Test Equipment Anonymous (TEA) group therapy thread

[URI]

Hi all, back from lurking around here after my post-vacation-catchup.   

Uploaded the HP 66311B teardown peek inside/testing pics at last. Not a full teardown as this thing is complex to disassemble and I had limited time and wanted to get to the testing bit. Fair warning, pic heavy post:

Front panel is a bit grubby, with a missing twirly-knob, the feet are missing, but at least there's no stupid tilting handle to remove. The dimple on the right side promises a useful hole in the moulding, hopefully there are at least two and preferably four, so I can add binding posts:


Bloody hell no wonder this thing is heavy, the case is 1.5mm thick, and near 400mm long! The transformer has a ludicrous number of taps, and looks at least 200VA, and like the K2000 it's mounted at the wrong end of the case!


[..]

Yeah, nice typical construction of the time. 

The transformer is at the right end of the case, indeed.
This nice little lab supply is not made for bench use only. For use in test systems, typically mounted in racks, the transformer at the front is nearest to the mechanical mounting point of the unit -minimizing the length of the lever.

Yup, it's really there... I am very impressed with the accuracy of the metering on this power supply, seems like I can stop looking for a precision supply as I now have one. I'm guessing the offsets I had to program in are possibly down to my hastily improvised output leads. I did make them twisted pairs as per the manual, but perhaps they are too small a gauge (0.22mm²).
I tried various loads, and linking them in and out was unable to get the output voltage to deviate by more than 200uV. Sadly this human forgot to make any noise measurements, I'll get to that later when I have the time (to warm all the units up and make a nice clean measuring setup).

Congrats, you got an nice working unit there. Order the missing knob and some nice binding posts and you'll have a real nice bench supply!   

[Cubdriver]

"As-is" 6206 picked up. It's more of an "As-was", TBH.  2 meagre layers of bubble wrap in an US Mail box. Meter pushed in. Rattles inside. The meter frame was found in the packaging, looks OK. Power switch rocker is ground flat to blend in with the front panel.

Mains cable was cut, already on the sale pictures, so this will be a multi-step approach; wiz:

• Get refund. 
• Test level of prior damage 
• Life support
• Un-gunk
• Fix

Oh joy. To be fair the meters on them have ridiculously brittle plastic. I had one of the little plastic cased ones turn up in pieces. Picture here from cubdriver who had one disintegrate on him ages ago:



I may still part with mine if you want one that isn't fucked as I mostly use the 6205 now

I recognize that power supply pile of parts!!  It's still squirreled away in a box somewhere here waiting for me to get ambitious.  People who can't pack worth a shit should be strung up by their thumbs.   

-Pat

[bd139]

Hahaha you get as bitter as me with those things 

[URI]

I remember my three attempts of buying a HP/Agilent 8110A and having it delivered safely in one piece that all failed due to poor packaging.
I can only add: hang'em higher!      

[capt bullshot]

Uploaded the HP 66311B teardown peek inside/testing pics at last. Not a full teardown as this thing is complex to disassemble and I had limited time and wanted to get to the testing bit. Fair warning, pic heavy post:
...

Looks like the smaller sibling of the HP6632 that I've got two of them. The transformer looks familiar, also the digital control board and display does.

[AVGresponding]

Hi all, back from lurking around here after my post-vacation-catchup.   

After your catch-up, you probably need another vacation!   

The transformer is at the right end of the case, indeed.
This nice little lab supply is not made for bench use only. For use in test systems, typically mounted in racks, the transformer at the front is nearest to the mechanical mounting point of the unit -minimizing the length of the lever.

That is undoubtedly similar to the argument Ferry Porsche made when he designed the 911.
Nevertheless I maintain it's at the wrong end! I have a few rack mount units, and this and the K2000 are the only ones with this mutant form.
I might add, that due to the ruggedness of the construction, you might reasonably say that the rack mounts on to the TE, and not the other way around...   

Looks like the smaller sibling of the HP6632 that I've got two of them. The transformer looks familiar, also the digital control board and display does.

It would make a great deal of sense for HP to limit costs by using common parts between units.
The full width rack HP supplies have been on my want list for some time, but they only seem to show up in the States, at least for reasonable prices anyway. This was quite a lucky find over here really.


I have noticed a tank-load of Keithley meters on eBay today, in Israel. I wonder if anyone will be brave enough..?


@bd139, I have "the stuff", thanks   

[capt bullshot]

It would make a great deal of sense for HP to limit costs by using common parts between units.
The full width rack HP supplies have been on my want list for some time, but they only seem to show up in the States, at least for reasonable prices anyway. This was quite a lucky find over here really.

A few years ago I had a talk to a German seller (not Rosenkranz) of used TE. He said, there's a lot of the 6632B and similar in some TE sellers stock, but they keep them deliberately back because the prices were too low.

