Test Equipment Anonymous (TEA) group therapy thread

[med6753]

I did not expect this to show up today. Tracking this morning showed that it was still 100 miles away. This is the 465B "parts" unit I ordered. Yep, it powers up and it works. Oh it has some issues. Dirty pots and the trace has some "fuzz" on it which appears to be power supply noise....or most likely a bastard tant somewhere. And there's a sticker on it says that on certain timebase settings the trace is missing on delayed sweep. That's probably what got it surplussed and put out to pasture. But all in all is not in bad shape. Which is NOT what I really was hoping for. I was looking to cannibalize a not worth fixing unit for parts, especially the channel 2 attenuator if the 4X attenuator still on it's way from Greece doesn't fix mine. So now I have a dilemma. IF the 4x attenuator doesn't fix mine do I sacrifice this one for parts or fix it's minor issues and perhaps try to swap over the DM44 and parts mule mine? I haven't looked into how difficult it would be to swap over a DM44 so I would have to check that. Decisions, decisions. 

     

[Neomys Sapiens]

Aluminium wiring, whether copper clad or not is a disgusting thing except for very large conductors and being handled by experts. But there are other nasty types of wiring.
In a flat used as office years ago I found a particularely evil kind. It was totally brittle and tended to give you nasty shocks FROM TOUCHING THE MANTLE.
I discovered it's makeup when I pried apart a piece. It had two conductors of about 1mm² which were brittle in themselves. Isolation was by wound paper strip, which must have been impregnated with something that was long gone. The outer cover was a folded/crimped strip of tin foil, which explained the shocking tendencies.
Later, I was told by an older electrician that it was material used in the time after WWII, when there had a lot of rebuilding to be done fast and proper materials were not yet available. The conductor material was a steel/copper alloy, which was not really suitable for bending. The tin cover was hidden mostly under paint, so that one was not intially aware of it's conductive nature.
Then we found that one of the walls was electrified.
We could measure AC of 20..50V by poking two test probes into it about 1m apart even with a 20k /V meter. That was the day when we started to rewire.

[Cubdriver]

That's in beautiful shape - you can't kill it!!!

-Pat

[bd139]

Totally agree. Buy another parts mule lol

[Specmaster]

I agree with Pat, looks like you'll be looking for another parts mule real soon.

[tggzzz]

Aluminium wiring, whether copper clad or not is a disgusting thing except for very large conductors and being handled by experts. But there are other nasty types of wiring.
In a flat used as office years ago I found a particularely evil kind. It was totally brittle and tended to give you nasty shocks FROM TOUCHING THE MANTLE.
I discovered it's makeup when I pried apart a piece. It had two conductors of about 1mm² which were brittle in themselves. Isolation was by wound paper strip, which must have been impregnated with something that was long gone. The outer cover was a folded/crimped strip of tin foil, which explained the shocking tendencies.
Later, I was told by an older electrician that it was material used in the time after WWII, when there had a lot of rebuilding to be done fast and proper materials were not yet available. The conductor material was a steel/copper alloy, which was not really suitable for bending. The tin cover was hidden mostly under paint, so that one was not intially aware of it's conductive nature.
Then we found that one of the walls was electrified.
We could measure AC of 20..50V by poking two test probes into it about 1m apart even with a 20k /V meter. That was the day when we started to rewire.

Under my parent's floorboards I found two "surprising" examples of earlier mains wiring, neither connected.

The first was individual single-insulated wires laid in a wooden E-cross section.

The second looked like modern flat cable except it was two insulated conductors surrounded by a heavy outer layer which wasn't very flexible. On careful inspection, the junction boxes were made of metal. Inside them there were two terminals, but the boxes also made large-area low-pressure connections - to that heavy layer that was made of lead. Shudder, electrically and chemically.

About 5 years ago the local telco got around to replacing the under-street cabling. I asked them, and they cut off a foot of it as a souvenir. Internally there were (48?) pairs of enamel wires with waxed paper wrapped around each wire. The sheath around all those wires was (also) made of lead.

[Neomys Sapiens]

On the topic of parts mules: didn't someone announce that he wants to open a thread for that? Can't find it now.

[mnementh]

@med -

That scope is too young and too pretty to die!!!

Time to make you some twins... It's not like you can't use this one until a parts beast arrives for your DM44 unit. You have plenty of meters now!

mnem
Priorities, man!

[tautech]

About 5 years ago the local telco got around to replacing the under-street cabling. I asked them, and they cut off a foot of it as a souvenir. Internally there were (48?) pairs of enamel wires with waxed paper wrapped around each wire. The sheath around all those wires was (also) made of lead.

