Early in the repair cycle of the 8640b, when I had just finished the brass gearset installation, I ran into a problem during the first power up after reinstallation of the deviation and range module. When I powered up the unit, I saw a flash from under the main board, and the unit came up […]
Another item on the 8640b refurbishment project was the broken Fine Tune control. I could rotate the control from the front panel, but it had no effect on the frequency generated. After removing the bottom cover, I could see the problem. The Oscillator Module was missing the shaft that connected the fine tube knob with […]
After replacing the gearset in my 8640b signal generator, the next item on the list was to repair the FM Deviation potentiometer, which had the shaft broken off where the knob would attach to the front. Since the pot is still electrically good, and I cannot locate another pot with the same value and length […]
Back in April of 2016, I bid on a Hewlett Packard 8640b signal generator to upgrade my test bench at home. This was from a local seller, and I won the bid for $115.00 + $20.00 shipping, for a total of $135.00. I figured for that price, I couldn’t go wrong. In working condition, these […]
