Test Equipment Anonymous (TEA) group therapy thread

[Ice-Tea]

PM5715. Seems to mostly work but the ranges jump all over the place if you think about it for too long. Not really a device I can spend too much time on, but I obviously can't resist popping the hood.

Suspect Philips radials all over the place, can't really afford to replace them anyhow, so not touching those.

The selector switches are open construction, old style and dirty. The ranges jumping around can probably be tied to that. The only problem is that I can't really access the contact area of the wipers. When applying contact spray I can remove a lot of crud, but not where it matters (inside of the contacts). Anyways, giving it a good soak, hoping it will be enough.

[factory]

I'll take the Mullard/Philips radials over the ITT ones. 

Beware that capacitor/filter attached to the IEC inlet, they like to short.

And you get the bonus of disguised tants  , in the cube/cuboid blocks.

David

P.S. The HP 416B ratio meter arrived safely from France on the 26th, forgot to post the picture.

[Vince]

Glad it arrived OK, great to see it in your lab on the other side of the channel, looking forward to seeing it fixed up and working one day... shouldn't be too hard to fix I think.

[Vince]

PM5715. Seems to mostly work but the ranges jump all over the place if you think about it for too long. Not really a device I can spend too much time on, but I obviously can't resist popping the hood.

Suspect Philips radials all over the place, can't really afford to replace them anyhow, so not touching those.

The selector switches are open construction, old style and dirty. The ranges jumping around can probably be tied to that. The only problem is that I can't really access the contact area of the wipers. When applying contact spray I can remove a lot of crud, but not where it matters (inside of the contacts). Anyways, giving it a good soak, hoping it will be enough.

I see them every now and then for sale here on leboncoin.fr , at 50 Euros usually.
I have been tempted once or twice... they are light and compact yet featureful and good specs, which fits my criteria. My digital GX5000 is more cumbersome to use, it's more suited to testing than development.

What a coincidence, right now, I am working on a analogue pulse gen of the same vintage. Not a Philips but a Tekelec-Airtronic TE 110 B . Too large for me and doesn't even work and not my "type"...and unsaleable if that's even a word.

Tomorrow morning I plan on similarly "processing" my GOULD 1604 scope, an engineering horror. Then in the afternoon, will do the same to my Tek 2215 scope. It's ill-born, beyond repair/fucked up, and an atrocity. Not every Tek scope made was grandiose, you gotta keep your critical thinking cap on...



Taking it apart as we speak. A few bits and bobs worth salvaging but not much.

[m k]

Am I seeing my own with PM5715?

Side connector between green and brown boards seem to be differently inserted from above and below.

[factory]

No it is wonky, the green board has come out of the mount at the side, the side board is banana shaped and the bracket bent by the power trannystors.
I think the Philips function gen I've been working on is just as bad, not helped by the possibility it was dropped at some point.

David

[Addicted2AnalogTek]

I've been rotating between two 485's on the workbench, trying to get each one of them repaired enough to calibrate without having to repeatedly stop for more repairs. First and foremost, I had to get the power supplies operational and correct, which was nothing more than a bunch of bad dipped tantalum capacitors. Working through the performance checks revealed the "Round 1" repairs for each unit. Aside from the basic adjustments needed, such as timebase, triggering, dc balance, z-axis, and front panel lights that are out, each has their own major issue to resolve.

Unit 1, B191843, has extremely loose, dirty, and noisy triggering switches.   I already went ahead and transplanted a much newer, cleaner set (A & B trigger coupling & source switches) from the donor scope, which was FAR from easy. I couldn't have done it without the little 5mm nut driver from my iFixit kit, some ignition wrenches, and some nice needle nose pliers - unless I opted to remove the entire front face frame from the chassis to get to them that way.

Unit 2, B166802, Both channels have a -3dB well over 500Mhz, so I'm expecting issues there. I have yet to take a look at rise time, but I'll have a look at that next. Channel 1 coupling switch also seems to have a mechanical alignment issue, and the V/div drum is either worn or loose, as in lateral movement.


