DSO-068 DIY kit Oscilloscope Assembly Help !

[bob195558]

DSO-068 DIY kit Oscilloscope_1aa.jpg

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DSO-068 DIY kit Oscilloscope_1aa.jpg
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I have had this DIY kit for several years and just did not time to work on it until now.
I find this DSO 068 DIY kit is shy on its assembly instructions.
So I am finding some difficulty in obtaining the info that I need
and understand what model kit I have.

This DSO-068 DIY kit came with two User Manuals (rev.02)
and no Assembly Guide, which there are two (2).

I found at JYE Tech DIY Oscilloscope Kits web page:
https://jyetech.com/dso-068-oscilloscope-diy-kit/
and in SUPPORT / 06804K
there are several PDF files.
But I am not able to discern between these two,
Assembly Guide (Version F PCB)
and
Assembly Guide (Version H PCB)

If anyone is able to help me understand which Assembly Guide
I need to be using, I would appreciate your assistance.

DSO-068 DIY kit Oscilloscope_1bb.jpg

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[Kilrah]

Well there likely will be a version printed on your PCB, use the matching one

[bob195558]

Thank You Kilrah,
I found this, PN:109-06800-00H
So I am leaning toward it being Assembly Guide (Version H PCB), because of the H.

So, update on my progress, I have the Resistors, Capacitors, Inductors, Diodes, Transistors, BOB Boards, Crystal, Buzzer,
Micro USB socket, power plugs and close the Jumper Connections JP9 and JP2 (JP2 is closed for testing only).

Powering up Test 1 is to check the 5V power circuit, which checks out OK (powered up using the USB).
Next Close JP4 jumper which powers the rest of the board and then check for more 5V voltages, which check is good.
Then press the reset switch "SW12" and viewed the proper LED blinking (one then two blinks), which is good.

So far so good.
Next I need to install more components before preceding to Powering up Test 2.

[bob195558]

End of today’s progress update:
LCD Installation completed
and Powering-Up Test 2 checks-out good.

Next: will need to Open the JP2 Jumper.

[bob195558]

Today's Update:

I am having trouble with Step 3 setup procedure,
but it may have more to do with me not fully understanding this setup procedure.

Adjust_Compensation Capacitors _3a.jpg

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Adjust_Compensation Capacitors _3b.jpg

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[ReSt]

The analog input has voltage dividers for the differnt input sensitivity (10mV. , .1V, 1V) This dividers are made with resistors.
The divider relation of resistors is correct for low frequencies down to DC. But you have stray capacities from the board that are connected in parallel to the resistors. For high(er) frequencies, this capacitive resistance that is in parallel to both voltage divider resitors misadjusts the voltage divider relation.
Therefor, a capacitive voltage divider with one adjustable capacitor is connected in parallel to the resistors. These capacitive dividers (inclusive the stray capacity) are then adjusted to give (in the best case) the same relation as the resitive dividers.
The rising edge of the rectangular signal shows the relation of capacitive to resistive divider.
If the left top edge is rounded, the voltages of the higher fequencies are to low and when the top left edge overshoots, they are to high.
A sharp top left edge with no under-/ overshot is optimal.

Reinhard

DSO68_Schematic_068H.pdf

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[bob195558]

Thank you Reinhard for your reply, it is helpful in understanding what I need to do.

I was having difficulty (and may still) in understanding the instructions of Step-3.
So I rewrote it in hope that I have it better to be understood more easily.
Please let me know if I have something incorrect.

Step 3 Procedures

1) Temporarily attach a wire between “Scope Input” and “Test Signal Output”.

2) Set the Slider Switches to:
(bottom) SW1: DC
(middle) SW2: 1V
(top) SW3: X2

Next Power-Up the dso068 H Oscilloscope.
Go to the Menu and select “TEST SIGNAL”
Set FREQ: to 10,000 Hz
and the (amplitude) AMP: to 5V
Then EXIT out of menu.