So you might ask e.g. Rosenkranz (https://www.rosenkranz-elektronik.com/) for a quote, this is where I've got mine from, for a lower price than they were offered back then on ebay. Assuming it's correct what I was told later by this other seller, there should be more available.

[bd139]

@bd139, I have "the stuff", thanks   [/color][/size][/b]

Enjoy. Hope Hermes didn’t customise it 

[Ice-Tea]

Why does it always have to be hard (no, I beg you, no...)? Why can't it ever be easy? 



After applying some elbow grease at those horrible rubber grime magnets, the E4402B looks great. But...



The ref input sits at -35dBm iso -20?? Why?

The tracking gen is spot on for -10dBm but diverges more and more if you go down.. WTF??



I hope some auto allignment will solve this, otherwise I'm down 2/2 today.

[capt bullshot]

Why does it always have to be hard (no, I beg you, no...)? Why can't it ever be easy? 
After applying some elbow grease at those horrible rubber grime magnets, the E4402B looks great. But...

The ref input sits at -35dBm iso -20?? Why?

The tracking gen is spot on for -10dBm but diverges more and more if you go down.. WTF??

I hope some auto allignment will solve this, otherwise I'm down 2/2 today.

Are you trying to tempt me? 

[Ice-Tea]

Into making lewd jokes? Not really 

[Saskia]

fuck. major mishap. my 17-40L is toast, 380summthang for fixeruppers.
 

Home office extended until End of March 21, no one here expects this to be over any sooner.

@Ice-Tea
well, I would need the base station. If I can aquire one I might ask you for one or to 6700 modules ...

at €19 for a new module I just could not resist.

[Ice-Tea]

well, I would need the base station.

Well, if you find one and it has a good looking sister...

Also, think I'm going to jump of a bridge now. The E4402B doesn't look better. And that's putting it mildly.

[bd139]

Ooh that burns. 

[mnementh]

An insight into what first got me into my whirry little flying things almost 2 decades ago... THIS is what I wanted to be able to do.

mnem

[mansaxel]

Ok, pics.

337: Front.

338: Ex-power-switch.

342: Flapper. Can't call it a fin, being that loose.

Case opened. I've never done this before, so thumbs held.

[bd139]

Ouch that took a beating 

[BU508A]

*sigh*

Why? Why is it that hard to pack things adequate?

 

The only explanations I have are: do not care, lazyness, dumbness in no particular order or amount.

          

[tautech]

Uploaded the HP 66311B teardown peek inside/testing pics at last. Not a full teardown as this thing is complex to disassemble and I had limited time and wanted to get to the testing bit.

Are those loose wayward washers  ? 

[mnementh]

   Gee, I wonder why it didn't want to run with all these flakes of rotten fuel line in the filter screen... New fuel lines, primer bulb and fuel filter, a little cleaning of the carb with my trusty spray bottle of alcohol and we are go; started and ran on 3rd pull. Now it starts with just a pull at idle.  I WAS tempted to try running it after just replacing the fuel lines & filter... glad I told bd139 Luci whispering in my ear to piss off. Was much less of a PITA to work with NOT full of gasoline.



Only thing left is to find a exploded view and see if this model has a clutch or not, as it acts like Yup, confirmed; it is direct-drive.

Then next victim!

mnem
*tinker-tinker... putter-putter...*

IT LIVES! Part Deux - Poulan Pro Leaf Blower



This was pretty much an exact repeat of the Craftsman WeedWacker; only it would start and run. Badly. I originally planned to just replace the carb with the new Chinesium one in my kit, but I noticed this motor actually has a Walbro carb on it (probably one of the things you get for the uptick "Pro" package); so I sucked it up, put up with the stinky old gas in everything, and cleaned the carb. Like before, I found flakes of rotten fuel packed into the inlet screen; cleaned it out with my squirt bottle of alcohol, replaced fuel lines & filter, and it was right as rain.

Not bad for US$87 for the two; plus expending a little techliness.

Plus I have oodles of spare bits I can use for other small engines; like a gas RC Truggy or somesuch thang. 

A free tech tip if you're ever working on the carb on one of these small 2-cycle motors: Once you put it all back together (note that the longer adjustment needle is usually the LO side), turn both adjuster screws all the way in until they bottom out, then back the LO one out 1 3/8 turns, and the HI one 1 7/8 turns. Prime, choke, etc per directions (some models have a half-choke position while some will automatically unchoke as soon as you crack the throttle open), then run the thing for a few minutes by feathering the throttle as needed to warm it up. NOW, adjust the HI by holding the trigger at WOT and cranking the HI screw out til the burn starts to clear up, then starts to break up, then crank it in until it starts to break up again. Set the HI screw halfway between the two points.

