- 2024
- Oct
- 26
A Heathkit IG-72 Signal Generator Part 3 - Do I need parts?
Now that the device is working, the next step is to see what parts are going to need to be replaced in order to make the thing work better.
The short answer is nothing. The capacitors in the filter for the oscillator are on point, the output is close enough that it’s probably not worth changing things, and the filters and electrolytics that connect stages aren’t showing any leakage. That’s pretty amazing for a device this old. I decided to do some checks anyway, just to prove the point.
There’s not much voltage on the resistors in the notch filter. I didn’t check any values, but these are all fairly low so I don’t expect them to have drifted out of tolerance that much.
When the particular part isn’t selected, there’s a little bit of AC on the resistors.
There’s no DC, indicating that capacitors aren’t leaky.
I did some checks on the filters and the other two electrolytics in the circuit - all of them showed a good value with low ESR. At this point, I will probably just check the resistors to make sure they haven’t drifted, and replace those that have. Stay tuned!
Next part of this series: Coming soon!
Previous part of this series: https://wereboar.com … r-part-2-suspicions/