Test Equipment Anonymous (TEA) group therapy thread

[med6753]

Unicorn alert for our American friends.

https://rover.ebay.com/rover/0/0/0?mpre=https%3A%2F%2Fwww.ebay.co.uk%2Fulk%2Fitm%2F123851591889

Edit: 485, pristine for 100 bucks.

That's OK, I'll struggle with the POS 485 I got for less than $50USD....probably get mad at it....and junk it. 

[Neomys Sapiens]

They are a delight to fly: responsive[1], fit like a glove, and great visibility. ...

I dimly remember from a job long ago that the pilot flying in front described it in other terms, but he seemed to talk about the same qualities of both the glider's pilot and his ride. Yet there it was, dancing through our intended flightpath with almost no effort, taunting us with it's movements, and worst: doing that for fun.

You might imagine the general class of designations as we were in a H500 with a big bucket of concrete suspended below.

[mnementh]

Unicorn alert for our American friends.

https://rover.ebay.com/rover/0/0/0?mpre=https%3A%2F%2Fwww.ebay.co.uk%2Fulk%2Fitm%2F123851591889

Edit: 485, pristine for 100 bucks.

And another one: 585 scope 100% working, 2 carts, one high voltage probe P602113a, one standard probe, 2 instruction manuals $300 (But pickup only in Detroit  ) : eBay auction: #123835165538 

mnem
*impairing productivity since nineteen mumblety-mumble*

[bd139]

Free headshot with that one 

[med6753]

For now that ends my diversion into time-nuttery. Back to restoring old Heathkits and dealing with fussy old Teks.    

Oh yea....still have a volt-nut project on the back shelf. The 500VDC reference. 

I need a counter that's small enough to perch on the 7904A.  Running a long coax over to the stack of HP equipment is getting old already.

The 7904 is on a wheeled cart that I built so it can easily be moved to where it's needed and having the counter on top increases it versatility. 

[med6753]

Unicorn alert for our American friends.

https://rover.ebay.com/rover/0/0/0?mpre=https%3A%2F%2Fwww.ebay.co.uk%2Fulk%2Fitm%2F123851591889

Edit: 485, pristine for 100 bucks.

And another one: 585 scope 100% working, 2 carts, one high voltage probe P602113a, one standard probe, 2 instruction manuals $300 (But pickup only in Detroit  ) : eBay auction: #123835165538 

mnem
*impairing productivity since nineteen mumblety-mumble*

I know where there is a 545A of unknown condition but appears intact and in good shape with a "make offer" and within 1.5 hours of me. So far I have resisted but it is eating at me. 

I've got too many other projects.....and almost no room.

You're retired so all the time for as many projects as you can stack up.........make room 

I've got too many other projects.....and almost no room.

You're retired so all the time for as many projects as you can stack up.........make room 

I've got too many other projects.....and almost no room.

You're retired so all the time for as many projects as you can stack up.........make room 

I've got too many other projects.....and almost no room.

You're retired so all the time for as many projects as you can stack up.........make room 

I've got too many other projects.....and almost no room.

You're retired so all the time for as many projects as you can stack up.........make room 

I've got too many other projects.....and almost no room.

You're retired so all the time for as many projects as you can stack up.........make room 

I've got too many other projects.....and almost no room.

You're retired so all the time for as many projects as you can stack up.........make room 

I've got too many other projects.....and almost no room.

You're retired so all the time for as many projects as you can stack up.........make room 

Round and round it goes. 

[tggzzz]

The shadow of my ass weighs more than that overgrown lawn dart.

mnem
 

Empty weight 1016lb, and you can add 353lb water ballast if you are racing. Pilots can add another 480lbs, provided trim limits aren't exceeded.

I don't mind pushing them - on the flat. But it still takes 3 people.

[tggzzz]

Good one! 

They weigh as much as a small car

[mnementh]

   
https://p50cars.com/

A VERY small car.

mnem
*puttt-puttt*

[worsthorse]

Here on the island of misfit gear...



... two more semi-ancient computing devices have been resuscitated.

Having finally found a functional USB floppy drive so I could make floppies, I got the Panasonic CF25 Toughbook running with MSDOS 6.22 and Windows for Workgroups V3.11. I can finally have the minesweeper experience Bill Gates intended. 

And wizzing forward a couple o' decades, the bargain Nexus 9 tablet has been reset, rooted and is ready to operate various bits of interesting ham radio related software.

[mnementh]

Urrrrggghh. Just spent the last hour emptying the big freezer in the garage because last time I got something out of it, something came loose and knocked the door ajar and the evap froze up. 
Threw out about half of it based on age and color and "ehhhhhhhh, I don't think so..."   

Emptied all the frozen veggies out of the top freezer inside and threw them and all my freezer packs in a big chest cooler, then filled the freezer with all the half-thawed bacon & hams I stocked up on last time they were on sale... also got several dozen burger patties, steaks, and a couple roasts I'm gonna have to cook right away. Terrible, terrible tragedy, that. 

I'm gonna go out and check to see if I still have a "freezer" now... pray for me. 

mnem

[Brumby]

   
https://p50cars.com/

A VERY small car.

mnem
*puttt-puttt*

Whenever I see a picture for one of those, I always chuckle - having seen Jeremy Clarkson wedged into one.

[bitseeker]

OK. I'll be away for work for the next day or so. But...I'll be back!

(Why do I feel like we've just gone head first down a massive rabbit hole? )

No doubt.   

Back. I started reading the 431B troubleshooting section and it says one of the first things to do is to determine if the problem is the meter, the cable, or the thermistor mount. No duh.

So, I did some digging around and just before I found the 478A manual, I found this little page that has a quick check to see if the thermistor is a lost cause, as well as a reprint of the potentially more dangerous, but more definitive, test from the 478A manual. I only did the quick check and both sets of thermistors in my mount read ~3kΩ, which is in the "healthy" range. So, that's a bit of a relief.

Not a lot of progress, yet, but figured I'd share that little tidbit.

[bitseeker]

So far I'm supper happy with the Explorer ST, its twin turbo 3L V6 makes 400HP and 415lb-ft torque, AWD with rear wheel drive primary.  First, its amazing how quite it drives.  Secondly, stand on the go peddle and it will surprise you.  I've not tested this myself, but reviewers are testing 0-60 in under 5 seconds and 1/4 mile times around 13.4 sec and factory speed limiter set at 143 mph, that's not bad for a stock production 5,000lb SUV.

Now to make this TEA related... Think of all the cool gear I can haul back home from a Ham Fest and do so quickly 

I'm looking forward to all the pics from your speedy hauls.

[bitseeker]

So I got lucky and found another 431B at the local surplus shop, in sad shape that I can break down for parts.

Oh, nice! Does it have feet?

[bitseeker]

Recently in this thread there have been too many wheels and not enough other mechanisms enabling vehicles to move.

To offset that preponderance, I offer a much more sexy vehicle (look at those curves!) with far more scope for TEA related fettling...

Yes! I've got to try that for real one of these days. Catching thermals is fun in a sim, but you can't feel anything.

[bitseeker]

And, the Fluke 7260A will now more or less be a permanent fixture on top of the 7904.

I like it. Looks like a robot with scope for a body and a frequency counter for a head. A FlukeTekBot.

[bitseeker]

Some more digging on the 431B power meter.

Yesterday, I was able to score another 431B at the local surplus joint, fairly beat up, but cheap. Functionally, however, it seems fine after I let it warm up and trimmed the -18V regulated supply. Crucially, this enabled me to come to the conclusion that both 431B meters are probably fine themselves, but there's a problem in the 478A thermistor mount I have, despite it working fine with my 432A (more on that shortly). 

The 431 and 432 meters use totally different methods of biasing the thermistors when a mount is connected. The 431B has a 10 kHz oscillator/amplifier circuit that generates a roughly sinusoidal 10 kHz tone. You can actually hear it if you get your ear close. It's got a little bit of crossover distortion, but that's normal. This oscillator free runs when I leave my thermistor mount disconnected. However, connecting the thermistor loads it way down and causes the meter to peg in any range except null. And the nulling adjustment (a potato slicer capacitor) has no effect. The 432 meter, in contrast, uses a dc bias circuit that, according to the manual for the 478A [1], is better because it reduces thermoelectric effects. The manual additionally states that the 431B meter pegging is a symptom of damage in the thermistor mount. 

