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Kenwood KPG-4 Programmer


This project was started to be able to program Kenwood TK941 radios in the amateur band. A commercial cable had been purchased which was not able to program the radios; however it could not generate enough voltage, as it used the DTR lead as voltage source. It turned out that the COM port could just not source the current, which varied between different machines.

These radios have the battery voltage present at the MIC connector, so this was a more reliable source with plenty of headroom. I cannot take credit for the original design as I found it online; however it is just a simple TTL-RS232 converter using a regulator and a MAX232 part. It can be used to program the following radios:
TK-7102, TK-7108, TK-8102, TK-8108, TK-760, TK-760GK, TK-762, TK-762G (VHF 8Ch), TK-768, TK-768G (VHF 128Ch), TK-780, TK-840, TK-840UF, TK-862, TK-862G (UHF 8Ch), TK-863G, TK-868, TK-868G (UHF 8Ch), TK-868G (UHF 128Ch), TK-940, TK-941, TK-840, TK-752, TK-759, TK-852, TK-859, TK-715, TK-815, TK-740, TK-705D, TK-805D, TK-706D, TK-806D, TK-630, TK-730, TK-830, TK-709, TK-809, TK-840, TK-760, TK-860, TK-762, TK-862, TK-760G, TK-860G, TK-780, TK-880, TKR-750, TK-885, TK-980, TKR-900, TKR-850, TK-7102, TK-8102, TK-7108, TK-8108, TK-768, TK-868, TK-768G, TK-868G,TH-F6,TH-F7

The programming software varies for each radio type, and may involve some old DOS-based code that can be run under DosBox, there is some windows code available for some radios that runs under XP. You can use this software to upload and download a file from the radio, but modifying it is another matter.

There are a couple of solutions for modifying the data file, the simplest method is to use a hex editor and there are also some other utilities around, but you will have to scour the web for them. Here you can find a home brewed Windows utility which currently supports the following radios:
  • Tk6110 10M and 6M radio
  • TK931 900 MHz radio