In this picture you see a (wired) remote panel for the Collins 20V-3. Almost every function and meter can be operated or read from a remote location. From this you can turn on or off the filaments and plate. Raise or lower output power. Read high voltage and current values. Even monitor output power. Transmit/Receive switching and sequencing is performed in a home brew relay panel (not shown) below the remote panel and the red "control room" switch on the front panel of the audio mixer.

Here is the Flex radio SDR-1000 and it's power supply. On the shelf above it  is the Delta 44 sound card interface and a Brandywine Communications GPS disciplined 10 mhz frequency standard. The GPS frequency standard not only keeps the Flex system as accurate as the National Bureau of Standards but when tied to any of the other test gear in the shack, it offers accuracy to within a few parts per million.