Author Topic: List your test equipment "scores" here!  (Read 504785 times)

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Offline VK5RC

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Re: List your test equipment "scores" here!
« Reply #975 on: November 02, 2016, 09:57:25 am »
I always feel I should pay the price agreed at the deal unless it is not as promised, I was a little bit upset when it arrived and it didn't work and sent off a polite  email and he was nice about it. The postage to return it would have been a killer , the seller was happy to strike a fair part refund and when it turned out to be a simple cable issue, perhaps it spent a lot of the trip upside down. I too want to encourage the good sellers with a fair deal.
Whoah! Watch where that landed we might need it later.
 

Online bitseeker

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Re: List your test equipment "scores" here!
« Reply #976 on: November 03, 2016, 10:12:29 pm »
Agreed. Good sellers are few and far between.
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Offline krivx

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Re: List your test equipment "scores" here!
« Reply #977 on: November 04, 2016, 10:14:51 am »
Is it worth taking the rust off files? I always assumed it would round the teeth and they wouldn't cut. My father has a box of rusty files, I wonder if I should take a brass brush to them.
 

Online Berni

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Re: List your test equipment "scores" here!
« Reply #978 on: November 04, 2016, 10:46:42 am »
Is it worth taking the rust off files? I always assumed it would round the teeth and they wouldn't cut. My father has a box of rusty files, I wonder if I should take a brass brush to them.

I seen someone take a wire wheel to files and then dunk them in acid for a bit to restore and "sharpen" them. But im not sure why would that work, but if anything it would get the crap out of the groves so it can dig in properly. Etching it should round and dull the teeth if you ask me.
 

Offline krivx

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Re: List your test equipment "scores" here!
« Reply #979 on: November 04, 2016, 11:08:12 am »
I am almost certain that acid "sharpening" is a myth.
 

Online Cubdriver

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Re: List your test equipment "scores" here!
« Reply #980 on: November 04, 2016, 04:23:48 pm »
I am almost certain that acid "sharpening" is a myth.

That's my thought as well - it would seem that the 'finer' features (such as sharp cutting edges) would be the FIRST thing that the acid would etch away, rounding and dulling them as the post above yours suggests.  Seems like a good way to TRASH a file, rather than sharpening it.  If you can put it into something that would dissolve whatever swarf is trapped in the grooves and NOT the file, that could clean it out well and potentially make it cut better if it's clogged up, but I fail to see how something like that could sharpen it at all.

-Pat
If it jams, force it.  If it breaks, you needed a new one anyway...
 

Offline SeanB

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Re: List your test equipment "scores" here!
« Reply #981 on: November 04, 2016, 07:19:24 pm »
To derust simply use a wire brush, hand held, and brush parallel to the teeth. On a crosscut file you need 2 passes, to get both angles of the teeth, then wash with some kerosene ( paraffin in the rest of the world) to clean the debris out. Then after that use a cloth dampened with light mineral oil to rub off all the remaining rust, and store where it will be dry. A wooden drawer that has bare wood, oiled with furniture oil, works best as a rust preventer, as the volatile oil compounds evaporate over the tools with time. You can buy corrosion protector tabs that are basically an oil soaked sponge that do the same.
 
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Offline AlfBaz

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Re: List your test equipment "scores" here!
« Reply #982 on: November 04, 2016, 11:32:29 pm »
... kerosene ( paraffin in the rest of the world)
kerosene here (kero)

The brush to use on files is called a card brush

 
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Online bitseeker

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Re: List your test equipment "scores" here!
« Reply #983 on: November 05, 2016, 01:41:20 am »
The brush to use on files is called a card brush

Aha! I've seen those. Didn't know what they were for or called.
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Offline CJay

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Re: List your test equipment "scores" here!
« Reply #984 on: November 05, 2016, 11:55:57 am »
The brush to use on files is called a card brush

Definitely, from what I remember using a brass brush on a file is a pretty good way to wreck it and if my metalwork (shop?) teacher caught us using anything other than the card brush we would be given a stern lecture about how not to destroy his files. (filing aluminium without using a lubricant was also a fairly dangerous thing to risk getting caught doing)
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Offline TerraHertz

