Test Equipment Anonymous

dl6lr wrote: ↑Wed Oct 11, 2023 7:06 pm

AVGresponding wrote: ↑Wed Oct 11, 2023 6:06 pm R223 has to be an NTC/MOV, given its placement.

Is Discord down for anyone else?

Hmm, I don't think R223 is a NTC either. Both have the same symbol with +Theta, I would expect -Theta for an NTC. And if its an NTC/MOV, the traces to it will explode with powerful +250Vrms fed into it.

Either way, with a 40kΩ input resistor there's going to be less than 1mA through it, and I'd expect the feedback network to be able to absorb excess voltage at those power levels.

AVGresponding wrote: ↑Fri Oct 13, 2023 10:42 am Either way, with a 40kΩ input resistor there's going to be less than 1mA through it, and I'd expect the feedback network to be able to absorb excess voltage at those power levels.

Hmm, the feedback loop is directly coupled to the input, the 40k is "only" in front of the op amp.
In range 20mA the feedback path is from the mA input thru 50R (R214||R215) K201 and R221 to the limiting Zeners V257/V258.
V207/V208 protect the op amp input with their BE voltage drop, the base current is limited with the 40k R209.
V209/V210 will protect the ADC input from high voltages that can occur from the input thru all the resistors (with K201/K202 closed, the effective resistance from the input is the 51k R222 with 5k in front).

Some pics of the Fluke 8060A from my recent job-lot score. I'll add pics of the other items as I investigate them. If people complain enough, I'll hive them all off to a separate thread...
The case is a bit yellowed, there's a tiny chip out of the left top corner of the top case, and a tiny crack (presaging a chip) in the top right. It has the expected sticker residues as befits TE of this age, but has an unexpectedly present battery door. The small dark grey part is from a range button, residue of a past repair as the current ones are undamaged.

The case interiors hold no hint of horrors

The PCB assembly appears reasonably good at first glance
A closer look reveals a bit of corrosion and probable bad solder joints
The fuses both test good, but the display is not so good

Part two, as we're limited to 10 attachments per post...
The display works, if you press it down, so I guess the zebra strip is toast. Worse news is that the readings are wrong. It does change ranges, but gives garbage readings on all of them, that I checked anyway. May just need a damn good clean and dose of De-oxit, hopefully.

EDIT: Just to mention some trivia; it's a pre-RMS daughter board version, the PP3 battery snap was competely corroded off, and someone (on here) already has first refusal.

https://www.ebay.co.uk/itm/256253701590
Fluke 8022B for £14, 200ohms doesn't work.

tggzzz wrote: ↑Fri Oct 13, 2023 3:54 pm https://www.ebay.co.uk/itm/256253701590
Fluke 8022B for £14, 200ohms doesn't work.

Display on the way out too.

AVGresponding wrote: ↑Fri Oct 13, 2023 3:33 pm Some pics of the Fluke 8060A from my recent job-lot score. I'll add pics of the other items as I investigate them. If people complain enough, I'll hive them all off to a separate thread...

Everything about these old meters here from their designer:
https://www.eevblog.com/forum/testgear/ ... ltimeters/

AVGresponding wrote: ↑Fri Oct 13, 2023 3:36 pm Part two, as we're limited to 10 attachments per post...

20231012_180457.jpg20231012_180412.jpg

The display works, if you press it down, so I guess the zebra strip is toast. Worse news is that the readings are wrong. It does change ranges, but gives garbage readings on all of them, that I checked anyway. May just need a damn good clean and dose of De-oxit, hopefully.

EDIT: Just to mention some trivia; it's a pre-RMS daughter board version, the PP3 battery snap was competely corroded off, and someone (on here) already has first refusal.

I refused 8060As years ago.

I just can't stand the silly buttons on the side, one or more always ended up coming off.
When Fluke came up with the 77, with the knob which could be turned with the same hand holding the DMM, the justification for the buttons disappeared.

When I worked in Commercial TV, we had an 8060A at the transmitter site, which wouldn't have been all that old at the time, ----inevitably, it had one button missing.
I seldom used it, usually just bringing my 77 with me!

vk6zgo wrote: ↑Fri Oct 13, 2023 11:24 pm
I refused 8060As years ago.

I just can't stand the silly buttons on the side, one or more always ended up coming off.
When Fluke came up with the 77, with the knob which could be turned with the same hand holding the DMM, the justification for the buttons disappeared.

When I worked in Commercial TV, we had an 8060A at the transmitter site, which wouldn't have been all that old at the time, ----inevitably, it had one button missing.
I seldom used it, usually just bringing my 77 with me!

My infatuation with the 80xx series of handhelds comes from two directions;

• They were the latest and greatest when I was about 17, and boy did I want one over the lethal pocket VOM that were reachable!
• On the 8060a specifically, I have found the audio slant on it to be particularly nice, what with measuring correctly over the entire AF range, and a dBm range at that.
• Bonus points given for lighting fast continuity and ready access to the enthusiastic designer of the meter.

