Test Equipment Anonymous (TEA) group therapy thread

[PA0PBZ]

Yes fairly low cost. Not a lot of practical use. Mode 4 and SIFF are obsolete now. He has complete panel mount transponders cheap too if that's your thing.

It's only the control box, no rf parts anywhere near.

[factory]

Now for some TEA !

Today my good friend visited me... the one who works in Telecom for Orange. You know the one who gave 2 weeks ago this very orange telephone hand set to test copper line, and these 2 huge Alcatel xDSL related boards.... well today he gave yet something ! 

In some technical building he was working in, as per usual... guess what he found ? Some other Tech left something behind ! A handheld xDSL test instrument !  Friend told me it works just fine, and battery even still fully charged ! Whoever lost it, was very recently !

---snip---

There are half a dozen cute little relays in the thing. Keyboard : tactile switches, however not the cheap kind : Look at them, 100% metallic construction ?!     Never seen luxurious ones like that... probably because all the ones I salvaged came form cheap consumer devices, not pro stuff made for field use !

Those switches are also found in some car keys, including those shite thin bendy ones from the Renault Espace, here are a couple I was persuaded to try & fix, can't remember if I was successful or not.


David

[mansaxel]

bought 2 Procurve 24 Port Gigabit switches with 4 SFP-Ports each for 50 Pesos.
The idea is to throw 2 fibre lines between the observatory (not the Winter Garden one, the one with the 2 telescopes) and the control room (30 m away).

I was thinking of using multimode cable buried in a cable tube without any additional special precautions, as this is to be an inexpensive solution to cover a maximum of 50 m ...
Any technical objections ?

(I know, why not also bury a cat 8 cable with it ... ... this is indeed planned ...)

Friends don't let friends run multimode. FS sells nice single mode transceivers and cable to go with it. Make sure you get "hp" firmware in the transceivers, "hp" switches are notorious in not accepting anything that does not look like genuine "hp" rebrand of the same optics you can buy at a fraction if it's unbranded. FS will pour the right secret sauce on the ones you order at no extra cost.

Finally: An optical connection is not to be mated until you have verified that the ferrules are clean. Cleaning and hoping it worked is not going to be good enough.

[factory]

Looked around and found the suicide cord, so I decided to quickly apply power to the 120B.  (Four AM on a work night, why go to bed?  That would be the sensible thing to do... )

No immediate smoke; it's drawing the roughly correct amount of power and I can get something on the screen with the beam finder.  There is at least some sweep, but the trace is off the screen to the top and the vertical controls have no effect whatsoever.  On the bright side, it isn't completely dead!   

View into top with cover off:


Detail of glowie bits:


Beam found:


Early 1966 engineering rev, and the 8005th one made:


-Pat

I was wondering if you had bought the 120B, glad to see you got it.
You rarely see anything other than standard P31 CRT with hp scopes, P7 occasionally and P11 quite uncommon, I've only got that P11 special high writing rate CRT (intended for use with scope cameras) for the 175A and possibly the 183B has one too. Also have a P7 140A and an untested P7 180A.

Oh no you beat me to it !

I too got an HP 120B recently, meant to start restoring it pretty soon, was very excited to post about it, but too late you came first ! 

Mine is Gemra made,  G245-00364.  So S/N much older than yours, or is the S/N specifict to each and every manufacturing plant ?! That's something I have never been able to determine for my old Tek scopes.

Anyway yours look beautiful with this blue CRT !
I immediately notice that the caps look of a newer/ better type, so your unit might quite recent.
I mean I am looking at the two side byt side axial caps at the back of the trigger switch assembly, the type that always fails I gather... on mine they are completely rotten, but yours look brand new.
Other clue : the shield on your CRT looks new, the pain I mean... mine is badly flaking off ! 

I don't even know if mine will power up... it's missing half its tubes ! 
.. so no idea about phosphor colour, hey maybe I will get lucky and have  a blue one like you ! No, not likely !


Anyway, looking forward to your restoration, and can't wait to start mine. Before I do anything with it, would like to buy a Variac as I can't afford to blow it.. have many Tek spares but only this one and only HP scope, zero parts handy to fix it if I screw up ! 

Build yourself a lamp limiter (aka dim bulb tester) & add a couple of lamps in parallel if needed. Much cheaper than a variac and you don't have the problem of variacs getting trashed by poor packing, assuming they weren't burnt out by the last owner/user.