I'm sure I've seen the same cable here but closer to the city.
These days everything is grease filled excepting some 50 yr old plastic coated, PCV paired dry core still in service around here, It still has a paper wrap under the PVC outer to help spread any moisture ingress along the cable. 
Still got a couple of meters of 25 pair dry core cable that I scrounged off a telco tech to chop up and use as breadboard jumpers.
When the kids were still at school their electronic teachers looked kindly upon them bringing in lengths of dry core cable for use on the school breadboards.
Embarrassing though when one year on the school board of trustees having to hand over the top prize in Electronics to your own son. 

[Specmaster]

Following on from the Simpson 260 on Ebay I came across this Fluke 87 III, not shown working but shows it has a CD for Fluke digital thermometers with it, currently selling for £62

[bd139]

Following on from the Simpson 260 on Ebay I came across this Fluke 87 III, not shown working but shows it has a CD for Fluke digital thermometers with it, currently selling for £62

I think that was a "just chuck any old shit in with it" auction. My 87V came with some megger test lead parts as well so you never know what the deal is with some people 

Edit: that one looks pretty neat actually. I've got an 87 and an 87V. Do I need an 87 III too?  Actually no, I'm having that 34401A

[Specmaster]

Following on from the Simpson 260 on Ebay I came across this Fluke 87 III, not shown working but shows it has a CD for Fluke digital thermometers with it, currently selling for £62

I think that was a "just chuck any old shit in with it" auction. My 87V came with some megger test lead parts as well so you never know what the deal is with some people 

Edit: that one looks pretty neat actually. I've got an 87 and an 87V. Do I need an 87 III too?  Actually no, I'm having that 34401A

There's another that I'm watching but does not have the yellow bumper with but is shown powered and comes with some leads, not sure if they are genuine Fluke leads or not. I too want a 34401A but not stupid money because I don't really need or want to go down that voltnuttery rabbit hole, just that I do like the extra digits which for some strange reason are a lure to me, when in practise I don't look beyond the 3rd decimal point, after all I've managed all these years with purely either a 20k OPV analogue meter or 3.5 digit digital one and never had any problems whatsoever.

[worsthorse]

I did not expect this to show up today. Tracking this morning showed that it was still 100 miles away. This is the 465B "parts" unit I ordered. Yep, it powers up and it works. Oh it has some issues. Dirty pots and the trace has some "fuzz" on it which appears to be power supply noise....or most likely a bastard tant somewhere. And there's a sticker on it says that on certain timebase settings the trace is missing on delayed sweep. That's probably what got it surplussed and put out to pasture. But all in all is not in bad shape. Which is NOT what I really was hoping for. I was looking to cannibalize a not worth fixing unit for parts, especially the channel 2 attenuator if the 4X attenuator still on it's way from Greece doesn't fix mine. So now I have a dilemma. IF the 4x attenuator doesn't fix mine do I sacrifice this one for parts or fix it's minor issues and perhaps try to swap over the DM44 and parts mule mine? I haven't looked into how difficult it would be to swap over a DM44 so I would have to check that. Decisions, decisions.     

That looks to be in better shape than my 475 bench scope. Can't turn *that* into a parts mule! Nice find.

[tggzzz]

Still got a couple of meters of 25 pair dry core cable that I scrounged off a telco tech to chop up and use as breadboard jumpers.

Ha! Mine came/comes from the London Air Traffic Control Centre at West Drayton, circa 1972.

I still have several other items from that era, e.g. a Rocky Horror Show T-shirt (not Picture show), some fanfold lineprinter paper, and some electronic items.

[bd139]

There's another that I'm watching but does not have the yellow bumper with but is shown powered and comes with some leads, not sure if they are genuine Fluke leads or not. I too want a 34401A but not stupid money because I don't really need or want to go down that voltnuttery rabbit hole, just that I do like the extra digits which for some strange reason are a lure to me, when in practise I don't look beyond the 3rd decimal point, after all I've managed all these years with purely either a 20k OPV analogue meter or 3.5 digit digital one and never had any problems whatsoever.

Look like fluke leads. Pomona made ones identical to that and they were the Fluke OEM. I got some for my old 8021B.

I'm mainly after a 34401A because they have a serial port and decent well documented automation so I can poke around with them like I did with the U1241C:



Edit: got head inside VTVM now. However I ran out of sodding desolder braid again - getting through about £10 a month of that now 

[tautech]

Still got a couple of meters of 25 pair dry core cable that I scrounged off a telco tech to chop up and use as breadboard jumpers.

