Test Equipment Anonymous (TEA) group therapy thread

[tautech]

Might have to scan it then, would be a shame to not have it be preserved.

Good plan and Kevin Chant is very approachable and I'm sure would be happy to host it.

A buddy also has a BWD Powerscope and just looked in my scope manuals folder and I have the 881 manual and schematics.....I think originally from Kevin so a little surprised he no longer hosts it.

[wolfy007]

I won a thing...

First and only thing I have ever won

[TERRA Operative]

Well, on the subject of the THM5xx series scope meters, I managed to get my hands on all that is needed to flash firmware and perform a full adjustment! 

https://www.eevblog.com/forum/testgear/tektronix-thm56x-portable-scope-hackteardowndiscussion/msg5847789/#msg5847789

If you have one of these instruments, head over via the link and we can get some stuff sorted to make it all super easy. (I'll be writing a Python script, and will need some help...)

[Vince]

Terra..... "I will be writing a Python script "... uh ?

I still remember not so long ago you explained that S/W was not at all your thing, that you programmed using your soldering iron ! 

What a change then !   

Is it your new job that got you to develop new skills ? 

[TERRA Operative]

I can dabble, but I'm very much a beginner.

Through my new job I hope to learn some VHDL, my boss and I are slowly getting around to making our version of a TDS500/600/700 series LCD conversion for our scopes (and will be opensourced) using the ice40 range of FPGA.
He'll take charge of software and teach me, and I'm doing the hardware.

[Vince]

Oh wow, your company develops stuff for old TE, how lucky, dream job ! 
Looks like you will learn and do lots of cool stuff, have fun ! 

[Ice-Tea]

Through my new job I hope to learn some VHDL, my boss and I are slowly getting around to making our version of a TDS500/600/700 series LCD conversion for our scopes (and will be opensourced) using the ice40 range of FPGA.

You do layout? If not, I'd be happy to contribute & get dabs at a few of those ;-)

Also: consider developping hybrids for that series. I'd contribute & pay for that too ;-)

[timeandfrequency]

I won a thing...

R&S also devises the NGE series and outcome was not very lucky.

[TERRA Operative]

I do mostly hardware design and board layout etc.

Once the design is complete, I'll be doing a manufacturing run of boards and metal brackets etc, so will make a thread on the forum about them.

[factory]

Seems the #2200 lamp is obsolete, only old stock available now, it's used in various Tek TE. But a smaller diameter lamp with the same electrical spec is still made #683.

Re: the extender, I'm wondering how hard it could be to make one, I've done an extender & various other boards using KiCAD, don't think it would cost too much as the boards look small and the rest is ribbon cables between the two. Of course I have nothing of the 5k series here and don't know what is hiding behind the extender covers.

David

I also made my own extender for 500 series scopes. I'm going to continue to search for the male/female connectors and make one.

Seems someone did make a board for the TM500 extender (even fits into a recycled module), maybe someone could make one for the Tek 5000 series, wouldn't be that difficult with KiCAD, assuming they are not the same.

This topic mentions a Rev B of the board.
https://antiqueradios.com/forums/viewtopic.php?p=3632748&sid=59d90369db75ffe66e056953d04ea0a5#p3632748

David

[Vince]

TE downsizing new episode... today we have this Enertec-Schlumberger model 4795 ... 500MHz RF generator, AM/FM modulation, analogue, levelled output.

Got it 7 years ago or something, was told it's faulty, not much details. Never touched it until today.

Goal : see what state it's in, and if possible (read : cheap and quick repair, a few days tops), get it working so I can get more money out of it, or sell it at all really.

Did I mention it's big and VERY heavy......like....VERY heavy !!! 

Symptoms : looks like we have two problems (that I can see, there may be more hiding of course, who knows...)

1) Power supply ? When I flick the power switch, no life on the LED display, but the needle of the galvanometer goes full scale hard.
The weird part : the frequency range switch, if I put it in the "16/32MHz" position, instantly the instrument comes to life ! And if I immediately rotate that switch to any other position, it powers off again ! .. except if I leave it on for a few seconds, then in this case rotating the switch in any position, can't power it off.  Isn't that funky as hell ?! 

