other components I made a weak AM transmitter. I'm interested in trying to increase the power in the signal so that I can transmit further. Before anyone asks, I'm nowhere near the legal power limit in my country for this frequency so am not breaking any laws.

I was just wondering if anyone could suggest what I do next, 1. as I said I'm looking to improve the power but it doesn't need to be a particularly long range (although I'm assuming power dictates the range it can transmit at?). I'm also keen to get it to work with a crude crystal radio circuit (just a diode, antenna and a crystal earphone)
2. is there anything I can do to my transmitter circuit to make it easier for a signal to be induced in the antenna - (it doesn't matter if it only works from across the room, so long as the signal is strong enough to induce RF in the antenna)?

As you do not indicate the frequency you use, there are several points to bring to your attention:
The transmitted power itself is not the only important quantity. You also need a good antenna, well matched to your transmitter. And with a low power, you need a better receiver than a crystal set.
I would recommend you to contact a local radio-amateur group. Radio amateurs do communicate around the world using short-wave bands and often low-power (QRP) transmitters. Find the ARRL Radio Amateur's Handbook where you can find many technical solutions.

 

[kspalla]

As you do not indicate the frequency you use, there are several points to bring to your attention:
The transmitted power itself is not the only important quantity. You also need a good antenna, well matched to your transmitter. And with a low power, you need a better receiver than a crystal set.
I would recommend you to contact a local radio-amateur group. Radio amateurs do communicate around the world using short-wave bands and often low-power (QRP) transmitters. Find the ARRL Radio Amateur's Handbook where you can find many technical solutions.

use high power amplifier for the last stage. design its driver stage/s and link current transmitter output to the driver

 

[Resistanceisfutile]

Woah, I'll check these out! Thanks!