Language: 
To browser these website, it's necessary to store cookies on your computer.
The cookies contain no personal information, they are required for program control.
  the storage of cookies while browsing this website, on Login and Register.

GDPR and DSGVO law

Storing Cookies (See : http://ec.europa.eu/ipg/basics/legal/cookies/index_en.htm ) help us to bring you our services at overunity.com . If you use this website and our services you declare yourself okay with using cookies .More Infos here:
https://overunity.com/5553/privacy-policy/
If you do not agree with storing cookies, please LEAVE this website now. From the 25th of May 2018, every existing user has to accept the GDPR agreement at first login. If a user is unwilling to accept the GDPR, he should email us and request to erase his account. Many thanks for your understanding.
Amazon Warehouse Deals ! Now even more Deep Discounts ! Check out these great prices on slightly used or just opened once only items.I always buy my gadgets via these great Warehouse deals ! Highly recommended ! Many thanks for supporting OverUnity.com this way.

User Menu

Tesla Paper

Free Energy Book

Get paid

Donations

Please Donate for the Forum.
Many thanks.
Regards, Stefan.(Admin)

A-Ads

Powerbox

Smartbox

3D Solar

3D Solar Panels

DC2DC converter

Micro JouleThief

FireMatch

FireMatch

CCKnife

CCKnife

CCTool

CCTool

Magpi Magazine

Magpi Magazine Free Rasberry Pi Magazine

Battery Recondition

Battery Recondition

Arduino

Ultracaps

YT Subscribe

Gravity Machines

Tesla-Ebook

Magnet Secrets

Lindemann Video

Navigation

Products

Products

WaterMotor kit

Statistics

  • *Total Members: 83793
  • *Latest: Bear

  • *Total Posts: 520029
  • *Total Topics: 15495
  • *Online Today: 44
  • *Most Online: 103
(December 19, 2006, 11:27:19 PM)
  • *Users: 0
  • *Guests: 15
  • *Total: 15

Author Topic: Test Equipment: Oscillocopes  (Read 65007 times)

Offline Brian516

  • Full Member
  • ***
  • Posts: 147
Re: Test Equipment: Oscillocopes
« Reply #120 on: February 23, 2015, 12:54:01 AM »
yeah, the trigger holdoff is causing me some weirdness.
Uploading a vid of it now...
https://www.youtube.com/watch?v=-QnIyMVbbHE

Those type of pots that are right up against the faceplate I haven't cleaned at all.  On all the other ones, of which were mostly noisy, I dripped a little Deoxit D5 on the shaft after cleaning the gunk/fuzz off, and worked them back and forth until the stuff got inside, then put another drop and repeated.  did this with 2 or 3 drops on each pot and all of those seem to be working fine.   Maybe I should start by doing that on the rest of these pots? Or do you think that it's most likely something else?

Oh, and the cover is off.

Free Energy | searching for free energy and discussing free energy

Re: Test Equipment: Oscillocopes
« Reply #120 on: February 23, 2015, 12:54:01 AM »

Offline Brian516

  • Full Member
  • ***
  • Posts: 147
Re: Test Equipment: Oscillocopes
« Reply #121 on: February 23, 2015, 05:14:15 AM »
Ok, I measured the voltage at the main power supply test points, and all the other ones.  Had some interesting results on the Vertical preamp board....

(TP1518   +110V)       110.3VDC
(TP1536   +55V)          54.93VDC
(TP1548     +15V)         14.95VDC         1.34VAC
(TP1558     +5V)          4.999VDC
(TP1568     -8V)           7.97VDC

TP1486    17.77V
TP1590    10.74V    3.264VAC
TP1594     9.54V     2.008VAC

Vertical Preamp Board:

TP162      started at .6mV then climbed to 2.6mV then dropped back down to .2mV and kept going back and forth.
          158.3mVAC
TP164      back and forth between 13.6mV and 14.2mV
          162.9mVAC
TP346  back and forth between 23.6mV and 29.2mV
          113.6mVAC
TP322     -29.7mV
          back and forth between 1.463mVAC and 1.490mVAC
TP374     -1.175V

TP324     -66.4mV
          46.2mVAC
TP364     -1.174V

TP262     back and forth between -18.8V and 19.8V
          75.8mVAC
TP147     8.35V
TP141     8.37V
TP247     8.33V
TP241     8.33V


Is it possible that the AC riding on the +15V rail is causing all of this instability and AC on all these test points?   seems like there is a good bit of AC running rampant in my scope.    I'm gonna start inspecting the schematics to see if I can narrow down what component it could be.   I'm sure you guys will be able to tell me exactly where to look, though. 