2) No output : I scoped the output, nothing but background noise comes out... except when I rotate the frequency range switch, for a split second while the switch transitions from one position to the next, I can see the start of a sine wave cycle, half of it maybe. Works every time, perfectly repeatable (but does it to better in some ranges than others). At first I thought it was read hearing, like the Sin(x)/x interpolation that was just drawing a sine wave in reaction to the transient, but no : I switched the acquisition mode to "linear" as well as "dots", and I get the exact same picture. So, there is indeed something sinusoidal that can manage to get to the output, which is god I guess.
I get the exact same behaviour by another means : there is push button to let your turn off and on the output, quickly. When I play with it, I get the same phenomenon. I guess that switch is, electrically, extremely close to the output connector, so that encouraging as well, means the signal might stopped very close to the output connector, meaning 99.9% of the instrument is probably working fine.

3) The LED display only ever displays : " 0000000000000000000000000 ".... but I guess it's normal. the instrument looks 100% analogue, it's not digital/synthetized, so it's not there to let you SET a desired frequency, but rather only display / measure the frequency of the output signal, then it's up to you to adjust it the way you want. So since we have no output, it makes sense that the display would read zero...


I scoped the rear of the instrument for the internal time base : I get the expected 5MHz reference, a beautifully clean and strong sine wave, so I am very happy with that, it's a good start for sure...

Needless to say I know squat about RF stuff and am completely incompetent and intimidated... have been watching Shahriar for years, he always somehow makes it look easy to fix that kind of stuff, but watching him on my computer, and having an actual such TE full of coax cables and shielded boxes, in the flesh on my bench, is quite something else. Oh my god.... 

I guess that's my chance to see if I actually learned anything from him ?! 

Plan of attack :

I have tons of documentation for this thing, printed on paper, so that's a good start, it's not a black box.
I will try to see how hard it is to check the power rails. Hopefully I just have some dying filter cap in the PSU.
Hopefully that will make it power up, and stay up, reliably. Then I can move on to diagnosing the no-output issue.

Wish me luck...

[factory]

I'm sure you wouldn't have any difficulty selling that even if not working, Electropuces advertised one at 400Euro (presumably working), it's an RF signal generator, which would normally be used for testing radio stuff, but still useful for testing the sensitivity of frequency counters, that is mostly what I use my Marconi TF2008 or HP 8640B for, both of those are heavy too.

The Marconi has the uncommon counter option, it only displays a reading when the RF output is switched on, the counter seems quite unreliable, I recently repaired the faulty digit, a duff 7475 IC this time. While I was in there I replaced the HT cap and two ITT can capacitors in the sig gen part, they were bulging in a bad way, one leaking too. And finally got round to making the plate that prevents accidental switching of the mains voltage selector, no idea why someone would remove this & lose it.

David

[wkb]

Well, 400 €-quid for a known-broken and really ancient instrument.. that would be highly optimistic in my book.

Wilko

[factory]

I'm sure that would be price for working, but even not working is still going to worth something, decent RF signal gens with proper heavyweight screened boxes & attenuator are still used by people repairing radios and comms receivers.

David

[InductorX]

I think I need to join this TEA group, it's anonymous right?

Just bought a DMM6500 still in warranty until next year March, I also got a R&S HMC8043 power supply recently, updated the firmware to the latest so it's definitely working. There's so much more I want, help? 

[TomKatt]

@factory - your avatar looks a lot like my HP 180A scope    Mine is as old as I am and probably in better working condition lol.

Anywho - always wanted one of those fancy development breadboards, so scored a Knight ML2010 at auction for $80.  These are frequently used by schools and mine appears new and unused.  LOTS of buttons and surprisingly useful features such as 3 DC + 1 AC power supplies, Signal generator, Pulse/PWM/PMM gen, etc.

[squadchannel]

Anywho - always wanted one of those fancy development breadboards, so scored a Knight ML2010 at auction for $80.

curiousmarc seems to like it.

[TomKatt]

Anywho - always wanted one of those fancy development breadboards, so scored a Knight ML2010 at auction for $80.

curiousmarc seems to like it.

