UK Vintage Radio Repair and Restoration Discussion Forum - View Single Post - Help needed with

3pinplug · 31st Mar 2023, 8:44 pm

Added the two extra diodes but display still scrolling, made no diferernce to original fault as when fitted with original diode.
taken with probe set t0 X10
Pic 1
Amp / Div 50mv
Time / div 1us

Pic 2
Amp/div 50mv
Time / div 50us

Also put frequency counter on TP6 and measured 4.505mhz coarse min and 4.75 mhz coarse max figures are approx as digits still scrolling.
If there is an IC feeding the caps / diode should we consider changing that?
Regards
Mark

31st Mar 2023, 8:44 pm	#289
3pinplug Pentode Join Date: Jun 2016 Location: Kent, UK. Posts: 190	Re: Help needed with - Racal Dana 9081 Added the two extra diodes but display still scrolling, made no diferernce to original fault as when fitted with original diode. taken with probe set t0 X10 Pic 1 Amp / Div 50mv Time / div 1us Pic 2 Amp/div 50mv Time / div 50us Also put frequency counter on TP6 and measured 4.505mhz coarse min and 4.75 mhz coarse max figures are approx as digits still scrolling. If there is an IC feeding the caps / diode should we consider changing that? Regards Mark Attached Thumbnails