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[Calambres]

What is the "Vloss" reding for capacitors?

[Specmaster]

What is the "Vloss" reding for capacitors?

Vloss is the percentage of volts that has been lost in the capacitor since the tester first charged it. A low value % is good as even a new one will have have lost some voltage as nothing is ever 100% perfect. As electrolytic's age, they dry out and the amount of drying out can be seen by the Vloss figure, the higher the value, the nearer a capacitor is to expiring so therefore it is wise to replace a capacitor that has significant Vloss and it is also very likely to have a high ESR reading as well. 

[Calambres]

But that should depend on the capacitance, right?

[netdudeuk]

I just received this (fake) Hakko FG-100 soldering iron tip thermometer. It arrived in just 11 days which is amazingly fast compared to other purchases I've made in ebay so far.

I've opened it up as per Dave's famous motto and it's the typical fake circuit without the trimmers or jumper to switch fom ºC to ºF (this one is in ºC). The make quality is not top notch, a bit on the cheap side but not that bad whatsoever. In the back of the PCB there are some unpopulated marks for a couple of thru-hole lytics, paralelling C3 & C7 SMD capacitors and a trimmer (VR1 - 1K).

The sensors blister clearly states: "contents 10pcs." but only includes 5    To be fair, the original ebay ad clearly indicated 5 sensors, not 10.

It seems to work well although I have not a means to compare the temperature reading (yet... awaiting  ) . Goes up to 400ºC with my old trusty JBC iron.

Some photos below.

By the way... how can I put the attached photos in the text, not just at the end? 

I thought about getting one of these but surely you cannot rely on the readings ?

[Calambres]

[netdudeuk]

Thanks.  I'll have a look later.

[Specmaster]

But that should depend on the capacitance, right?

Yes it does, ESR also depends on the capacitance value as well and both will be affected by the capacitor drying out as it ages and or is exposed to high levels of heat for extended periods.

[Calambres]

Then... is there a table "a la ESR" for valid Vloss values?

[ManuelMcLure]

Yesterday I ordered a couple pairs of 1m 14AWG silicone stackable banana leads (https://www.ebay.com/itm/172002582714) and this morning I ordered an Aneng AN8009 to back up my main handheld DMM - an HP (none of this Agilent/Keysight junk) 974A (with ProbeMaster leads). I'll keep the 974A for when I need to work on high energy stuff, but the AN8009 has several features that the 974A doesn't. I could get the thermocouple probe for the 974A but it would cost me almost 3 times what the AN8009 cost!

[GreyWoolfe]

I have been on the hunt to find a broken piece of HP test gear to get the pushbutton caps to replace the broken ones on my HP 3312 Function Generator.  I was at the local surplus store and found an HP 5314A frequency counter that they hadn't looked at or priced yet.  After an inquiry, the owner said he would look at it and let me know a price but it would take a day or two.  I was getting ready to leave and saw he had it powered up and after saying he still didn't know if it worked, I could have it for $20.  I bring it home and make the mistake of hooking it up to a function generator for kicks.  Of course it works.  Now I have 2 pieces of gear that need the button caps.   The surplus store has 2 HP pulse generators that look good at $40 each, but I am afraid to bring one home and find out it woks also.  I hope to find something cheeeeeep at the Orlando Hamcation next month.

[Specmaster]

Then... is there a table "a la ESR" for valid Vloss values?

None that I'm aware of, there does exist many tables for various ESR values v Capacitance value but each manufacturer appears to have different values, these can be found if you google for them. The ESR is most critical value, it can effectively kill a piece of equipment if this value is high enough, particularly on power rails, instead of offering any AC ripple a route to ground, it shuts that route off and the AC gets into places where you don't want it to with dire consequences.

[BU508A]

Received today some goodies from forum member Franky (iloveelectronics):

[bitseeker]

I was getting ready to leave and saw he had it powered up and after saying he still didn't know if it worked, I could have it for $20.  I bring it home and make the mistake of hooking it up to a function generator for kicks.  Of course it works.

Don't you hate it when that happens? 

Now I have 2 pieces of gear that need the button caps.

3D print replacements? Or consolidate the original caps to one of the counters and get new ones (which likely won't be tapered like the HP ones, but still fit on the switch shafts) for the other.

[rsjsouza]

I was getting ready to leave and saw he had it powered up and after saying he still didn't know if it worked, I could have it for $20.  I bring it home and make the mistake of hooking it up to a function generator for kicks.  Of course it works.

Don't you hate it when that happens? 

  That is the problem with quality gear - they actually survive the passing of time. I am on the same boat and I always promise myself to sell them before I get too attached. Obviously that does not happen...

