I am going to be building a Poindexter soon and I'd really like to include a switch allowing me to select different diodes. I've never done this before. In principle I understand what needs to be done, but can anybody walk me through how to actually do this? I am guessing that wires will have to be jumpered from the pads on the board to the switch --- but what happens after that? I'm not sure which lugs on the switch connect to those jumpers, or how to connect the diodes to the switch, or even what type of switch I would need (DPDT? 3PDT?). I just want to be able to select between Ge diodes and Si diodes. Any help would be greatly appreciated.
I'd stick to similar low forward voltage diodes. Maybe try some BAT41 or BAT46. Possibly the 1n914 although those are higher Vf.
Anyway, it's simple. Just do the diodes on a bit of perf or vero. You only need to use an On/On SPDT switch. Here's a simple diagram. D1 and D2 and the germanium. D3 and D4 are your new diodes. The diodes are all connected together at the bottom, which is the part that gets wired back to the ground pad on the PCB. At the top, you have D1/D2 back to back, and one wire that connects to the outside lug of the switch. Same thing with D3/D4, which are connected to the other outside lug. Then the middle lug is wired back to the PCb to the D1 square pad.
Thanks Brian...so helpful. I'll report back when I've finished the job.