Where's Help with learning Capacitor Markings?

[Guitarist1983]

Cap markings are a tad confusing.
For example, I've got a blue 7mm square cap (3 mm thick, 5 mm between leads) marked u1j100 A1j5. I've searched the interweb for the answer and came up empty.   Digikey - nope,  Mouser - nope.

It's obvious to me that I don't know how to look up caps.   Any pointers?
 

[thermionix]

That's a weird one.  My best guess is 100pF, but I don't recall seeing a box cap with a value that small.

[Guitarist1983]

I'm about to guess u1j100 is 0.1 uF,  j= 5% tolerance, and 100 Volt   the A1j5 is some manufacturing stamp?

[EBK]

I bought one of these to help me read oddly marked caps:

[Rob Strand]

I've got a different spin on this to thermionix.

Normally letters like K (10%) and J (5%) are for the tolerance.   Quite often you will see the marking as 100K 2n2K (or 222K).  Then you might get 2n2K100 (or 222K100)for 2.2n 10% and 100V.  The thing I'm working off here is the ordering.

So u1J100  I'm *guessing*  0u1 = 100nF  J 5% and 100V.

As for the A1J5  I don't know.  I can only assume it's the manufactures code for the model details.

EDIT: Guitarist1983  just posted the same thing as me!

[thermionix]

I'm about to guess u1j100 is 0.1 uF,  j= 5% tolerance, and 100 Volt   the A1j5 is some manufacturing stamp?

Yeah that's probably more likely.  Would've been nice of them to put "0u1" at the start.  But Eric has the ultimate solution.

[thermionix]

EDIT: Guitarist1983  just posted the same thing as me!

And I was simul-posting with you.  (Got distracted for a few minutes)

[Rob Strand]

FYI, See reply #4
http://www.madbeanpedals.com/forum/index.php?topic=1733.0

(Got distracted for a few minutes)

Everyone has to scratch at some point 

[davent]

I've these bookmarked for help.

http://www.hamradio.cc/electronics/capacitance_conversion_chart.php
https://www.electronics-tutorials.ws/capacitor/cap_5.html
dave

[amptramp]

I'm another one who uses a bridge, in my case an AideTek DM4070, to ensure anything I put in circuit is what I think it is.  I had an 20µF 450 volt cap that measured 0.2µF on the bridge after long storage.  I am certainly happy to see that components have not deteriorated over time and even happier to see ones that should be culled.

[Guitarist1983]

I've these bookmarked for help.

http://www.hamradio.cc/electronics/capacitance_conversion_chart.php
https://www.electronics-tutorials.ws/capacitor/cap_5.html
dave

These look great! I've bookmarked them now, too.

[Guitarist1983]

I'm another one who uses a bridge, in my case an AideTek DM4070, to ensure anything I put in circuit is what I think it is.  I had an 20µF 450 volt cap that measured 0.2µF on the bridge after long storage.  I am certainly happy to see that components have not deteriorated over time and even happier to see ones that should be culled.

Perhaps Santa will order me an AideTek DM4070 or some other LCR meter from Amazon. I assume using an LCR is "the" way to check the caps in my old amps.

[duck_arse]

Cap markings are a tad not in the slightest bit confusing.
For example, I've got a blue 7mm square cap (3 mm thick, 5 mm between leads) marked u1j100 A1j5. I've searched the interweb for the answer and came up empty. ....

me too, only mine are 7,5mm spacing, and marked [Siemens logo] µ1K100. which I know is 100nF, 10%, 100V. I also have a green ERO marked "1," on the roof, and on one face "K 63 1826 X7", which I know is a 1uF 10% 63V from their 1826 range of MKT's. also a yellow marked "D105J [some 8-bit logo]" which I can say is 1uF 5%, but I can't quote a voltage.