[codefox1]

Almost all old tube sets have variable capacitors (aka condensers.) An awful lot of 5 or 6 tube superhets use a two stage tuning capacitor, the larger (more plates) is as often as not 365 or so mmfd. So if you can srounge up one, you're probably good to go. I'd loosen up the padder (screw adjustment capacitor) of the scrounged part.