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Re: List your test equipment "scores" here!
« Reply #985 on: November 05, 2016, 05:37:23 pm »
The brush to use on files is called a card brush

Definitely, from what I remember using a brass brush on a file is a pretty good way to wreck it and if my metalwork (shop?) teacher caught us using anything other than the card brush we would be given a stern lecture about how not to destroy his files. (filing aluminium without using a lubricant was also a fairly dangerous thing to risk getting caught doing)

I'm amazed at the things people say & believe sometimes.
Please explain how soft, fine brass wire tips are going to damage the high-carbon steel of a file? Considering that the file can cut into solid brass all day and not get blunt.
As opposed to the hardened spring steel of any kind of steel wire brush. You _can_ use a steel wire brush, if you're careful to only run parallel to the file grooves. Which you do if you're trying to remove stuck swarf. Go the other way and you might as well file hardened steel (ie throw the file away, because you just ruined it.)
The card brush is useful because the bristles are both short and mounted in a flexible base sheet that allows them to tilt. So it's a way to apply a stiff but limited force to stuck swarf. But I don't bother with them - just one more rarely used special tool I can do without.

Personally to clean files I never use anything but soft brass wire brushes, and kerosene as a releasing/penetrating lubricant (because it's cheaper than WD40.) If some metal has stubbornly stuck, then run the tip of a scriber along the file grooves that need cleaning.

Removing surface rust is a different problem to stuck swarf, since it's all over all surfaces. Needed some scrubbing across the grooves too, so definitely only with a brush much softer than the steel.

Actually it was surprising. I don't know what wear-state the files were in before they were left to rust in a tub of rainwater for a while. But after scrubbing the rust off (and high-carbon steel seems to rust less than other steels) the files were all very sharp, like near new. Maybe a little rusting is similar to the acid-etch sharpening method?

And though I've never tried acid-etch (keep meaning too), I don't know why some people can't see how it would work. The solution doesn't preferentially eat corners, it takes off _surface_. So, think of a triangular point, but with the point slightly rounded. Now remove a little of all surfaces. Yes, it reduces the radius of the rounded bit, and can re-create a sharp point.

Btw, I had some more contact with the people who tossed that Tektronix digital video gen. And did score some other assorted bits and pieces, more on that later. But the answer to the mystery is that the owner was a hoarder, the Tek was something he bought at an auction, and no he didn't have the rest of an editing suite to go with it. Which was a great relief in a way, since the first person I spoke to with good English mentioned they'd already sent piles of stuff to recycling, and I was getting pretty depressed wondering if some really nice things had been scrapped. Still wish I'd seen the house though. Always satisfying to see a _worse_ hoarder's pile than my own.
Collecting old scopes, logic analyzers, and unfinished projects. http://everist.org
 
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Offline CJay

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Re: List your test equipment "scores" here!
« Reply #986 on: November 07, 2016, 11:50:32 am »
The brush to use on files is called a card brush

Definitely, from what I remember using a brass brush on a file is a pretty good way to wreck it and if my metalwork (shop?) teacher caught us using anything other than the card brush we would be given a stern lecture about how not to destroy his files. (filing aluminium without using a lubricant was also a fairly dangerous thing to risk getting caught doing)

I'm amazed at the things people say & believe sometimes.
Please explain how soft, fine brass wire tips are going to damage the high-carbon steel of a file? Considering that the file can cut into solid brass all day and not get blunt.
As opposed to the hardened spring steel of any kind of steel wire brush. You _can_ use a steel wire brush, if you're careful to only run parallel to the file grooves. Which you do if you're trying to remove stuck swarf. Go the other way and you might as well file hardened steel (ie throw the file away, because you just ruined it.)
The card brush is useful because the bristles are both short and mounted in a flexible base sheet that allows them to tilt. So it's a way to apply a stiff but limited force to stuck swarf. But I don't bother with them - just one more rarely used special tool I can do without.

Personally to clean files I never use anything but soft brass wire brushes, and kerosene as a releasing/penetrating lubricant (because it's cheaper than WD40.) If some metal has stubbornly stuck, then run the tip of a scriber along the file grooves that need cleaning.