And yes the hp serial numbers are specific to each factory, they may or may not have started at number 00100 for each site (I have seen the occasional one below 00100), German made ones are extra confusing as they rarely ever seem to be documented in the manuals and they often added or changed bits.

Just think how difficult it would have been in the 1960's if they had wanted to make them sequential across all sites in the world, imagine them calling up in the middle of the night to the US to allocate a batch of serial numbers , it would never happen, but could these days with the web.

David

[Saskia]

bought 2 Procurve 24 Port Gigabit switches with 4 SFP-Ports each for 50 Pesos.
The idea is to throw 2 fibre lines between the observatory (not the Winter Garden one, the one with the 2 telescopes) and the control room (30 m away).

I was thinking of using multimode cable buried in a cable tube without any additional special precautions, as this is to be an inexpensive solution to cover a maximum of 50 m ...
Any technical objections ?

(I know, why not also bury a cat 8 cable with it ... ... this is indeed planned ...)

Friends don't let friends run multimode. FS sells nice single mode transceivers and cable to go with it. Make sure you get "hp" firmware in the transceivers, "hp" switches are notorious in not accepting anything that does not look like genuine "hp" rebrand of the same optics you can buy at a fraction if it's unbranded. FS will pour the right secret sauce on the ones you order at no extra cost.

Finally: An optical connection is not to be mated until you have verified that the ferrules are clean. Cleaning and hoping it worked is not going to be good enough.

Kindly enlighten me. Why not Multimode ? Especially if we are talking only 30 - 50 m ?

[Cubdriver]

I was wondering if you had bought the 120B, glad to see you got it.
You rarely see anything other than standard P31 CRT with hp scopes, P7 occasionally and P11 quite uncommon, I've only got that P11 special high writing rate CRT (intended for use with scope cameras) for the 175A and possibly the 183B has one too. Also have a P7 140A and an untested P7 180A.

David

Yes - thanks again for the tip on it!  Sounds like you have an interesting stable of old HP scopes there.

-Pat

[Cerebus]

bought 2 Procurve 24 Port Gigabit switches with 4 SFP-Ports each for 50 Pesos.
The idea is to throw 2 fibre lines between the observatory (not the Winter Garden one, the one with the 2 telescopes) and the control room (30 m away).

I was thinking of using multimode cable buried in a cable tube without any additional special precautions, as this is to be an inexpensive solution to cover a maximum of 50 m ...
Any technical objections ?

(I know, why not also bury a cat 8 cable with it ... ... this is indeed planned ...)

Friends don't let friends run multimode. FS sells nice single mode transceivers and cable to go with it. Make sure you get "hp" firmware in the transceivers, "hp" switches are notorious in not accepting anything that does not look like genuine "hp" rebrand of the same optics you can buy at a fraction if it's unbranded. FS will pour the right secret sauce on the ones you order at no extra cost.

Finally: An optical connection is not to be mated until you have verified that the ferrules are clean. Cleaning and hoping it worked is not going to be good enough.

Kindly enlighten me. Why not Multimode ? Especially if we are talking only 30 - 50 m ?

Because he's a singlemode snob. I was back in the days when I used to have to get signals kilometres or into and out of DWDM to let them someone else take them millions of metres but for stuff just at home I use multimode nowadays.

[tggzzz]

bought 2 Procurve 24 Port Gigabit switches with 4 SFP-Ports each for 50 Pesos.
The idea is to throw 2 fibre lines between the observatory (not the Winter Garden one, the one with the 2 telescopes) and the control room (30 m away).

I was thinking of using multimode cable buried in a cable tube without any additional special precautions, as this is to be an inexpensive solution to cover a maximum of 50 m ...
Any technical objections ?

(I know, why not also bury a cat 8 cable with it ... ... this is indeed planned ...)

Friends don't let friends run multimode. FS sells nice single mode transceivers and cable to go with it. Make sure you get "hp" firmware in the transceivers, "hp" switches are notorious in not accepting anything that does not look like genuine "hp" rebrand of the same optics you can buy at a fraction if it's unbranded. FS will pour the right secret sauce on the ones you order at no extra cost.

Finally: An optical connection is not to be mated until you have verified that the ferrules are clean. Cleaning and hoping it worked is not going to be good enough.

Kindly enlighten me. Why not Multimode ? Especially if we are talking only 30 - 50 m ?

Because he's a singlemode snob. I was back in the days when I used to have to get signals kilometres or into and out of DWDM to let them someone else take them millions of metres but for stuff just at home I use multimode nowadays.

