20-10-2018, 06:40 PM
Hi.
You can see the results from the recent work in the pictures. The focus isn't too bad at low brightness and contrast but the focus is not so good on the left hand side of the screen, if you juggle the focus coil and position it differently in relation to the gun it will de-focus on the RHS instead. The CRT has been regunned in the past and laying a straight edge on the gun it is out by a couple of degrees so all the focus issues in my opinion is purely CRT based. I did try the CRT on the B&K and it was showing leaks from all electrodes, a sure sign the CRT is gassy.
I've strapped the SP41, top screening caps together and to earth and you can see the result on Franks converter switched to 5:4, very good indeed.
You can see the results from the recent work in the pictures. The focus isn't too bad at low brightness and contrast but the focus is not so good on the left hand side of the screen, if you juggle the focus coil and position it differently in relation to the gun it will de-focus on the RHS instead. The CRT has been regunned in the past and laying a straight edge on the gun it is out by a couple of degrees so all the focus issues in my opinion is purely CRT based. I did try the CRT on the B&K and it was showing leaks from all electrodes, a sure sign the CRT is gassy.
I've strapped the SP41, top screening caps together and to earth and you can see the result on Franks converter switched to 5:4, very good indeed.