That's where I got the idea 

Though his is even older and I prefer his desktop version over the suitcase version that mine has.  I just modified the hinges so the top is removable and it works pretty well.

[factory]

@factory - your avatar looks a lot like my HP 180A scope    Mine is as old as I am and probably in better working condition lol.

Anywho - always wanted one of those fancy development breadboards, so scored a Knight ML2010 at auction for $80.  These are frequently used by schools and mine appears new and unused.  LOTS of buttons and surprisingly useful features such as 3 DC + 1 AC power supplies, Signal generator, Pulse/PWM/PMM gen, etc.

It's my rackmount 180A from this post, the avatar is cropped/rotated from the last picture in that post.
https://www.eevblog.com/forum/testgear/test-equipment-anonymous-(tea)-group-therapy-thread/msg3619001/#msg3619001



No idea if it's still working at the moment, really need a bigger bench to set it up, currently I'm working from a small computer desk in the living room, hence why I've got the Marconi TF2008 sig-gen in use, instead of the HP 8640.
On the subject of the HP 180 series, I've noticed hardly any of them have the 100MHz vertical plug-in, for some unknown reason (maybe cost) everyone must have gone for the 50MHz 1801A plug-in.

David

[TomKatt]

On the subject of the HP 180 series, I've noticed hardly any of them have the 100MHz vertical plug-in, for some unknown reason (maybe cost) everyone must have gone for the 50MHz 1801A plug-in.
David

I've got the military version (US Navy) in the vertical desktop case.  It has the 50MHz 1801A plugins.  It's actually a very nice scope, even in today's age.  If you watch any Curiousmarc videos, you'll see he has a 180A as well 

[awesomechapro]

A buddy also has a BWD Powerscope and just looked in my scope manuals folder and I have the 881 manual and schematics.....I think originally from Kevin so a little surprised he no longer hosts it.

Might want to check that your buddy has checked for RIFA caps, just found four of the buggers hiding under a cover in the power supply. Might save them a big headache later on.

Ended up just removing them, as there is an IEC mains filter anyway.

[tautech]

A buddy also has a BWD Powerscope and just looked in my scope manuals folder and I have the 881 manual and schematics.....I think originally from Kevin so a little surprised he no longer hosts it.

Might want to check that your buddy has checked for RIFA caps, just found four of the buggers hiding under a cover in the power supply. Might save them a big headache later on.

Ended up just removing them, as there is an IEC mains filter anyway.

I think a Dr of EE knows all about old RIFA mains filter caps. 

Actually I had to borrow his Kenwood Chef mixer for the wife when ours blew out the magic RIFA smoke when doing the christmas cake annual binge the good Dr so loved.
It took her some years before she would trust it again......

[duckduck]

I think I need to join this TEA group, it's anonymous right?

Just bought a DMM6500 still in warranty until next year March, I also got a R&S HMC8043 power supply recently, updated the firmware to the latest so it's definitely working. There's so much more I want, help? 

What other test equipment are you looking to buy? We can help you. 

[TobyG]

My most recent addition, a Heiden Power 1136 series DC Load/Power Supply with some features specifically tailored towards the automotive sector.

Well...I couldn't help it.
Heiden 1136-042 (42 volts 12A nominal, 24A boost) got added.

Bought on auction, looks like it's been in the bin already, going by the scratches and dents it came with,
nevermind the -initially- missing voltage and current knobs (praised be the 3D printer!).
Works a charm, though.

Same hardware revision as the -016 I have, but older I/O card, with IEEE 488.2/GBIP.
There was an older hardware revision, probably the same internals, but the heatsink of the older one doesn't extend past the case/there is no cutout for the heatsink in the back of the case. And the -042 of the older hardware revision is specced for 10A/20A (boost), only.
Might get a chance to take a closer look at one of those, too, soon.

[factory]

Anyone recognise this German made power connector (made by Hirschmann) and know what the part number of the cable mounted connector is?
It's been fitted to a Meratronik V543 multimeter at some point in the past 35 years, this is not urgent as the DMM is supposed to be faulty (does not respond to any input) and I've got other more urgent things in the repair queue.

David