Test Equipment Anonymous (TEA) group therapy thread

[Neomys Sapiens]

I hate that PB free muck with a passion so much so my PB avatar was selected to display such. 

Most ROHS solders are pretty bad if you're used to and use them just like poison solder. The unleaded Balver Zinn that we did a group buy on in here is my new favourite. I alternate between it and a Multicore 60/40 roll for repair work. I have a more conventional ROHS roll from Stannol too, but I'm not very fond of it. Getting an iron suited to it made things a lot better, though.

Lead is bad for you, seriously so. Working to avoid it is worth some compromises.

I will think about that when I'm done machining this Beryllium and got that cadmium-plated connector out of my teeth.

[Cerebus]

Nice of you to say, but I suspect that I'm more notable for my pratfalls and encyclopaedic knowledge of perversions, fetishes and other paraphilias and tendency to spot the double entendre  potential for the latter in anything.

That's all very clever but when dealing with Neanderthals like me the true meaning, be it an insult or whatever, may not be realized until sometime later when the light bulb comes on or you may be dealing with a burnt out light bulb. Blunt force is always so much more effective and satisfying and it leaves no doubt that you've been kicked in the nuts.   

Yeah, but it's a little bit better than admitting flat out that I'm a dirty minded little fucker who knows way too much about the ways that perverts get their jollies. People might ask: "Why?".

Anyway, you're not a specimen of Homo neanderthalensis. Homo telotractus surely? 

The English art of insulting someone so that they don't immediately know that they've been insulted was invented to level the playing field between humanities' bad mouthed knuckle draggers and humanities' frail academics. The idea is that you can call one of the apes a motherfucker, but in such a way that you've get a head start on the running away before they realise that they've been insulted.

[Neomys Sapiens]

So how come I think the lamp made of auto parts is super cool yet a lamp made of an old and obsolete AVO meter is sacrilege? 

Rational explanation welcome because I don't have one. 

One is the destruction of a classic design, the other involves something with too many wheels and too few wings.

Now what exaxtly are you trying to say here?

[Robert763]

Anybody is looking for a good old 26GHz VNA for 450$ ? Shipping might be a bit expensive though

https://www.ebay.com/itm/284461294599



This is sad but I don't think I have the place for a giant like that.

NOoooo run away.....
Two big issues, no RF source (needs a 8341A) and that big slot on the top right side marked "Tape" 
About the only bit of any value is the S parameter test set and even that needs major mods to work with other analysers.
Then there all the cables, calibration and verification kits.
You can do much better for les total outlay unless you really need ultimate performance.

True about the source, this is a problem.

You can have it. I'm not interested anymore 

I don't want it. I tripled my collection a of HP VNAs on monday and they all have the correct leads. 

[mnementh]

      

I picked up this audiophool-grade S-video cable at the Thrift the other day because 25 ft/7.6m of nice slinky pliovic coax for ~US$4. Ends are good quality 4-pin mini-DIN; cable itself is 8mm OD with 2 shielded conductors and another shield wrap around them both. Looks like ~22-24ga center conductor, and typical consumer AF cable construction so  probably ~75Ω impedance.

So now just trying to decide WTF to use it for, as it's pretty much useless for its intended purpose. 

mnem

[Atomillo]

Hi!

This is my first post here, and it comes after many hours of drooling and such. Today I restored my first truly functional vintage piece of test equipment: a Keithley 246 High Voltage Supply.

With the wonderful help of this forum (thanks specially to Gyro, bdunham7 and floobydust!) I performed my first recapping of old electrolytics and turned on the unit, only to find out that nothing exploded, catched fire, smelled terribly or popped! Instead, everything seemed to work fine up to the 1kV I tested. I attach pictures of the patient.

At the moment I'm only going to power it up to 500V or so to examine the counting curve of various "low voltage" GM tubes, but in the future I will need up to 2kV for Photomultipliers as well as Proportional Counters. Anyone has any good idea about a source of 3 or 4kV coaxial cable? 

Of course for all I know at the moment, the unit might decide to spontaneuosly combust tomorrow, but after seeing the supply working I already felt the desire to plunge into eBay once again. Dear God, what has this forum done to my free time (and my wallet!)!?

[Neomys Sapiens]

Hi!

