Just wondering if any British ATC units are still using one of these today. Leeds Bradford had a few from the 1960s to the late 1970s, before headsets were adopted there and I know Carlisle ATC had one in the VCR. Lasham also, in the radar room. They frequently turn up in the used market and I've bought and restored (cleaned and rewired) one myself. It strikes me as a durable and rugged piece of equipment but I've also heard of reliability issues, especially with the wiring in the base.
Apparently they are quite popular with Radio Amateurs using the HF bands, probably something to do with the moving iron high impedance (2400 ohms) microphone element.
This is mine:
