hybridfree/eevblog-posts huggingface dataset:
Guildline 9700PL - Page 1
Forum section: electronics / general

author: jfphp
author_rank: Regular Contributor
timestamp: March 04, 2018, 12:18:55 pm
content: Hello,I am looking for the specifications and a manual for an old Guildline 9700PL. Is it still up to date compared with a Fluke 720A/752A and a 3458A or only usefull for bodybuilding ? Thank you.

author: alm
author_rank: Super Contributor
timestamp: March 04, 2018, 02:29:23 pm
content: Looks like its design was based onthis NBS research paper, which might contain some helpful information. According tothis document, ratio accuracy is 5 ppm, which sounds like it is substantially worse than the Fluke 720A or 752A. Not sure if self-calibration, like on the Fluke dividers, can improve the uncertainty.
Is it safe to open a defective 10MHz rubidium oscillator module? - Page 1
Forum section: electronics / general

author: carl_lab
author_rank: Frequent Contributor
timestamp: February 28, 2018, 11:02:02 am
content: I have a defective spectratime LPFRS-01 module laying on my bench, waiting for repair.Unfortunately I do not really know, what kind of hazardous things could be inside the shielded aluminum can.So, if somebody knows about some hazardous toxic material, radiation (microwaves, laser, radioactive...), high voltage or other dangerous things that could be used in such a module, please let me know!

author: PA0PBZ
author_rank: Super Contributor
timestamp: February 28, 2018, 11:15:04 am
content: Completely safe as long as you are not trying to eat it allReference thread:https://www.eevblog.com/forum/repair/repair-temexspectratime-lpfrslpro-10mhz-rb-generator-(drifting-like-mad)/TL;DR: replace the electrolytic caps.

author: carl_lab
author_rank: Frequent Contributor
timestamp: February 28, 2018, 11:40:12 am
content: Thanks for your reply and the nice link to TiN's teardown!

author: Quarlo Klobrigney
author_rank: Super Contributor
timestamp: February 28, 2018, 02:35:55 pm
content: Keep the rubidium crystal away from incandescent lamps, especially if they are held in a bedspring.The resulting beam can actually melt metal.

author: carl_lab
author_rank: Frequent Contributor
timestamp: February 28, 2018, 04:45:26 pm
content: Quote from: Quarlo Klobrigney on February 28, 2018, 02:35:55 pmI do not understand, can you explain please?

author: TiN
author_rank: Super Contributor
timestamp: February 28, 2018, 05:10:26 pm
content: That was a bad joke.

author: floobydust
author_rank: Super Contributor
timestamp: February 28, 2018, 09:54:14 pm
content: Product Safety Data Sheet (PSDS) for Rubidium OscillatorsJoke is from a Star Trek espisode where Mr. Spock makes a laser and busts out of prison

author: Quarlo Klobrigney
author_rank: Super Contributor
timestamp: March 01, 2018, 09:58:20 pm
content: Sorry I couldn't help myself....

author: carl_lab
author_rank: Frequent Contributor
timestamp: March 02, 2018, 12:39:41 am
content: No problem.

author: texaspyro
author_rank: Super Contributor
timestamp: March 03, 2018, 05:33:01 am
content: Lady Heather v6 Beta works with the LPFRS.I have also done a replacement interface board for the LPFRS to connect it to my X72 BNC connector breakout board (it also works with LPROs). The connector board has BNC or SMA connectors for sine wave output, PPS output, PPS input, EFC input, and ACMOS square wave outputs.The interface board has places for a PICDIV chip to generate a buffered 1PPS output, a PICPET 100 ns res timestamping interval counter, a stable adjustable EFC voltage, and a buffered ACMOS level square wave 10 MHz output. Hopefully the boards will be here in a few weeks.
Fluorescent cardboards as UV-screens - Page 1
Forum section: electronics / general

author: Physikfan
author_rank: Regular Contributor
timestamp: February 24, 2018, 04:54:17 pm
content: The spectra are Hg spectra, photographed from a Canon 10D, light source is a Hg high pressure lamp, the entrance slit is imaged with a quartz lens via a reflection grating on different screens:There are the spectra of the screens, in order from left to rightAs you can see, these cheap cardboards with fluorescent paint are well suited and only cost a few dollars for half a square meter.
Fluke 5500A Multifunction Calibrator: Short Teardown - Page 1
Forum section: electronics / general

author: Echo88
author_rank: Frequent Contributor
timestamp: February 21, 2018, 06:04:53 pm
content: Today i had the chance to take a few photos of a defective Fluke 5500A which we have at work. I couldnt find the error and will reassemble it tomorrow, so it can be repaired by Fluke. So if there are any needs for more photos of a particular board say it now. Enjoy.Outer case photos and manuals can be found here:https://doc.xdevs.com/doc/Fluke/5500A/Also pictures of the Keyboard Assembly, which i didnt take photos of.Time limited repair attempt failed, but heres the repair-thread:https://www.eevblog.com/forum/repair/fluke-5500a-startup-error/

author: Echo88
author_rank: Frequent Contributor
timestamp: February 21, 2018, 06:06:27 pm
content: The reference on A6_2 shows the LTFLU-1ACH flying in the breeze, they didnt even bother to squeeze it in a heated enclosure. Of course its sufficient to this mediocre class of calibrators but it kinda hurts to see.

author: Echo88
author_rank: Frequent Contributor
timestamp: February 21, 2018, 06:13:06 pm
content: All in all it was interesting to disassemble it, but of course it doesnt come close to a Fluke 57XX Calibrator with all its shielding and TaN-Resistornetworks.

author: TiN
author_rank: Super Contributor
timestamp: February 22, 2018, 12:14:43 am
content: Thank you for photos.LTFLU in these is very same REF as used in Fluke 8842A, even resistor is same.