This is my first post here, and it comes after many hours of drooling and such. Today I restored my first truly functional vintage piece of test equipment: a Keithley 246 High Voltage Supply.
.
.
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Anyone has any good idea about a source of 3 or 4kV coaxial cable? 

https://www.hivolt.de/hochspannungskabel/

[xrunner]

Regarding the HP8347A: The thing is here and as we can see, it is exactly the same as pictured:

I won't be able to rest it until 2 weeks from now and will not look at the interior before that. But a manual supporting the existence of this version still needs to be found.

I guess I like a challenge, so I have continued to search for your model. I have not found a single picture of an hp 8347A like yours. I have gone through the manual with a fine-toothed comb and there is no mention of such an optional configuration. On the back of yours, a person wrote "K47" for the option (in other words a machine did not officially print that). The only option listed in the manual is "Option 910" which refers to additional manuals you can get. There are no other options listed.

As you can see, Fig. 5-6 shows how the hard line is assembled. It is not a flexible cable situation where it is easily routed to rear connectors. So the situation would require a set of those lines to be manufactured to get to the rear in an acceptable manner. The rear panel of yours is definitely a different panel. Even considering that the SMA connectors could be retrofitted in place of the existing BNCs, which pertain to detector out and ext. AM out, there is no hole at all where the RF blanking BNC would have been.

There you have it. I will be interested in the inside pics of yours when you get to it.

[Cubdriver]

Hi!

This is my first post here, and it comes after many hours of drooling and such. Today I restored my first truly functional vintage piece of test equipment: a Keithley 246 High Voltage Supply.

With the wonderful help of this forum (thanks specially to Gyro, bdunham7 and floobydust!) I performed my first recapping of old electrolytics and turned on the unit, only to find out that nothing exploded, catched fire, smelled terribly or popped! Instead, everything seemed to work fine up to the 1kV I tested. I attach pictures of the patient.

At the moment I'm only going to power it up to 500V or so to examine the counting curve of various "low voltage" GM tubes, but in the future I will need up to 2kV for Photomultipliers as well as Proportional Counters. Anyone has any good idea about a source of 3 or 4kV coaxial cable? 

Of course for all I know at the moment, the unit might decide to spontaneuosly combust tomorrow, but after seeing the supply working I already felt the desire to plunge into eBay once again. Dear God, what has this forum done to my free time (and my wallet!)!?

Welcome!  Come on in, the water's fine!   

RIP your bank account.

Congrats on your first restoration - addictive, isn't it?

-Pat

[mansaxel]

But if we did the same thing to a Yugo... now THAT would be art.

Goes for the Trabi too:



When they rigged them as lighting pods for the tour (they were suspended from the lighting rig on winches) the story is that there were serious problems with the shells melting from all the lights they'd bolted on and in them.

[Robert763]

Hi!

This is my first post here, and it comes after many hours of drooling and such. Today I restored my first truly functional vintage piece of test equipment: a Keithley 246 High Voltage Supply.

With the wonderful help of this forum (thanks specially to Gyro, bdunham7 and floobydust!) I performed my first recapping of old electrolytics and turned on the unit, only to find out that nothing exploded, catched fire, smelled terribly or popped! Instead, everything seemed to work fine up to the 1kV I tested. I attach pictures of the patient.

At the moment I'm only going to power it up to 500V or so to examine the counting curve of various "low voltage" GM tubes, but in the future I will need up to 2kV for Photomultipliers as well as Proportional Counters. Anyone has any good idea about a source of 3 or 4kV coaxial cable? 

Of course for all I know at the moment, the unit might decide to spontaneuosly combust tomorrow, but after seeing the supply working I already felt the desire to plunge into eBay once again. Dear God, what has this forum done to my free time (and my wallet!)!?

Welcome to the nut house 
I'm also a radiation nutter as well as test equipment. I scrapped a Gamma counter last friday and recovered 10 NaI(Tl) scintillation detectors from it.
RG58 or RG59 (75R) coax is fine at these voltages because we are using low energy / current sources. The biggest issue is connectors. A qualty pressure sleeve BNC, carefully assembled is good to 2 or 3 kV. MHV is better of course.

Edit Looks like your Keithley has an MHV. Do you have a matching plug?  A BNC can be forced on but can cause damage.

[Robert763]

Regarding the HP8347A: The thing is here and as we can see, it is exactly the same as pictured:

I won't be able to rest it until 2 weeks from now and will not look at the interior before that. But a manual supporting the existence of this version still needs to be found.

I guess I like a challenge, so I have continued to search for your model. I have not found a single picture of an hp 8347A like yours. I have gone through the manual with a fine-toothed comb and there is no mention of such an optional configuration. On the back of yours, a person wrote "K47" for the option (in other words a machine did not officially print that). The only option listed in the manual is "Option 910" which refers to additional manuals you can get. There are no other options listed.

As you can see, Fig. 5-6 shows how the hard line is assembled. It is not a flexible cable situation where it is easily routed to rear connectors. So the situation would require a set of those lines to be manufactured to get to the rear in an acceptable manner. The rear panel of yours is definitely a different panel. Even considering that the SMA connectors could be retrofitted in place of the existing BNCs, which pertain to detector out and ext. AM out, there is no hole at all where the RF blanking BNC would have been.

There you have it. I will be interested in the inside pics of yours when you get to it.

Probably a special to go into an ATE set-up.

[Atomillo]

The promise of getting useful equipment, gaining a great insight on how it works and all at a fraction of the price for new is quite addictive!
The gut wrenching feeling of not knowing if it works or not for certain might be not so much...

[mansaxel]

Just received a small envelope with two tubes of IC's, Beiling Shanghai BL3101 and BL3207, admitted clones of the Matsushita MN3101 and MN3207. They're, respectively, clock generators and bucket brigade delays for analog signals,  used together to create an analog delay, most often today with some clock LFO modulation causing  Doppler distortion effects known as "flanger" and "chorus" to the musicians. There is an abundance of borderline cargo cult level "knowledge" on these effects among the "circuit benders", but also in this flood of misunderstandings, cause/effect mixups, beliefs and folklore there can be found solid engineering tips. Currently sorting through all those sources trying to decide which circuit to start with.

This is a winter evening project with the Middle Boy.

Back in my studio days we got an Eventide Harmoniser stuffed full of BB delay lines. For the next three months it was the most overused bit of kit in the back rack until we and and all the producers that came in got tired of putting pitch shifts, flanging, delays and all the other things it could do onto almost every bloody rock or pop track that we mixed. Cost a small fortune.

Yes, the Eventide family is something of a holy Grail among the pitch/modulation instruments, together with the Roland rack mount chorus.  I'm slowly trying to fill my FX rack with old gear, one piece at a time. I've got a SPX-90, and a Roland digital delay, where the latter is presently used for chorus duty with Middle Boy and his guitar, patched in the FX loop of his amp. For being digital, it does not sound half bad.  Grails for me in the FX dept. would be Lexicon PCM-70 and tc electronic 2290, but I'll settle for tc M-One XL and D2.
I've got a bunch of Behringer Composer compressors, one of the first Behringers after the exciter. The exciter being an Aphex clone, and the Composer a dbx one. Early examples had Neutrik connectors and real dbx VCA's, and sound pretty much as the originals, just a bit cleaner. Mine are the generation after that, and sport Chinesium XLRen, and the print on the VCA is slightly more shady. Still sound quite nice, TBH. I'd really like to get hold of a larger mixing desk, so I can tell the people dragging in iPad-controlled digital mixers to put them away, but that's still a bit too hard to come by, at a decent price.

It's pretty much like old TE. You can get bargains on the stars of yesteryear, if you're out and about.

[Atomillo]

A Nal(Tl) crystal is no laughing matter. I've never used Photomultipliers (always tinkered with low energy gamma solid state and gas detectors) but I imagine that good enough light shielding will be a major problem.

I will try jellybean RG58. If it arcs, no biggie, the supply has a current limit and in the manual it proudly proclaims that it is short circuitable (new word!) without problems.

The BCN actually fits without forcing it but looking at the schematic you are right. This is quite the pain. I have a NIM HV supply I've wanted to use for some time but struggle to find a SHV cable (and I fear my dexterity isn't good enough to assemble the connector to a normal cable).

EDIT: I'm sorry  I wrote these replies from my phone. I though that clicking Reply to the message would automatically quote it but this is not the case. My bad!

[mnementh]

But if we did the same thing to a Yugo... now THAT would be art.

Goes for the Trabi too:



When they rigged them as lighting pods for the tour (they were suspended from the lighting rig on winches) the story is that there were serious problems with the shells melting from all the lights they'd bolted on and in them.

Heh... when that was going on, I was a punk kid trying to escape rural New York. I thought they were all nucking futs; and I just could not understand why the eff everybody around me was giving the Gipper credit for them tearing down the wall.

I didn't realize those things were produced until 1991. I thought they'd stopped in the 70s. 

mnem
This too will pass.

[Cubdriver]

A Nal(Tl) crystal is no laughing matter. I've never used Photomultipliers (always tinkered with low energy gamma solid state and gas detectors) but I imagine that good enough light shielding will be a major problem.

I will try jellybean RG58. If it arcs, no biggie, the supply has a current limit and in the manual it proudly proclaims that it is short circuitable (new word!) without problems.

The BCN actually fits without forcing it but looking at the schematic you are right. This is quite the pain. I have a NIM HV supply I've wanted to use for some time but struggle to find a SHV cable (and I fear my dexterity isn't good enough to assemble the connector to a normal cable).

EDIT: I'm sorry  I wrote these replies from my phone. I though that clicking Reply to the message would automatically quote it but this is not the case. My bad!

That bites me frequently, too - I hit 'reply' then have to cancel and go to quote.  No need for apologies - I give you credit for doing forum posts on a phone - doing them on the iPad is aggravating enough to me - much prefer typing on a real mechanical keyboard.

-Pat

[mansaxel]

The Fluke 27 kit has arrived. I have three words for the condition it's in: New. Old. Stock. Display film is still on, it was shipped with the battery removed, the manuals all are there, in pristine unopened condition, and the kit is basically complete, save for the TL75 lead set that was supposed to go with it.  But, the 40KV and 6KV probes are there, the Type 85 RF probe is there, with its BNC push-on adapter and the croc clips from the TL75 set were left in the Type 85 bag. The case is in as-new condition. The shipping carton even was the original Fluke one!

It's been out of the box a bunch of times, but that's because of its history: It's full of USMC calibration stickers and has not been opened since its last (perhaps first, it's so new it's got a IEC Cat. rating!) calibration, done 2009, and supposedly good until 2012. Nevertheless, it's still within spec for Ohms, the only thing I've checked so far. 

I'll try to get a bunch of pics up soon, but to sum impressions up: I got way more than I asked for, and it's impeccable to boot. 

At this point in time, I'm very happy that I didn't fall for the temptation to get a Merkava chock-bloc from the desert, but instead grab this one.  (But Cerebus posting that his one does smell of Tank was a bit more tempting in the provenience and provenance department.)

[Atomillo]

A Nal(Tl) crystal is no laughing matter. I've never used Photomultipliers (always tinkered with low energy gamma solid state and gas detectors) but I imagine that good enough light shielding will be a major problem.

I will try jellybean RG58. If it arcs, no biggie, the supply has a current limit and in the manual it proudly proclaims that it is short circuitable (new word!) without problems.

The BCN actually fits without forcing it but looking at the schematic you are right. This is quite the pain. I have a NIM HV supply I've wanted to use for some time but struggle to find a SHV cable (and I fear my dexterity isn't good enough to assemble the connector to a normal cable).

EDIT: I'm sorry  I wrote these replies from my phone. I though that clicking Reply to the message would automatically quote it but this is not the case. My bad!

That bites me frequently, too - I hit 'reply' then have to cancel and go to quote.  No need for apologies - I give you credit for doing forum posts on a phone - doing them on the iPad is aggravating enough to me - much prefer typing on a real mechanical keyboard.

-Pat

I was quite brace to try to write from the phone yes. I would say *too* brave!

[Neomys Sapiens]

Regarding the HP8347A: The thing is here and as we can see, it is exactly the same as pictured:

I won't be able to rest it until 2 weeks from now and will not look at the interior before that. But a manual supporting the existence of this version still needs to be found.

I guess I like a challenge, so I have continued to search for your model. I have not found a single picture of an hp 8347A like yours. I have gone through the manual with a fine-toothed comb and there is no mention of such an optional configuration. On the back of yours, a person wrote "K47" for the option (in other words a machine did not officially print that). The only option listed in the manual is "Option 910" which refers to additional manuals you can get. There are no other options listed.

As you can see, Fig. 5-6 shows how the hard line is assembled. It is not a flexible cable situation where it is easily routed to rear connectors. So the situation would require a set of those lines to be manufactured to get to the rear in an acceptable manner. The rear panel of yours is definitely a different panel. Even considering that the SMA connectors could be retrofitted in place of the existing BNCs, which pertain to detector out and ext. AM out, there is no hole at all where the RF blanking BNC would have been.

There you have it. I will be interested in the inside pics of yours when you get to it.

This is exactly what I found too.

[mnementh]

A Nal(Tl) crystal is no laughing matter. I've never used Photomultipliers (always tinkered with low energy gamma solid state and gas detectors) but I imagine that good enough light shielding will be a major problem.

