HFU HF Underground

Technical Topics => The RF Workbench => Topic started by: IRF510 on January 04, 2014, 1641 UTC

Title: AM generator
Post by: IRF510 on January 04, 2014, 1641 UTC

Hello,

I'm looking for schematic of AM signal generator(with voice input).
I don't like x-tal - i want schematic on LC(capicator and coil in shield).
http://www.qsl.net/df3lp/projects/lftx/tx50.gif

73! irf510

Title: Re: AM generator
Post by: ff on January 05, 2014, 0133 UTC

Here's a link for a coil and cap exciter:

http://radio-circuits.blogspot.com/2011/02/marathon-low-power-transmitter-for-136.html

This circuit generates the carrier. Modulating the driver stage should be straightforward.
I hope you have plenty of space for an antenna!

Title: Re: AM generator
Post by: bumbelstock on January 07, 2014, 1139 UTC

Hello irf510!
..will post again in right topic ;)

I have built this MW TX for my home and i think this TX will work on LW with change the Coil 'L'.
Picture and schematics in Attach.
Greeting's and good DX!

 R1 = 1k
 R2 = 2,7 k
 R3 = 2,7 k
 R4 = 2,7 k
 C1 = 0,22 µF (Tantal)
 C2 = 100 pF
 C3 = 390 pF
 C4 = 390 pF
 T1 = JA 101 (any HF - Transistor (BF xxx), PNP, 30V and 0,2A  are perfect)
 L = ca. 80 - 100 Wdg. (for MW !)  ;D

Title: Re: AM generator
Post by: IRF510 on January 21, 2014, 1839 UTC

it don't works
on collector i have 4 V
on base 3.4 V

Edit:

IT works