Test Equipment Anonymous (TEA) group therapy thread

[Brumby]

A very complete one for the AVO nuts out there too. eBay auction: #233944670135 $15 AUD post to me and on shipping at cost ENABLING available to non locals

 

This is starting to lose its appeal - even with no shipping and a cupful of fuel.

Four days to go and we have two bidders bouncing back and forth a couple of times.  Bound to be more bouncing ... and then there's the sniper unknown.


Anyone want to take a punt at the final price?

$134.50 Aussie pesos.  Way more than I would have thrown at it.

[McBryce]

Ah....  We're back!

That was a long few days.

Unfortunately, SWMBO noticed my lack of focus and I fell into a strange world activity which I had not experienced for such an extended period of time.  Damn I got a lot of stuff done around the house!

I fear this may have repercussions....

Luckily I foresaw that situation happening and decided to stare at a different Forum with the same style so that SWMBO wouldn't notice any difference. 

McBryce.

[beanflying]

A very complete one for the AVO nuts out there too. eBay auction: #233944670135 $15 AUD post to me and on shipping at cost ENABLING available to non locals

 

This is starting to lose its appeal - even with no shipping and a cupful of fuel.

Four days to go and we have two bidders bouncing back and forth a couple of times.  Bound to be more bouncing ... and then there's the sniper unknown.


Anyone want to take a punt at the final price?

$134.50 Aussie pesos.  Way more than I would have thrown at it.

Not that you NEED another scope    eBay auction: #154405003584

For a collector price is a bit secondary. Some of my Manual Brewing Coffee collection was way to many $ for function but I just had to have the item 

I sold one of the two in front for $150. Makes one single cup at a time but more than a bit rare. Way better Coffee makers out there for way way less.

[Robert763]

Talking of OXCO's I've been putting one of my HP 10811Ds into a case and fired it up for the first time on Tuesday. Frequency was fine with No EFC and the mechanical trimmer untouched since it was removed ftom a 8922 cell test set abou 4 years ago and has been in a storae container for at least a couple of years the error to GPS was 0.052Hz.
Overall I'm pretty pleased. I made one difficult decision to use a DC-DC converter so it can run off mains or 9-18V DC. I'm seeing a little bit of nise from the DC-DC on the output. It goes up with the oven current and appears to be short bursts of noise. It's good enough as a frequency reference but not to multiply up to microwavs frequencies. I'll have to do a bit of work and see if I can knock it down a bit further.

[Kosmic]

What was I saying about using "the cloud" for everthing last week....

The cloud would have survived this. This would have been an "availability zone failure" which is easy to architect around. In fact I spent a week about 2 weeks ago actually just pulling plugs metaphorically speaking with no side effects at this level.

What happened here is "lowest bidding hoster had a massive shit show" not "the cloud".

And just remember that the guys running the "lowest bidding hoster" know more than the average person.

Your stuff is safer in the cloud. If you do it properly.

And the data security argument is void. What you post on a public forum is public. What you post in a private S3 bucket in AWS is not.

Edit: I notice the forum is running like shit now as well. Another problem easily resolved by upping the instance size transparently rather than buying another physical machine 

Yep, something happen because they don't use modern tools.

With just an automated deployment process they would have been up and running in another datacenter in 1 hours.

[Kosmic]

Ah, ok. I've (the company I worked for) already had massive problems that cost millions due to lost cloud data.

I've read about 50 case studies where that happens and it's always someone doing something stupid, a low ball provider, or PaaS, or Atlassian 

IaaS cloud = win.

I second that. IaaS == you are free to move elsewhere and change provider.

[Cerebus]

Talking of OXCO's I've been putting one of my HP 10811Ds into a case and fired it up for the first time on Tuesday. Frequency was fine with No EFC and the mechanical trimmer untouched since it was removed ftom a 8922 cell test set abou 4 years ago and has been in a storae container for at least a couple of years the error to GPS was 0.052Hz.
Overall I'm pretty pleased. I made one difficult decision to use a DC-DC converter so it can run off mains or 9-18V DC. I'm seeing a little bit of nise from the DC-DC on the output. It goes up with the oven current and appears to be short bursts of noise. It's good enough as a frequency reference but not to multiply up to microwavs frequencies. I'll have to do a bit of work and see if I can knock it down a bit further.

Aye, there's the rub. Now I'm mucking about with building frequency standards I'm beginning to feel I need an SA.

Woe is me, it just looks like I'll have to start looking for one. 

[mnementh]

Just as when the microwave oven craps out and makes you acutely and painfully aware of how you rely on it, you don't realize how frequently you pop in here to take a quick look until popping in here no longer works.  Good to see that the forum has returned - that was a long couple of days.

-Pat

I blame Vince... 

mnem
"...mistakes were made; others will be blamed..."