I will try jellybean RG58. If it arcs, no biggie, the supply has a current limit and in the manual it proudly proclaims that it is short circuitable (new word!) without problems.

The BCN actually fits without forcing it but looking at the schematic you are right. This is quite the pain. I have a NIM HV supply I've wanted to use for some time but struggle to find a SHV cable (and I fear my dexterity isn't good enough to assemble the connector to a normal cable).

EDIT: I'm sorry  I wrote these replies from my phone. I though that clicking Reply to the message would automatically quote it but this is not the case. My bad!

That bites me frequently, too - I hit 'reply' then have to cancel and go to quote.  No need for apologies - I give you credit for doing forum posts on a phone - doing them on the iPad is aggravating enough to me - much prefer typing on a real mechanical keyboard.

-Pat

I was quite brace to try to write from the phone yes. I would say *too* brave!

Yeah, I positively loathe trying to post from my tablet... android versions of my favorite browsers are too damned helpful and drive me batshit crazy with having to unfuck what they guess wrong.

Welcome to the insane asylum! Your madness is just beginning; if you hang out here we'll soon develop it to a proper psychosis.

Help yourself to the neverending taco truck in the corner; I think there's some sausage, potato & egg left from breakfast.

The juddering corner is over there, and there's always someone willing to help you find a new rabbit hole, or to polish your current one. 

mnem
*toddles off to do something constructive*

[Wolfgang]

Anybody is looking for a good old 26GHz VNA for 450$ ? Shipping might be a bit expensive though

https://www.ebay.com/itm/284461294599



This is sad but I don't think I have the place for a giant like that.

NOoooo run away.....
Two big issues, no RF source (needs a 8341A) and that big slot on the top right side marked "Tape" 
About the only bit of any value is the S parameter test set and even that needs major mods to work with other analysers.
Then there all the cables, calibration and verification kits.
You can do much better for les total outlay unless you really need ultimate performance.

True about the source, this is a problem.

You can have it. I'm not interested anymore 

I don't want it. I tripled my collection a of HP VNAs on monday and they all have the correct leads. 

This thing is only for people with nostalgia AND hernia. 

[bd139]

Page 125 has lots of interesting info for time nuts. Covers the Apollo mission time and frequency standards:

https://www.hq.nasa.gov/alsj/NASA-SP-87.pdf

Actually the whole thing is interesting.

As for tablets I’m posting this from my phone in the bath. Good reading time

[capt bullshot]

More fun with TEA time ...

A slightly different setup, but similar to that:

This is the setup: The TA520 Time Interval Analyzer, the dual channel Tek AWG, a scope, a thermometer, a roll of RG174, a splitter and a dual mixer time difference contraption



The DMTD contraption:



So, fire it all up and wait for the measurement to settle. The TA520 shows a nice horizontal line (time difference between the mixer outputs at 100Hz offset frequency). So 100ns equals 1ps in real.
Doing the numbers from the readout, the DMTD contraption has 1.1ps peak-to-peak / 0.16ps rms noise floor.

Same scope, time interval analyzer and AWG, but different DMTD contraption:



Using XOR gates instead of real mixers. In theory the XOR gates act just like mixers would do with square wave input. The XOR gate plus IF filter / amplifier / comparator circuit was build onto some real estate on my older frequency difference measurement experiment. The STM nucleo module isn't used here, it's a very simple circuit as shown in the detail photo.




Result isn't as good as the one with the real mixers, about 2.86ps peak-to-peak noise floor over 30 seconds, and it's quite sensitive to ambient temperature. That's why the "high quality" thermal shield was used



Here's the jitter visible on a scope, set to 5s persistence:

[Saskia]

short update:
Hubby will need another angioscopy. He has decided going for lowcarb/keto after seeing the available data.

This is an excellent presentation on that particular topic:
https://youtu.be/KlHPmJTihBc

The insulin sensor: the proposal has been submitted and I need to keep quiet about it now due to corporate guidelines. @AaronLee sorry, no longer allowed to say anything about the progress, I have to adhere to our guidelines due to compliance regulations.

My personal calorie burn: managed to increase from about 17000/week in July to >22000 last week, this week looking good so far. Need to further throttle my energy intake, would like to see at least 1 kg, better 2 kg/week in weight loss. Further optimizing the diet and trying to reduce stress. Currently walking between 50 and 70 km/week, slowly but steadily increasing distance and duration to about 3 - 4 hours/day. Will readjust my total weight loss target again once I reach 75% of my current objective which is 50 kg.