18-11-2016, 09:30 AM
In my experience, carbon track pots. are not as good a wirewound ones, and in a number of reaction receivers that I have made in the past, I have noticed that the reaction no longer works after a while, until the pot. has been replaced, and there is no current flowing through them either! I know it will not make much sense to some, but I long-since gave up trying to make sense of what goes on in valve radios. When I had a 10K pot. in the grid bias circuit, it did not work as smoothly at the 5K one, and both were wirewound! Maybe the 10K was faulty - but I don't really know. 
Bob
Bob