author: dl1640
author_rank: Regular Contributor
timestamp: February 23, 2018, 12:48:49 am
content: Looks A6 was repaired, residual flux on U45.
HP 3468B resistance measurements - Page 1
Forum section: electronics / general

author: johngalt47
author_rank: Newbie
timestamp: February 20, 2018, 05:23:02 pm
content: I have a weird issue with this meter. I leave it on all the time, hoping for some consistency. I usually measure a batch of around 15 resistors at a time. Let’s say that it has been a couple of hours since using the meter. The first couple of resistors in a batch display stable readings immediately. The one after that require several seconds to display a stable reading. For example, a 2400 ohm resistor might read 2406.45 as soon as it is connected with my Kelvin leads. Then it starts counting down and may reach 2406.37 before it stops. So why would the first couple in the batch be display a value that does not change.Since I leave the meter on I would think that the temperatures have stabilized.Bythe way, I usually measure Vishay/Dale RN55 or RN60 metal film, high quality ones.

author: kj7e
author_rank: Frequent Contributor
timestamp: February 20, 2018, 10:15:23 pm
content: So your talking about the measured value dropping 0.08 on the 3K ohm scale? The 24 hour spec for the 3K range is 0.0035%, which comes to 0.084 Ohms of 2400. You may be asking for more than stability the 3468 is capable of providing.Slight drift can be normal while taking a measurement, the constant current source could drift slightly, perhaps the 3k range current sense resistor is warming and the tempco being seen, maybe the DUT is warming (or cooling for that matter) and your seeing the DUT's tempco? The 3468 is a good meter but not a particularly high accuracy meter and you seem to be within spec.

author: johngalt47
author_rank: Newbie
timestamp: February 20, 2018, 11:41:07 pm
content: My problem is that the first two of any batch DON’T drift while the remaining ones do. I could understand it if I left the meter off and did not let it warm up when measuring the first two. I could understand thermal drift, but not inconsistency.

author: kj7e
author_rank: Frequent Contributor
timestamp: February 21, 2018, 12:08:40 am
content: Is it always the same exact resistors that show drift? Or does the drift show after so much time making measurements, that is, regardless of the resistor, but after say 1 min of testing the drift shows.

author: 2N3055
author_rank: Super Contributor
timestamp: February 21, 2018, 12:11:38 am
content: Maybe cables / clips heating from hands.. ??

author: johngalt47
author_rank: Newbie
timestamp: February 21, 2018, 12:20:29 pm
content: I only use the clips to pick up the resistors. I will have to do some more testing, but it seems that maybe some values may be more solid than others. I was thinking along the lines of maybe a slightly cold solder joint.
UV sensitivity of a Nikon D70 - Page 1
Forum section: electronics / general

author: Physikfan
author_rank: Regular Contributor
timestamp: February 22, 2018, 02:33:59 pm
content: The UV sensitivity of a Nikon D70 was measured by using a Hg spectrum. The camera was used without a camera lens in an open spectrometer configuration, consisting of a quartz lens, a reflection grating and a Hg high pressure lamp as a light source:In addition to the 436 nm and 404 nm lines of the Hg spectrum, the 365 nm line of the Hg spectrum in red is clearly visible.

author: Svgeesus
author_rank: Regular Contributor
timestamp: February 24, 2018, 04:14:22 pm
content: I expect that you already know about this lens, but just in case: there is aNikon 105mm f/4.5 UV-Micro-Nikkor.QuoteQuotehttp://www.company7.com/nikon/lens/0105f4.5uv.html

author: Physikfan
author_rank: Regular Contributor
timestamp: February 24, 2018, 05:45:04 pm
content: Unfortunately the price of this 105mm UV Nikkor is very high.

author: Physikfan
author_rank: Regular Contributor
timestamp: February 28, 2018, 01:43:50 pm
content: The UV sensitivity of a modified Nikon D70 was measured:In addition to the 436 nm and 404 nm lines of the visible Hg spectrum, the 365 nm line of the Hg spectrum and two new UV lines in red (false colour) are clearly visible.

author: Physikfan
author_rank: Regular Contributor
timestamp: March 01, 2018, 08:03:56 pm
content: Here you can modify your Nikon D70 or do it yourself:https://www.lifepixel.com/tutorials/infrared-diy-tutorials/nikon-d70-d70s

author: The Soulman
author_rank: Super Contributor
timestamp: March 02, 2018, 12:25:03 am
content: Quote from: Physikfan on March 01, 2018, 08:03:56 pmThat is about a IR conversion, did you use a different filter for UV or no filter at all?

author: Physikfan
author_rank: Regular Contributor
timestamp: March 02, 2018, 06:01:32 am
content: This modified Nikon D70 is now a full spectrum camera, IR VIS UV.
AE Utilizing New Generation Stress Free Bulk Metal Foil technology? - Page 1
Forum section: electronics / general

author: 0.01C
author_rank: Regular Contributor
timestamp: February 16, 2018, 04:19:41 pm
content: Stress Free?Excellent long term stability of resistance less than 0.2 ppm/year (0.05 ppm/year actual)Excellent temerature coefficuent less than A±0.05 ppm/°C, B±0.005 ppm/°Chttps://www.escomponents.com/resistors-standard-calibration-resistors/http://cloud.tapatalk.com/s/5a870439f41ad/20160720184802DB0111-1706-EN-AE-Std-Resistors_final_28Jun2017.pdf
Keithley 150A, 60Hz -> 50Hz conversion? - Page 1
Forum section: electronics / general

author: zhtoor
author_rank: Frequent Contributor
timestamp: February 10, 2018, 05:56:51 pm
content: Hello Friends,i am in the process of acquiring a Keithley 150A micro-voltmeter, pico-ammeter.i understand that the unit is designed to operate on a 60Hz power supply,but in the part of the world i live in has 50Hz power supply,has anybody done a conversion to this effect?regards and thanks.-zia

author: Echo88
author_rank: Frequent Contributor
timestamp: February 10, 2018, 09:53:50 pm
content: I havent done it myself and just read the manual: As far as i can see you need to change C107/117, also i think the chopper doesnt need to be changed, although Keithley has different labels for the 50/60Hz-versions. Keep in mind to check if the transformer-wiring is correct to accept your mains voltage.