When I started working with optical fibres, it was multimode only; single mode was still being explored by GPO Martlesham Heath and others.

[BU508A]

Do you remeber this lot of six devices which I've picked up on Sunday afternoon?

With this posting I'm going to start a mini series, called

Echoes from a distant past

Part one - The Siemens Rel. send. 22b

Edit:
Part one - The Siemens Rel. send. 22b
Part two - The Two Transformers
Part three - The Rohde & Schwarz NGU laboratory power supply unit for vacuum tubes
Part four - The Rohde & Schwarz Vacuum Tube Meter URI BN 1050
Part five - The Rohde & Schwarz UVN BN 12001 NF Millivoltmeter
Part six - The Nordmende digital multimeter DIVO 3355 (with Nixie tubes!)

Hello,

I'm starting with the oldest device in this lot (based on the date on the manual: November 1946), the test transmitter Rel. send. 22b from Siemens & Halske (in cooperation with Telefunken). It can generate output frequencies between 80kHz and 28MHz. The output can be modulated (AM) with the internal 400Hz oscillator or modulated from an external source. Output goes from several 10mV down to 8µV.

I haven't switched it on yet because I want to take a closer look at the mains cable and the electrolytic capacitor first.
The device itself is in a very good shape, nearly no rust and the variable capacitor for tuning the output frequency works smoothly.

Let's start with the pictures.
First, the documents which I got with the device.
Please note: the parts list is saying 2x EF12 but the tubes are 2x AC2. The rectifier tube is a RGN354. I'm not sure where those differences are coming from. EF12 is a pentode tube but the tubes being used here are triodes.



Some personal notes of the previous previous owner. I was told, that he was a technician at Radio Bremen.
Translation of the handwritten note:
"Excerpt from the "Handbook of Broadcast Repair Technology". W. Diefenbach, Franke Verlagshandlung Stuttgart. Copyright 1948 - Publisher number 2474"



Views of the outside with some details. The RF output socket is the same as in old car radios.



The mains cable and the plug need some closer inspection / repair / cleaning.
The fuse is a 500mA 5x25mm type. While pulling it out I've destroyed it. 
Replacements are already ordered (correct value is 250mA as per manual). 



Looks of the inside, left back side, mid bottom side, right front side.



Various switches, this transmitter has a few of them. 
Mains switch, frequency range switch (top side), frequency range switch (bottom side), attenuator switch (coarse) with red resistors, switch internal / external modulation and a switch at the banana socket, disabling the internal capacitor for the 400Hz oscillator when an external capacitor will be used to change the modulation frequency between 200Hz and 4000Hz.



Detailed views of some parts.
Rectifier (not sure, if this is a selenium rectifier), electrolytic capacitor with datecode 4/63, the variable capacitor for tuning the frequency, trimming capacitors to trim the frequency ranges (e.g. after changing the oscillator tube), one of the oscillator tubes, I think this one is for the 400Hz oscillator (unverified)



This is a mod of the rectifier tube. I think, it is related to the notes from above but I haven't checked this yet.
Detailed view of the frequency scale.



I hope, you've enjoyed this teardown. Please stay tuned for part two: the two transformers.

Thank you for watching.

[Robert763]

I shown an in-service optical fibre in 1979. It was a telephone link in the USA. A Big Deal back then. I was 17

[med6753]

No TE today. Yesterday got 2nd Covid shot. Everyone said the 2nd shot on the next day you will feel side effects. I'm happy to report other than sore spot at injection site no side effects.

Today was follow-up appointment with urologist. Bottom line: see you in 6 months. 

Next week is follow up with the hernia surgeon. I expect that appointment to take about 5 minutes. 

[mansaxel]

Kindly enlighten me. Why not Multimode ? Especially if we are talking only 30 - 50 m ?

Because multimode is going to have a hard time with as slow speeds as 10Gbit/s over 50m, unless you have special mode conditioning patches, the right OM<number> cable, et c.

When you want to do 100G you're out of luck.

In contrast, singlemode will laugh at anything <2000m, and only require effort at 100G; but I run 100G over 28km spans of dark fiber, in the 1310nm band, and in parallel with 40 channels of 10G down at 1510nm. And that's with the 1-2dB of loss in a passive filter.

Why is this so? (some hand-waving below, please excuse. I'm pretty sure I don't get the fundamentals wrong.)