Ha! Mine came/comes from the London Air Traffic Control Centre at West Drayton, circa 1972.

Copper is a thing of the past in new developments here with fiber laid into sections now.
Just were we are a bit outside of the city is were the copper still is. We off it now with a 5 GHz link for data and phone but the now 50 year old cable is still in use that was mole ploughed in when I still was at primary school. 
Still remember it clearly with a vibrating mole plough on skids pulled with a D4 winch mounted into a 3 point linkage frame mounted on a Ford 5000 wheel tractor. They ploughed it down the road verges and when they needed to straight across metaled roads too !

Always thought is was a novel concept, that is a 3 point tractor mounted winch and ~20 years later built my own using a 10,000 lb rated Garwood from an ex-army 6x4 truck. 90 yds of 5/8" wire rope filled the spool but impacted on pull so I cut it back to 60yds and gained a slower retrieve and heaps more pull. 
Got us out of many predicaments over the years, the last major one when my youngest partly slid a 12t hired digger into one of our dams.   

[Neomys Sapiens]

Still got a couple of meters of 25 pair dry core cable that I scrounged off a telco tech to chop up and use as breadboard jumpers.

Ha! Mine came/comes from the London Air Traffic Control Centre at West Drayton, circa 1972.

Copper is a thing of the past in new developments here with fiber laid into sections now.
Just were we are a bit outside of the city is were the copper still is. We off it now with a 5 GHz link for data and phone but the now 50 year old cable is still in use that was mole ploughed in when I still was at primary school. 
Still remember it clearly with a vibrating mole plough on skids pulled with a D4 winch mounted into a 3 point linkage frame mounted on a Ford 5000 wheel tractor. They ploughed it down the road verges and when they needed to straight across metaled roads too !

Always thought is was a novel concept, that is a 3 point tractor mounted winch and ~20 years later built my own using a 10,000 lb rated Garwood from an ex-army 6x4 truck. 90 yds of 5/8" wire rope filled the spool but impacted on pull so I cut it back to 60yds and gained a slower retrieve and heaps more pull. 
Got us out of many predicaments over the years, the last major one when my youngest partly slid a 12t hired digger into one of our dams.   

What is a 'metaled road'?

[Neomys Sapiens]

AAAAHH! TEA has opened my eyes! 
Before, I would have thought those test leads to be sufficient!

(ok, I admit that there is a second wall, but I can't show it now because I have stuff from work hanging there)

[0culus]

See I can't store leads like that because I have two cats who LOVE dangly things...  bonus points for shiny on the end. 

[bd139]

We have a winner. Replaced three drifted resistors inside the VTVM and did cal and it's bang on!

This is 3V RMS at 1MHz. The thing is dead flat to 4MHz, even with crappy cable.

No probes yet so DC cal is not done thus it all might go to hell yet. Hopefully get the probe kit before the weekend.

Nesting on top of next victim:



Edit: considering a Heathkit tube scope next 

Edit 2: or perhaps an HP VTVM. Hmm

[0culus]

That thing looks practically new! Really cool.

[Neomys Sapiens]

These days everything is grease filled excepting some 50 yr old plastic coated, PCV paired dry core still in service around here, It still has a paper wrap under the PVC outer to help spread any moisture ingress along the cable. 

Eeewww - don't remind me of that grease-filled comms cable. It was directly after my school when I worked with a telco contractor at Stuttgart airport, which was undergoing a major extension. I had to splice that grease-filled cable to the interior one in the creepspace under the earthquake-resistant police building. Had to redo it three times. With a building on springs above me, everything reeked of that orange-based solvent and a headlamp.

[beanflying]

What is a 'metaled road'?

Perversely it means STONE (latin origin) and these days ashphalted

[Neomys Sapiens]

What is a 'metaled road'?

Perversely it means STONE (latin origin) and these days ashphalted

Never heard that expression before - I was thinking about those sheet metal things that are used by engineer troops.

[Specmaster]

@bd, that sure does look nice that meter and and its dead nuts on the AC. How did you manage to separate the DC socket from the chassis which you earthed? When I had mine I couldn't see a way around that problem, plus I wanted to make still have the same convenience factor as your 87V, i.e., 1 set of leads for both AC and DC without having to change leads or sockets. I was scared that if I did anything other than follow the same train of thought it might result in Kaboom. Not that I've ever managed to blow up a meter yet but there's a first time.