author: zhtoor
author_rank: Frequent Contributor
timestamp: February 10, 2018, 10:34:10 pm
content: thanks, i get it, we have a resonant amplifier at our hands... interesting...don't you mean to change C106 (by adding a parallel .002uf cap) to resonate the tank @ 100Hz?the trimmer C117 may not have enough headroom to adjust the resonant frequency.btw, a very interesting design.best regards.-zia
Datron board swapping?? 4700, 4705, 4707, 4708 - Page 1
Forum section: electronics / general

author: acts238willy
author_rank: Regular Contributor
timestamp: February 07, 2018, 11:43:41 am
content: The usual dilemma... an old machine with no available replacement boards.My 4708 (AC only) has quit on me.Will boards from the 47xx series swap with each other...Or, do I need to use only 4708 boards to repair mine?HELP!

author: tggzzz
author_rank: Super Contributor
timestamp: February 07, 2018, 11:59:23 am
content: Double posted!That's, ahem, suboptimal for many reasons.I suggest people reply to the other post.

author: acts238willy
author_rank: Regular Contributor
timestamp: February 07, 2018, 01:10:32 pm
content: 18 views in 'test equipment'45 views here.It says I can't delete it over there?As you can see, I'm new here.

author: Simon
author_rank: Unknown
timestamp: February 10, 2018, 08:43:14 am
content: As this thread has no real replies I have locked it please feel free to continue on the other one:https://www.eevblog.com/forum/testgear/datron-4708-possible-board-swapping-with-4700-4705-and-4707/Double posting topics does tend to annoy people with good reason as it means you end up with two parallel discussions that aren't aware of each other and people get pretty frustrated when they find a parallel discussion where somebody has already suggested the same thing they have or they have missed out on valuable information that would of helped them to help you.
UV lines of mercury spectra at a ZnS screen - Page 1
Forum section: electronics / general

author: Physikfan
author_rank: Regular Contributor
timestamp: February 09, 2018, 06:57:29 pm
content: The spectra are Hg spectra, photographed from a Canon 10D, with increasing intensity from top to bottom, light source is a Hg high pressure lamp, the entrance slit is imaged with a quartz lens via a reflection grating on a zinc sulfide screen:
Fluke LCR adaptor question - Page 1
Forum section: electronics / general

author: rolkinas
author_rank: Contributor
timestamp: February 06, 2018, 08:52:13 pm
content: Hello!Can someone help finding part number or source of Fluke LCR meter Kelvin adapters as in picture.Will be used with Fluke PM6303.

author: HighVoltage
author_rank: Super Contributor
timestamp: February 06, 2018, 10:34:43 pm
content: These parts were made for Philips / Fluke and I don't think you will be able to find them new anywhere these days.I might have a brand new set that I could sell, but I have to look first for them.

author: rolkinas
author_rank: Contributor
timestamp: February 06, 2018, 10:46:37 pm
content: Quote from: HighVoltage on February 06, 2018, 10:34:43 pmThat's great. Please drop me PM if you find them

author: HighVoltage
author_rank: Super Contributor
timestamp: February 07, 2018, 11:07:09 am
content: I looked but can not find any extra of these clips anymore. I have only as many pairs as I have instruments, sorry.Sometimes the LCR meters are offered on ebay with them. Probably your only hope.

author: rolkinas
author_rank: Contributor
timestamp: February 07, 2018, 12:48:09 pm
content: Thanks for looking.May I ask you to measure diameter of original connector pins on these adaptors?I will wait a bit in case someone have them before DIY solution kicks in.
Reading out Calibration data from Datron/Wavetek 4808?  FRAM ? - Page 1
Forum section: electronics / general

author: perdrix
author_rank: Frequent Contributor
timestamp: February 06, 2018, 09:20:15 am
content: I really need to change the calibration memory retention battery in my 4808.What I intend is to use a small floating PSU with a blocking diode to supply just under the battery voltage to the memory circuit, then unsolder and replace the battery.However mistakes do happen, so does anyone know of a way to read the contents of the Calibration RAM (and to restore in case of disaster)?Has anyone ever been down the FRAM route? The existing RAM is a TC5564PL (8k x 8 ) so a FM1608 may well work fine...ThanksDave Partridge

author: quarks
author_rank: Frequent Contributor
timestamp: February 06, 2018, 05:07:08 pm
content: you can change the cal RAM battery with a battery connected to the 5 V rail on the board and use a battery powered (or isolated) soldering ironabout cal RAM readout, I have not seen anyone using it on a 4808 but on 1281/71https://www.eevblog.com/forum/repair/datron-12811271-cal-ram-backup-how/msg1390517/#msg1390517about FRAM, I have not seen anyone using it on a 4808 but on 1281/71https://www.eevblog.com/forum/metrology/yes-another-3458a-repair-and-nvram-replacement-to-ramtron-fram/msg1111377/#msg1111377

author: perdrix
author_rank: Frequent Contributor
timestamp: February 07, 2018, 12:45:17 pm
content: I just did the job with 5V supplied to the board which worked fine.However I'd still be interested to know of a good way to actaully read the content of the Cal Ram. I suppose it may be possible to use an LA to read it, but I can't quite work out how I'd do that. I have an LA, but am really not well clued up on how best to use them, the "Training Kit for the Agilent Technologies 16600/700 Series Logic Analysis System" (16700-97021) really didn't work for me as a good tutorial.I don't think the CalRam can be read using GPIB, as far as a can tell from the manual the only commands for this are a few "Diagnostic commands":Quotebut I don't think they provide enough to recover the contents of the RAM.Dave
Correct exposure times for recording spectral lines - Page 1
Forum section: electronics / general

