I have always enjoyed building and experimenting with vacuum tube radios and amplifier designs as one of my hobbies. Changing soldered parts can be frustrating to get a circuit to work. What would be nice is to have a vacuum tube solderless breadboard to test circuit designs. So… I decided to make a solderless breadboard for tubes. I explored online several vacuum tube breadboard designs and ideas. Some used pcb pressure screw connectors for wiring which is a good idea but I see a problem. This type of connector is really meant for a one time connection and running the screw in and out constantly will most likely wear out the connector fairly quickly. I looked at other types of small connectors for wiring and came to the conclusion that the old workhorse Fahnestock clip invented back in 1907 is the best wiring connector for my breadboard.
Below are photos of the vacuum tube breadboard that I assembled. The breadboard consists of individual component modules mounted on 12” x 12” x ¼” thick Baltic birch plywood. For each module base I used 1/8” thick Garolite cut to 2-1/2” x 3” and 2-1/2” x 4-1/4” for different sized components. Each module is attached to the breadboard using two 6-32 x 1/2”L male thumbscrews that screw into two 6-32 x ¼”L T-nuts on 2” centers in the board. At the top of the breadboard is a Garolite strip with 12 banana jacks wired to Fahnestock clips for tube power, voltage bias, filament power and antenna connections. What’s nice is that it’s easy to shift modules around on the board for component layout. I have only made tube modules for 4, 5, 6-pin tubes thus far and I’ll be making additional modules for 7, 8 and 9-pin tubes in addition to other passive components as needed. The breadboard is only capable of handling simple 1 and 2 tube designs. I’m thinking of making a second breadboard to be used in tandem for larger circuit designs.