View Full Version : 1950 Motorola, not enough width/HV


nasadowsk
11-15-2008, 09:42 PM
Ok, my TS-67 chassis can light the new CRT, but the width isn't there, the HV isn't there, and I've got an annoying series of vertical dark bars that don't seem to be video amp related (I've not ruled that out yet, though).

The horizontal drive looks like this:
http://farm4.static.flickr.com/3248/3033057089_1e0f49af88_o.jpg

50V / 20us V/H settings on the scope.

I carefully clipped the scope to the plate lead's insulation, and got this:

http://farm4.static.flickr.com/3176/3033897058_7599e62ed7_o.jpg

20V / 20us settings.

I'm not sure if that ringing is normal.

The yoke's a Meritt MDF-70, the transformer's a Thoradson FLY-40, brandie new from Moyers. The yoke's capacitors are 50pf, though the Sams says I should have 60pf. I'm not sure if that's what's screwing me up.

HV is about 12 or so kv, not the 17kv we want. Caps are brand new ceramite doorknobs (Newark has them in stock - $30 a piece)

Any ideas where to look?

nasadowsk
11-16-2008, 09:20 PM
Ok, *blush* I found a missing cap, but that only 1/2 fixed my issues - the HV's up, but I still have some bars on the lefthand side, a nasty drive line, and poor focus. IT's annoying too, cause you can see the potential in the picture, and I KNOW there's some IF/Video issues in there...