[BU508A]

Talking of OXCO's I've been putting one of my HP 10811Ds into a case and fired it up for the first time on Tuesday. Frequency was fine with No EFC and the mechanical trimmer untouched since it was removed ftom a 8922 cell test set abou 4 years ago and has been in a storae container for at least a couple of years the error to GPS was 0.052Hz.
Overall I'm pretty pleased. I made one difficult decision to use a DC-DC converter so it can run off mains or 9-18V DC. I'm seeing a little bit of nise from the DC-DC on the output. It goes up with the oven current and appears to be short bursts of noise. It's good enough as a frequency reference but not to multiply up to microwavs frequencies. I'll have to do a bit of work and see if I can knock it down a bit further.

Aye, there's the rub. Now I'm mucking about with building frequency standards I'm beginning to feel I need an SA.

Woe is me, it just looks like I'll have to start looking for one. 

Tautech could help you out with some recommendations, I think.

[tggzzz]

Talking of OXCO's I've been putting one of my HP 10811Ds into a case and fired it up for the first time on Tuesday. Frequency was fine with No EFC and the mechanical trimmer untouched since it was removed ftom a 8922 cell test set abou 4 years ago and has been in a storae container for at least a couple of years the error to GPS was 0.052Hz.
Overall I'm pretty pleased. I made one difficult decision to use a DC-DC converter so it can run off mains or 9-18V DC. I'm seeing a little bit of nise from the DC-DC on the output. It goes up with the oven current and appears to be short bursts of noise.

I went overboard with mine: capacitance multiplier, 723 regulator (since the diode is low noise), and ferrites/caps. I may be able to provide a screenshot later

[tautech]

Talking of OXCO's I've been putting one of my HP 10811Ds into a case and fired it up for the first time on Tuesday. Frequency was fine with No EFC and the mechanical trimmer untouched since it was removed ftom a 8922 cell test set abou 4 years ago and has been in a storae container for at least a couple of years the error to GPS was 0.052Hz.
Overall I'm pretty pleased. I made one difficult decision to use a DC-DC converter so it can run off mains or 9-18V DC. I'm seeing a little bit of nise from the DC-DC on the output. It goes up with the oven current and appears to be short bursts of noise. It's good enough as a frequency reference but not to multiply up to microwavs frequencies. I'll have to do a bit of work and see if I can knock it down a bit further.

Aye, there's the rub. Now I'm mucking about with building frequency standards I'm beginning to feel I need an SA.

Woe is me, it just looks like I'll have to start looking for one. 

Ask this brother what he thinks of his new one:
https://www.eevblog.com/forum/testgear/test-equipment-anonymous-(tea)-group-therapy-thread/msg3467528/#msg3467528

[bd139]

More OCXO fun! Stuck on a mandatory conference call for 2 hours resulted in some soldering...





Works. EFC gives 0-4V range as per datasheet. 230mA idle current.

I shall install it in the 5384A later. That will require some rework I think as per the service manual to remove the existing crystal oscillator.

[Cerebus]

The black soldermask looks OK. How about a shot with grazing light (i.e. trying to catch a reflection of the light source in the soldermask) so's we can all get a proper feel for it? Pretty please?

[mnementh]

Definitely worked out better than doing spreadsheets. 

You can see your neighbors; they're too fucking close. 

mnem
current mood: dickwise

I suppose Canadians aren't used being able to see their neighbours, even if they and their neighbours are standing on the roof of their houses.   McBryce.

P.s. AND STOP MAKING ME WANT TO BUY A CASIO EDIFICE!!

LOL... I've been this way since long before I ran away to Canuckistan... I inherited that attitude from my grandparents. 

mnem

Eevblog down... nothing to repair... Yeah, I went and bought a Casio Edifice.     McBryce.

Nice timepiece. I especially like how the left edge of the dial does that LCD count-up then count-down for the seconds. Also, how the buttons are shrouded just enough to prevent accidental mode changes.  Right now, I'm rockin' a '90s vintage Columbia CL-3005; just did the rubbed oil thing on the band and it came up very nice. It might be the best $9 watch I've ever bought.

If it's any consolation... when eevBlog went down, I took the boi for a walk to the park and shot hoops with him for 3 hours... *ouchies*



Then the next day, I spent $500 Canadian pesos on a new fatbike, which I am currently modding the handlebars so I can ride it without being hunched over like a Morlock. More moneys. 

mnem
 

[bd139]

The black soldermask looks OK. How about a shot with grazing light (i.e. trying to catch a reflection of the light source in the soldermask) so's we can all get a proper feel for it? Pretty please?

It's pretty nice so far. Excuse my crappy board cleaning 

[Cerebus]

Cool. Thanks.