The secret is in the name. Multimode works by having the same signal modulate several parallel rays of light (modes) into a fairly thick optical fiber, 50 or 62,5µm. This is done so optics (transmitters and sensors) and fibers can be made more cheaply. The cheapness also dictates that all modes aren't coupled into the glass exactly parallel, and that they're confined to the core of the fiber by reflecting on the cladding, essentially bouncing around. Since not all modes bounce exactly alike (more so in 62,5µm than 50µm cable) there is going to be a hazy aggregate waveform on arrival, where the eye diagram of the received transmission will degrade directly related to length, even if the signal is strong enough. I use the concept of "light reverberation" to describe the problem, since it is exactly the same but with light:
The Kölner Dom, with its 13s RT60 is going to put some restraints on how fast you can speak and still be understood.

In contrast, single mode fiber systems couple all light in one mode, straight into the 9µm core, and the doping of the glass is such that the light mode is steered, rather than bounced, along the glass. As long as you have sufficient signal levels, the waveform is going to be sharp, regardless of distance.  This used to be much more expensive, but thanks to massive metro- and longhaul markets creating demand for singlemode optics and cables, not anymore.

Today, the prices are similar, and the only thing speaking for multimode is that is worse.

[Specmaster]

No TE today. Yesterday got 2nd Covid shot. Everyone said the 2nd shot on the next day you will feel side effects. I'm happy to report other than sore spot at injection site no side effects.

Today was follow-up appointment with urologist. Bottom line: see you in 6 months. 

Next week is follow up with the hernia surgeon. I expect that appointment to take about 5 minutes. 

That is I think good news yes?

[mnementh]

this is just for tracking my rockets .... I don't know what you are afraid of.

Anybody got a GPS that is good for > mach 5 ?

What am I afraid of...?

A) I have a whit of common sense

2) The remote for my suborbital crowbar launcher is AWOL again.

Those, compounded with you having long-range observation and ranging capability... even if you can't see me around the curvature of the earth, still a legitimate concern for some of our members...

mnem
...and anyone else who may have pissed you off. *coughPinballMachineGuycough*

[med6753]

No TE today. Yesterday got 2nd Covid shot. Everyone said the 2nd shot on the next day you will feel side effects. I'm happy to report other than sore spot at injection site no side effects.

Today was follow-up appointment with urologist. Bottom line: see you in 6 months. 

Next week is follow up with the hernia surgeon. I expect that appointment to take about 5 minutes. 

That is I think good news yes?

Yep. 

[Specmaster]

Looks like I should get my input jacks for the Fluke tomorrow, fingers crossed. It has made good progress once it arrived at Heathrow Cargo 

[mnementh]

Sore point that  . No bought lights 

So... a well-lit shithole then...?

mnem
Just like this place...

[mnementh]

I bought a Keithley 197A off of Craigslist. ... Green backlight is pretty dim.

I'm having th same prob with another DMM from the same era. Lighting is by a PCB with dozens of microscopic SMD-LEDs, all of them covered in blobs of some transparent glue that has obviously hardened/shrinked and cracked most of those LEDs.

Ralf

Sorted.

      

You can do better. I'm a blithering idiot and I managed this.

mnem
 

[Saskia]

Kindly enlighten me. Why not Multimode ? Especially if we are talking only 30 - 50 m ?

Because multimode is going to have a hard time with as slow speeds as 10Gbit/s over 50m, unless you have special mode conditioning patches, the right OM<number> cable, et c.

When you want to do 100G you're out of luck.

In contrast, singlemode will laugh at anything <2000m, and only require effort at 100G; but I run 100G over 28km spans of dark fiber, in the 1310nm band, and in parallel with 40 channels of 10G down at 1510nm. And that's with the 1-2dB of loss in a passive filter.

Why is this so? (some hand-waving below, please excuse. I'm pretty sure I don't get the fundamentals wrong.)

The secret is in the name. Multimode works by having the same signal modulate several parallel rays of light (modes) into a fairly thick optical fiber, 50 or 62,5µm. This is done so optics (transmitters and sensors) and fibers can be made more cheaply. The cheapness also dictates that all modes aren't coupled into the glass exactly parallel, and that they're confined to the core of the fiber by reflecting on the cladding, essentially bouncing around. Since not all modes bounce exactly alike (more so in 62,5µm than 50µm cable) there is going to be a hazy aggregate waveform on arrival, where the eye diagram of the received transmission will degrade directly related to length, even if the signal is strong enough. I use the concept of "light reverberation" to describe the problem, since it is exactly the same but with light:
The Kölner Dom, with its 13s RT60 is going to put some restraints on how fast you can speak and still be understood.

