Philco squeals on weak stations

[andrefranc]

After changing filters the radio squealed at just some volume settings. I recapped and repaired all block capacitors and now it will squeall on shortwave stations in the same manner but BC band seems to be OK now.
when squealing I can turn the volume control slightly and this will usually stop the squealing. I tried a new volume control with the same results. Using one setting of the tone control signal is suppressed but doesn't seem to ever squeal. I disconnected the tone circuits but stilll had squealing.