re making up odd resistor values required by filters idh nessie mcc ac uk ian hawkins writes when constructing active filters odd values of resistor are often required i e something like a k ohm resistor it seems best to choose common capacitor values and cope with the strange resistances then demanded is there a pd program out there that will work out how best to make up such a resistance given fixed resistors of the standard values per decade etc it is a common enough problem yet i cant recall seing a program that tells that rx ry rz gives rq starting with q and finding prefered values x y and z cheers ian h when trying to choose a resistor with a tolerance better than you need a trimmer or to screen devices it can t be made from adding resitors of value in parallel since the smaller device will have the error of to cope with you have choices a live with the error of tolerance devices for low q circuits or low sensitivity designs b buy resistors with better than tolerance vishay dale c use trimmers or sot s select on test dino inqmind bison mb ca the inquiring mind bbs winnipeg manitoba
