The main reason of this mod is to extend TS-570’s TX range beyond radio amateur bands in order to support MARS/CAP operation in US.
After March 29, 2009, the available spectrum in 40m amateur band (IARU Region 1, SVland) extended from 7,000-7,100 MHz to 7,000-7,200 MHz. TS-570 has to be modified according to MARS/CAP mod in order to be able to operate in this part of the band.
Googling can find detailed descriptions of the mod procedure.
e.g. http://www.hampedia.net/kenwood/ts-570dg-mars-cap-modification.php or http://www.kb2ljj.com/data/kenwood/ts-570.htm
Here are some more detailed photos of the mod
73 de SV2DOF