Brian


Hmm, interesting.   I adjusted the 55V adjust pot to EXACTLY 55V, and now there is absolutely no AC on the +15V rail.    or any of the others. 
I am going to go thru and check everything else for stability and AC now....

Some new numbers after the +55V rail adjust and disappearance of the AC on the +15V rail:
(A9 board)
TP1486    18.38V (the manual says that this is linked to the Intensity adjustment and varies from 0V to 75V)
TP1590    9.54V
          3.268VAC
TP1594    10.76V
          2.011VAC
TP1423 (-2450V rail)   No AC.   My meters max out at 1000V so I'm not checking the DC at that point.  Wish I could.... maybe a X10, or even a X3 probe can be made for a DMM??  I don't see why not, but in order for it to be accurate I would have to use exact value components, and add in a tuning cap and maybe small VR? hmm.....  could come in handy if it can be made......

(Vertical Preamp board)
TP162     3.3mV to 4.5mV
          158.7mVAC
TP164     12mV to 8.8mV
          163.3mVAC
TP346     -32.6mV to -25.6mV
          114.7mVAC to 114.3mVAC (rapidly changing)
TP322     -32.2mV to -31.3mV
          4.60mVAC
TP374     -1.178V
          2.7mVAC to 4.4mVAC
TP324     -69.3mV
          46.3mVAC
TP364     -1.177V
          0mVAC to 1.4mVAC
TP262     -23.5mV to -24.5mV
          76mV
TP147     8.37V
TP141     8.38V
TP247     8.35V
TP241     8.34V

The manual says that these are what the values of these test points should be
TP147     8.5V
TP162     0V
TP141     8.5V

TP241     8.4V
TP247     8.4V
TP262     0V

These two test points are in the Calibrator circuit.  The values I am getting are way under the values that the manual shows I'm supposed to have...
(Page 234 of the Tek 465 manual linked to by TinselKoala on page 5 or 6?)

TP1590     10.8V
TP1594     54.7V

This circuit draws it's power from the 55V, 15V, and 5V rails, so if my values are off it must be one of the components in that circuit that is damaged, correct?
I am going to hook up to the closest ground and check to see if the values match the specified ones in exactly the places where the arrows are pointing to.
All of the rails appear to be doing great, especially now that I have gotten rid of the AC on the 15V.  I have had it running for the last several hours non stop except for a couple of minutes and everything is good.  Before I adjusted the 55V adjuster, I had adjusted the "A trigger Level" and "A trigger holdoff" to try and keep the trace steady constantly, but it still glitched a little from time to time. However after adjusting the 55V, it hasn't glitched a single time that I have noticed. :)
There are still definitely some issues to be worked out, though.   I think here after I check a few spots for their specified voltages, I am going to pull the knobs on the A and B trigger level/slope and the A trigger holdoff and put a couple of drops of Deoxit on the shaft and let it sit, then work it around in the morning and maybe put one more drop in, too, just to "rinse" off any crud.  I can't get the stuff out of there, so I can't be putting too much in, obviously.

I shall attempt to isolate all the other issues according to the manual as soon as I get a chance to tomorrow.    I'm going to start finding deals on all the stuff listed in the "calibration" section that I will need for a performance check first of all, and then calibration.  I will have to wait until I can pick up a good quality function gen that has all the functions I need in the tolerances I will need them in. I'm sure that won't be a problem.   Oh, and a good Variac....


