nenea dani
Junior Member level 1
Dear colleagues, I want to fix the PLL from the attachment. It is from an SA at the beginning of the 80's. On the top right of the diagram, see the RF input signal from YIG sweep between 2 and 4.1Ghz. I encounter difficulties in understanding this system.
1. A phase comparison is made between RF input and a harmonic of the 1Mhz reference produced by the CR1 diode?
2. Is X2 used as a filter?
3. Q10 does any compensation or do not understand the role of diode CR4, Q10 and the configuration of Q7?
I checked the ESR electrolytic capacitors, the whole device works, but the LED lock indicator does not turn on after a few hours of operation with PLL on setting.
1. A phase comparison is made between RF input and a harmonic of the 1Mhz reference produced by the CR1 diode?
2. Is X2 used as a filter?
3. Q10 does any compensation or do not understand the role of diode CR4, Q10 and the configuration of Q7?
I checked the ESR electrolytic capacitors, the whole device works, but the LED lock indicator does not turn on after a few hours of operation with PLL on setting.