Re: 6-gang FM stereo tuner heads
I have been suspicious about the value of n =3.73 in my previous post. I would expect n to be between 0.3 to 2. I have checked a 1967 IEEE paper, the previous equation only applies to a single varactor diode. Therefore I should have repeated the measurement with only one diode to obtain the correct n from the slope of the Log(C) vs Log(V+phi) graph.
Based on R. De. Cola's IEEE paper "Varactor Tuning applied to Am-FM receivers", the model of two back-to-back varactor diodes are rather complicated as shown in the attachment. In this case, it is not possible to find n using linear regression.
BTW the IEEE paper is full of maths and quite difficult to understand.
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