That which came first
The QTC Clock
After researching the various tube types and options, I settled on a kit featuring with ZM1210 tubes. The ZM1210’s were manufactured by Telefunken in Germany and come with a nice red coating (which can be removed if desired).
This is a really nice kit which will support a variety of different tube types. It features tubes mounted on carriers which can be changed easily (Quick Tube Change) in case of failure.
The well produced PCB is nicely laid out and features all manner of components including resistors, capacitors, inductors, transistors, a PIC micro controller and specialist tube driver IC’s.
The build process is well documented and the whole thing took about 10 hours (for the first one anyway!) to complete. Having never soldered anything before, Jo has completed most of her QTC construction in around 5 hours!