author: Physikfan
author_rank: Regular Contributor
timestamp: February 06, 2018, 11:23:34 am
content: Correct exposure times for recording spectral linesThe spectra are Hg spectra, photographed from a Canon 10D, with increasing exposure times from top to bottom, (1/90 s, 1/30 s, 1/10 s, 1/2 s, 3 s), light source is a Hg high pressure lamp , the entrance slit is imaged on a screen with a quartz lens via a reflection grating, the left part consists of an ultraviolet luminescent screen to detect the UV lines:In the last two spectra, the overexposure of the 546nm and 577nm lines is already clearly visible.Further experiments with quartz prism are in preparation.

author: awallin
author_rank: Frequent Contributor
timestamp: February 07, 2018, 10:51:20 am
content: Maybe look at how people are using webcams and DSLRs for astrophotography.The optimal strategy will depend on what type of noise is limiting, dark-current in the sensor, sensor readout, photon statistics, or something else.Stacking multiple short exposures might be a good idea to try.
IR thermometer help. - Page 1
Forum section: electronics / general

author: Terry01
author_rank: Frequent Contributor
timestamp: March 05, 2018, 09:32:30 pm
content: I was looking to get an IR thermometer and was right about to pull the trigger on the Fluke 64 MAX but i ended up seeing the EBRO TFI-550 and liked the look of it so took a punt hoping I was getting a "better" instrument. Now I am not so sure I did the right thing. I can't help feeling I should just have stuck with the known name brand Fluke.Does anyone here know enough about these things to be able to tell me one way or the other??

author: Terry01
author_rank: Frequent Contributor
timestamp: March 06, 2018, 10:34:27 pm
content: Anyone ? ? ?

author: Edwin G. Pettis
author_rank: Frequent Contributor
timestamp: March 07, 2018, 04:21:37 am
content: It depends on what you want to do with it, how accurate, repeatable and from a reputable source. There are some little hand held gun models out there selling for under $20, they are pretty accurate, you can find them on eBay. Yes they are from China, I have one of them and so far, it is certainly worth the price I paid. ±1.5°C/±1.5% is not too shabby. Now if you need better performance, then the Fluke is likely the better buy even though it costs more. If that little gun is good enough, then there's your answer, otherwise a Fluke.

author: texaspyro
author_rank: Super Contributor
timestamp: March 07, 2018, 05:17:44 am
content: Also look at the Melexis IR temp sensors. They speak IIC (actually SMBus with a 8-bit CRC). They have several different versions that run on 3.3 or 5V and with different fields of view. Most are packaged in a TO5-ish windowed package. The narrow field of view models can get pricey.

author: Terry01
author_rank: Frequent Contributor
timestamp: March 07, 2018, 08:27:24 am
content: Cool. Thanks for the replies. It's just for hobby use and general around the house or whatever. I won't need no scientific results or anything like that.As you say it'll be near enough...I'm a happy chief temperature taker again!
HP 3457A (last cal in 2000) vs DMM7510 - Page 1
Forum section: electronics / general

author: kj7e
author_rank: Frequent Contributor
timestamp: February 04, 2018, 06:07:40 pm
content: Picked up a very clean HP 3457A just over a week ago, the more I play with it the more impressed I am. Just had to show this, room temp held steady at 23 deg C, fresh auto cal on both DMM7510 and 3457, measuring my ovenized LTZ1000A.I was considering sending it in to Keysight for a cal, but now I don't think it would benefit the meter at all. Currents and resistance are well within spec as well. Already changed out the CALRAM battery.

author: Kleinstein
author_rank: Super Contributor
timestamp: February 04, 2018, 07:37:03 pm
content: Usually the 3457 is not considered such a good meter. It is relatively noisy and the voltage rages are a bit unusual that there is no range with an amplifier gain of 1 and thus no range with really good long time specs. Also high impedance is only for the 3 V and 300 mV range. 30 V is already with an input impedance of 10 M.The optional internal scanner is a nice feature, but that is about it.A similar instrument would be the Keithley 2001, with advantages on the 2001 side.

author: kj7e
author_rank: Frequent Contributor
timestamp: February 04, 2018, 09:43:55 pm
content: I've read that, but its still a great meter for the price.

author: Insatman
author_rank: Frequent Contributor
timestamp: February 06, 2018, 03:39:13 am
content: Is that a HP3456A sitting open-top on your bench?

author: kj7e
author_rank: Frequent Contributor
timestamp: February 06, 2018, 03:45:08 am
content: Quote from: Insatman on February 06, 2018, 03:39:13 amYep, just replaced all the power supply caps today;https://www.eevblog.com/forum/testgear/fluke-8505a-vs-hp-3456a/25/
What gauge of Silicon cable should I use to make up some new meter leads? - Page 1
Forum section: electronics / general

author: Specmaster
author_rank: Super Contributor
timestamp: January 29, 2018, 11:53:14 am
content: I would like to make up of my own meter leads in nice soft and flexible silicon cable but not sure what gauge I should use for this, any ideas?

author: fcb
author_rank: Super Contributor
timestamp: January 29, 2018, 12:06:36 pm
content: We keep hanks of fine stranded silicone 0.75mm in-stock for making our own general purpose test leads.Usually from Rapid Electronics:01-0641 (black)01-0640 (red).

