Since we were having a long delay in a system I came to measure the delay of a traveling wave tube (TWT) amplifier. The delay is in the order of 40ns, which at 34.6GHz correspond to about 1380 wavelengths or 13m of free space. The tube is in the order of 30cm long. I was aware it has two helix inside but considered them to be 10 turn or so.
13 years ago