Since these aren't just your average old scopes, I've decided to go through each step of the calibration procedure. I will be rotating almost every trimpot and trimmer cap to be certain that it is functional and in good condition. I'm not touching the inductors unless I have to, though. If I don't have to risk splitting a core in half, I'm not going to.

[ME]

the github link addy in the pic gives 404 not found.

[tautech]

I've been rotating between two 485's on the workbench, ............

Unit 2, B166802, Both channels have a -3dB well over 500Mhz, so I'm expecting issues there. I have yet to take a look at rise time, but I'll have a look at that next. Channel 1 coupling switch also seems to have a mechanical alignment issue, and the V/div drum is either worn or loose, as in lateral movement.

What are you expecting to see when the 485 is rated at just 350 MHz BW ?

[Addicted2AnalogTek]

I've been rotating between two 485's on the workbench, ............

Unit 2, B166802, Both channels have a -3dB well over 500Mhz, so I'm expecting issues there. I have yet to take a look at rise time, but I'll have a look at that next. Channel 1 coupling switch also seems to have a mechanical alignment issue, and the V/div drum is either worn or loose, as in lateral movement.

What are you expecting to see when the 485 is rated at just 350 MHz BW ?

I should reach the -3dB point around 265Mhz at 1M input impedance and around 375Mhz at 50 Ohm input impedance. Significantly less or significantly more and I expect there to be compensation issues.

[TERRA Operative]

Just fixed my spare EPM-442A 2-channel power meter. 

Got it cheap with a busted channel. Was able to measure the signals at the test points on the good input module to narrow down the fault in the bad one.

Turned out to be a jellybean TL074C opamp that went faulty, which I had spares of, so now it's all fixed. Win!
Should be able to sell it off for a decent price...


Now to find a spare input jack to install into my other single channel power meter, an E4418B (it has a serial port that the A model doesn't have) to upgrade it to a 2-channel E4419B model. I got all the other parts needed, including a new front panel sticker.
Just that input connector is a little hard to find...



I'm currently recapping a HP 4263A LCR meter that was bought for work. The caps were very much leaked requiring PCB repairs, but it's going smoothly.
It was filthy inside, but the dust washed foo easily, thankfully revealing an interior in perfect condition (minus the capacitor damage).
I'll also be able to update my 4263B option unlocker script to also work with the A model now too, so that's cool.
https://github.com/JaredCabot/HP-Agilent-4263B-Option-Unlocker



I also won an auction on a Tektronix THM565 too. It looks to be in great condition and has accessories, so that will be fun to play with when it arrives.
(Picture is from the auction).

[wkb]

Just fixed my spare EPM-442A 2-channel power meter. 

Got it cheap with a busted channel. Was able to measure the signals at the test points on the good input module to narrow down the fault in the bad one.

Turned out to be a jellybean TL074C opamp that went faulty, which I had spares of, so now it's all fixed. Win!
Should be able to sell it off for a decent price...


Now to find a spare input jack to install into my other single channel power meter, an E4418B (it has a serial port that the A model doesn't have) to upgrade it to a 2-channel E4419B model. I got all the other parts needed, including a new front panel sticker.
Just that input connector is a little hard to find...



I'm currently recapping a HP 4263A LCR meter that was bought for work. The caps were very much leaked requiring PCB repairs, but it's going smoothly.
It was filthy inside, but the dust washed foo easily, thankfully revealing an interior in perfect condition (minus the capacitor damage).
I'll also be able to update my 4263B option unlocker script to also work with the A model now too, so that's cool.
https://github.com/JaredCabot/HP-Agilent-4263B-Option-Unlocker



I also won an auction on a Tektronix THM565 too. It looks to be in great condition and has accessories, so that will be fun to play with when it arrives.
(Picture is from the auction).

The input connectors have this slightly weird cir-clip mount, and of course the flex circuit to connect to the measurement PCB. I have never seen this connector mounting style apart from these HP meters. Hopefully not a HP custom jobby?

Wilko

[factory]

I also won an auction on a Tektronix THM565 too. It looks to be in great condition and has accessories, so that will be fun to play with when it arrives.
(Picture is from the auction).