I'm aiming for one (who am I kidding, I mean two) meter each to all my children, the 8060A for electronics use, and something sturdier, perhaps a Fluke 10 or similar for mains work. (Regs here say you must have a meter that indicates above SELV voltages even without batteries, for mains absence testing, so I'll probably have to pop in a third one too, like a Duspol or so. )

The dodgy display on the 8060A is almost certainly a issue with the zebra strip. There ate two types used and the later one was often retrofitted to early meters. In any case it can almost always be cured by cleaning the strip. LCD contacts and PCB.
Use a lint free claoth moistened, not wet, with 99% IPA. Wipe the zebra strip, LCD fingers and PCB pads in that order. Do not wet the strip or LCD with IPA it can affect adhesive on LCD (and old style zebra strip) and rubber in strip.
For the bad readings the first thing is to do is check the electrolytic capacitors and clean the PCB with IPA.

vk6zgo wrote: ↑Fri Oct 13, 2023 11:24 pm

AVGresponding wrote: ↑Fri Oct 13, 2023 3:36 pm Part two, as we're limited to 10 attachments per post...

20231012_180457.jpg20231012_180412.jpg

The display works, if you press it down, so I guess the zebra strip is toast. Worse news is that the readings are wrong. It does change ranges, but gives garbage readings on all of them, that I checked anyway. May just need a damn good clean and dose of De-oxit, hopefully.

EDIT: Just to mention some trivia; it's a pre-RMS daughter board version, the PP3 battery snap was competely corroded off, and someone (on here) already has first refusal.

I refused 8060As years ago.

I just can't stand the silly buttons on the side, one or more always ended up coming off.
When Fluke came up with the 77, with the knob which could be turned with the same hand holding the DMM, the justification for the buttons disappeared.

When I worked in Commercial TV, we had an 8060A at the transmitter site, which wouldn't have been all that old at the time, ----inevitably, it had one button missing.
I seldom used it, usually just bringing my 77 with me!

Comparing a 8060A to a 77 is not a fair comparison. The 8060A is 41/2 digit True RMS and high accuracy. The 77 is 33/4 digit, average rsponding and lower accuracy.
The only "advantage" of the 77 is autoranging and that is subjective. The 8060A has additional features like wide bandwidth, dB, fast continuity, frequency.
The buttons on the side of the 8060A (andother 80xx handhelds) allow single handed operation. The 77 needs two hands. OK you don't have to change range on the 77.
Loosing buttons is actually rare unless the meter has been abused.

Robert.

MED6753 wrote: ↑Mon Oct 09, 2023 11:45 am Latest project? Might be. Thinking it over. It's a 150 mile (240km) round trip.

https://newjersey.craigslist.org/ele/d/ ... 65817.html

Decision made. Picking it up later today. Stay tuned for pictures.

MED6753 wrote: ↑Sun Oct 15, 2023 10:55 am Decision made. Picking it up later today. Stay tuned for pictures.

That content is, according to Shannon, information free. After all, it contains zero unpredictable "surprises".

mansaxel wrote: ↑Sat Oct 14, 2023 8:08 am

vk6zgo wrote: ↑Fri Oct 13, 2023 11:24 pm
I refused 8060As years ago.

I just can't stand the silly buttons on the side, one or more always ended up coming off.
When Fluke came up with the 77, with the knob which could be turned with the same hand holding the DMM, the justification for the buttons disappeared.

When I worked in Commercial TV, we had an 8060A at the transmitter site, which wouldn't have been all that old at the time, ----inevitably, it had one button missing.
I seldom used it, usually just bringing my 77 with me!

My infatuation with the 80xx series of handhelds comes from two directions;

• They were the latest and greatest when I was about 17, and boy did I want one over the lethal pocket VOM that were reachable!
• On the 8060a specifically, I have found the audio slant on it to be particularly nice, what with measuring correctly over the entire AF range, and a dBm range at that.
• Bonus points given for lighting fast continuity and ready access to the enthusiastic designer of the meter.

I'm aiming for one (who am I kidding, I mean two) meter each to all my children, the 8060A for electronics use, and something sturdier, perhaps a Fluke 10 or similar for mains work. (Regs here say you must have a meter that indicates above SELV voltages even without batteries, for mains absence testing, so I'll probably have to pop in a third one too, like a Duspol or so. )

Interestingly, my understanding is that they used to issue Fluke 8060As to new employees when they started at my place then changed to issuing different model Flukes after the 8060A was discontinued. Sometime after that they went from issuing Flukes to not issuing new employees multimeters at all, and I think being able to use one might have been dropped as a requirement. I'll ask the two newest people on Monday if this was something that came up when they were interviewed.

In case anyone’s interested:

Hewlett-Packard coffee mug
https://www.ebay.com/itm/266433925393? ... R7LN36TnYg And the (in my experience as I only found out about it this past year) much rarer blue version:
https://www.ebay.com/itm/196005622635? ... R7DN36TnYg -Pat

<edit to add images>

The time scale on the side seems to be about the same pace I drink my coffee
Never had coffee as cold as -40 though. Don't live far enough south for those kind of shenenigans.