For reasons I'm not entirely sure of yet, there is likely a form of failure mode in the thermistor that causes it to fail to work in 431 meters with the null adjust and 10 kHz biasing signals, but work fine in 432 meters with just dc bias. I have good certainty the 478A + 432A combo is at least functional, because it agrees nearly perfectly with both my 8566A and 8568B spectrum analyzers. So they are either all three wrong or they are all right. 

Anyway, I called Keysight and they still work on 478A thermistor mounts with NO projected end of life, because they are used as a primary standard in rf labs to this day. However, the quote for repair and basic cal....about 2 kilobucks.  Considering I got mine cheap, and given the cost of unknown ones on ebay, I am considering just laying this cash out and having one I can fully trust instead.


[1]: https://literature.cdn.keysight.com/litweb/pdf/00478-90021.pdf?id=414274

Did you measure the thermistors (paragraph 67 in the 478A manual)? If they're within the "healthy" range, you might be able to recompensate them instead of having Keysight repair it. Hopefully, it's a bit less expensive to just get a new compensation chart made for it.

[bitseeker]

Unicorn alert for our American friends.

https://rover.ebay.com/rover/0/0/0?mpre=https%3A%2F%2Fwww.ebay.co.uk%2Fulk%2Fitm%2F123851591889

Edit: 485, pristine for 100 bucks.

And, it's gone. Sure looked like a nice one, just missing a fuse.

[tggzzz]

Recently in this thread there have been too many wheels and not enough other mechanisms enabling vehicles to move.

To offset that preponderance, I offer a much more sexy vehicle (look at those curves!) with far more scope for TEA related fettling...

Yes! I've got to try that for real one of these days. Catching thermals is fun in a sim, but you can't feel anything.

Do try it, even if it is only a "bucket list" activity.

Unfortunately in the US there are only a very few places that do nice cheap fast winch launches (and no bungy launches!). That means you will be towed sedately behind another aircraft, whereas in a winch launch it is 0-50 in 5s, then climb with your feet higher than your head.

But you can still make your own roller coaster in the sky. Gliders are aerobatic, some manoeuvres are "normal" and taught before going solo, others can be very extreme.

Even on everyday flights it isn't unusual to pull +3G in a tight thermal. I once did that for a couple of 1-2minutes continuously, rising at >1000ft/min. There was another glider doing the same, at the same altitude, so we looked upwards and saw the top of the other pilot's hat (bank angle 70 degrees ).

Or, if you prefer, you can float in intense relaxed concentration, looking for the next thermal - often signposted by summer "ice cream" Cu clouds or go and join some circling rator(s).

[bd139]

Decided to amble over to Chippenham tomorrow for the rally. tggzzz - If you're going I'm intentionally not taking enough cash to relieve you of a scope. Going cold turkey!

[med6753]

Decided to amble over to Chippenham tomorrow for the rally. tggzzz - If you're going I'm intentionally not taking enough cash to relieve you of a scope. Going cold turkey!

Yea, sure....with an ATM on site. 

[Specmaster]

And above all pack your wellies after all this flaming rain, but it has taken the heat level down a bit but still feels sticky because its so humid now.

[med6753]

Wellies? Looked it up. It figures.     Wellies.com

Typical English in formal shirt/tie/hat and walking stick ambling across the soggy country side in knee high rubber boots and drinking brandy.

How fucking quaint. 

[tggzzz]

Decided to amble over to Chippenham tomorrow for the rally. tggzzz - If you're going I'm intentionally not taking enough cash to relieve you of a scope. Going cold turkey!

Anything you are looking for? I might have something

Not sure if I'll bother to tru to flog stuff - but how about a juicy 7.5 digit DVM with panaplex displays and a custom carrying case? Or maybe some PTFE heatshrink, just right for voltnut games?

Or even a nice Goblin TEAsmade?