HP Attenuator 355C

I picked up this attenuator at the Foothill flea market for $10. I've bought similar units on eBay in much better shape for $30 and have seen like new for $100 This attenuator is rated DC-1.GHz from 0 to 12 db attenuation in 1 db steps, 1/2 watt 50 ohm. This has BNCs, some versions have N connectors. The main body is a non-ferrous casting, probably aluminum. The weight of the unit is 23.5 oz. It has a top and bottom sheet metal covers with generous number of 4-40 screws.

This unit has an interesting system of cams for selecting which switch is activated.

The bottom reveals discrete 0.5% resistors. It is interesting the thin shields between the stages.

There is a PC board for each section behind the PI network resistors.

This was photographed with a Sony F717 and Novatron flash head.

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