Test Equipment Anonymous (TEA) : Discussion and Group Therapy Thread

[MED6753]

I guess I should have included some pictures of the trophy vehicle.




And the steering wheel is on the "correct" side.

[Cubdriver]

It’s in beautiful condition for a near twenty year old New England car! Nice, Mike - looks fresh from the showroom!

-Pat

[Specmaster]

And the steering wheel is on the "correct" side.

Ok, I dare you to hop on a plane, go over to Japan and tell them that.

[mansaxel]

...doing the job than a hack with a oxy-acetylene cutter, an angle grinder and a wild idea..

mnemeth is writing....

mnem
meh.

That's what you'll get for being the resident motörhead, mnem.

lovingly,

[MED6753]

Ok, I dare you to hop on a plane, go over to Japan and tell them that.

Civic's for the U.S./Canadian market are built in Ohio. Over 70% of the parts content was sourced from U.S./Canadian suppliers. Some wiring harnesses from Mexico. The only major component sourced from Japan is the transaxle. The Civic as built here I don't think are even available in Japan although I could be mistaken.

The bone heads who call it "Jap Crap" are the same bone heads driving around in Fords made in Mexico.

[mnementh]

...doing the job than a hack with a oxy-acetylene cutter, an angle grinder and a wild idea..

mnemeth is writing....

mnem
meh.

That's what you'll get for being the resident motörhead, mnem.

lovingly,

You know I cannae help m'self. If it's a machine, I'm all up innit.

mnem

[Specmaster]

Ok, I dare you to hop on a plane, go over to Japan and tell them that.

Civic's for the U.S./Canadian market are built in Ohio. Over 70% of the parts content was sourced from U.S./Canadian suppliers. Some wiring harnesses from Mexico. The only major component sourced from Japan is the transaxle. The Civic as built here I don't think are even available in Japan although I could be mistaken.

The bone heads who call it "Jap Crap" are the same bone heads driving around in Fords made in Mexico.

They do say that Japanese cars these days are extremely well-built and reliable and from what I've seen that would certainly seem to be generally true, however, I'm currently driving around in a Japanese car, a Nissan Qashqai which what they call a mild hybrid, a 1.3L petrol (gasoline) and while it was some pretty good tech going on, I don't like it. The hybrid seems to want to kick in when it feels like it, seeing I was taught to drive by a bus driver, I was taught then you come to a halt, you gradually ease off the brakes, so you don't actually have a jolt when you stop, thus giving your passengers a nice smooth ride. Do that with the Qashqai, it will sometimes send all the stored up energy (like the F1 Kers system) to the electric motor and will attempt to drive you forwards with a real severe jolt, even though you still have the brakes applied. It has huge great tyres with massive sidewalls but still manages to be a rough ride with almost every bump and pothole felt inside the car.

Space in the back, forget it, not really usable as a family of 4 adults and the boot is miniscule. I can't wait for Thursday to come, and I get to leave this piece of "Jap Crap" at a garage 145 miles away when I collect my replacement car following the accident I was involved in. Yes its taken 8 and a half weeks to get a decent settlement for my write off and, locate another similar car which is more civilised than the "Jap Crap", here is a photo of one, only the one I have on hire is a red one, and the birds love to crap on it every night as I currently have to park on my drive which has a tree overhanging it and pigeons roost in it every night, thanks to my neighbour's family who have between them 5 vehicles and they seem to beat me to the spot outside my house.

qashqai.jpg

[Cubdriver]

My ‘96 Miata is a made-in-Japan car and was nigh on mechanically bulletproof. If it wasn’t half rusted away from the liquid car dissolver that CT puts on the roads in winter (it supposedly also melts snow/ice), I’d likely still be driving it. It currently sits in my garage with ~352k on the clock (~566.5k km for you metric types) waiting for me to find time to do some bodywork on it. During the seventeen years I used it as a daily driver, it never left me stranded, and the only unscheduled repairs it needed were a differential seal at about 66k; alternator brushes, a water pump, a rear wheel bearing and an exhaust system weld in the 200k range; and finally a fuel injector and rear calipers some time between 300k and when it was parked. There might also have been something in the 100k period, but if there was it was too minor to recall. About all it needed was a timing belt every 60k and brake pads - fronts roughly every 60k and rears every 90. It did get some go-fast goodies early on - aftermarket shocks, springs and and sway bars, but once installed they were never touched again. I did eventually put an aftermarket exhaust on it, too, but that was a want, not a need. Got tired of waiting for the factory one to rot out so I’d have an excuse, and just replaced it.

Excellent vehicle.

