Longwave transmitter

*READ DESCRIPTION*

I got a couple of requests for the circuit diagramm of a longwave transmitter that I made - well I don´t have this transmitter anymore, so I´m not sure if I could draw a correct circuit diagramm. So I made a new transmitter. This longwave transmitter is able to transmitt from 180 up to 280Khz, with a range of 2 to 3 meters (when using a 2 meter long wire antenna). The transmitter has an antenna tune circuit that acts as antenna tuner and harmonic filter. When powered with a stabilized voltage source the transmitter is pretty frequency stable. Here is the circuit diagramm for the transmitter: http://imageshack.us/photo/my-images/200/longwavetransmitter.gif/
Information for those who want to built the transmitter:

The transmitter requires a good ground otherwise there will be some "Fm-ing". You could ground the transmitter on a water pipe (gnd connection or "-" from power source)

The transmitter should be powered with batteries aswell I would suggest to use a portable audio device for audio input.

The 590pF capacitor has been made by connecting a 470 and a 220pF capacitor in parallel

The antenna can be tuned with the 5-90pF capacitor the value of "Cx" counts for a 2 meter long wire, if you are planing to use a longer/shorter antenna you have to try out new values for Cx. If you can´t find a 5-90pF capacitor other values will work aswell (smaller values) but therefore you will have to experiment with the value of Cx (add a few pF if the capacitor you use is smaller than 5-90pF)

Category:

Science & Technology

Tags:

• longwave transmitter
• am transmitter
• transmitter
• longwave
• 2N3904
• 2N3906
• radio transmitter

[yhaxxy]

where can I find the circuit digram for this Longwave transmitter

[hbycoily]

dear stefan hi,

id like to chat with you on your various interesting transmitter projects.im having problems with 27mhz oscillators. i can get 10 or 100mhz easily but 27mhz is problematic. can we exchabge some emails please.

thanks

steve

[odessa999]

Thats really neat. I'm going to make this and have a play about with it .... Good work !!

[TheHackZone5]

what do u use to receive the signal