Oh, it is great treasure. I’ve made sweep generator, but I didn’t build any attenuation device for it. I’ve tested regular carbon variable resistor, but the output was too noisy. I’ve also tested high resistance wire wound variable resistor, but the inductance was too high and the attenuation in higher frequency was horrible.
By a chance I found very old (~1964) sweep generator made by some USA company. It was full tube design and not working and partially disassembled. But I was in luck and original attenuator was intact. Also, the device as build in stand alone version- two solid metal cans with BNC connectors. The only problem was t find some inch-based, American tools to unscrew all nuts. I live in normal world where metric system is used.
These two metal cans are stepped variable resistors. But they are calibrated and designed to work in wide frequency range. One attenuator is for tens of decibels and other for apiece (ones). Smaller one has 0, 10, 20, 30, 40 and 50 dB attenuation and bigger one is in full scale from 0 to 10 dB and one very useful position- open circuit.
The device is very solid, very well build and working without any glitch. And device is about 43 years old!