Brian


Ah, poop.... I'm going to have to redo all of that again tomorrow WITHOUT anything hooked to the input..................  ::)
« Last Edit: February 23, 2015, 07:41:09 AM by Brian516 »

Offline picowatt

  • Hero Member
  • *****
  • Posts: 1988
Re: Test Equipment: Oscillocopes
« Reply #122 on: February 23, 2015, 07:57:03 AM »
Brian,

Regarding the trigger holdoff, for repetitive signals such as the square wave from the calibrator, you will use the minimum holdoff setting of that control.  Set it there and forget about it for now.

The trigger level control should be able to be set for stable triggering in both positive and negative going slope selection, AC, DC, HF reject, etc when looking at the calibrator.

Regarding the ripple disappearing when the 55V rail was adjusted.  As per the manual, that rail was already within spec.  Possibly the Vadjust control was noisey, but it is difficult to grasp how adjusting it cleaned up the ripple issue.  When you get a probe, you can use the scope to look at the supplies for ripple.

Regarding the calibrator TP measurements,  what is the level that you are seeing on the screen when connected to the input channels?  I think it is supposed to be around 300 milivolts PP and if it is, move on.  Keep in mind that the calibrator is typically used as only a fairly rough reference regarding amplitude and frequency.  Its main function is to provide a fairly fast risetime signal to calibrate (adjust) the probe's compensation cap (when you get a probe).

Other than verifying the main supplies, as you have done, I would suggest using the scope or going thru the performance verification part of the manual to see what all is and is not working.  A full calibration is going to require a few pieces of equipment you may not have.  As well, it must be done in the order given in the manual, which typically begins with power supply rails. 

You can do some DC measurements to verify the channel inputs are close.  Use a 9V battery, connect it to an input channel, see what it reads using the scope and verify that voltage with your DVM.  Repeat for other channel.  This will give you at least an idea of where the preamp inputs are.  You can repeat using a lower V battery to check accuracy at various voltages.  Of course, if you have an adjustable DC supply, use that instead.

Don't start randomly tweaking cal trims in the scope unless you are setup to do the cal correctly with the required equipment.  You may be able to do DC offset adjust and some other cals but I would use the scope a bit and see what is or is not working well.

Do you have a signal/function generator?

PW

 

Free Energy | searching for free energy and discussing free energy

Re: Test Equipment: Oscillocopes
« Reply #122 on: February 23, 2015, 07:57:03 AM »
Sponsored links:




Offline TinselKoala

  • Hero Member
  • *****
  • Posts: 13968
Re: Test Equipment: Oscillocopes
« Reply #123 on: February 23, 2015, 04:40:11 PM »
@Brian: To display both traces with signals from the calibrator, you don't need to use different V/div settings, you simply use the channel's Vertical Position control to put one trace on the upper part of the screen and the other trace on the bottom part of the screen. Set Vert Mode to "Alt" . Set the CH1 input coupling to "ground" to set the baseline on some graticule line in the upper part of the screen, then turn the channel input coupling back to "DC" or "AC" and scale the trace using the V/div control so it just spans a couple of vertical divisions. Do the same with CH2 except use some graticule line on the lower part of the screen for the "ground" or zero volts baseline. Then you'll have two traces that don't overlap (unless you scale them to do so using the V/div control) and since both will have the same setting on the V/div control you can compare their amplitudes, which should be the same . (Red "var" knob on the V/div controls fully CW and in the detent.)

Offline TinselKoala

  • Hero Member
  • *****
  • Posts: 13968
Re: Test Equipment: Oscillocopes
« Reply #124 on: February 23, 2015, 05:03:55 PM »
yeah, the trigger holdoff is causing me some weirdness.
Uploading a vid of it now...
https://www.youtube.com/watch?v=-QnIyMVbbHE

Those type of pots that are right up against the faceplate I haven't cleaned at all.  On all the other ones, of which were mostly noisy, I dripped a little Deoxit D5 on the shaft after cleaning the gunk/fuzz off, and worked them back and forth until the stuff got inside, then put another drop and repeated.  did this with 2 or 3 drops on each pot and all of those seem to be working fine.   Maybe I should start by doing that on the rest of these pots? Or do you think that it's most likely something else?

Oh, and the cover is off.

OK< I see that you have figured out how to show both traces properly separated using the vert position controls. It doesn't look "weird" to me now. I think the issue you are seeing now has to do with the trigger _level_ setting rather than the trigger holdoff. For this signal turn trigger holdoff to the "norm" position and leave it there.

