schmobi2001

modified 9 years ago

Simple Transmitter

399

08:15:43

I have built this for real and it receives fine at about 900 khz with any AM radio. Replace the ac source with a Line In from pc or ipod i.e. 

In my case I had a range about 2 meters.

published 9 years ago

giomix

9 years ago

Which transistor model do you have used in real life?

schmobi2001

9 years ago

It was a 3906 i guess. I will check again and tell later

schmobi2001

9 years ago

The values of the resistors and capacitors don't have to be accurate like in this sim. You can play with the values. Especially with the coil. There you can change the frequency.

giomix

9 years ago

Ok, many thanks for informations.

schmobi2001

9 years ago

I have changed the values of the capacitors, coil and resistors to the values in reality. The transistor is a 2N 3906 331

giomix

9 years ago

Ok, but in Simulator it seems not oscillate locally at 1 Mhz or similar. Seems to be in output only LF signal at 1khz, not RF modulated.

nikisalli

9 years ago

Giomix se togli il generatore da 1khz e regoli un po la base di tempo oscilla perfettamente a 1,08Mhz

giomix

9 years ago

Ok grazie infatti mi sembrava idonra l,

giomix

9 years ago

Induttsnza

giomix

9 years ago

Ora sto guidando, poi faccio snche io prove grszie

schmobi2001

9 years ago

Yes. Indeed. Something I didn't understand with every circuit. Why does it oscillate, when I decrease sim speed?

giomix

9 years ago

Niki, sul mio android aziendale non sembra oscillare neanche staccando il generatore. Che tempi hai settato? La formula di risonanza mi dice 1.023Mhz (reattanza 1.414 ohm).

giomix

9 years ago

Schmobi2001, sorry we are talking in Italian, we are discussing about oscillator simulation, Niki can see oscillations detaching 1Khz generator and setting time , instead I'm not able.

giomix

9 years ago

The reason beacuse it's working decreasing time is sampling

schmobi2001

9 years ago

Sorry, but I do not understand. sampling? What do you mean?

schmobi2001

9 years ago

The same issue I has here... http://everycircuit.com/circuit/6138889666822144

giomix

9 years ago

Please, search in EC project named "Simulation Limits", written by Hurz , to understand sampling . And please tell me which time you have set to see 1Mhz oscillations in oscilloscope.

schmobi2001

9 years ago

I have removed the 1 khz source. Otherwise you cannot decrease speed below 800 ns/s. Now, when you start the sim, wait for 3 sec and then it should osscilate at about 1 MHz.

giomix

9 years ago

Ah ok, I was simply detaching a connection wire from 1 khz generator and so I was not able to decrease time so much. Thanks for your indication. This simply circuit is usefull to create a AM signal to test and repair old tubes radio (is an hoby) in Italy remains only a national channel transmitting in AM.

schmobi2001

9 years ago

Glad I can help. In germany there are no AM stations left. And I guess soon they will also remove FM radio and replace with digital radio.

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