I did some experiments with the receiver IC KT0936M lately. I built a simple SW and MW receiver with this chip. To be able to do some experiments with the MW radio I thought it would be a good idea to make a small MW LP (Low Power) AM transmitter.
Medium Wave receiver with KT0936M
For reasons of stability I started with a 1015 kHz crystal oscillator. The modulation of the transmitter is done by a 5W LF amplifier TDA2030A. The output of the LF amplifier goes into the input of the small transformer in the DC supply line.
I used a 2N2219A as PA stage. I think it delivers about 500 mW. A pi-filter provides the proper interface to the antenna.
MW LPAM Transmitter schematic
With this low power AM modulated medium wave transmitter I have a good radio signal in the house. Of course our radio liscence does not permit the use of this transmitter for broadcast purposes.
MW LPAM transmitter
The LF amplifier;
