02-14-2021, 12:32 PM
If you want to replace a variable capacitor or calculate a local oscillator coil or antenna coil then this might be useful.
Enter the IF Frequency of the radio.
Put in the Min/Max pF values of the broadcast band and local oscillator Variable Capacitors
Then adjust the trimmer values of each section until the variances are very low, near zero.
If the trimmer value is within the range of the trimmer then you're good to go, otherwise you might need an additional or different trimmer.
That should calculate the values for the coils. I find it also useful in determining whether I can use an off-the-shelf LO coil, or if a dual VC is useable as a replacement.
Hyperlink: VC Calculator Page
![[Image: vc%20tuner%20example.jpg]](http://bingamon.com/Radio/Calculations/vc%20tuner%20example.jpg)
Enter the IF Frequency of the radio.
Put in the Min/Max pF values of the broadcast band and local oscillator Variable Capacitors
Then adjust the trimmer values of each section until the variances are very low, near zero.
If the trimmer value is within the range of the trimmer then you're good to go, otherwise you might need an additional or different trimmer.
That should calculate the values for the coils. I find it also useful in determining whether I can use an off-the-shelf LO coil, or if a dual VC is useable as a replacement.
Hyperlink: VC Calculator Page