Steve Anderson wrote:Harry, I think this should be about right. As the tube runs on a lower voltage than the 3BP1 the bias needs reducing, so the 75V Zener is now 24V. All changes from the 3BP1 arrangement have been marked in red...quite a few.
Oh thanks there Steve boy your quick ! no wonder your good at all this !
Those changes are not to bad i was always wondering about that 75 volt Zener but i also was interested to see what would happen as is .
Also as a lower-voltage tube the deflection sensitivity is higher so we may need to reduce the gain of the deflection amps, but we'll worry about that when we get there. Only two resistors in each deflection amp would need changing.
Thats also not to bad well designed circuit indeed .
Also for the 'AC on the plates test', use a centre-tapped transformer, centre-tap to pin 9 and the two others to (say) pins 11 & 7, Connect pins 8 & 10 direct to pin 9. This is only temporary. This should give you a straight line across the tube.
Steve A.
[/quote]
Well that would not of crossed my mind so thats a procedure i i will remember !
Thank you Steve i wish i could get out to the shed and do the changes tonight ...also tomorrows a big 40th birthday for my brother inlaw so no soldering for me very keen to do the changes may be early in the new week ..
BTW i was looking at the investigator Scope about the only schematic with voltage points shown .