author: ManateeMafia
author_rank: Frequent Contributor
timestamp: January 29, 2018, 12:52:43 pm
content: Pomona 6733-0 and 6733-2 use 18 awg wire. They are rated for up to 20A.https://www.digikey.com/product-detail/en/pomona-electronics/6733-0/501-1281-ND/737851

author: fanOfeeDIY
author_rank: Unknown
timestamp: January 29, 2018, 12:59:08 pm
content: My usage is not for Metrology,these were when I was making only for my handheld DMM and bench DMMAWG 16 or 1.25sqfor large current leads.AWG 18 or 0.75sqfor soft and comfortable leads.

author: fanOfeeDIY
author_rank: Unknown
timestamp: January 29, 2018, 02:04:53 pm
content: I buy silicon cables at Akihabara in store to check softness and flexibility by touching them before I buy them, because not all silicon cables are soft, some are sticky, worse than the PVC.The good one feels as if it has a powder coating.The one I bought from Franky's store was the best among I bought online.https://www.ebay.com.au/itm/One-Pair-of-16-AWG-16-Gauge-Silicone-Wires-Silicon-Cables-1m-Red-1m-Black-/200893010111

author: Specmaster
author_rank: Super Contributor
timestamp: February 01, 2018, 09:31:39 pm
content: Thanks guys, I have ordered some 18 AWG cables as the most current I'll be measuring is 5A and the cable will be nice and super flexible, just what I want.
UV lines of mercury spectra - Page 1
Forum section: electronics / general

author: Physikfan
author_rank: Regular Contributor
timestamp: January 28, 2018, 12:23:27 am
content: The spectra are photos of Hg spectra with increasing exposure time from top to bottom, light source is a Hg high-pressure lamp, the entrance slit is imaged with a quartz lens via a reflection grating on a screen, to detect the UV lines, the right part of an ultraviolet screen:Only in the first two spectra do the colors correspond to the visual impression with unarmed eyes.The blue line on the far left in the last spectrum is a ghost.Further experiments with quartz glass prism and zinc sulphide screen are in preparation.

author: T3sl4co1l
author_rank: Super Contributor
timestamp: January 28, 2018, 02:34:56 am
content: This isn't accurate, right? -- Because UV+vis covers more than an octave bandwidth, so the green lines are second order vis lines, no?Tim

author: LaserSteve
author_rank: Super Contributor
timestamp: January 28, 2018, 02:56:42 am
content: He's projecting on a Green Phosphor.. That looks exactly correct..see:https://physics.nist.gov/PhysRefData/Handbook/Tables/mercurytable2.htmSteve

author: cdev
author_rank: Super Contributor
timestamp: January 28, 2018, 04:00:18 am
content: see image.The filter is a dichroic filter originally meant for scientific instruments. I've had it for ages. Thats my monitor here, right now.The color output of an LCD with a florescent backlight.You can clearly see the lines with all sorts of light sources.

author: John Heath
author_rank: Frequent Contributor
timestamp: January 30, 2018, 03:27:32 pm
content: It should look like this with a cool thumb print of the two very close lines at 3650 3653. I would venture a guess that the two greens in the third brightest photo is the tell tail thumb print 3650 and 3653.
The Ring Reference Divider - Page 1
Forum section: electronics / general

author: Jos
author_rank: Newbie
timestamp: January 31, 2018, 12:05:13 pm
content: Hi All,Studying the Fluke book Calibration Philosophy in Practice I came across the ring reference divider. (see attachment)Can someone explain to me how this is used in practice, and give me some examples.Thanks in advance.Jos
732A Hint for the voltnuts - Page 1
Forum section: electronics / general

author: Henrik_V
author_rank: Regular Contributor
timestamp: January 30, 2018, 07:11:47 am
content: Just saw a 732A at Helmut-Singer for less than 200€Couldn't find the hookEarly bird

author: Henrik_V
author_rank: Regular Contributor
timestamp: January 30, 2018, 09:39:15 am
content: And passed ...

author: TiN
author_rank: Super Contributor
timestamp: January 30, 2018, 10:15:09 am
content: What is the point in posting such threads?those who actively looking for device, have traps already set, those who are not , well, get inflated prices as result.

author: Echo88
author_rank: Frequent Contributor
timestamp: January 30, 2018, 11:30:02 am
content: Aww, i also need a 732A/B... Anyway, Helmut lowered the price of the Keithley 706 to 35€ which is interesting to me.

author: guenthert
author_rank: Frequent Contributor
timestamp: January 30, 2018, 12:24:57 pm
content: Quote from: Henrik_V on January 30, 2018, 07:11:47 amCondition: as is

author: Henrik_V
author_rank: Regular Contributor
timestamp: January 30, 2018, 12:35:48 pm
content: Quote from: TiN on January 30, 2018, 10:15:09 amI wasn't shure.. I don't want to spam this nice boardBut IMHO that was a nice oppurtunity for the voltnuts and I for that price even I was tempted ...(OK, I couldn't resist a GR 722-D)Greetings from GermanyHenrik

author: guido
author_rank: Regular Contributor
timestamp: January 30, 2018, 06:46:42 pm
content: I took the risk and applied, think not too long after it was listed. Too late. I did get a Fluke 750A there recently, together with some ESI stuff.One of the ESI devices contains an HP 419A. Already have a Fluke 335D. So all i'm missing is a good referenceAnyone in for a swap? I have three good telco grade 10MHz cesium standards, could part with one. For anythingreallyvolt nuttery. Sent me a PM, don't want to spam this board either.Note that i don't want to ship; you need all kind of warning stickers (dangerous when wet, no passenger aircraft, cesium etc) that i don't expect regular post will handle it. So NL, BE and parts of DE only.