Make sure Trigger Source is on CH1 or CH2, mode is AUTO and adjust A Trigger Level for a stable display. Horiz Display on "A".
Try turning the horizontal timebase to a faster setting so you are only displaying three or four cycles of the waveform on the screen. This will help with some diagnostics, now that you are getting traces there is no need to keep the scope in the 1 ms/div setting.

Anyhow, it does look much better now, perhaps your cleaning did indeed fix it! Or maybe it just likes running on its side.   ;)

Running a full calibration is probably overkill.  It would be nice if you could use some different input signals, like from your GenRad oscillator, for some higher-frequency testing.

It is likely that the little ripple you are seeing is due to the casual grounding we have been using for the input signals, or perhaps some ripple on a power supply due to a faulty capacitor.

Free Energy | searching for free energy and discussing free energy

Re: Test Equipment: Oscillocopes
« Reply #124 on: February 23, 2015, 05:03:55 PM »
Sponsored links:




Offline TinselKoala

  • Hero Member
  • *****
  • Posts: 13968
Re: Test Equipment: Oscillocopes
« Reply #125 on: February 23, 2015, 05:25:45 PM »
On testing the HV supply: Don't bother! This has to do with the display itself and that seems to be working just fine. If you didn't have a trace, or trace too dim,  or improper blanking or something like that, then that's the time to worry about the HV supply. It's just too tricky to mess with that unless you actually suspect some problem and I don't think you have any reason to suspect a problem in the HV circuitry at this point. 

Also, in regards to the calibration.... again... you are looking at "overkill" here. The equipment necessary to do a full and proper calibration is going to be expensive, and you'd be better off spending that money on something else that you'll use all the time. Who needs a time marker generator or a calibrator generator or a signal pick-off unit for anything, except a bench technician who spends all day every day calibrating old analog scopes? Plus you need another scope to do a full calibration anyway.
 
You can look for a good modern full-function Function Generator, and do most of the performance verification and much of the calibration checks with that. Plus your GenRad oscillator for higher frequencies. And a Variac is always handy around the lab. These, some patch cables, adapters and a 50 ohm terminator, are enough.

Offline MileHigh

  • Hero Member
  • *****
  • Posts: 7600
Re: Test Equipment: Oscillocopes
« Reply #126 on: February 23, 2015, 06:51:14 PM »
I found these chips:

http://www.analog.com/media/en/technical-documentation/data-sheets/AD9837.PDF
http://www.analog.com/en/products/rf-microwave/direct-digital-synthesis-modulators/ad9833.html#product-overview

Cheap:
http://www.digikey.ca/product-detail/en/AD9837ACPZ-RL7/AD9837ACPZ-RL7TR-ND/2677471

•Digitally Programmable Frequency and Phase
•12.65 mW Power Consumption at 3 V
•0 MHz to 12.5 MHz Output Frequency Range
•28-Bit Resolution (0.1 Hz @ 25 MHz Ref Clock)
•Sinusoidal/Triangular/Square Wave Outputs
•2.3 V to 5.5 V Power Supply
•No External Components Required
•3-Wire SPI Interface

Another virtual project in a box:  You buy a tiny Arduino board with a VGA out and a USB port for your mouse.  You run Linux for the GUI and write a small program to poke the registers of the oscillator chip.  With two small isolation transformers and three wall warts you can get a "floating set" of +5, -15, and +15 volts.  You buffer the output of the oscillator chip with an op-amp.   You have analog gain and offset knobs.  You have direct out and 50-ohm out.  You can even do the high-current transistor out if you want using a pair of external batteries as the power source.

A small box that you plug in the wall, and there are a few BNC panel-mount connectors on the box, and you use an old VGA monitor and mouse lying around.  You "cheat" and there is just a neatly wired breadboard inside the box along with the Arduino module.

I know I am so out of date, perhaps there is a module that does that all for you.  But then you miss out on the fun of making it!

