VHF tuners that use the frame grid type RF amp and a pi tuned input circuit have a MW breakthrough coil fitted.
The older style VHF tuners with an RF transformer input do not need the coil. Whether that is the case in this set and that coil is broken or the set design is prone to the problem I don’t know.
A really good write up in RC.
https://www.americanradiohistory.com...RC-1965-09.pdf
Appreciate it could still be breakthrough due to poor screening of the 6 Mhz IF strip, still the RC article is worth a read.
Surprise myself on what I sometimes remember, forgot about this problem. A braid breaker is an RF transformer, I used to carry one for TVI problems, can be very effective. It was an engineer from the PO interference service who showed be them in the 60’s.