9 Oct
2007
9 Oct
'07
3:28 a.m.
First, the CRT in the VT100 is a M31-340W.
On Mon, 8 Oct 2007, Tony Duell wrote:
Not according to my 1988 Philips CRT Databooks!
The coding is explained as follows :
[...]
1988 is pretty new... Did they really change the nomenclature of the
tubes? I thought that
First letter
A: Electrostatic focusing
D: Oscilloscope tube
M: Magnetic focusing
Second letter (and later last letter)
B: blue/blueish
G: green/greenish
W: white
X: colour
First number: diameter in centimeters
Second number: "random" model number
There are many Mxxxxxx CRTsa in the books, _all_ of
them are
electorstatically focussed (one of the electron gun electrodes is
described as the focus electrode).
I hate Philips and everyone who thinks he needs to change a good and
established system...
I've not seen a mgnetically-focuessed CRT since I
repaired an _old_ Bush
TV. Old meaning System A, 405 lines. The focussing in that was controlled
Well, System A was broadcast until the 80s ;-))
According to my tube books one of the newest magnetic focus CRTs for
television sets should be the MW53-80 and MW61-80 (around 1958/1959).
But they don't use fixed magnets, instead a focusing coil is used.
getting the convergence and purity right!), but nonoe
of the monochrome
monitor service manuals I've read mention magnetic focussing. I've never
seen a yoke with anything other than centering rings on it.
VT100 Series Pocket Service Guide, page 59/60.
other than the VT100, can you give me a definite
pointer to a
terminal/monitor service manual that uses magneitc focussing?
Other than for the VT100 I don't have such detailed service manuals for
monochrome terminals and monitors, at least they don't tell you much about
the CRT.
But I know that the tube in the SIG100 terminal (attached to the
Telefunken TR86-S and TR440, around 1972) was a M-type, too. But
apparently that doesn't mean anything now...
Christian