Free Energy | searching for free energy and discussing free energy

Re: Test Equipment: Oscillocopes
« Reply #126 on: February 23, 2015, 06:51:14 PM »
Sponsored links:




Offline MarkE

  • Hero Member
  • *****
  • Posts: 6830
Re: Test Equipment: Oscillocopes
« Reply #127 on: February 23, 2015, 07:03:01 PM »
eBay has lots of function generators and kits built around DDS chips, some for under $20.  Pirate Bill asked about using one.  Complete and in a box you can buy one that does 5 MHz or 10 MHz for around $70.

Offline Brian516

  • Full Member
  • ***
  • Posts: 147
Re: Test Equipment: Oscillocopes
« Reply #128 on: February 24, 2015, 12:00:08 AM »
I found these chips:

http://www.analog.com/media/en/technical-documentation/data-sheets/AD9837.PDF
http://www.analog.com/en/products/rf-microwave/direct-digital-synthesis-modulators/ad9833.html#product-overview

Cheap:
http://www.digikey.ca/product-detail/en/AD9837ACPZ-RL7/AD9837ACPZ-RL7TR-ND/2677471

•Digitally Programmable Frequency and Phase
•12.65 mW Power Consumption at 3 V
•0 MHz to 12.5 MHz Output Frequency Range
•28-Bit Resolution (0.1 Hz @ 25 MHz Ref Clock)
•Sinusoidal/Triangular/Square Wave Outputs
•2.3 V to 5.5 V Power Supply
•No External Components Required
•3-Wire SPI Interface

Another virtual project in a box:  You buy a tiny Arduino board with a VGA out and a USB port for your mouse.  You run Linux for the GUI and write a small program to poke the registers of the oscillator chip.  With two small isolation transformers and three wall warts you can get a "floating set" of +5, -15, and +15 volts.  You buffer the output of the oscillator chip with an op-amp.   You have analog gain and offset knobs.  You have direct out and 50-ohm out.  You can even do the high-current transistor out if you want using a pair of external batteries as the power source.

A small box that you plug in the wall, and there are a few BNC panel-mount connectors on the box, and you use an old VGA monitor and mouse lying around.  You "cheat" and there is just a neatly wired breadboard inside the box along with the Arduino module.

I know I am so out of date, perhaps there is a module that does that all for you.  But then you miss out on the fun of making it!

Hells yeah, man!
That's pretty awesome you found that... I might just have to order a couple when I do place an order.  I know I could just buy a cheap Chinese $20 function gen,  but I need the experience learning how to design and build circuits, and learn how to write code for Arduino, so that would be a great project for me to get into. With the help of progs like ExpressPCB and SCH and a good simulator, and referencing schematics for function gens, I'm sure I could get it figured out.  Plus I have the Arduino - the Mega 2560, Yun, and one of those little bits kits to play with.  Might be something good to use one of my old laptops for, since it takes practically nothing to run Linux.
Who knows though, maybe I'll end up buying a good high quality function gen before I get it finished......  That's a lot of stuff to learn, but I'm def up for the challenge - once I've got this scope thing down.

Well, time to hook up the scope and get going on the stuff that has been suggested I do by TK and PW.... that is, until I have to go grocery shopping.  It seems like time just flies by...  where's that fancy remote that slows everything but you down????

Brian

Free Energy | searching for free energy and discussing free energy

Re: Test Equipment: Oscillocopes
« Reply #128 on: February 24, 2015, 12:00:08 AM »
3D Solar Panels

Offline Brian516

  • Full Member
  • ***
  • Posts: 147
Re: Test Equipment: Oscillocopes
« Reply #129 on: February 24, 2015, 06:03:24 AM »
MileHigh,

What you think of using this to build a function gen around?

http://parts.arrow.com/item/detail/arrow-development-tools/bemicromax10#2FFJ

Brian

Offline MileHigh

  • Hero Member
  • *****
  • Posts: 7600
Re: Test Equipment: Oscillocopes
« Reply #130 on: February 24, 2015, 06:32:37 AM »
Brian:

I only know very little about what's out there.

The software tools, feature set of the board and price are your three main considerations.  That board looks like an FPGA along with a CPU.  That's pretty amazing but you don't need the FPGA.  I am not sure what hardware and software features you want.  Then just shop around to find a board with all or most of your features.  The brand or the architecture of the CPU are really irrelevant here.  Jut get something mainstream.  This app requires no real processing power.

