Mark and All,
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I tried to use Mark's data of 10/4/24 where he ran a single loop model in EZNEC to ascertain whether Chavdar's test simulator is designed correctly:
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f = 15 MHz , Isc = 0.707 mA ( short circuit current ) , Xa = 382.6 Ohms
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If we walk backwards from Norton's model to Thevenin's the predicted voltage of open circuit shall be:?
? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ??
? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? V'oc = Isc x Za, or Isc x Xa? since Xa > Ra
? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?V'oc =0.707 mA x 0.3826 KOhms = 0.27 V
Since Chavdar uses two 1 Kohms resistors in his test simulator the V oc across the 50 ohms load ( secondary side of the balun ) shall measure:
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? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? V oc = V' oc x 2000/ 382.6 = 1.414 V?
Meeting this condition we can state the transform from Thevenin to Norton model is done correctly based on equal power requirement.
However, VNA cannot produce across port CH0 the required 1.414 Volts...that will create 0.707 mA of short circuit current.
Do I miss anything ?
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Raphael? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?
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