[mnementh]

Is this enough fine control of wattage...? They make these for putting lots of cheap LED floodlights in the garage; I've used one with appliance bulbs to fine-adjust max current on my dim-bulb tester. Costs $10-15 on Amazon: https://www.amazon.com/s?k=bulb+splitter+7+in+1

Interesting ! 

However no it still does not cut it. It makes it more practical to adapt the wattage to the DUT, but still is an on/off safety device. I was talking about fine control as far as ramping up the voltage slowly. A dim bulb tester is no help for this, no matter how fancy one makes it.

Yeah, I'd still want one of these inline with a variac, myself. A lot of the time you'll find that once things start turning on in a SMPS, especially the older designs, that's when a short appears. The scariac doesn't stop the magic smoke from coming out then, but rather encourages the switcher transistor to try and sink more current to make up for the lower voltage.

mnem
 

I don't think I'd try to soft start an SMPS with a variac; an SMPS is a constant power device, it'll just draw more current at lower voltages...

Once it's up and running, yes. But most of the inrush current at start-up is charging the DC rail capacitor(s), that is going to be voltage dependant (a simple lumped component model would be an RC circuit and some diodes). Somewhere there's a crossover point where the steady state current exceeds the inrush current.

It's all theoretical though, because for most off-line SMPS the minimum voltage that it will start up at is going to be pretty close to the rated minimum input voltage. If you've got an off-line SMPS rated for 90-265 V rms input the wiggle room at the bottom end is going to be pretty small because at some point you'll hit the duty cycle limit of the buck regulator - despite the usage of every bloody sports commentator and every overblown drill sergeant in the world, you can't "give it 200%".

Yeah, particularly the older more primitive ones for sure. But on the old RCAs with the "chopper" PSU, and pretty much all that followed where the HOT was the main regulator for the entire power supply... the only reliable way to bring them up safely without just replacing parts until it stopped popping HOTs was just this: A variac feeding a dim-bulb tester feeding a isoformer. 

Pretty much every TV shop I worked at had such a setup back in the day... tho many did go commando & omit the isoformer.

mnem
 

[Specmaster]

And the data security argument is void. What you post on a public forum is public. What you post in a private S3 bucket in AWS is not.

Unless you you leave your S3 bucket credentials on Github. 

You've probably done something wrong if that matters ...

1. Your access credentials shouldn't survive long enough for that to be an issue (temporary creds always)
2. IAM role should have a trust policy saying where you can access the bucket from (least priv)
3. Your account shouldn't have the ability to do that anyway or make the bucket public (least priv)
4. Require MFA for console access so if you lose your login, meh (mfa)
5. Actually look at the complaining Trusted Advisor does (audit/analyse)

If you skipped all that then it's your own fecking fault 

Until that is someone hacks it, I really doubt that there is anything out there that is not hackable. I have a Samsung tablet that has a micro SD cardholder that is accessible without having to open it up and so it is perfectly feasible to keep all personal data or sensitive / important data on a card and remove it when access is not required. The same with my desktop PC, it has 2 hot-swappable drive bays, 3.5 and 2.5 inch that I can store all real personal info on and then remove the drives and store them. Nobody can hack into that data when it's not in the PC. I also have the option of using security locked USB flash drives on the tablet and PC for even further security. Info locked away in the cloud is accessible to would be hackers 24/7.

[mnementh]

What was I saying about using "the cloud" for everthing last week....

The cloud would have survived this. This would have been an "availability zone failure" which is easy to architect around. In fact I spent a week about 2 weeks ago actually just pulling plugs metaphorically speaking with no side effects at this level.   What happened here is "lowest bidding hoster had a massive shit show" not "the cloud".  And just remember that the guys running the "lowest bidding hoster" know more than the average person.

Your stuff is safer in the cloud. If you do it properly. And the data security argument is void. What you post on a public forum is public. What you post in a private S3 bucket in AWS is not.

Edit: I notice the forum is running like shit now as well. Another problem easily resolved by upping the instance size transparently rather than buying another physical machine 

I've been the rented monkey in the DC the day after such a catastrophe. The first few hours onsite was spent with the bridge in my ear locating and turning off specific devices that didn't have full connectivity to stop the packetstorm of constant pings and unresolved requests, just so the admins could get some fucking work done. That partially live DC was its own DDOS attack on the remaining live hardware.

Not saying that's the case here and now, just passing on that experience in hopes it puts some of this in context.

mnem
 

[Robert763]

Talking of OXCO's I've been putting one of my HP 10811Ds into a case and fired it up for the first time on Tuesday. Frequency was fine with No EFC and the mechanical trimmer untouched since it was removed ftom a 8922 cell test set abou 4 years ago and has been in a storae container for at least a couple of years the error to GPS was 0.052Hz.
Overall I'm pretty pleased. I made one difficult decision to use a DC-DC converter so it can run off mains or 9-18V DC. I'm seeing a little bit of nise from the DC-DC on the output. It goes up with the oven current and appears to be short bursts of noise. It's good enough as a frequency reference but not to multiply up to microwavs frequencies. I'll have to do a bit of work and see if I can knock it down a bit further.

