开云体育

Hello group

(This also posted elsewhere)

After almost a 12 month postponement with a number of other more straightforward projects suddenly taking up bench space I'm back onto this elusive problem where the FT101E clarifier is working when it's turned off! The voltage swing at the VFO osc input is not as great as when its on, being about 0.35V. Compared to about 3.0V when clarifier switch is on (I really want to solve this because cosmetically this radio is in great condition and I've replaced the usual final cage suspect caps, the HV electrolytics and those on the regulator board). There remains just this one thing to resolve and I feel (after several hours) I have reached the limit of my knowledge in relation to what may be causing this. Thanks to many folk who have provided useful input to help me so far.

Here is what I have tested or tried but with no success -

• Checked relay grounding is sound
• Checked the clarifier push button switch is not faulty or intermittent
• Checked front panel VFO selector switch
• Swapped out Regulator/Calib module for known working one
• Swapped out Local Osc module for known working one
• Checked disc ceramic cap and diode (D13) wired directly onto clarifier switch/potentiometer

?

I don't know what to do next and would certainly appreciate any ideas please :)
Thank you
Grant

Hi Grant,
I would go back to the relay contacts again. Using a grounded probe jumper the C5 contact to ground. If that doesn't help ground the clarifier switch contact connected to D13.

73
Roger VE7LB

Hi Roger
Thank you. I have tried that with no success and no discernable change in the frequency either (swapped out D13 as well).???Whole thing is not making much sense to me at all!?

73 Grant