Now the LO screw: 9 times out of 10, you don't need to adjust this at all from 1 3/8 turns; first set the idle SPEED screw so it keeps running, then crank it out until it starts to buck/labor. Now turn the idle speed in (higher rpm) again until it smooths out, plus half a turn.

At this point, if the engine is warm, you should be able to hit the throttle and it'll ramp up quickly. If it bogs, open the LO screw a hair... like 1/16 turn at a time... until it ramps up like it should. Now a final check of the HI screw at WOT again; it may need 1/16 or so either way to clear up, but usually will be right on here too, and should idle down without dying. If it dies, adjust the idle SPEED up a hair, checking for bogging vs dying as it comes down from WOT.

If your engine doesn't behave like this, almost without a doubt you've missed something while cleaning, or if it is old enough, the primary diaphragm has gotten stiff and a proper rebuild with kit is necessary. But note: both of these machines are 12 years old, came from a snow-belt climate, and were still easily restored with just new fuel lines/filters and a proper cleaning.

Now go burn some 2-cycles!!!

mnem
 

[Ice-Tea]

The only explanations I have are: do not care, lazyness, dumbness in no particular order or amount.

The perpetual underestimation of the ability of parcelmonkeys to abuse your package? There does not seem to be a level of protection that shields a device from **all** possible abuse, with the possibe exception of bags of foam that set around it with 10cm of padding on all sides.

[mnementh]

   Also, think I'm going to jump off a bridge now. The E4402B doesn't look better. And that's putting it mildly.

Before you do anything rash... have you tried a different patch cable? Something known 50-ohm with N-connector one end and BNC the other, no adapters? Preferably known sweep-tested to 10-12GHz...?

When you get up into these frequencies... a hinky cable or adapter can hose you big time.

Good luck my friend!

mnem
 

[Saskia]

wellllll ...

back in those days:
TNT managed to catapult a 5.25" full height hard drive through the casing of a Silicon Graphics Iris 4D35.
Back in those days this was somewhat high end equipment, and they had to shell out big buckos for that.

Lufthansa air cargo managed to trash a very well packaged parcel by dropping the container from the ramp onto the tarmac. needless to say, the fibre channel enclosure with the discs plus the notebook screens were toast.
some 25000 reimbursement.

Back in those days I was earning money like shit, so I could afford reasonable orders of TE.

[Saskia]

@mnem
Leaf blower Saskia style ...
(have to manage the expectations)

https://youtu.be/tNjWMGdrVJE

[tautech]

A free tech tip if you're ever working on the carb on one of these small 2-cycle motors: Once you put it all back together (note that the longer adjustment needle is usually the LO side), turn both adjuster screws all the way in until they bottom out, then back the LO one out 1 3/8 turns, and the HI one 1 7/8 turns. Prime, choke, etc per directions (some models have a half-choke position while some will automatically unchoke as soon as you crack the throttle open), then run the thing for a few minutes by feathering the throttle as needed to warm it up. NOW, adjust the HI by holding the trigger at WOT and cranking the HI screw out til the burn starts to clear up, then starts to break up, then crank it in until it starts to break up again. Set the HI screw halfway between the two points.

Now the LO screw: 9 times out of 10, you don't need to adjust this at all from 1 3/8 turns; first set the idle SPEED screw so it keeps running, then crank it out until it starts to buck/labor. Now turn the idle speed in (higher rpm) again until it smooths out, plus half a turn.

At this point, if the engine is warm, you should be able to hit the throttle and it'll ramp up quickly. If it bogs, open the LO screw a hair... like 1/16 turn at a time... until it ramps up like it should. Now a final check of the HI screw at WOT again; it may need 1/16 or so either way to clear up, but usually will be right on here too, and should idle down without dying. If it dies, adjust the idle SPEED up a hair, checking for bogging vs dying as it comes down from WOT.

If your engine doesn't behave like this, almost without a doubt you've missed something while cleaning, or if it is old enough, the primary diaphragm has gotten stiff and a proper rebuild with kit is necessary. But note: both of these machines are 12 years old, came from a snow-belt climate, and were still easily restored with just new fuel lines/filters and a proper cleaning.

Now go burn some 2-cycles!!!

mnem
 

While those tips are correct for those with experience tuning small 2 stroke engines they shouldn't be attempted without a rev counter AND the manufacturers WOT max rpm spec.
Many small engines will tune happily a few 1000rpm past their max spec however it limits their life drastically.
When I was on the tools and very familiar with many small motors I would tune 'by ear' and consistently get within a few 100 rpm of spec but not now as 'the ear' is now well out of calibration. 

Most of us have a suitable RPM counter on our bench.....a DSO and with a probes reference lead clipped to the grabber makes for a fine near field ignition pickup and a little maths gives us a frequency to tune to with the Hi screw.
Eg. 12000rpm/60 = 200 Hz.