[Wendymott]

Malcolm. How accurate do you need to be ?. The online calculators I use are my "go to". I am often making resonant circuits, my maths are diabolical.. There are trimmers and variable cores to make anything resonate at the required frequency. I bought a tray of 100 5 pin 10x10 mm inductors "toko type"... and I know or can easily guess the number of turns required. Abacs are/ were very useful in the day but my "go to" is the PC.