In contrast, single mode fiber systems couple all light in one mode, straight into the 9µm core, and the doping of the glass is such that the light mode is steered, rather than bounced, along the glass. As long as you have sufficient signal levels, the waveform is going to be sharp, regardless of distance.  This used to be much more expensive, but thanks to massive metro- and longhaul markets creating demand for singlemode optics and cables, not anymore.

Today, the prices are similar, and the only thing speaking for multimode is that is worse.

ok, I see. This application calls for 1G tops, there are no plans to go any faster than this. So even with Single mode the maximum we would go for would be 1000-LX for preferably 2 cables going through that cable guide.
I am looking at the single mode cable, combining https://www.fs.com/de/products/32152.html with https://www.fs.com/de/products/97941.html (I know that's not meant to be a patch cable, but it is available in 50m length and for use outside) or https://www.fs.com/de/products/106591.html (which would be a patch cable).

Actually the cable would be less expensive than the multimode cable, if only 30m were needed. Am I on the right track ? Could I use the FTTA-cable to hook up to switches in case I need 50 m ?

[Saskia]

this is just for tracking my rockets .... I don't know what you are afraid of.

Anybody got a GPS that is good for > mach 5 ?

What am I afraid of...?

A) I have a whit of common sense

2) The remote for my suborbital crowbar launcher is AWOL again.

Those, compounded with you having long-range observation and ranging capability... even if you can't see me around the curvature of the earth, still a legitimate concern for some of our members...

mnem
...and anyone else who may have pissed you off. *coughPinballMachineGuycough*

ah, poppycock. Mostly harmless and no dyed hair yet. No time to fart around anyway, need to get back into Ketosis, work on my health, and have the company doctor appointment on Thursday regarding permanent teleworking.

[mnementh]

Now for some TEA !

Today my good friend visited me... the one who works in Telecom for Orange. You know the one who gave 2 weeks ago this very orange telephone hand set to test copper line, and these 2 huge Alcatel xDSL related boards.... well today he gave yet something ! 

In some technical building he was working in, as per usual... guess what he found ? Some other Tech left something behind ! A handheld xDSL test instrument !  Friend told me it works just fine, and battery even still fully charged ! Whoever lost it, was very recently !

---snip---

There are half a dozen cute little relays in the thing. Keyboard : tactile switches, however not the cheap kind : Look at them, 100% metallic construction ?!     Never seen luxurious ones like that... probably because all the ones I salvaged came form cheap consumer devices, not pro stuff made for field use !

Those switches are also found in some car keys, including those shite thin bendy ones from the Renault Espace, here are a couple I was persuaded to try & fix, can't remember if I was successful or not.


David

Also found in my cheap-ass curb-score Samsuck TV... and on Amazon for $12 delivered: https://www.amazon.ca/gp/product/B07LCBLB8N

mnem
*clicky-clicky...clickety-clickety...*

[Saskia]

nice find.

[mnementh]

this is just for tracking my rockets .... I don't know what you are afraid of.

Anybody got a GPS that is good for > mach 5 ?

What am I afraid of...?

A) I have a whit of common sense

2) The remote for my suborbital crowbar launcher is AWOL again.

Those, compounded with you having long-range observation and ranging capability... even if you can't see me around the curvature of the earth, still a legitimate concern for some of our members...

mnem
...and anyone else who may have pissed you off. *coughPinballMachineGuycough*

ah, poppycock. Mostly harmless and no dyed hair yet. No time to fart around anyway, need to get back into Ketosis, work on my health, and have the company doctor appointment on Thursday regarding permanent teleworking.

Of course it is. Hello...! mnem the fat dwagon, purveyor of "that's just 6 kinds of wrong" and 99 other flavors of poppycock...? Any of that ring a bell...?

mnem
*waves* Have we met...?

[mnementh]

Looks like I should get my input jacks for the Fluke tomorrow, fingers crossed. It has made good progress once it arrived at Heathrow Cargo 

What they're not telling you is it's actually the national sorting center just south of me in Mississauga. 

mnem
 

[tggzzz]

I shown an in-service optical fibre in 1979. It was a telephone link in the USA. A Big Deal back then. I was 17

There were a small number of in-service multimode links in the UK in 1978; they were effectively "pilot plants" rather than "lab experiments". Even as late as 82 when I left the field, multimode dominated installed fibres - but single mode was clearly the future.