I am pretty sure the SPI interface can be done with a few I/O pins and a readily available library, you should check that.  It looks like writing your own SPI interface driver would be pretty easy also but it has to exist already.

MileHigh

Free Energy | searching for free energy and discussing free energy

Re: Test Equipment: Oscillocopes
« Reply #130 on: February 24, 2015, 06:32:37 AM »
3D Solar Panels

Offline MileHigh

  • Hero Member
  • *****
  • Posts: 7600
Re: Test Equipment: Oscillocopes
« Reply #131 on: February 24, 2015, 06:46:19 AM »
Here is an interesting Plan B:

You don't even buy a microcontroller board.   You do all of the software for the frequency generator register poking and the GUI on your PC and you get a USB to SPI dongle.

http://www.cypress.com/?rID=57207

Then the external box just has the waveform generator chip, the power supplies, and the support electronics, etc.

Offline MarkE

  • Hero Member
  • *****
  • Posts: 6830
Re: Test Equipment: Oscillocopes
« Reply #132 on: February 24, 2015, 10:37:26 AM »
Here is an interesting Plan B:

You don't even buy a microcontroller board.   You do all of the software for the frequency generator register poking and the GUI on your PC and you get a USB to SPI dongle.

http://www.cypress.com/?rID=57207

Then the external box just has the waveform generator chip, the power supplies, and the support electronics, etc.
First the development board that Brian found is for an FPGA.  There is not a hardware uC on board.  Any uC would be soft in the modest sized FPGA.  A uC is useful for things like a front panel display.  So the USB to I2C dongle is a better way to go.  If there were enough interest we could kick around an open source design for a USB based function generator with really nice capability, like +/-20Vpp output drive.

Offline Brian516

  • Full Member
  • ***
  • Posts: 147
Re: Test Equipment: Oscillocopes
« Reply #133 on: February 24, 2015, 02:39:00 PM »
MileHigh:

I know that I won't need an FPGA for the function gen project, but I was just thinking that might be a nice to have dev board for a large variety of projects.  But now that I'm fully rested and awake, I think I would likely dedicate whatever is used to the FG, so you're right, it's pretty pointless to get for this project.  Maybe later on down the road when/if I find something I would need the FPGA for.  Plus I see now that it doesn't have I2C or SPI, either.

I don't see a price for the DG USB to SPI/I2C dongle on that page. Maybe one has to contact them to find out.. It's obv from Germany so maybe shipping would be more then the device itself, but still should be fairly cheap anyway.  Either way, it would be a great tool to have.

I was poking around the other day and found a schematic and instructions for building an easy USB to I2C dongle that I'm sure could be adapted for SPI.  I couldn't find the link right off hand, but I'm pretty sure I saved the page in a folder and will find and add it once I do.

Speaking of PC based, Check this out:
http://hackaday.com/2014/10/22/function-generator-with-zero-cpu-cycles/

It says it was only used for 200khz, but maybe there is a similar chip to the PIC32 that can get us to the Mhz range?  They don't really give enough info on it so I'll have to dig around for more info.    Chances are, this is specifically around the PIC32 chip and doesn't work with any that will get us in the Mhz range, but it's an interesting article/idea anyway.  Good to know about if someone ever needs a quick, clean sine wave up to 200khz if nothing else.

I don't know if it was just my PC/connection, but for most of the day yesterday this site was almost completely unavailable as if there were some major server issues. Anyone else have that problem?  If not I'm going to have to do some PC cleaning........  I need to put a partition on here and put Linux on it anyway.

Brian

Offline MarkE

  • Hero Member
  • *****
  • Posts: 6830
Re: Test Equipment: Oscillocopes
« Reply #134 on: February 24, 2015, 04:24:51 PM »
The PIC scheme is a poor match to a DDS chip.  The PIC scheme can only output values at integer divisions of the DMA clock.  DDS performs M/N*FCLOCK frequency synthesis.   Up to the resolution of the internal numeric represetnations, you can get pretty much any frequency that you want.   

 

OneLink