What can you do with a Waveform Monitor or Vector Scope, other than TV measurements?


 

Hi guys,
there are many cheap Waveform Monitors and Vector Scopes around, and -
given that their main use is utterly obsolete, because nobody uses PAL
or NTSC anymore or will stop using it soon - are there other uses for
those units that a layperson such as myself wouldn't know about? Can
they somehow be used as more general instruments? Do some of them at
least yield parts useful in other equipment?

Thanks,
Damian


PA4TIM
 

Interesting, I got some for free a year or to ago, but never used them.  Can not find much about them, probably ome semi-custom things because they also have non-tek colors. One was a waveform monitor, One was a vector display, it looked like a polar diagram so I was happy, I wanted to use it for my HP VNA ( I know nothing about Video and the guy who gave them either, and we did not have a clue about what they were used for, HP had a polar display for that VNA so i hoped this was an equivalent from Tek, but then I find out they were for video) The 3rd is a big orange XY diplay ( no typenumber, it comes out of a medical instrument) and I use that for a noise/gain analyser. 

Fred PA4TIM

Op 19 jul. 2013 om 09:35 heeft "cheater00 ." <cheater00@...> het volgende geschreven:

 

Hi guys,
there are many cheap Waveform Monitors and Vector Scopes around, and -
given that their main use is utterly obsolete, because nobody uses PAL
or NTSC anymore or will stop using it soon - are there other uses for
those units that a layperson such as myself wouldn't know about? Can
they somehow be used as more general instruments? Do some of them at
least yield parts useful in other equipment?

Thanks,
Damian


Don Black <donald_black@...>
 

Fred,
        The NTSC and PAL color systems encode the two chroma signals on the color oscillator in quadrature (90 degrees phase difference). Then a phase sensitive detector in the receiver is able to recover both signals, not just in amplitude but polarity. The resultant mixed signals can have any magnitude or phase (referenced to the main oscillator). In the receiver the local color oscillator is phase locked to the modulator by the sample color burst signal during horizontal blanking when there's no signal (at the end of each scanned line while waiting for the trace to return for the next line scan). The familiar color bar test signal includes all the three primary colors (red, green blue) and their combinations as a standard test signal. The resulting chroma signal has these colors as standard values, both amplitude and phase for each color. A Vectorscope displays the signal in both amplitude and phase so any errors in either are readily apparent. In effect the Vectorscope is a color receiver that plots the chroma signal as X and Y co-ordinates to produce the polar response. The PAL signal is a variant of the original NTSC standards that reverses the phase of one signal by 180 degrees on each alternate line (PAL is Phase Alternate Line). this allows great error correction in the receiver, somewhat optically where there's no electronic correction but in all modern PAL sets it's done electronically very effectively.

Don Black.

On 19-Jul-13 7:12 PM, Pa4tim wrote:
 
Interesting, I got some for free a year or to ago, but never used them.  Can not find much about them, probably ome semi-custom things because they also have non-tek colors. One was a waveform monitor, One was a vector display, it looked like a polar diagram so I was happy, I wanted to use it for my HP VNA ( I know nothing about Video and the guy who gave them either, and we did not have a clue about what they were used for, HP had a polar display for that VNA so i hoped this was an equivalent from Tek, but then I find out they were for video) The 3rd is a big orange XY diplay ( no typenumber, it comes out of a medical instrument) and I use that for a noise/gain analyser. 

Fred PA4TIM

Op 19 jul. 2013 om 09:35 heeft "cheater00 ." <cheater00@...> het volgende geschreven:

 

Hi guys,
there are many cheap Waveform Monitors and Vector Scopes around, and -
given that their main use is utterly obsolete, because nobody uses PAL
or NTSC anymore or will stop using it soon - are there other uses for
those units that a layperson such as myself wouldn't know about? Can
they somehow be used as more general instruments? Do some of them at
least yield parts useful in other equipment?

Thanks,
Damian



ditter2
 

--- In TekScopes@yahoogroups.com, "cheater00 ." <cheater00@...> wrote:

Hi guys,
there are many cheap Waveform Monitors and Vector Scopes around, and -
given that their main use is utterly obsolete, because nobody uses PAL
or NTSC anymore or will stop using it soon - are there other uses for
those units that a layperson such as myself wouldn't know about? Can
they somehow be used as more general instruments? Do some of them at
least yield parts useful in other equipment?

