I have been rebuilding my local AoO (Area of Operations) Comms capability, here for the last few months. First was to replace the old ALINCO Dual Bander, with a used Kenwood TM-D710a Vhf/Uhf APRS/Packet/SkyCommand II Radio. Getting this integrated with my New Kenwood TS-590 for SkyCommand II, is still ongoing, but I have the GPS Input and Internal TNC talking to my local Network, and iMac, running WinXP in a Virtual Machine. Then I found a used Kenwood TH-72a Dual Band Vhf/Uhf/GPS Handheld on QRZ.com, It is basically the TM-D710a, in a Handheld Unit. It does just about everything that the mobile does, in a handheld package. both Have 1000 Memories and when CAP/MARS'd Opened, have the same Frequency Coverage. Very useful, out here where I live.... the final item, just happen to come up cheap on QRZ.com. A used Kenwood TM-D700a Dual Band Vhf/Uhf APRS/Packet/SkyCommand II Radio. This is the earlier version of the TM-D710a and basically does everything that the later Unit does, but only has 200 Memories.The GPS Input was not functional, and there were a few MODs that need to get done, before it was ready to install in my Rhino 660. After working over the radio, and doing the MODs, I started to look at the GPS Input issue. This used the same Input as the 710, but it wasn't seeing the incoming Data Stream. After a few hours of starring at the circuits in the Service Manual, and tracing out connections, on the SMD type Main Board, under a BIG Magnifier, I determined that the GPS Data Ground was Open to Radio Ground, and with no Data Ground Reference, the internal TNC couldn't see the Data Stream. Apparently the Previous Owner had put some voltage on the GPS Data Ground, and burnt the choke, and parallel resistor, Open. In doing a few other MODs, I added a Switched 13.4VdcLine to Pin 1 on the DB-9M Data Port, as well as a solid Radio Ground to Pin 6 to Power the external GPS from the Radio. So once I found the open GPS Data Ground, I added a short 28Ga. Jumper from the GPS Port Data Ground Pin, to Pin 5 on the DB-9M DataPort. Then I got to thinking, if I am Powering the GPS from this Port, I could also put in a couple more 28Ga. Jumpers and bring the GPS Data Stream In thru Pin 4, and the Data Stream Out on Pin 9. Now I can just use a Single Plug to power and connect the GPS to the Radio. Once everything was done, I reassembled the radio, and connected everything up. Then hit the Power Switch, and went to the Position Screen on the Internal TNC, and Wahoo, there was the GPS Data and a blinking GPS Indicator on the radio LCD. Way cool... Blinking GPS means it is receiving the Data Stream correctly. Nice. Now, ready to install the System in the Rhino, when it finally stops raining for a day or two. The try out the APRS functions, and finally the SkyCommandII system for controlling, and working the TS-590 from the Rhino, or the HandHeld..... Could be useful, when the Black Helicopters, come looking for the clandestine HF Radio, operating from Bush alaska.....