working on my R3132 2nd LO again.
This time its the VCO itself ...when manually tuned when setup with external supplies the output would die when the tune voltage hit around -2
Bad varactor diode ..two of them in this circuit ...series capacitance to lower the total
Anyone have the part number for the varactors ?
These were marked with a "41" and a "67" or an "L9" depending on how you look at it.
order a few of a very low capacitance varacator diodes and will probably start with the lowest first.
Part shouldn't be that critical ..between the tuning stub and PLL range should be able to get it