For several years the VHF handheld radio in the shack has been the no-frills Kenwood TH-K2 (2-meter band only). It has followed in the tracks of the venerable TH-G71A, a model long discontinued.
The TH-K2 can be programmed using the Kenwood proprietary MCP-1A software, whose version 3.11 still can be downloaded from the Kenwood website (http://www.kenwood.com/i/products/info/amateur/mcp1a_e.html).
The only other accessory required to interface the TH-K2 with a computer is the also Kenwood proprietary PC interface cable PG-4Y (which has been in the shack since the times of the TH-G71A).
A problem is that the TH-K2 model also has been discontinued, and that the MCP-1A software, last updated by Kenwood in November 2013, is no longer supported. In addition, this software would have only operated in a MicroSoft Windows environment, and I wanted to interface the radio with a MacBook Pro.
To the rescue comes CHIRP: “a free, open-source tool for programming your amateur radio” available for several operating systems (http://chirp.danplanet.com/projects/chirp/wiki/Home).
First I had to download and install the KK7DS Python runtime for Mac OS X, which was done by clicking the appropriate link in the following page: http://chirp.danplanet.com/projects/chirp/wiki/Download.
Then I downloaded and installed the CHIRP.app (i.e., the …app.zip file) from http://trac.chirp.danplanet.com/chirp_daily/LATEST/
A window appeared indicating that CHIRP comes in a signed package and that Mac OS X users should disable signed package checking for the CHIRP.app, something easily done by accessing Security & Privacy in the System Preferences of the Mac. The CHIRP app was then transferred to the Applications folder.
With the radio OFF I connected the PG-4Y cable (i.e., it must never be connected to the radio with the radio ON). To it I then connected the USA-19HS Keyspan USB-serial cable, which in turn was plugged to one of the USB ports in the MacBook Pro (i.e., the Keyspan driver had long been installed). Then I switched the radio ON, and chose PC ON in its Menu 31 (i.e., to enable it to interface with the computer).
Then I went to Beginners Guide in the CHIRP page (http://chirp.danplanet.com/projects/chirp/wiki/Beginners_Guide) and found out that CHIRP modifies radio memories either in Clone (requiring an upload to the radio after changes have been made on the scree) or Live mode (the changes are immediately reflected in the memories of the radio).
From the Applications folder I clicked on the CHIRP app. As instructed in the Beginners Guide, I clicked the Radio menu and chose Download from Radio. The program asked to select the Port (which in this case was named /dev/cu.USA19H141P1.1), and to enter the Vendor (Kenwood) and the Model (TH-K2). Then a window appeared informing that CHIRP deals with the TH-K2 in Live mode and that hence any changes on the screen would be immediately reflected in the memories of the transceiver, implying that a back-up in either .csv or .chirp format would be the way to preserve the original values. Once that was done the screen was ready for manually refreshing the data of the local repeaters.
Upon switching the radio OFF, disconnecting the cables and bringing the TH-K2 back ON, everything looked in good order, and before I could say CQ the TH-K2 was already CHIRPing happily into several of the repeaters.