There are two photographs here. The top one shows the breadboard in the center. Part of an oscilloscope can be seen behind and to the right of the breadboard. To the left is a DMM showing the reading 121.1 DC V. numerous test leads are clipped to the circuit and other leads emerge from behind the breadboard and go out of frame to unseen power supplies. The bottom picture is a close up showing the detail of the small printed circuit board which can be seen in the upper photograph. The solder breadboard is built on what was once a 12 by 7 by 4 inch Bud box. The box was made in two parts each one having three sides of the rectangular 6 sided solid. The 12 by 7 inch face is the top. The two 12 by 4 faces make up the front and back as positioned in the picture. The ends are open. The bottom would also be open but for a 12 by 7 by 1/2 inch piece of plywood that I mounted to the aluminum box to make it more sturdy. The other half of the box was used for another project many years ago. It is built like a chassis that has been turned upside down and inside out. The tube sockets are mounted on the top with their terminals upwards and the tubes below the metal surface. Many solder terminal strips are also mounted between the tube sockets. I can change tubes by reaching in the open ends which are to the left and right in the picture. Four small knobs and one larger one with a pointer can be seen in the picture. The small knobs go to pots of various resistance values that are mounted inside the chassis. The large knob turns a two gang A M, BC variable capacitor. The circuit constructed on the breadboard is anything but neat. But hay, it's a breadboard. It's not a permanent project and I'm not going to send it to the moon. Soldering gives it much greater stability and reliability than a quick connect style. The metal chassis gives it a ground plane that is almost as effective as standard construction on a regular chassis. The small trimmer capacitors and semiconductor devices are not compatible with this style of construction. The printed circuit board is one of a set that can be purchased from Amazon and I imagine on eBay as well. The left end of the board contains the 2 k trim pot and the two 5.6 k ohm resistors that are connected in the cathode circuit in figure 8. On the right side of the board are the 500 ohm trim pot, the IXCP10M45S m o s f e t, and associated resistors. Two screws were used to mount the board to two of the terminal strip lugs to provide sufficient stability for adjusting the small trimmers. This completes the description of the photographs.
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