author: guido
author_rank: Regular Contributor
timestamp: February 04, 2018, 07:24:30 pm
content: Talked to Singer yesterday when i visited. Kinda obvious, but the 732A was kaput. They are not doing repairs anymore.This time i bought a number of 48V supplies for my Cesium references. And a BK precision 8500 load for 30 euro's. Obviously also broken, hopefully not beyond repair.
3458a A9 board details - Page 1
Forum section: electronics / general

author: mimmus78
author_rank: Unknown
timestamp: January 20, 2018, 07:35:36 pm
content: Did anyone noticed that by pin 1 of J400 you can change temperature set point of the board?Wondering if they use it for accelerated ageing by changing or cycling LTZ1000 temperature.Also the heater driving pin at base of the transistor is rooted from J401-1 to P401-1 on the A1, than it passes via a relay somewhere to be read. The schematic is to much complicate for me to figure out what happens but it seems this is used somewhere.I cannot hear any relay click during normal operation. Wondering it it's used and when, maybe during acal to get an idea where the heater is for sanity check?

author: Kleinstein
author_rank: Super Contributor
timestamp: January 20, 2018, 08:38:23 pm
content: There seems to be no connection to J400-Pin1. So likely something for the test jig only. Besides changing the temperature, this could also act to monitor for drift of the two critical resistors that set the temperature.J401 Pint 1 seems to have a path to the ADC somehow - though a little odd. I don'T see relays involved - only CMOS switches. HP uses a little odd symbol that looks a little like a relay. Since the signal would go to the normal ADC, I somewhat doubt they would use it in normal operation. I would guess more like during self test and maybe for a sanity check during ACAL.

author: mimmus78
author_rank: Unknown
timestamp: January 20, 2018, 10:01:47 pm
content: Maybe they wanted to do some digital temperature compensation in the same way of the "400k*" resistor, but in this case wasn't better to measure voltage drop of the heater like in the 400K resistor?

author: mimmus78
author_rank: Unknown
timestamp: January 20, 2018, 10:04:03 pm
content: Maybe next 3458a that TiN will repair he can stick a probe on this switch to check when it's used.

author: Kleinstein
author_rank: Super Contributor
timestamp: January 21, 2018, 09:06:33 am
content: It does not make a big difference whether the heater resistor or the emitter resistance is measured. The BE drop depends on a closely related temperature and both voltages go down when the temperature goes up.
late Santa drop off......NOS ltz's - Page 1
Forum section: electronics / general

author: lowimpedance
author_rank: Super Contributor
timestamp: January 30, 2018, 02:37:47 am
content: Returned from holiday to find Santa had left on my bench an old box he found in some odds and ends in an old cupboard somewhere.Pictures of box as found below. Shame the supplied quantity does not match the box number. I guess a few must have been used since 1990 !.Maybe next Christmas he might have found some resistors in the same odds and ends........perhaps.

author: CalMachine
author_rank: Frequent Contributor
timestamp: January 30, 2018, 02:48:59 am
content: Quote from: lowimpedance on January 30, 2018, 02:37:47 amWow!!! Fantastic find.Silver leads? Interesting!

author: TiN
author_rank: Super Contributor
timestamp: January 30, 2018, 04:03:11 am
content: I haveone or twoof these.One actually riding happily 24/7 inside my 3458A.

author: lowimpedance
author_rank: Super Contributor
timestamp: January 30, 2018, 04:22:33 am
content: Quote from: TiN on January 30, 2018, 04:03:11 amAh so you do..
Capacitor to replace C8 on 3458A A6 board - Outguard PSU - Page 1
Forum section: electronics / general

author: perdrix
author_rank: Frequent Contributor
timestamp: January 16, 2018, 06:42:19 pm
content: This is a 53D capacitor, 8300uF (-10% +75%), 35V. The original was 85C, the current version is 105C (53D832G035JP6E3).Sadly though this doesn't appear to be available in UK (except with a £15.95 surcharge for shipping from Newark to UK Farnell) which effectively doubles the price.Can anyone suggest a suitable axial alternative and source in UK.ThanksDave

author: MisterDiodes
author_rank: Frequent Contributor
timestamp: January 16, 2018, 08:45:06 pm
content: See if you can find Illinois Capacitor 109TTA035M (or similar) . Should fit...since the one you're replacing had such a loose tolerance, this will still cover that range with similar ESR.

author: perdrix
author_rank: Frequent Contributor
timestamp: January 16, 2018, 10:35:45 pm
content: And only £6.31 from UK Mouser - way cheaper and similar rating. Pity it's only an 85 degree part, but as the original was also 85C, that's OK.CheersDave

author: perdrix
author_rank: Frequent Contributor
timestamp: January 17, 2018, 12:26:00 pm
content: While I was waiting for the new capacitor to come in I put the old one on the LCR bridge.ESR was 0.2 ohms which is quite lot more than the 34mOhms it would have had when new, and capacity was really quite low at 7700uF, so glad I've ordered that replacement.Dave
Oh dear, another drifty 3458A - Page 1
Forum section: electronics / general

author: perdrix
author_rank: Frequent Contributor
timestamp: January 14, 2018, 01:40:01 pm
content: I'm currently running the Service note 18 drift test, and am already way out of bounds after a few daysThe error bars on the CAL72 values are set to 3.4E-5 percent of the reading which I think is the 0.34 ppm magic number.The meter was powered on after a long period in storage on the day before the first reading in the graph.Is this a definite case of "you need a new A3 board", or is there some hope that it can be fixed or will stabilise after a few more days?ThanksDave

author: TiN
author_rank: Super Contributor
timestamp: January 14, 2018, 02:07:18 pm
content: I'd leave meter to run a week or two after storage and then do the test. You may have got just long storage stress.

