02-12-2016, 03:27 PM
I have now almost completed the panel interface between the valve-holders and the Avo Mk1 valve tester. (Fixed the two units on a baseboard.) The tester is connected to the appropriate valve pins by short jump leads between the top black panel and the upper row of red pin sockets, 1 to 9. Any electrode links that may be required such as Anode to G2, or Cathode to G3 are completed by putting short jump leads with spade terminals on each end, across the appropriate black screw terminals along the bottom of the lower panel. In order to forestall anyone saying how horribly dangerous it is, because of the exposed brass bolt ends on the lower screw terminals, the final task is to make nine insulating blanking buttons to glue in the tops of the terminals. Nine steel washers will be placed below the terminals to lower the height of the bolt heads in the tops of the terminals. The cable, top right, is plugged into the side connection of the valve tester.
When testing more modern pentodes, such as the EF95, there is some instability in the form of hand capacity. After setting the zero, the needle goes well up into the scale when I remove my hand from the control. The only answer so far seems to be, keep hold of the control when at zero, and push the joystick over with the other hand, then it is OK.
I see I have missed off the "d" from "required" in the central info strip!
Bob
When testing more modern pentodes, such as the EF95, there is some instability in the form of hand capacity. After setting the zero, the needle goes well up into the scale when I remove my hand from the control. The only answer so far seems to be, keep hold of the control when at zero, and push the joystick over with the other hand, then it is OK.
I see I have missed off the "d" from "required" in the central info strip!
Bob
