Leiser
Automotive
- Apr 19, 2007
- 92
Hi,
Higgler, Comcokid and VEB1LL thanks all for your very useful comments. I also asked a former collegue from MACOM and replayed the same answer plus a test in the lab which I copy. VEB1LL thanks also for your comment about doc size, after sending it I realized that I could have compressed the photos with Word.
Now, what you could do is power-up the circuit and with a very high impedance probe, measure the resonant frequency. If you then short across the two main terminals (i.e. not the third pin you that say is grounded) and the frequency should change. From this change you may be able to calculate the difference into reactance and hence calculate the inductor value (or capacitor value if the frequency shifts in the oposite direction!). Just remember that what is required of the circuit here (across pins 4 & 6) is a resonator or resonant circuit, which is the local oscillator of the quadrature demodulator (which basically two mixer circuits with a difference of 90 degrees phase shift one relative to the other...quadrature = I & Q, also SSB FM demodulator - its is all the same.
Higgler, Comcokid and VEB1LL thanks all for your very useful comments. I also asked a former collegue from MACOM and replayed the same answer plus a test in the lab which I copy. VEB1LL thanks also for your comment about doc size, after sending it I realized that I could have compressed the photos with Word.
Now, what you could do is power-up the circuit and with a very high impedance probe, measure the resonant frequency. If you then short across the two main terminals (i.e. not the third pin you that say is grounded) and the frequency should change. From this change you may be able to calculate the difference into reactance and hence calculate the inductor value (or capacitor value if the frequency shifts in the oposite direction!). Just remember that what is required of the circuit here (across pins 4 & 6) is a resonator or resonant circuit, which is the local oscillator of the quadrature demodulator (which basically two mixer circuits with a difference of 90 degrees phase shift one relative to the other...quadrature = I & Q, also SSB FM demodulator - its is all the same.
