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Vintage Test Gear and Workshop Equipment For discussions about vintage test gear and workshop equipment such as coil winders. |
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23rd Mar 2018, 5:59 am | #1 |
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X-Y/Lissajou mode on Telequipment D54?
Hello, forum newbie here from across the pond. On a whim I recently picked up a bargain Telequipment D54. I have been trying to discover if it is possible to employ the x-y mode for this vintage scope. There is no explicit XY button or place on the timebase knob, but there is a position for "EXT X". Unfortunately I can't figure out how to use it!
The manual says "The EXT X setting enables an external signal to be applied between the EXT X and GND terminals to provide horizontal deflection of the beam." Additionally, "EXT X provides d.c.-coupled access to the input of the horizontal amplifier. This facility is of use with Lissajous and swept-frequency techniques." But there is no explanation of how to connect the signals to achieve the desired effect. Since Lissajous is the primary usage I envision, I would like to know how to connect the signals correctly. I include a picture of the timebase section of the front, with connection terminals. If anyone can help with instructions on how to connect, I would be greatly appreciative. If more information is needed I will be happy to provide. Thanks! |
23rd Mar 2018, 9:56 am | #2 |
Nonode
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Re: X-Y/Lissajou mode on Telequipment D54?
To get the classic lissajou display, apply one sine signal to the Y-input as normal and another sine signal to the Ext X input. It should work straight away. Get the required patterns by adjusting the two frequencies.
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23rd Mar 2018, 2:00 pm | #3 |
Dekatron
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Re: X-Y/Lissajou mode on Telequipment D54?
Welcome to the forum, you wouldn't be making Mr Carlson's component tester/ curve tracer by any chance?
Some scopes have a dedicated position on the Y axis/time div knob for XY mode, it looks like your D54 does. Try setting knob in alignment with the X "line" and see if that does the trick. Others you have to play with the time/div knob to get the best trace. Andy.
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23rd Mar 2018, 10:19 pm | #4 |
Nonode
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Re: X-Y/Lissajou mode on Telequipment D54?
I don't have manual to hand, but I would guess about 1v per div sensitivity. Just feed in that 1v pp cal signal in to Ext in with TB set to that position and see what happens. The same signal fed to the Ch 1 input (set to 1v/div)should give a stationary figure on the screen with same vert and hor deflection IF it is 1v/div of Ext.
With many scopes, the X signal is connected to Ch 2 with switches set as appropriate. The bandwidth of the X amp is probably 1Mhz compared with the 10MHz of the Y amp. Expect distortion with signals approaching 1MHz frequency. Les. |
24th Mar 2018, 3:49 am | #5 | |
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Re: X-Y/Lissajou mode on Telequipment D54?
Quote:
The other anomaly is that the "normal" XY slope from applying identical signals was reversed - instead of bottom left to top right it was top left to bottom right, like a 180 degree phase difference. Not sure why that is occurring, but not really a huge problem. I can still use it to generate some impressive graphics. I will not complain getting a fully functional scope for about 25 USD! Cheers! |
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24th Mar 2018, 5:10 am | #6 |
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Re: X-Y/Lissajou mode on Telequipment D54?
From time axis div. knob on my D-54, go anti-clockwise all the way to bottom left, a line points to X input below.
Rodney |
24th Mar 2018, 3:25 pm | #7 | |
Octode
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Re: X-Y/Lissajou mode on Telequipment D54?
Quote:
It has to be said, though, that Lissajous figures are, though sometimes pretty, of limited use... Colin. |
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24th Mar 2018, 5:26 pm | #8 | |
Dekatron
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Re: X-Y/Lissajou mode on Telequipment D54?
Quote:
To this day, I have never found a practical use for lissajous patterns. I suppose they may have some merit when checking phase errors in audio amplifiers?
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24th Mar 2018, 9:02 pm | #9 |
Nonode
Join Date: Dec 2012
Location: Kirk Michael, Isle of Man
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Re: X-Y/Lissajou mode on Telequipment D54?
We used lissajous figs in Physics at tech, but I had already seen them in use at work. One of our SOs was trying to develop a non destructive method of assessing strength of salt glazed drainage pipes. A fairly good relationship between ultimate strength and Young's modulus had been established, so this was determination of YM by finding standing wave nodes using LF oscillator and transducer for input, and a record player stylus and cartridge to find the nodes.
Later at tech, the same sort of measurements, so I already understood it. LONG time ago! Ziggy, have you tried the cal signal as I suggested for simple testing. You do have a cal variable by using the red "X gain" control. Easy to input a 1v DC at X input and choose a suitable position of X gain, ergo, calibrated X deflection. But it is very limited compared with Y-input gains. Les |
24th Mar 2018, 11:06 pm | #10 |
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Re: X-Y/Lissajou mode on Telequipment D54?
I have't tried it yet, but what a about a certain value pot in the EXT. X input of the D-54, would this not give you a better and quicker method and control of the signal amplitude or signal?
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25th Mar 2018, 7:35 am | #11 | |
Nonode
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Re: X-Y/Lissajou mode on Telequipment D54?
Quote:
Chris
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25th Mar 2018, 8:03 am | #12 |
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Re: X-Y/Lissajou mode on Telequipment D54?
Doh! Your right Colin, well caught, got me X and Y mixed up.
Have a look at this - https://www.youtube.com/watch?v=YqSvkNjWnnQ he takes it to another level. The X/Y function can be useful for quick fault finding EG by comparing the two channels on an amp, one channel good, tother bad by used with an Octopus, see here - http://www.solorb.com/elect/testcirc...us1/index.html and for testing zeners etc. there are better one's like the one Mr Carlson made on his patreon channel. Andy.
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25th Mar 2018, 8:06 am | #13 |
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Re: X-Y/Lissajou mode on Telequipment D54?
Handy for calibrating the scale on a home-made audio oscillator, using mains as the reference.
used for trimming the frequency of quartz watches. David
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25th Mar 2018, 4:26 pm | #14 | |
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Re: X-Y/Lissajou mode on Telequipment D54?
Quote:
Again, I am working with the relatively low output of a PC soundcard. With a proper signal generator I'm sure I could make prettier pictures. |
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25th Mar 2018, 6:48 pm | #15 |
Heptode
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Re: X-Y/Lissajou mode on Telequipment D54?
That sounds about right. The spec for X includes the following for volts per cm.
Horizontal amplifier Deflection sensitivity approx. 600mV to 3V/cm Maximum input 400Vp
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