Unfortunately many Long Wave radio stations have closed down over the past couple of years and very little remains to test our beloved radios. Even BBC Radio 4's days are numbered.
This little module allows you to hear what AM radio really sounded like back in the 50's and 60's. The few remaining signals on AM are heavily compressed and limited in bandwidth.
The board runs from 12V dc at 60mA and takes a line level input from a computer or smartphone, The modulation frequency response is very flat and is only 3dB down at 20KHz. Thanks to the Class E transmitter design the modulation characteristics are very good indeed.
The RF output impedance has been designed to be around 1000 Ohms and a length of wire can be used as an 'Antenna' to couple the modulator to your vintage set. Do not connect directly to any receiver without a suitable attenuator as you may damage the receiver. It is generally sufficient to 'loosely couple' the modulator to the receiver.
The range of the modulator is only a few feet depending on what is used as an antenna. This is not intended to be a long range radio transmitter. It is a high quality modulator to allow you to use your vintage equipment and feed whatever audio you desire to it.
The audio level required for 90% modulation is approximately 1 Volt peak to Peak (350mV RMS).
The listing is for the PCB only (built and tested). Please note that you will either have to solder input and output connections to the module or source some suitable plugs as these are not supplied.
These are hand made and tested using brand new components. The board measures less than 7 x 4 cm.
The frequency can be re-tuned between 153 and 200 KHz so can be set to the old Droitwich frequency, either 198 or 200 KHz (1500 Metres) once transmissions cease on that frequency.
Thanks for looking!
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