List your test equipment "scores" here!

[Johnny10]

Great Price !

[kwass]

I already have a low-power BK 1739 power supply, and really like it.  It's linear, fanless, has a simple, effective UI with an extremely low noise output



Street price is around $550, high for such a low wattage supply, but right now, for some strange reason, Amazon has them on sale for only $180:  https://www.amazon.com/gp/product/B00B03X1A2/ref=od_aui_detailpages00?ie=UTF8&psc=1

A very good deal, I think -- I just bought another one. 

I do have two minor gripes with it:

1) The ON/OFF output state is remembered when you shut off the supply.  So if you turn it back on when the output were enabled it will come back on in that state.  You need to get in the habit of disabling the output before you shut it off.

2) The output binding posts are really cheesy.

[nctnico]

If the equipment was built prior to or well after the capacitor plague of the late '90s to late '00s, they often are OK. That decade of bad electrolytics kind of made everyone paranoid. Of course, antique paper caps are a different story altogether.

I don't agree with this. Electrolytics can go bad but it depends on their use and operational temperature. I have two HP6024A (switching) lab power supplies and almost all electrolytic capacitors in them where bad. The smell of cat wee is a tell tale sign.

[nctnico]

I got myself a Lecroy LC584AL (1GHz, 2Gs/s 1Mpts) scope from the broken test equipment asylum called Ebay. According to the seller it doesn't show a picture so it was cheap after making an offer.

This is the picture from the Ebay listing:

I'm starting to worry I have to un-score this. It has been marked 'shipped' more than 3 weeks ago from the US and the Ebay seller has not provided me with a tracking number despite several requests so I have no idea when it will arrive or wether it is stuck somewhere. I'd really hate it if I have to open a Paypal claim.

[bitseeker]

If the equipment was built prior to or well after the capacitor plague of the late '90s to late '00s, they often are OK. That decade of bad electrolytics kind of made everyone paranoid. Of course, antique paper caps are a different story altogether.

I don't agree with this. Electrolytics can go bad but it depends on their use and operational temperature. I have two HP6024A (switching) lab power supplies and almost all electrolytic capacitors in them where bad. The smell of cat wee is a tell tale sign.

Certainly, it depends on many things, which is why I said they're often OK, not always OK. The point being that blindly replacing all caps (the context of which was in a prior post) just because they're electrolytic is also incorrect.

[Cubdriver]

Certainly, it depends on many things, which is why I said they're often OK, not always OK. The point being that blindly replacing all caps (the context of which was in a prior post) just because they're electrolytic is also incorrect.

Exactly.  I think it's something that's best done on a case by case basis as needed, rather than taking a shotgun approach.  As I discovered when searching out the datasheet for the example cap that I posted earlier, unless an exact replacement was purchased the regular run of the mill electrolytic that I might have replaced it with would almost certainly not have been as good a part as the original that is nearly 44 years old at this point.  (And for the record, it was an unexpectedly heavy little bugger!)

-Pat

[james_s]

Where I do use the shotgun approach is SMT electrolytics, those things are horrible, I don't know why but in my experience they *will* leak and corrode the board, it's just a question of when. You do have to watch out though, there are organic polymer capacitors that look almost identical but don't leak. The electrolytics I normally replace with tantalum or ceramic chip capacitors although I did find one application, a Sega Game Gear handheld where ceramic capacitors caused a very washed out looking display. I don't know why.

[Towger]

But how can you 'properly' tell if a capacitor is bad unless you remove it. At that stage you may as well replace it.  And if you find one bad, there maybe more.  For example last month I recaped a two channel 90s vintage TTI power supply, which appeared to have lived in a damp shed for years.  The caps on initial inspection all looked fine, but on removal several had signs of leaking on the bottom.  A couple of these were well below spec.  Interestingly the same caps were effected on bother channels.

[CJay]

But how can you 'properly' tell if a capacitor is bad unless you remove it. At that stage you may as well replace it.  And if you find one bad, there maybe more.  For example last month I recaped a two channel 90s vintage TTI power supply, which appeared to have lived in a damp shed for years.  The caps on initial inspection all looked fine, but on removal several had signs of leaking on the bottom.  A couple of these were well below spec.  Interestingly the same caps were effected on bother channels.