US is a paradise for such gear, especially the local ads.

[rdl]

...
  Now I have 2 pieces of gear that need the button caps.   The surplus store has 2 HP pulse generators that look good at $40 each, but I am afraid to bring one home and find out it woks also.  I hope to find something cheeeeeep at the Orlando Hamcation next month.

Those kind of pushbuttons are common, maybe an industry standard, and with a little digging you may be able to find some caps that will fit the plungers and work as a replacement. I seem to remember seeing some that were trapezoidal shaped when looking to fix my E3610A power supply. Or if you replace all of them, maybe regular rectangular types would look okay. Painting will probably be necessary for a color match though, all I could find was red and black.

Replacement caps on the bottom unit.



https://www.eevblog.com/forum/repair/hp-e3610a-does-this-look-worth-fixing/msg616470/#msg616470

[Cubdriver]

I have put up an antenna (horizontal loop) that seems to be a bit quiet re all the *******. SMPSU hash around here, so am firing up my boat anchor, an Yaesu FT 101E.  I found an external VFO unit (FV101B) to go with it. I have the receiver FRG-7, the monitor scope YO-100, now for the PA

Rob, is that a Sparton Bluebird I see in the background?

-Pat

[kelchm]

I was at the local surplus store and found an HP 5314A frequency counter that they hadn't looked at or priced yet.

How does one go about finding a local surplus store like this?

[blueskull]

I was at the local surplus store and found an HP 5314A frequency counter that they hadn't looked at or priced yet.

How does one go about finding a local surplus store like this?

How does one go about finding a dumpster like Dave's .

[cdev]

Areas that are blessed by a NASA center or national lab's presence often have good surplus stores.

Good book stores for lovers of technology books too.

I was at the local surplus store and found an HP 5314A frequency counter that they hadn't looked at or priced yet.

How does one go about finding a local surplus store like this?

[JoeN]

Areas that are blessed by a NASA center or national lab's presence often have good surplus stores.

Sometimes those stores have insane prices.  I don't recall the details now, but I remember going to one such store in Los Alamos years ago, around 2003 and they had total junk the the prices were insane.  There wasn't anything remotely useful or in decent condition at any price, not even worth haggling.

[paulca]

RS Components.  I had a box delivered.  It measured 14" cubed.  Big enough to put a fully inflated soccer ball in.

What was inside it?

A single flux pen.

WTF?

[woody]

RS prices warrant a big box   

[GreyWoolfe]

...
  Now I have 2 pieces of gear that need the button caps.   The surplus store has 2 HP pulse generators that look good at $40 each, but I am afraid to bring one home and find out it woks also.  I hope to find something cheeeeeep at the Orlando Hamcation next month.

Those kind of pushbuttons are common, maybe an industry standard, and with a little digging you may be able to find some caps that will fit the plungers and work as a replacement. I seem to remember seeing some that were trapezoidal shaped when looking to fix my E3610A power supply. Or if you replace all of them, maybe regular rectangular types would look okay. Painting will probably be necessary for a color match though, all I could find was red and black.

Replacement caps on the bottom unit.



https://www.eevblog.com/forum/repair/hp-e3610a-does-this-look-worth-fixing/msg616470/#msg616470

I have tried looking by part numbers and there hasn't been any love on that.  I was figuring a cheap piece of BER gear would do the trick.  Not everything at the surplus store is working but everything I have bought has been or just needed some basic maintenance.  As far as 3D printing as bitseeker suggests, I don't know anyone with a 3D printer.  I could care less about color matching.  Anyway, I can still  engage the buttons with broken caps.  Patience will be my reward.  Besides, the Orlando Hamcation hamfest is next month.  I might be able to find something there.

[rdl]

I have tried looking by part numbers and there hasn't been any love on that.  I was figuring a cheap piece of BER gear would do the trick.  Not everything at the surplus store is working but everything I have bought has been or just needed some basic maintenance.  As far as 3D printing as bitseeker suggests, I don't know anyone with a 3D printer.  I could care less about color matching.  Anyway, I can still  engage the buttons with broken caps.  Patience will be my reward.  Besides, the Orlando Hamcation hamfest is next month.  I might be able to find something there.

Here is the data sheet for the C&K F series pushbutton switches. I think most switch manufacturers make a version of this type. Page 6 has the caps. A little measuring and you may find one that works. That's what I did. Mouser stocks some of these and they don't cost much (under a dollar).

https://www.mouser.com/ds/2/60/-221978-1159732.pdf

[kelchm]

As far as 3D printing as bitseeker suggests, I don't know anyone with a 3D printer.

Sure sounds like a good excuse to buy one to me.