3) Adjust Oscilloscope Trigger Level:
Adjust up and down using “VPOS” the Wave-Form to the center of the screen.
Then select “LEVEL” to move the Trigger-Point, so that it is in the middle right side of the screen.

Next adjust “C8” so that the Wave-Form has sharper corners like the center picture looks.

4) Go to the Menu and select “TEST SIGNAL”
Change the (amplitude) AMP: to 1V.
Then EXIT out of menu.

Next change Slider Switches to:
(middle) SW2: 0.1V
(top) SW3: X5

Then adjust “C5” so that the Wave-Form has sharper corners like the center picture looks.

[ReSt]

I don't have the DSO-068 nor its manual, only the DSO-138 ( the simpler one) but your description sounds ok.
1) that wire connects your scope input with the built in signal generator so that you display the waveform of the test signal.
2) you set the sensitivity of the scope to 2V/div and the amplitude of the test signal to 5V so that the diplayed signal fits on the screen (2.5 divisions).
3)adjusting V-level and triggerpoint is required to get a stable display.
The reason for all the above steps is what you do now, Adjusting C8 to a sharp rectangle display.
4) Now you do this setup and adjustments for the remaining voltage ranges of the scope.
When everything is adjusted, you remove the wire between test signal output and the scope signal input.

Reinhard

[bob195558]

Hi Reinhard,
In my 4th post down from the top, I posted two photos that need to be clicked on for them to show.
They are of the Assembly Guide Step-3.

Here are some dso068 screen photos of my Step-3 procedure from today.
I am not sure I have it adjusted correctly as it looks to be a bit bumpy with the wave form.
Not looking like the Step-3 Assembly Guide middle photo.

I did a “RESTORE DEFAULT” first, which seemed to be a help in the beginning.

RESTORE DEFAULT_a.jpg

RESTORE DEFAULT
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dso068 screen photo_b.jpg

Note: you will need to click on photo link to be able to see it. Adjusting C8

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dso068 screen photo_c.jpg

Note: you will need to click on photo link to be able to see it. Adjusting C8

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dso068 screen photo_d.jpg

Note: you will need to click on photo link to be able to see it. Adjusting C8

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dso068 screen photo_e.jpg

Note: you will need to click on photo link to be able to see it. Adjusting C8

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dso068 screen photo_f.jpg

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dso068 screen photo_GG.jpg

Note: you will need to click on photo link to be able to see it. Adjusting C5

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dso068 screen photo_HH.jpg

Note: you will need to click on photo link to be able to see it. Adjusting C5

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[ReSt]

The signal looks a little noisy.
What does it look like when you connect the input to ground instead of the test signal. Do you get a clean line?
Can you try supplying power from a battery instead of a power supply?
Did you check, if the firmware version of your set is the latest one ? (www.jyetech.com)

Reinhard

[bob195558]

Hi Reinhard,
It does look noisy to me too.
I will finish assembling (Step 4) and then see what it looks like.

[bob195558]

Hi Reinhard,
Finish assemble Step-4 and it is looking better, but not perfect.

DSO068 Adjust Cap C8_aa.jpg

DSO068 Adjust Cap C8
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DSO068 Adjust Cap C5_CC.jpg

DSO068 Adjust Cap C5
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[bob195558]

So after completing Step-4 it looks much better then it did.

No change when the probe is connected to ground.

Powering Oscilloscope with a battery I have not tried.

I have not updated the firmware.

DSO068 (“H” version PCB) was purchased March 8, 2017.
This is what I see when the Oscilloscope is booting up.
---------------------------------------------------------------------------
Boot Loader
Ver:113-06803-020
---------------------------------------------------------------------------
Main:06801-060
Key Board:06802-030
PCB:
---------------------------------------------------------------------------


===================================================
The last Revision History date is: October 25, 2015
and the Main Firmware Version Number: 113-06801-061
There is no listing for 06801-060, so I believe this is the same as 06801-061 ?

[ReSt]

I believe that the version you have, is the latest (061)
I found this information in their forum for the DSO-068:
They obviously forgot to update the version number in the 061 version, so that it still displays the older version of 060

Reinhard