Bought an old Hacker Democrat that was not working, the usual problem I thought, AF117's need replacing. Replaced them with AF137's, but the radio is still not working. I've cleaned the MW and LW switches plus the On/Off volume pot and still not working. When I turn on I can get feedback through the speaker from my mobile phone, which is near to the set, also if i touch the contacts on the back of the on/off volume pot I get the scratching noise through the speaker. What would be the next step to try
. I'm still a bit of a newbie to vintage radios and just love these old Hacker's, any help appreciated