Make sure you replace the peeing Nichicons before attempting to power it up (& hope the previous owner didn’t power it up), failure to do so can destroy the power supply converter ICs, they were $10 each a few year ago.

https://www.eevblog.com/forum/testgear/test-equipment-anonymous-(tea)-group-therapy-thread/msg5019691/?topicseen#msg5019691

David

[TERRA Operative]

The auction pics show it powered on and working, so I might be lucky that it isn't busted, but it will be summarily recapped as soon as I get my hands on it.

[AVGresponding]

I'm currently recapping a HP 4263A LCR meter that was bought for work. The caps were very much leaked requiring PCB repairs, but it's going smoothly.
It was filthy inside, but the dust washed foo easily, thankfully revealing an interior in perfect condition (minus the capacitor damage).
I'll also be able to update my 4263B option unlocker script to also work with the A model now too, so that's cool.



https://github.com/JaredCabot/HP-Agilent-4263B-Option-Unlocker

What the heck..? Was it run with the cover off in a dust factory all its life?

[TERRA Operative]

Yeah, good question, it doesn't even have a fan!

[Runco990]

I bought one of those TEK Meters a year ago.  Didn't power it on, looked inside first.  Looked PERFECT, but ordered the caps anyway.  Well... once I removed the old one's... there it was.  They DID start leaking.  I also replaced the caps on the other side, that seem to affect the meter part.  They were due.  The unit now works perfect, and I'm trying to figure out WHY I bought the silly thing in the first place!  TEAS is an affliction.... 

[factory]

Yes all six were leaking* in my Tek THM565, luckily for me the battery tray was corroded & not making a good connection, so the seller wasn't able to bugger it up further.
It's a handy small isolated scope (not very high spec these days) and not some unsafe junk from no-name brands.

*Some of the same surface mount caps are used in the THS7xx series too, but hadn't leaked in mine, the through hole ones were just starting to pee though.

David

[Ice-Tea]

Am I seeing my own with PM5715?

Eh? Not sure what you're saying?

Also: factory called it. Noticed after posting the vertical board is distinctly banana shaped. Not sure if I'll try to fix that too.

[m k]

Single row connector is not connecting like that very easily.

Yeah, good question, it doesn't even have a fan!

Maybe it actually was cover off for extra ventilation in high ambient temp environment.

[Vince]

Next in line in my TE downsizing adventure : an HP 4951C
[...]
Not holding much hope for this thing, but if you don't try you don't get 

A miracle happened... I found a taker for the little HP, his life is spared ! 
Goes to my retired EE friend in France. Maybe he can get it going again...

[Addicted2AnalogTek]

While working on the 485's, I had the opportunity to take side-by-side photos of the 670-1512-01 (1974) Hi-Z board and the -06 variant (1980). The provided dates are only these particular boards.

https://imgur.com/a/MXvq8XA

Upon looking around for manual change information, I found M34869 (670-1512-02 Hi-Z revision), M35808 (670-1512-04 Hi-Z revision, 670-1662-01 A7 Vertical Board) on Tekwiki and others, and I have M39817 Rev. 1 (670-1662-04 A7 Vertical Board, 670-1666-02 A11 H Amplifier Board) and M38853 (C57 & R57 addition to Hi-Z with 337-1478-03 Attenuator Bottom Shield) in my paper copy.  I'll scan and post the two Manual Change documents from my manual soon. Does anyone else have any other 485 manual change documents?

Edit: Removed the enormous inline image I had. It's just a thumbnail now.

[awesomechapro]

Just picked up this BWD "Power Scope." Appears to be hand-assembled in Australia! Came with all 9 proprietary high voltage probes, and the instruction manual.



It is an interesting scope, with 4 differential channels at a 30Mhz bandwidth, plus one addition regular channel at a 50Mhz bandwidth. It can go all the way up to 200V/Div, and can measure signals up to 1000V! It also has a multiplication feature to measure power real-time, and a digital phase angle measurement function.

Will make a fine addition to my collection

[tautech]

Yep totally Ozzie made.
Just would happen to be 881A manual is the one Kevin doesn't have:
https://www.kevinchant.com/bwd.html

[awesomechapro]

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