author: tggzzz
author_rank: Super Contributor
timestamp: January 14, 2018, 02:12:41 pm
content: Keep measuring before spending moneyMy Solartron 7081 has an interesting maintenance procedure after being in storage: wrap it in insulation and keep it powered for 24 hours to raise the internal temperature.I used a blanket, and the internal temperature rose to, IIRC, around 40C. It was noticeably better thereafter.I make no comment about the relevance or otherwise to your 3458.

author: perdrix
author_rank: Frequent Contributor
timestamp: January 14, 2018, 03:30:16 pm
content: Doh! It's nowhere near as bad as I initially thought - the limits are 0.43ppm per DAY, not 0.34 per week which is what I had misremembered!I've since updated the spreadsheet to set the errors bars at 4.3E-5 percent.The only period in which the limit was exceeded was the first one where the delta was 0.9ppm.The next 24 hour drift was 0.13ppm.So fingers crossed!Dave

author: MisterDiodes
author_rank: Frequent Contributor
timestamp: January 14, 2018, 07:40:35 pm
content: It's probably fine, and you'll probably see it settle down a bit more. Let it run for -at least- a few weeks after a long power-off storage period before gathering any serious data.

author: Pipelie
author_rank: Regular Contributor
timestamp: January 15, 2018, 03:07:15 pm
content: fingers crossed!

author: mimmus78
author_rank: Unknown
timestamp: January 16, 2018, 09:26:27 pm
content: My 3458a despite having a jumpy reference with a horrible temperature coefficient A9 has a very good "resistor switch/chip".23/12/2016 35.20 997.87684909/01/2018 35.20 997.8765750.3ppm per year seems to qualify as "good enough" also for the 0.34ppm per week (but also month or year)

author: TheSteve
author_rank: Unknown
timestamp: January 16, 2018, 11:13:32 pm
content: Quote from: mimmus78 on January 16, 2018, 09:26:27 pmThis looks impressive - has it been powered on for the entire time(it is only legit if powered on).

author: mimmus78
author_rank: Unknown
timestamp: January 16, 2018, 11:43:01 pm
content: Quote from: TheSteve on January 16, 2018, 11:12:06 pmNo not 24/24, let say 20% ... anyway still impressive. It has the new analog board.Inviato dal mio ONEPLUS A5010 utilizzando Tapatalk
Specs on this Electronic Research Co OCXO oscillator ? - Page 1
Forum section: electronics / general

author: wkb
author_rank: Super Contributor
timestamp: January 13, 2018, 06:40:24 pm
content: Picked up this Electronics Research Co 800-SMI-1 OCXO at a local HAMfest.Works OK as far as I can tell, compared the output freq to my Rb oscillator.But: does anyone have the specifications for this OCXO?tia, Wilko
Symmetricom SA22.c rubidium oscillator breakout board - Page 1
Forum section: electronics / general

author: texaspyro
author_rank: Super Contributor
timestamp: January 12, 2018, 05:05:07 pm
content: I've finished a prototype layout for an interface board for the Symmetricom SA22.c rubidium oscillator that allows it to be connected to my X72 BNC connector board. I've shipped it off to OSHPARK. Should be here in a couple of weeks for testing. There is more info in the X72 breakout board thread:https://www.eevblog.com/forum/metrology/symmetricom-x72-(and-other-rubidium-oscillator)-signal-breakout-boards/Next up is an interface board for the LPFRS and LPRO rubidiums. It will have a PICDIV chip for generating a 1PPS output.
Choosing a 3d scanner for metrology purpose. - Page 1
Forum section: electronics / general

author: Shpak
author_rank: Newbie
timestamp: December 06, 2017, 02:41:35 pm
content: I have to choose a 3d scanner which mostly will be used for metrology purpose. Which means I need to get very accurate data of the geometry of object to be scanned. However, sometimes it will be used to create good renders.Right now I have two options.Artec Spiderwhich as I understand can be used to perform accurate measurements and also provides textures.FARO Laser TrackerION as it provides much higher precision but no textures (If I got it right). And in addition second scanner, less accurate, but good for textures. MaybeEvaor maybe something else.I need an advise here.

author: 3dtech
author_rank: Newbie
timestamp: January 05, 2018, 03:10:13 pm
content: Hi ShpakThe best for you is the it provides highest precision3d professional scannerwith texture CREAFORM 3D Scanner.Hope that's will be helpful for you

author: Shpak
author_rank: Newbie
timestamp: January 11, 2018, 02:40:27 pm
content: Which exact model do you recommend?
philips pm3230 oscilloscope test - Page 1
Forum section: electronics / general

author: davy peleman
author_rank: Regular Contributor
timestamp: January 10, 2018, 02:49:19 pm
content: i just purchased an old scope and i wanted to test it. so i took a little oscillator circuit i had laying around. it runs at 30 hz and is powered with a small transformer (fully rectified and a 4700uf cap). now the signal has a lot of hum (60 cycle from the line). when i touch the positive probe and the transformer the hum is gone and i see an nice clean square wave. can someboby explain what is happening. should i ground the transformer? the scope could also use some new electrolitics, but still waiting on the order.
Forcing the Fluke 5440B in a specific range - Page 1
Forum section: electronics / general

author: e61_phil
author_rank: Frequent Contributor
timestamp: January 10, 2018, 09:10:38 am
content: Hi,due to the superb linearity of the Fluke 5440B DAC it would be nice if it would be possible to force the Fluke 5440B in a user defined range. For example using the 275V Range to output 100V AND 10V for a 10V to 100V transfer. The same for 1000V and 100V in the 1100V range.Is there any hidden GPIB command I've missed or something else one could do without modifying the calibrator?ThxPhilipp

author: Echo88
author_rank: Frequent Contributor
timestamp: January 10, 2018, 01:10:08 pm
content: Maybe zlymex knows the answer, considering he had many of those 5440B. Time to lure him back to this forum.
NON Heated LTZ1000 characteristics  - Page 1
Forum section: electronics / general

author: vb
author_rank: Newbie
timestamp: January 05, 2018, 09:54:19 am
content: Hi,Sorry if this was asked before but I am unable to find it on the board.As part of my Masters requirements, I need a PTAT generator and I have access to an LTZ1000 chip as the Zener donor die.Did anybody has measured the following please:Characteristics V to I of the non heated LTZ1000?Noise vs current bias?Zener voltage dependancy vs temp?All these are above my current setup accuracy both in terms of temperature control and current or voltage generation/measuringThank you.......