Cubdriver wrote: ↑Mon Oct 16, 2023 9:07 pm In case anyone’s interested:

Hewlett-Packard coffee mug
https://www.ebay.com/itm/266433925393? ... R7LN36TnYg
00BC732B-D4E5-4A7F-A79C-EFB5B0D91243.jpeg

And the (in my experience as I only found out about it this past year) much rarer blue version:
https://www.ebay.com/itm/196005622635? ... R7DN36TnYg
AB7D5D72-22CB-4881-9AEB-22C8C31BD25A.jpeg

-Pat

<edit to add images>

Thanks. I'm going to be on the phone with one of my American friends later today about something else and I'm going to ask if he can bid/buy one or both of these for me so they wouldn't have to go through that god-awful global shipment nonsense to try and reduce the likelyhood of them getting destroyed this time around.

25 CPS wrote: ↑Tue Oct 17, 2023 3:23 pm Thanks. I'm going to be on the phone with one of my American friends later today about something else and I'm going to ask if he can bid/buy one or both of these for me so they wouldn't have to go through that god-awful global shipment nonsense to try and reduce the likelyhood of them getting destroyed this time around.

Good - I hope it works out. It was very disappointing to hear that the ones you bought years ago were destroyed in shipment. Not sure if I'd blame eBuy's GSP for that though - the one I got was shipped in what I assume was the tiny carton it was initially packed in - no packing or cushioning whatsoever - that seller was an idiot. I know a mug is made from relatively heavy glass, but it's still, well, GLASS!!! How anyone can think that shipping it in a single-wall box it's a tight fit in is acceptable is beyond my comprehension, but then again it seems some sellers reach rock bottom then break out a rock drill and dynamite and start going down further in their quest for new lows.

-Pat

"Off topic" a bit, but we don't seem to have a category for "Whinging", complaining about my health, etc. My posting belongs in the latter.

I've caught bloody Covid 19!
It comes with all the symptoms "shown on the box".
Peeing yourself on & off (in my case), intermittent diarrhoea, hallucinatory sleep, enhancement of existing aches & pains, throat & deep chest infection occasioning much coughing.

My wife & daughter also have it.
Us two OFs, as we are "Seniors" qualify for anti-virals, which, along with having 3 "jabs" definitely reduces the severity, if not the unpleasantness of the disease.
My daughter doesn't have the anti-virals, but has had 4 jabs & has had two earlier bouts of Covid, so she gets the job of looking after us.

I have quite long periods of feeling reasonable, so to take a bit of the work off her hands I set out to feed the dogs yesterday.
Bending down to pick up a dog dish, I lost my balance, & fell on my back on a metal pipe frame dog bed.
It hurt like buggery!

I lay there for a while, then thought, "This isn't getting me anywhere", dragged myself up onto my hands & knees, crawled in the sliding door, pulled myself upright using the kitchen counter, "shook myself" (ouch!), then went in assure SWMBO that her silly old dodderer didn't need an ambulance, & then toddled off to bed, leaving the poor pups hungry.

Of course, Covid was delighted to "enhance" my back ache!

Ya had be better by Xmas Bryan when we are to visit or I'll start polishing the bullet.
GWS mate.

vk6zgo wrote: ↑Fri Oct 20, 2023 7:47 am I've caught bloody Covid 19!

Get well soon. I got it, my son got it, my wife got it twice. But we all had no health problems with it despite feelings like having a flu.

Sorry to read about all this Covid on here, it seems that its coming back again, my Son has just had it as well, myself and SWMBO have just had our 4th set of jabs against it.

hey specky

who told you to get a 4th jab?

my quack said to get flu shots, so swmbo and i both just ran out to the clinic and got them. but she never mentioned anything about covid. (she knows that we had the 3 previous shots and that we both had the dread disease a year ago)

on tv there are adverts for covid shots sponsored by a manufacturer ......seems strange that our gp let it slide. (maybe the distribution chains have just not kicked into high gear around here?)

nixiefreqq wrote: ↑Sat Oct 21, 2023 11:29 am hey specky

who told you to get a 4th jab?

my quack said to get flu shots, so swmbo and i both just ran out to the clinic and got them. but she never mentioned anything about covid. (she knows that we had the 3 previous shots and that we both had the dread disease a year ago)

on tv there are adverts for covid shots sponsored by a manufacturer ......seems strange that our gp let it slide. (maybe the distribution chains have just not kicked into high gear around here?)

I've just had my 5th COVID jab, at the same time as my flu jab. Haven't had COVID, yet

The NHS is pro-active in this respect: they suggested I came and had them. I originally booked an appointment, then cancelled it in case the plane from Meereen was late. It wasn't, so I turned up on spec at the surgery, and they gave them to me as they normally have some spares. During these sessions, the surgery has several people doing the jabs at probably 2 minute intervals. Slick, effective.

My (lack of) understanding is that if you get COVID, the main thing you can do to make it worse is to go back to work (etc) too soon. Much like glandular fever/ mononucleosis in that respect.