On Mon, Jan 18, 2021 at 10:51 AM, Ozan wrote:
Hi Stephen,
Before I derailed the thread (Tom opened a new one for those of us who can
talk about two transistors for hours) I gave some suggestions to debug in
#176717
/g/TekScopes/message/176717
Take a look at B sweep to rule out nonlinearity in A sweep generator.
When I suggested to check the voltages I meant to check the voltages shown in
the schematic sheet <6> (Probe Adjust, XY Amplifier, Horizontal Output). In
particular voltages at the base of Q780 and Q770, and voltage at the cathode
of VR764. You need to put the scope in a setup shown in "Control Settings"
section prior to the schematic. Voltages could be slightly off but pay special
attention to the difference, i.e. if everyone is up/down by 100mV could be OK.
Report back here if any voltages are off.
Hi,
Base of Q770 reads +6.090 VDC, while the base of Q780 reads +6.081 VDC
However, the cathode of VR764 reads high a +5.135 VDC....