-Pat

[Specmaster]

This is what I come out to each morning and I have had to be continually washing Qashqai almost daily because of the pigeons. This photo was taken the morning after I had washed the car, it is really disgusting and the authorities won't do anything about the tree or help to solve the street parking issue.

Bird Poop.jpg

[MED6753]

Toyota, Honda, Subaru, and Mazda are generally very good. Nissan is fucking junk.

[mnementh]

...I can't wait for Thursday to come, and I get to leave this piece of "Jap Crap" at a garage 145 miles away when I collect my replacement car following the accident I was involved in. Yes its taken 8 and a half weeks to get a decent settlement for my write off and, locate another similar car which is more civilised than the "Jap Crap", here is a photo of one, only the one I have on hire is a red one, and the birds love to crap on it every night as I currently have to park on my drive which has a tree overhanging it and pigeons roost in it every night, thanks to my neighbour's family who have between them 5 vehicles and they seem to beat me to the spot outside my house.

qashqai.jpg

You need to go steal you some traffic cones.

mnem

[25 CPS]

Yesterday was pretty busy with test equipment at home.





First, the 8656B came out of the rack and was replaced with the 8657A that I got a while ago. The 8656B got kicked out to the driveway, but more about that later.



Did a bunch of testing and the 8657A checked out fine. In this grab shot picture, you can see the harmonics on the spectrum analyzer but they're all down -40 dBc or more so it beats the minimum spec of -30 dBc, so no problem there.









The next project up was to build a couple of cheap and nasty test fixtures for automotive accessories. The one that dead ends in stripped wire is just to be able to power things up on the bench. It was about to get a banana plug connector when I realized that most of my power supplies don't have banana sockets so I left it at stripped wire. The other one is a line splitter so that current clamps can be used to monitor current draw. Terminals intentionally left exposed for now to allow a voltmeter to be clipped on.



In use, out in the truck, we have 12.5 V on the U1252B off the battery booster I was using to power up some accessories so I didn't have to run the engine or drain the car battery, and about 1.07 A on the U1252A being drawn by a two way radio at idle, aftermarket carplay unit, and phone being charged from the Hantek current clamp at 1mV/100mA.



There's a test signal nearby.



It's coming from that 8656B that got kicked out to the driveway.



I needed to do a bunch of specific testing with the two way radio that came with my truck so I spent a good chunk of yesterday afternoon shaking it down. There isn't much documentation out there on this radio so it took some trial and error to sort things out but it turns out it'll be usable after all for something I've had in mind.



Frame grab from a video I shot and sent to the others involved in this project.

1K tone gets old pretty fast and I wanted to hear what this radio sounded like on actual audio for some testing so the iPad provided program material for several tests. Here it's wideband 5kHz deviation and Paul Carrack music.

The truck getting worked on, the test equipment going on with the truck getting worked on, the big mean signal generator, the scary spectrum analyzer, the plaster rabbit from my grandparents' balcony propping the iPad up, the test tones and music, I never did see that awful lady next door, but I'm sure it didn't go over well. It's anybody's guess how many pieces my back yard Christmas lights are going to get hacked into over this. In any event, it was an enjoyable day and good to knock out a few projects involving the truck and the truck's two way radio that have been waiting for a while and get some of the bench reconfiguration that I've been meaning to do done. The B&W bookshelf speakers have been disconnected for a while but still need to come down. I replaced them with a pair of floor standers located elsewhere and I need the shelf space back to allow for another equipment shuffle that's been pending.

And the 8656B is back inside. Being kicked out to the driveway was only temporary for testing the two way on the truck. It's back inside safe and sound stored away. This was one of the reasons why I wanted the HP 8657A when it came available locally along with the 8904A: I wanted to have something that can be taken on the road easily without having to be removed from the test bench shelves so the 8657A is on the bench permanently and the 8656B is now the dedicated mobile signal generator. It'll be going back out in the driveway next week for some additional testing of that Baojie BJ-318 in the truck since there are some additional measurements I want to make on it that I didn't get a chance to do yesterday that weren't essential items on the to-do list for that.

[mnementh]

I suggest running a electric fence wire along the same path as the lights "ferr the squirrels whutt keep chewin' on muh wires"...

mnem
I prepared Kilovolt Runes today...

[AVGresponding]

Was ist das, bitte?



Some sort of active probe amplifier or summat? No branding or model numbers/letters anywhere.



EDIT: That power connector looks a lot like the one on my HP 1120A probe.

[Robert]

Almost certainly a custom made unit. The box is a Greeenpar modular one. Removing one screw, furthest from the longitudinal joint lines and the side connectors, should allow the cover to come off. You might have to loosen the other three slightly.
Can't even guess function without a internal picture.

Robert.

[AVGresponding]

Another person that wants me to buy it, to find out what it is!