Aye, there's the rub. Now I'm mucking about with building frequency standards I'm beginning to feel I need an SA.

Woe is me, it just looks like I'll have to start looking for one. 

I have a Marconi TF2370 available to a good home. Only 110MHz but digital storage and 5Hz resolution bandwidth make it better than a lot o SAs for looking at close in noise.

[Brumby]

Not that you NEED another scope    eBay auction: #154405003584

Already have one 1740A.  Do I need two?

Can I do stereoscopic traces??

[mnementh]

Now, what was I saying before I was interrupted by someone sneeking off behind the generator shack for a quick fag? Oh yes, OCXOs.

So, my batch from what turned into a distributed group purchase took 9 days door to door. Ordered two and like BD, got twice as many for my money.

Desoldering turned out to be relatively easy for a part on a 10 layer board - just desoldered each pin with Chem-Wik (that stuff's good) and went around the board with a small screwdriver for a lever and gave each pin a lift while heating it with the old Metcal. No application of 60/40, chip-qwik or anything similar needed. All four survived the ordeal of having the board next to them violently cut and being desoldered.

Here's how they all performed:   

Sorry for the laziness of a screenshot, but converting to SMF's table notation is too much of a fag. Readings taken with my TTi TF930 that was last adjusted against GPS a year ago. All with enough range left to be steerable to 10.000 000 00 MHz at an appropriate EFC voltage with room to spare for future ageing (i.e. GPSDO fodder). None good enough to be used "out of the box" as a 10 MHz reference without trimming, unless you were more interested in stability than accuracy. I tried a few random selections for stability, using another known good uncalibrated 10 MHz OCXO as reference input to the TF930, and they stayed stable at the limit of the counter's resolution (10 mHz or 1 ppb) for as long as I was prepared to wait - several hours in one case.

Conclusion: £13.90 well spent.

Mine are still on the way; I too had a "Me three!!!" moment. As Canoodlian Post is the last mile carrier, we typically only get actual deliveries 2-3 times a week, so no idea when I'll actually see them.

mnem
 

[Robert763]

Talking of OXCO's I've been putting one of my HP 10811Ds into a case and fired it up for the first time on Tuesday. Frequency was fine with No EFC and the mechanical trimmer untouched since it was removed ftom a 8922 cell test set abou 4 years ago and has been in a storae container for at least a couple of years the error to GPS was 0.052Hz.
Overall I'm pretty pleased. I made one difficult decision to use a DC-DC converter so it can run off mains or 9-18V DC. I'm seeing a little bit of nise from the DC-DC on the output. It goes up with the oven current and appears to be short bursts of noise.

I went overboard with mine: capacitance multiplier, 723 regulator (since the diode is low noise), and ferrites/caps. I may be able to provide a screenshot later

 Thought I'd done a reasonable job with post converter filtering and 12V requlator (MC7812CT NOS actually very low noise and specified at 15V input) for the oscillator. Problem is the noise is very low level on the 'scope so hard to track down the exact entry point. It might be common mode or coupling through the heater.
Plan is to break ot the OXCO supplies and run them through an external clean source with the DC-DC on a resistive load Make sure that is clean, then start connecting things up to see how it is getting in.
Plan B is to use the mains supply and have an external dedicated battery DC supply for portable use. I don't like being beaten by noie though.

[mnementh]

Ah....  We're back! That was a long few days. Unfortunately, SWMBO noticed my lack of focus and I fell into a strange world activity which I had not experienced for such an extended period of time. 

Damn I got a lot of stuff done around the house! I fear this may have repercussions....

I know... strange darkening of the skin from direct exposure to the sun, increased lung capacity from exposure to outdoor air, a unfamiliar urge to actually go places and *gasp* interact socially... 

Oh, wait... here comes the Wave 3 COVID lockdown... 

Woops... gotta go do something now, even if it's wrong. I've used up my allotment of surf potato time.

mnem
 

[McBryce]

Ah, ok. I've (the company I worked for) already had massive problems that cost millions due to lost cloud data.

I've read about 50 case studies where that happens and it's always someone doing something stupid, a low ball provider, or PaaS, or Atlassian 

IaaS cloud = win.

I second that. IaaS == you are free to move elsewhere and change provider.

Nope, in our case it was the fact that some of our data was on the same physical medium as data that was involved in a serious crime and the drive was seized as evidence. They told us we could access that data again in 24 months when the drive was returned. 
There was a backup, but it was 24 hours old which is a lifetime for the particular data involved.

McBryce.