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Lprimary tuning calculation
Original poster: Terry Fritz <laptop@xxxxxxxxxxxxxxxxxxxxxxx>
Hi All,
We know that the primary system needs to be tuned about 5% lower than
the secondary due to streamer loading. While playing with ScanTesla,
I realized that the streamer loading and how it affects tuning is
fairly straight forward. A very good estimate (1%) of tuned Lprimary
inductance is:
Lp = Ls x (Cs + Ca) / Cp
Where:
Lp = Primary coil inductance
Ls = Secondary coil inductance
Cs = Secondary capacitance
Ca = Arc capacitance = 1pF / foot of streamer
Cp = Primary capacitance
Almost all of the secondary frequency drop is due to the capacitance
of the streamer and the 220k part of the streamer load is fairly
insignificant. Thus we can simply add 1pF/foot of capacitance to
Csecondary for the calculation.
Cheers,
Terry