Ok. Let’s try this again…RCA 9TC240 Alignment

[Chris K]

Originally Posted by old_tv_nut

Note in both cases the upper and lower coils are each tuned correctly. The only difference is the amount of coupling. Too much coupling will produce a wide double-humped response with low center frequency response.

Wow...thank you so much. Resonance...harmonics etc...these concepts have always been the most challenging things for me. I can understand a vibration stimulating something else at rest to vibrate but at the same frequency. I don't entirely understand the production of other frequencies from the primary one.

So by coupling here you mean frequency or vibrational coupling...one coil and slug stimulated electrically transferring this frequency based energy to an adjacent coil? These traps are tuned to eliminate specific frequencies from the signal circuit resulting in a broader bandwidth. At least that's my understanding from an earlier part of this thread. How does this primary/secondary tuned pair do that? I have an idea as to how but I'm not very eager to put it out there!