[R-390] leaky filters

[bernie nicholson]

 HI To everybody  ,        I also have seen quiet a few leaky filters , its caused by the foam packing inside the filter becoming crumbly and sticky and mildly Conductive , I have looked inside a few filters and this seems to be something that will eventually happen to all of them in time, The same problem is also happening in Kokasai filters, I have removed the 2&4 KHZ filters in a couple of receivers and replaced them with dedicated USB&LSB filters and Crystal locked the bfo on 455KHZ with a built in product detector {double Triode in the ballast tube socket} its a different receiver altogether from the original , but when you switch off the BFO it reverts to the original circuit for AM .