Absolutely, the heating, cooling cycle of two soldering operations may well have altered a duff cap or cause it to fail when you solder it back in so there's just no point doing it unless the caps are something *really* special.

Having said that, I don't necessarily remove a cap to test it, I like the octopus tester on my Hameg, gives me a really good indication of a cap's health.

[james_s]

I use an ESR meter for most of my capacitor testing. Between that, evaluation of the performance of the circuit the capacitor is in, and a bit of intuition I can usually get by.

[nctnico]

Where I do use the shotgun approach is SMT electrolytics, those things are horrible, I don't know why but in my experience they *will* leak and corrode the board, it's just a question of when. You do have to watch out though, there are organic polymer capacitors that look almost identical but don't leak. The electrolytics I normally replace with tantalum or ceramic chip capacitors although I did find one application, a Sega Game Gear handheld where ceramic capacitors caused a very washed out looking display. I don't know why.

Replacing electrolytics with tantalum or ceramic isn't a good idea in general. Sometimes circuits are designed with the relatively high ESR of electrolytics in mind. Tantalums may get an inrush current which is too high and may ignite them (I don't use tantalums at all). A particular problem with ceramics is the voltage dependant capacitance change which can be really bad so the capacitance can be way too low.

[james_s]

That's probably why tantalum capacitors didn't work well in the Game Gear.

Most of the time the ones I've replaced are used for power supply decoupling and occasionally DC blocking. I've re-capped dozens of 80s Mac motherboards with tantalum chips and they work fine.

I don't know why but SMT electrolytic capacitors are very leak prone. I don't think I've ever seen a through-hole electrolytic leak.

[nctnico]

I don't think I've ever seen a through-hole electrolytic leak.

Oh they can leak for sure! I've replaced many of them in various equipment.

[james_s]

I've seen them bulge and leak out the top, but I have not see boards destroyed by leaking electrolyte like happens with those surface mount ones. They get about 10-20 years old and start leaking all over and corrode the board.

[bitseeker]

Through-hole ones also leak out the bottom via the seal around the leads. They corrode the leads, the board traces, etc. Unfortunately, it's not always readily visible, especially if the caps are affixed to the PCB with Silastic or similar around the base.

Check out TiN's post at the link below. The first photo is the result of a leaking through-hole electrolytic cap in a Keithley 2001.

https://www.eevblog.com/forum/testgear/restoration-glory-of-keithley-2001-dmm/msg650609/#msg650609

This one's even worse. The electrolyte of one of the caps migrated to rot away other components.

https://www.eevblog.com/forum/testgear/restoration-glory-of-keithley-2001-dmm/msg360824/#msg360824

[Berni]

I also never came across failed electrolytic caps in old test equipment, but then again when i buy a piece of gear advertised as broken i usually get ones that look like they have a simple power issue (Was as simple as a fuse twice already) and tend to stay away from things that fail weird self tests or have dead channels etc.

But that does not mean that caps don't fail, just that most caps used in test equipment tend to be reasonable quality parts rather than the cap they could get the cheapest this week in Shenzhen China. I see the cheap caps fail all the time in computers and other consumer electronics, but even good quality caps can fail on rare occasion, or they are from a bad batch or something.

[cncjerry]

My third 856x spectrum analyzer, this one initially thought to be an 8568a, turns out it is a 'B' model that sat in a closet since 1985 when it was last calibrated.  Cables included.  I open it up to tweak the CRT and it is perfectly clean, all the nuts and bolts are there, cables perfectly routed and not falling apart.  It has a sticky button or two on the display unit and the RF unit has a coating on it I can't get off. And as my kids used to say, "needs a battery" but the calibration constants are near spot-on and DOBA (that's an industry term).

I paid $175 plus the guy drove it from Boise to Tahoe where I picked it up.  This has to be a record low for a functioning 8568B or even an 8568A, which is on the cover.  He overlooked the - 01K option that adds the 'B' processor and other hardware an d documentation.