author: tszaboo
author_rank: Super Contributor
timestamp: January 05, 2018, 10:28:23 am
content: The temperature control has attenuation of about 1mK/K ( AKA 0.001) so, without heating it has 1000 times bigger tempco. Other characteristic dont change really. It has like 5% initial accuracy, temp change is smaller than that.

author: CopperCone
author_rank: Super Contributor
timestamp: January 06, 2018, 02:14:34 am
content: I thought the 'materials properties' drift got worse when its hot (aging).Are you saying that the servo loop its in when heated keeps stability 1000 times better?I thought proper it was 'really' better cold, but the servo look makes it work better hot.It being more stable simply being at 70 degrees C ambient does not make sense to me.
2465B CTT calibration question - Page 1
Forum section: electronics / general

author: mmaseda
author_rank: Contributor
timestamp: January 01, 2018, 03:26:42 am
content: I need to run the CTT calibration routine to remove an error message but I don’t have pulse and time-mark generators. I have several function generators, signal generators, and 1MHz and 10 MHz TCXO. Can any of these be used to run the routine?

author: SoundTech-LG
author_rank: Frequent Contributor
timestamp: January 03, 2018, 09:22:14 pm
content: I really suggest you get the recommended equipment to run the cal. I tried using other equipment with very limited success. Once I got the right gear, it was pretty easy.

author: mmaseda
author_rank: Contributor
timestamp: January 04, 2018, 03:58:39 pm
content: Thanks to those that replied. I was able to perform the calibration by just using a 1MHz 1v peak to peak signal from a TXCO.

author: SoundTech-LG
author_rank: Frequent Contributor
timestamp: January 04, 2018, 09:56:15 pm
content: Making some sort of adjustment to get it to pass power on testing is certainly possible using a 10mHzTCXO output signal, performing a critical calibration is certainly another thing altogether. I doubt Tek would suggest the equipment listed unless there was a pretty good reason to not follow their suggestion. If it passes the power on test though, hey, maybe you got lucky.
DC VOLTAGE CURRENT STANDARD CALIBRATOR EDC CR-13R - Page 1
Forum section: electronics / general

author: msobreira27
author_rank: Contributor
timestamp: December 08, 2017, 03:35:41 am
content: Does anyone have the documentation or owns a DC VOLTAGE CURRENT STANDARD CALIBRATOR EDC CR-13R. I was thinking on acquiring one of that but I can't find any documentation, even on the obsolete list of Krohn-Hite. Is it a reliable standard?

author: Awesome14
author_rank: Regular Contributor
timestamp: December 09, 2017, 03:27:18 pm
content: I think you mean the CR-103Rhttp://exodus.poly.edu/~kurt/manuals/manuals/Other/EDC%20CR103%20Operating%20&%20Service.pdf

author: msobreira27
author_rank: Contributor
timestamp: December 29, 2017, 06:27:34 pm
content: Nope. I wish I had taken the one you refer to - plenty of documentation. But it may be the same circuitry minus the gauge. See the picture from an auction on ebay:
Temperature & Humidity Logger/VB Interface - Page 1
Forum section: electronics / general

author: daveyk
author_rank: Frequent Contributor
timestamp: January 09, 2018, 10:50:49 pm
content: Hello Everyone,Up until this point, I have been using a Veriteq Spectrum SP2000 Environmental Data Logger. I use their API to interface it to VB6 and actually to VBA in Microsoft Access. When I perform a Certification, I can have my Certification program/database, look up the average Temperature and Humidity during the time I was performing the calibration. In fact it takes each data point (every five minutes) and creates a nice chart on the back of the cert.Anyway, the SP2000 got left in a tool box in my jeep (rather than in my laptop case in the warm hotel room). It was real cold and that killed its lithium battery. I am pretty sure that you can not just change the battery as the calibration tables are backed-up by that battery. Well, it no longer communicate thanks to the dead battery. It talks just enough to give its ID (SN) and model but will not send any data, even current data. It will probably cost me close to $600 to send it back to Veriteq for repair and calibration. If I want a new one, last time I checked two years ago, they were over $1200. There is not an awful lot to them, but you pay for the technology and development.Is there and pre-made kits anyone it aware of that are easy to hook to a laptop via USB and to talk to with VBA or VB6 that would log temperature and humidity? I don't want to build one on my own, I just don't have the time. Software modification to talk to an get data from a new one would be fun as long as there is a relatively easy way to tie it in to VBA/VB6.I see there are a number of people using Ardrenoes to do similar things. I do not want o learn those things (I am just too busy for many reasons). I would pay for a premade programmed kit that could interface to a computer and that I could adapt my software for. I would have a little more control over it and more easily replace it when it fails. I guess it would be nice if I could get it certified (room temperature and not over a huge range.Perusing Amazon, I can find sensors and what not but I don't see information on APIs or other methods of interfacing them to VB.Hopefully someone here knows of one or a few.Thanks kindly

author: 2N3055
author_rank: Super Contributor
timestamp: January 09, 2018, 11:32:22 pm
content: You need to specify your performance targets... SP2000 seems to be very high performance and with traceable calibration... What you are suggesting as a replacement is neither of those...Does that mean that you would be satisfied with lesser specs and no formal calibration and traceability?Regards,Sinisa