I was lead believe it's because the brass can clog the teeth on fine files rather than blunting them and that, I would assume, would also depend on the type of brass alloy used.

Your use of kerosene as a lubricant may also negate the effect entirely.

I just know that a card brush didn't require the use of lubricants to clean a file, as such it seemed sensible to use one when cleaning a file.
M0UAW
 

Offline JacquesBBB

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Re: List your test equipment "scores" here!
« Reply #987 on: November 07, 2016, 07:40:13 pm »
I just got a TDS220 from my favorite dumpster.

When I powered it,  the screen  was  dark, but I noticed that it  was working. obviously,  the CCFL tube was dead.
I checked the power supply that looked OK, and ordered a CCFL on aliexpress.
The best deal I found was 10 for 16 € ( in fact I received 11, so its less than 1.5 € each).

I have changed now the CCFL. Many plastic parts were very brittle, and I had to  use some Kapton tape for remounting,
but everything is now fine and in working order.

So the total cost of the repair was 1.5€.

I have already several other scopes, including a recent Rigol1054z (the only one that I had to pay for),
but I like the TDS220.
It has roughly the same form factor as the Rigol, and same bandwidth (100 Mhz). Of course, it has not
as many features, and is only 2 channels.
But it has a huge advantage :

It is totally silent !

I was really looking for such a scope. It is very enjoyable when you are in a quiet atmosphere,  not to have  the fan noise
of some modern devices.
In fact, my old fashion power supplies (coming straight from the dumpster) are linear PSU and also totally silent, contrary
to many new SMPS that usually need a fan.

I am sure that the evolution will go towards fanless devices, as it is now for many  laptops,  but  makers are probably still
thinking that a lab is a noisy atmosphere, so additional noise is not a problem, and they prefer to increase the performances,
without considering the noise level.  I am sure this will change. Meanwhile, its nice to have some of the old,
not so performant but silent stuff.
 

« Last Edit: November 07, 2016, 07:43:10 pm by JacquesBBB »
 

Offline tautech

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Re: List your test equipment "scores" here!
« Reply #988 on: November 08, 2016, 05:29:01 am »
I just got a TDS220 from my favorite dumpster.

When I powered it,  the screen  was  dark, but I noticed that it  was working. obviously,  the CCFL tube was dead.
I checked the power supply that looked OK, and ordered a CCFL on aliexpress.
The best deal I found was 10 for 16 € ( in fact I received 11, so its less than 1.5 € each).

I have changed now the CCFL. Many plastic parts were very brittle, and I had to  use some Kapton tape for remounting,
but everything is now fine and in working order.

So the total cost of the repair was 1.5€.
..............
A TDS210 I was given had a dead backlight too, confirmed by the torch method.  ;)
They use a discrete push pull oscillator on the backlight inverter primary and the dipped ceramic cap for it measured pF's.  :scared:
IIRC it was supposed to be 0.047uF.
That's all that was wrong with it.  :)
« Last Edit: November 18, 2016, 10:02:01 am by tautech »
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Online Berni

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Re: List your test equipment "scores" here!
« Reply #989 on: November 08, 2016, 07:47:57 am »
Getting a bunch of those drivers is probably a good idea given how much test equipment with LCDs uses them for backlights. Even brand new equipment made today seams to use them on larger displays.

I also think too much equipment has fans, ridiculously loud ones sometimes even. My lab tends to be pretty quiet as the PC in there is fitted with quality fans and set up for speed control so as a result the PC is so quiet i don't even hear its on unless one of the mechanical harddrives are spinning. Turning on a piece of equipment with a loud fan in there makes it seam like a jet engine just started up. I tend to replace loud fans in equipment, but that's not always possible. For example my HP 8566 gets pretty hot even with the loud hurricane creating fan blowing trough it
 

Offline nctnico

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Re: List your test equipment "scores" here!
« Reply #990 on: November 18, 2016, 08:37:13 am »
Yesterday I managed to 'win' an Ebay auction for an Agilent N3305A 150V/60A 500W electronic load module listed 'for parts'.