Thanks,
Damian
Doorstops and boat anchors....

Seriously, I am an advid collector of Tek equipment, and have none of these in my collection. I don't see the value for test equipment that measureses signals which virtually do not exist anymore. In most cases, you would need to buy a Tek signal generator to test these.

The tube models *may* have common parts with a few scopes of the same era. However, as I understand it, the vertical amplifier design for TV waveform monitors it totally different.

- Steve

- Steve


wallace.gibbons
 

Well, guys,
I made a scope clock out  of one.It's in my office. Part of my collection of esoteric electronic digital clocks.

Wally


On Fri, Jul 19, 2013 at 1:35 AM, cheater00 . <cheater00@...> wrote:
 

Hi guys,
there are many cheap Waveform Monitors and Vector Scopes around, and -
given that their main use is utterly obsolete, because nobody uses PAL
or NTSC anymore or will stop using it soon - are there other uses for
those units that a layperson such as myself wouldn't know about? Can
they somehow be used as more general instruments? Do some of them at
least yield parts useful in other equipment?

Thanks,
Damian



Peter Gottlieb <hpnpilot@...>
 

The Tek AVC-20 is a box which encodes stereo audio signals onto the subcarrier so you can use a vectorscope as an audio X-Y monitor scope. It generates a graticule and has a few different modes. These are available very cheaply on ebay.

I had gotten one but couldn't find any info on it so reverse-engineered it and drew out a schematic so I could understand how it worked. It uses two MC1496 modulators in quadrature fed from the left and right audio as well as patterns generated by ROM and twin DACs.

A fun toy! I plan on using it with a big Tek vectorscope and NTSC generator for a very retro looking display.

Peter

On 7/19/2013 5:42 AM, Don Black wrote:

Fred,
The NTSC and PAL color systems encode the two chroma signals on the color oscillator in quadrature (90 degrees phase difference). Then a phase sensitive detector in the receiver is able to recover both signals, not just in amplitude but polarity. The resultant mixed signals can have any magnitude or phase (referenced to the main oscillator). In the receiver the local color oscillator is phase locked to the modulator by the sample color burst signal during horizontal blanking when there's no signal (at the end of each scanned line while waiting for the trace to return for the next line scan). The familiar color bar test signal includes all the three primary colors (red, green blue) and their combinations as a standard test signal. The resulting chroma signal has these colors as standard values, both amplitude and phase for each color. A Vectorscope displays the signal in both amplitude and phase so any errors in either are readily apparent. In effect the Vectorscope is a color receiver that plots the chroma signal as X and Y co-ordinates to produce the polar response. The PAL signal is a variant of the original NTSC standards that reverses the phase of one signal by 180 degrees on each alternate line (PAL is Phase Alternate Line). this allows great error correction in the receiver, somewhat optically where there's no electronic correction but in all modern PAL sets it's done electronically very effectively.

Don Black.

On 19-Jul-13 7:12 PM, Pa4tim wrote:

Interesting, I got some for free a year or to ago, but never used them. Can not find much about them, probably ome semi-custom things because they also have non-tek colors. One was a waveform monitor, One was a vector display, it looked like a polar diagram so I was happy, I wanted to use it for my HP VNA ( I know nothing about Video and the guy who gave them either, and we did not have a clue about what they were used for, HP had a polar display for that VNA so i hoped this was an equivalent from Tek, but then I find out they were for video) The 3rd is a big orange XY diplay ( no typenumber, it comes out of a medical instrument) and I use that for a noise/gain analyser.

Fred PA4TIM

Op 19 jul. 2013 om 09:35 heeft "cheater00 ." <cheater00@gmail.com <mailto:cheater00@gmail.com>> het volgende geschreven:

Hi guys,
there are many cheap Waveform Monitors and Vector Scopes around, and -
given that their main use is utterly obsolete, because nobody uses PAL
or NTSC anymore or will stop using it soon - are there other uses for
those units that a layperson such as myself wouldn't know about? Can
they somehow be used as more general instruments? Do some of them at
least yield parts useful in other equipment?

Thanks,
Damian
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