I've recently built a selectable signal attenuator to use with my signal generator.
I needed a 50mVpp square wave to test wave forms on a device's circuits,and my SG has a -20dB adjustable attenuator,but it will only drop the output voltage to 150mVpp on a 50ohm terminated coax.
So I built an attenuator box,with a 50ohm input pad(to match the 50ohm out on my SG) and 5 selectable outputs with:
1) A straight through Zero Ohm(no pad)connection
2) A 50ohm pad(no attenuation)connection
3) A 75ohm pad(no attenuation)connection
4) A 50ohm, -10dB connection
5) A 50ohm, -20dB connection
I used some scavenged parts, some new resistors, made a box, installed 2 sets of T-Section attenuators, and the 50ohm & 75ohm pads, a six position rotary switch and 2 female BNC connectors.
I was going to install an adjustable circuit using a 500ohm pot, but decided I didn't really need it.
I've only tested it up to 200kHz,(on a Telequipment D54 mind you) above that it shows a little distortion on the front edge of the square wave, but for inserting a 1kHz square wave for testing it does a great job, and I can drop the output voltage from my SG to 15mVpp!
Here's some pics I took of the box assembly, I didn't get pics when I wired it up cause I had a photographic issue with my equipment (I was lazy and in a hurry!) :~)
It wasn't that hard to make, didn't cost me ANYTHING! Just took a little time to construct and determine wiring for the rotary switch.
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Here's a couple links to the information I used to construct this:
