Degradation of resonant sine wave signal in coil/solenoid after adding second layer
Answering because the real question is starting to emerge in the comments. These will go away eventually, so please edit the question to ask the real question.
How do I design an inductor to hit a specific self- resonant frequency without thermal drift?
Now...
You'll get temperature drift in the coil itself. Thermal expansion will change its dimensions, which will change the inductance.
Take your nominal coil design and enter its parameters in any online calculator for air-cored inductance. Or look up the formulae/approximations in books. And calculate the inductance.
Look up the thermal COE (coefficient of expansion) of copper and re-calculate those nominal dimensions for (say) a 10C temperature increase : recalculate the inductance. You can now get a thermal coefficient for your inductance by dividing the ratio Lhot/Lcold by 10.
Next: Old radio ham trick : use a network of capacitors to create a capacitance with the opposite thermal coefficient to cancel out most of that drift.
Then you can use a more reasonable coil and save your fingers. And use fatter wire, decreasing R and increasing Q if that would help performance for whatever the application is.
Your 3000 turn coil appears to have a Q about 4, estimated from the rate of decay of the sinusoid (to about 1/e in about 4 cycles). Not surprising with such high resistance wire.
Get hold of Pat Hawker (G3VA)'s book &quot;Amateur Radio Techniques&quot; if you can find it
Or maybe something from the late 1920s when big open inductors and very simple circuits were SOTA, and people really cared about good resonant circuits before &quot;supersonic heterodyne&quot; (superhet) techniques made them unnecessary for radio. &quot;The Manual of Modern Radio (John Scott-Taggart, 1933) is probably too late. &quot;The Admiralty Handbook of Wireless Telegraphy&quot; (1925 edition) may be a better bet.