Tweed Fender Champ Power Tube – 6V6GT
The 1959 tweed Fender Champ is a 5 watt single ended Class A amplifier. That means that in addition to having one preamp tube, it has one power tube – the 6V6GT. The 6V6GT is a smaller glass form factor of the 6V6. The 6V6 is a beam-power tetrode, similar to its predecessor the 6L6.
Wikipedia has a great write up about all the details. Looking at the electronics, the 6V6GT is right in the middle. The 6V6GT on my amp was manufactured by Sylvania.
I found a great video tour of the 6V6GT on YouTube. The focus is a bit spotty, but it is an interesting clip nevertheless.