[R-390] Z-503 Repair

[Steve Hobensack]

I was looking through my 1964 ARRL Handbook. There is a homebrew Q multiplier project. It uses a pair of 455 khz rf coils mounted 1 inch apart for coupling. L1 is 1000-2000uh slug tuned. L2 is 500-1000 uh slug tuned with  100pf cap in parallel. L1 part number is North Hills Electronics 120-K. L2 is part number North Hills Electronics 120-J. It might be worth an Ebay favorite search.
----Steve N8YE