04-03-2017, 08:43 PM
Sure, you can use a film cap instead of an electrolytic. In fact I would recommend it for the first filter after the rectifier. The 4 or 8 uF electrolytics available today are not rated for the high ripple current of a vintage radio power supply, especially a big one like a 116 and will have a short life.
The film cap is non-polarized so you can connect it either way
The film cap is non-polarized so you can connect it either way