One of these I am going to add the SimmConnLabs LCD to, maybe my 8566b, but the 8568s have such low noise and most of my playing is in HF.  Had to get my son to help lift it into the rack, these things are real beasts.

Jerry

[Johnny10]

Great Score Jerry   

[Berni]

That is a beauty and for a bargin price too.

Already having 3 of those things? The one i got is taking up enough space as it is, due to how big they are. Also because of its hefty weight it is forever destined to live in the rack since i sure don't like moving it. Been thinking of upgrading it to a LCD but the CRT still works fine so i left it (Is showing a little bit of age tho)

[bitseeker]

What a score, Jerry! Broken ones that I've seen go for more. People want that much for the two interconnect cables.

One of these days, I hope to find one at a reasonable price. Meanwhile, I'll be interested to see the LCD replacement and your experience with using it.

[Cubdriver]

Wow!  For $175 you really hit that one out of the park and into the next county!  That's phenomenal!  Especially in that condition - it looks beautiful.

-Pat

[cncjerry]

The focus on the screen looks off but it is from the picture.  It is clear when viewing.

$175 - That's why I grabbed it.  I bought an 8566B, near perfect, last year for $500.  I thought that was a steal as well.  The 8566B works well but when I opened it up it had covers missing, bolts, screws not replaced.  All the cables had their coatings flaking off, etc.  I mean it works well but nothing compared to this one. 

I am a major bottom feeder on craigslist or ebay.  I paid $500 for the signal generator in that picture, an HP 8648C, as well.  I thought that was a good deal.  The guy that sold the signal generator to me said he had 6 calls after he committed to me. 

I find all the best deals on craigslist.  You do have to know what you are looking for vs value, though.  But the key advantage of buying off craigslist (other than the testing) is no shipping to worry about for cost and potential damage.  I can't imagine buying an 8568 or 8566 and shipping it across country even using freight with it nailed to a skid.  These units are built like tanks but you don't want the CRT banging around.  I don't care how well they are packaged, they weigh a ton and the average UPS guy is going to set it down as quickly as possible when he finds a spot.

Jerry

[bitseeker]

Most of the time the stuff I see on craigslist is as expensive as eBay and sometimes even more. However, I can attest that good deals do come up on occasion. I once scored an Agilent 34410A from a small engineering firm for less than $300 cash and a 40-minute drive round trip. Rare, but sweet and with some concept of the conditions under which it lived.

[AF6LJ]

My third 856x spectrum analyzer, this one initially thought to be an 8568a, turns out it is a 'B' model that sat in a closet since 1985 when it was last calibrated.  Cables included.  I open it up to tweak the CRT and it is perfectly clean, all the nuts and bolts are there, cables perfectly routed and not falling apart.  It has a sticky button or two on the display unit and the RF unit has a coating on it I can't get off. And as my kids used to say, "needs a battery" but the calibration constants are near spot-on and DOBA (that's an industry term).

I paid $175 plus the guy drove it from Boise to Tahoe where I picked it up.  This has to be a record low for a functioning 8568B or even an 8568A, which is on the cover.  He overlooked the - 01K option that adds the 'B' processor and other hardware an d documentation.

One of these I am going to add the SimmConnLabs LCD to, maybe my 8566b, but the 8568s have such low noise and mist of my playing us in HF.  Had to get my son to help lift it into the rack, these things are real beasts.

Jerry

All that HP iron from the eighties is heavy....

[mtdoc]

Most of the time the stuff I see on craigslist is as expensive as eBay and sometimes even more. However, I can attest that good deals do come up on occasion. I once scored an Agilent 34410A from a small engineering firm for less than $300 cash and a 40-minute drive round trip. Rare, but sweet and with some concept of the conditions under which it lived.

I've only had one good Craigslist TE score. An excellent condition Tek 465b and Tek scope cart for $100. It was in Tacoma which is a 2 hour drive from our home - but luckily the timing was perfect and we we're passing through on our way back from Sea-Tac airport so I convinced my wife that we should stop to take a look.  The funny thing was that the owner wasn't there but his wife was and showed me the scope in the garage. Once I agreed to take it the looks exchanged between his wife and mine were priceless!