This is supposed to go into a DC load mainframe which I already have (bought from a forum member) and it came up just in time because I have a project coming up where it will be usefull. I have been angling for one of these modules for years on Ebay and now I got one. Unfortunately it was an auction so I put in a bid a couple of hours before the end and just see where it goes. Much to my surprise the price stayed well below my bid at US$56 and only one 'sniper'. Still I can do without the excitement though.
There are small lies, big lies and then there is what is on the screen of your oscilloscope.
 

Offline rx8pilot

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Re: List your test equipment "scores" here!
« Reply #991 on: November 18, 2016, 03:52:21 pm »
Yesterday I managed to 'win' an Ebay auction for an Agilent N3305A 150V/60A 500W electronic load module listed 'for parts'.

If it does not immediately work....hopefully an easy fix. I got a lot of Chroma DC modular loads in various condition. The broken parts have all been trivial - the circuits that do the heavy lifting are fairly difficult to damage. Good luck.
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Offline nctnico

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Re: List your test equipment "scores" here!
« Reply #992 on: November 18, 2016, 04:29:59 pm »
Fortunately -in line with HP's spirit- the full schematics for the N3300 series mainframes and load modules are available!  :-+
There are small lies, big lies and then there is what is on the screen of your oscilloscope.
 

Offline PaulAm

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Re: List your test equipment "scores" here!
« Reply #993 on: November 18, 2016, 06:46:31 pm »
Recently someone was selling Fluke 27/fm meters on ebay for $15 US ea with free shipping.

Not guaranteed, no accessories and power on test only, but heck, $15?  I bought 2.  We'll see when they show up, but reports so far have been favorable.  They're worth it just for spare parts.

I'll probably regret not buying more.
 

Online bitseeker

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Re: List your test equipment "scores" here!
« Reply #994 on: November 18, 2016, 11:58:33 pm »
Great score, nctnico. That's only $0.11/watt. ;D
I TEA.
 

Offline retiredcaps

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Re: List your test equipment "scores" here!
« Reply #995 on: November 19, 2016, 12:04:47 am »
Recently someone was selling Fluke 27/fm meters on ebay for $15 US ea with free shipping.
Originating thread might be at

http://www.antiqueradios.com/forums/viewtopic.php?f=8&t=310451&sid=dbeba29713fb8afd3b55daad910f56c8
 

Offline wasyoungonce

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Re: List your test equipment "scores" here!
« Reply #996 on: November 20, 2016, 09:10:14 am »
Picked up an older Analogue Scope, Tektronix 2236, for $135 in Australia (Melb) this morning.  Purchased off Gumtree (like USA craigslist) so no fee's!   Found most people on fleabay (and Gumtree) wanted way too much but this was ok price.  Appears to be working A1 so far.   I'll do the PSU capacitors just to be sure!  Need to get a decent repair manual...the online A4 sized documents just don't cut it.

The guy purchased from is giving up TV/radio repairs.  Just no money in it these days and I tend to agree.   We had a good chat, nice to meet like folks.
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Offline blueskull

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Re: List your test equipment "scores" here!
« Reply #997 on: November 20, 2016, 09:17:29 am »
Not exactly a test gear, just picked up a used hot plate and built a small hollowed ceramic tile stand to make my hot air soldering easier.

I can also use it to reveal thermal induced issues.
 

Offline mtdoc

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Re: List your test equipment "scores" here!
« Reply #998 on: November 20, 2016, 06:37:49 pm »
Picked up an older Analogue Scope, Tektronix 2236, for $135 in Australia (Melb) this morning.

Nice!  The first used Tek scope i bought was a 2236. I still enoy using it. The multimeter functions are not much use in the age of cheap DMMs but the counter and scope measurement functions I still find useful.
 

Offline Alex Nikitin

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Re: List your test equipment "scores" here!
« Reply #999 on: November 22, 2016, 12:46:47 pm »
The latest addition to my home lab. Measured on a freshly calibrated HP3458A shows the value of +5.5ppm from 10K, or less than +6ppm from the original measuremed value printed on the unit (which is in turn less than the uncertainty of the HP3458A measurement).

Cheers

Alex



 


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