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how to find h frequency on monitor

M

Matt J. McCullar

Jan 1, 1970
0
Is there an easy way to figure out the horz frequency on ac computer monitor
( cga, ega , etc)
Like looking for rc combination.

You can do it with an oscilloscope. Hold the probe close to the high
voltage cable without touching it (inductive coupling) and count the time
between pulses. The inverse of that number is the drive frequency.

You can do the same thing by connecting the probe directly to the horizontal
yoke leads.
 
S

Sam Goldwasser

Jan 1, 1970
0
Matt J. McCullar said:
You can do it with an oscilloscope. Hold the probe close to the high
voltage cable without touching it (inductive coupling) and count the time
between pulses. The inverse of that number is the drive frequency.

You can do the same thing by connecting the probe directly to the horizontal
yoke leads.

Yeah, if you want to smoke the probe. :)

If what the poster really meant was to determine the acceptable scan range of
a computer monitor, there is no easy guaranteed safe (for the monitor) way.
Specifications rule!

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N

Nomen Nescio

Jan 1, 1970
0
Is there an easy way to figure out the horz frequency on ac computer monitor
( cga, ega , etc)

CGA scans at the NTSC scan rate of 15.75KHz. EGA varies between the CGA
scan rate and 21.85KHz. CGA and EGA are obsolete digital displays and
you'd know it if you had one. Multisync and fixed frequency analog
monitors have numerous scan rates.

Extron used to make a great product where you'd hold a small box to the
face of the CRT, and it would display the scan rates.

http://www.extron.com/product/product.asp?id=sri200&subtype=44&view=desc#tabs

Looks like the product has been "retired." Too bad.
 
G

Guest

Jan 1, 1970
0
Is there an easy way to figure out the horz frequency on ac computer monitor
( cga, ega , etc)
Like looking for rc combination.

TIA

Wendell
 
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