@MED6753 this seems the sort of question you'd be better at answering than me, though I have tried a bit: https://www.eevblog.com/forum/testgear/ ... es-scopes/

[Zenith]

I'd guess it's home made or a one off test fixture, rather than a commercial unit with missing labels. It could be all sorts of things. The only way to shed light on it, is to open it up and see what's inside.

[AVGresponding]

I'm not curious enough to spend a tenner. I'll post the link in ebay tat, in case anyone wants to have a pop at it.

[Zenith]

All that's definite about it is that it has three used BNC connectors and a die cast box which might to for something if you were stuck. The seller hasn't bothered to open it. It might have a couple of RF goodies in, but it probably doesn't.

It looks like the sort of thing that you find in boxes of oddments at radio rallies, and you might expect to pay 50p for. If you buy something costing say a fiver, they are known to chuck in two or three things like that, to get rid of them.

[vk6zgo]

I'd guess it's home made or a one off test fixture, rather than a commercial unit with missing labels. It could be all sorts of things. The only way to shed light on it, is to open it up and see what's inside.

I vaguely remember seeing something like that before.

Not being labelled doesn't rule out a commercial origin, it could have been part of a larger piece of equipment, never meant to be sold separately.
It looks a bit too neat for a "homebrew" effort-----maybe from a Uni or Tech school lab, but it just doesn't look "hobbyist" standard.
One thought comes to mind---perhaps an RF "sniff" which supplies both undetected & detected RF, the latter using the "DC" connector.

[AVGresponding]

I'd guess it's home made or a one off test fixture, rather than a commercial unit with missing labels. It could be all sorts of things. The only way to shed light on it, is to open it up and see what's inside.

I vaguely remember seeing something like that before.

Not being labelled doesn't rule out a commercial origin, it could have been part of a larger piece of equipment, never meant to be sold separately.
It looks a bit too neat for a "homebrew" effort-----maybe from a Uni or Tech school lab, but it just doesn't look "hobbyist" standard.
One thought comes to mind---perhaps an RF "sniff" which supplies both undetected & detected RF, the latter using the "DC" connector.

The spacings are all spot on, unusual for a homebrew, as you say. Also it uses the HP power connector, though I don't know if that is proprietary or not.

[Robert]

I picked up a bit of TE on Thursday. A HP 8920A communication test set. It was a Buy It Now on ebay. Only acouple of pictures of the front. "for spares or not working" with a note that the power supply was blown. Price was only £75. Collection only. No time to ask questions, I hit buy. I thught unles it is completely gutted Id get my money back in parts. Bit if a road trip to get it but I dropped the dog off at the vets to have her teeth seen to as it was two thirds of the way there. Got to the seller and first thing I did was look at the back. Calibration seals intact and a load of options. These include the spectrum analyser and tracking generator. So far so good.
I've repaired the power supply on these before and they are a bit of a pig. Hard to get apart and limited data. This one had an obilterated fuse, and obvious blown 47nF RIFA. Not a RFI filter cap, a snubber on the main switch. As a result the main switch, a IRF840 MOSFET was blown apart. Also gone were the driver, two resistors and worst of all the little feedback/driver isolation transformer had an open winding. Additionally athough looking fine the output filter electrolytics were leaking. Long story (about 6 hours work) short I replaced all those and repaired the transformer and I now have a working 8920A I think thats another Jammy Git.

[Zenith]

A nice find.

Was the transformer hard to fix?

Usually with HP gear the service manual is easy to find on the WWW.

[Robert]

The transformer is the little toroid with 3 windings. Operation is odd. One winding seems to go to an oscillator on the mains side, one drives the main switch MOSFET gate and the third is feedbck from the DC side. I think the feedback saturates the core cutting the drive.
I was able to dig out the fused end of the winding, extend it and re-attach.
It's a 3rd party PSU by computer products so HP never published the schematic. A partial schematic of one version (I've personally seen 3 variants) has "escaped" from CP but does not include some of the control circuitry.
It is an unusual design that has Mains or 11-32V dc input. The DC feeds a unregulated "push-pull" inveter and regulator that charges the same filter capacitor as the mains.

8920A PSU Schematic.jpg

[Robert]

I've had another look at the Advance OFS-2B frequency referene. Thanks to Frequency I have a manual. It's clear the unit is not operting correctly even when fed a generated 200kHz signal. The AGC deos not seem to be working proprly. Unfortunatly the circuits in the manual do not match the unit I have. There are significant differences. I think I have an earlier unit. The unit will go on the too be done shelf. Probably best as a case, PSU and antenna for a new design (maybe Andy G4JNT's) of 198kHz unit.

Robert.