TS-430 DRM Conversion


N2NOV and myself converted his Kenwood TS-430 HF transciever for DRM (and SDR) use.  This radio uses the ubiquitous MC3357P FM demodulator chip and so is pretty easy to convert. This mod should also work on other radio's employing the MC3357P FM chip. The usual helath warnings apply. Investments may go down as well as up. Consult your doctor to see if Cialis is right for you.

This conversion requires the following items;
On a clean work surface place the radio upright with it's rear connectors facing you. Remove the top cover, disconnect the speaker. Remove the screws that hold the amplifier compartment to the main chassis. Gently prise the amplifier compartment out so that it sits at about 45 degrees.

If installed, remove the FM-430 board. This is the left-most board in the radio. Put the radio to one side and turn the FM board over so as to expose the solder side.


Solder a length of hookup wire from any of the components that connect to pin 5 of the MC3357P FM demodulator chip and attach this to the input of your IF convertor board. Connect the matching ground wire to the largest PCB track you can find. There's a convenient point just above the MC3357P's pin 5. We used some cables we "liberated" from an old PC case.  These just happened to have the right connector on them so as to fit over the pins on our IF board.

Now for the power. Solder another length of hookup wire to pin 3 of the multipin connector that is found in the middle of the board. Pin 3 is the 3rd pin from the bottom of the connector. Again, solder the matching ground to the largest PCB track.

Note that the capacitor on the bottom of our board was already there.


Prepare the RG-174 coax cable and connect it to the output of the IF convertor board. Install the FM-430 board back into the radio. Run the coax along the back of the radio between the tray that holds the FM-430 board and the amplifier housing. When you reach the far right of the radio run the coax into the amplifier housing and out through the small rectangular hole that's already there on the back panel. Put your favourite connector onto the end of the coax so that you can connect it to your PC. 




Now inspect your work and connect it to your PC. Using DReaM software tune you your local DRM station and watch the level indicator. Turn the variable resistor on your IF board such that the level indicated is just peaking in the red. When you're happy disconnect it all from the PC.

That's it! Now re-assemble your radio taking care not to save any screws for later. Don't forget to reconnect the speaker too.

In practice we found that careful adjustment of the RF gain control would yield better results. The strongerr the station the lower one should turn the RF Gain control on the radio.

We also noted that one needs to select "Flip Spectrum Input" when using the DRM software.


CopyWrong 2008 Mark Phillips & Charles Hargrove. All rights abandonded.