View Single Post
Old 24th Jul 2017, 10:02 am   #32
1100 man
Octode
 
1100 man's Avatar
 
Join Date: Apr 2016
Location: Ventnor, Isle of Wight, & Great Dunmow, Essex, UK.
Posts: 1,255
Default Re: Kolster Brandes RV 10 (Crown)

Thanks John, At least I can see what's going on!
The boost cap is the one next to the inductor in V8's anode (PY83). The boost supply from this is used to feed the frame oscillator via the height control and also the focus supply.
Other likely culprits are the coupling cap to the line coils and the two tuning caps in parallel across the primary.
Change the boost cap and the coupling cap in the grid of the PL81
Is the voltage on the triode section (line osc) of the PCF80 correct?
As John said, what is the screen voltage on the PL81?
Try changing the PCF80, PL81 and PY83.
Check that you get a low resistance between the top cap of the PY83 & PL81 through the primary of the LOPT (with the set switched off!!)
By the way, don't try and measure the voltage on either top cap- there are very high peak voltages and your meter will not like it
Let us know what happens after doing all that.
Good luck
Cheers Nick
1100 man is offline