Exactly. Two different things. Both hard to describe. A drive line
as we knew it was a true failure. Often seen on SS sets when the
1.5 ohm base resistor changed value. It has a fold over look just
like vert fold over. You can see backwards elements of the scene
moving about in a apx 1 inch area. Damage WILL occur eventually.
Snivets did not distort the pix geometry wise. They come & go
& are usually narrow ( < 1/2 inch ). May or may not go top to bottom.
Usually have squigglys in them. Move around sometimes. They
also radiate & can bust up a lesser set like a GE, Emerson etc.
One of our by-outs was a wanna be radio shack. They loaded this
poor cat with thousands of tubes. Al were IEC service master, Ratheon
& Lindals. Every HO tube gave snivets........ We used them in
"last time" repairs on junkers to save the customer $$.
73 Zeno
Quote:
Originally Posted by jr_tech
Read here about "reaction scanning" describing the phases of the horizontal scan process on a CT-100 (and likely most other tvs with a flyback transformer).
http://www.earlytelevision.org/Deksn...implified.html
I suspect that the "drive line" is visible when the transition between the various scan states is not correct due to leaky caps out of spec resistors, weak damper or HO tube, miss adjusted grid drive, while BO is a self oscilation of some HO tubes, which can indeed be stopped by a magnetic field from an ion trap mounted on the tube. Two different causes of lines, IMHO.
jr |