old cga/vga monitor to oscilloscope ?

[tanveerriaz]

vga oscilloscope

how can i convert a old cga are vga monitor to oscilloscope (low bandwith)
for spectrum analyzer ?

 

[House_Cat]

oscilloscope vga

The link below gives a simple explanation.

h**p://www.dansworkshop.com/Homebuilt%20oscilloscope.shtml

(replace * with t above)

 

[Highlander]

vga monitor oscilloscope

Hi,
Look at this!
There is better idea
h**p://www.qsl.net/pa3ckr/xydisplay/
Best,





*=t

 

[Borber]

monitor to oscilloscope

Converting monitor to xy display for spectrum analyzer is dificult. You will need at least 500kHz bandwidth. If you are satisfied with 100kHz bandwidth you can use so called raster technique. First you should rotate deflection coils for 90 degree. Change their role as in the first reply. Time base signal is now connected to horizontal deflection coil (former vertical) and on vertical coil you should connect 50kHz sine wave current source capable of delivering few anp's peak-peak current to achieve full vertical deflection. Next step is to use bidirectional one-shot (N8T20 or 8T20) with 50-80ns pulse duration. You compare input y signal and sample of y deflection current. Output pulses from monostable multivibrator you must connect to Wenelt greed (first greed) of CRT to modulate beam intensity (z axis). In such way you can get smooth curve. This raster princilpe was used with Rohde&Schwartz PolyskopIV about 30 years ago.

 

[tanveerriaz]

vga monitor to oscilloscope

hi
i need more info about vertical sync circuit .
can i need blaking plus ?