Bridging the IC-7610, KAT500, and KPA500
I’ve been working on a project to get my station fully remoted while keeping all my gear in sync. My goal was to have my Icom IC-7610 work seamlessly with my Elecraft KAT500 tuner and KPA500 amplifier, managed through a Raspberry Pi (running the RigPi image). I have documented my initial steps to facilitate operating CW remotely using wfview, RigPi Hub and some custom Python code.
Streamlining the Rig Control
I had previously set up the IC-7610 to a Raspberry pi running the rig control software. I was originally planning to use the RigPi web interface to control the radio, But the IC-7610 has a built-in remote server that has better features. So I ended up using wfview on my Windows machine to handle the direct operation of the rig. This greatly simplifies things because it manages the high-quality remote audio and spectrum display natively over the network as well as instant access to memory presets.
RigPi radio control allows to setup a Hamlib instance for each radio defined. But, wfview talks directly to the radio's internal server, the immediate operation of the rig doesn't depend on Hamlib. However, for radios not supported by wfview, or for other logging software the Hamlib server will come in handy. I personally use Log4OM for my logging, which connects via Hamlib to track frequency changes and keep my logs accurate in real-time. One can also control the frequency changes right from this software if desired.
Connecting the Elecraft Duo
The hardware side involves connecting the IC-7610, the KAT500, and the KPA500 directly to the Raspberry Pi via USB cables. For the KAT500 I used the Elecraft KXUSB cable. The KAT500 is picky. It did not accept my DIY cable with an FTDI/USB adapter. The KPA 500 was more forgiving and worked happily with a generic FTDI serial to com adapter with a DB9 terminator.
However, this is only half the battle. To make the Elecraft duo accessible to my Windows machine, I use a few key tools:
ser2net: This utility on the Pi "exposes" the physical USB ports for the tuner and amp as TCP network ports (e.g., ports 3002 and 3003).
com0com & hub4com: On Windows, com0com creates a pair of virtual ports linked together like a software "null modem" cable. I then use hub4com to bind one end of this virtual pair over the LAN to the ser2net port on the Pi. This allows my Elecraft Utilities to connect to the other end of the virtual com0com pair, seamlessly remoting the connection to the Raspberry Pi. As far as the utilities are concerned, they are operating with locally attached KAT500 and KPA500 respectively.
The Synchronization Script
The final piece of the puzzle was getting the Elecraft gear to follow the Icom's frequency. There are other hardware solutions possible, but Elecraft does not really play nice with the ICOMs frequency output. Their advice has been to rely on the lightning fast frequency counters within the KAT500 and KPA500. There are some commercially available software that can also provide this integration; but I was not willing to go down that route.
However, as we can see we have all pieces in place for a software solution. All we need is a glue that will tie the different protocols, I wrote a simple Python script that runs on the station server.
The script polls the radio's frequency through the Hamlib server and pushes the matching frequency and band commands to the KAT500 and KPA500 via the ser2net ports. By enabling multiple connections in ser2net, the script can handle the background tracking without interfering with the Elecraft utilities I have running on my screen.
Final Results
As mentioned earlier, I also have my remote CW keying integrated into the Pi, making the whole system a very functional, modest-budget remote station where different brands of gear work together quite well.
