# Value of a ceramic capacitor

Discussion in 'Electronic Basics' started by fpd, Jun 19, 2005.

1. ### fpdGuest

I am asking if anyone can give a guess at the value of a capacitor just from
my following description...

I have a cheap AM/FM radio with a ceramic (wafer) capacitor that has a
broken lead. The physical size of the ceramic part is 2cm diameter. An
underlined number "3" is printed on it. The capacitor is located very
close to the tuning capacitor. My guess is 30pf.

Is this the same value as a ceramic capacitor with the number "103" printed
on it?

Thank you for your help.

2. ### Andrew HolmeGuest

103 means 10nF

2cm dia.is large for a ceramic capacitor. Is it an old set?
The biggest I have in my junk box is 15mm dia. (100nF)

You could try a few values: 100pF, 1n, 10nF, 100nF and see what works best.

3. ### Tom BiasiGuest

By the size I don't think 30 pF. 103 is .01uF
Any guesses are meaningless, at least find another one that looks like it.
Good Luck,
Tom

4. ### fpdGuest

I am sorry for my typo... I meant to write "MM" rather than "CM" for the
diameter... thank you.

5. ### fpdGuest

Thanks for the info on the "103"
I made a typo... "2mm" rather than "2cm" (about the size of a lentil bean)

Thank you for the help.

6. ### Andrew HolmeGuest

It's probably in the 10 - 100pF region then.

7. ### Tom MacIntyreGuest

....or 3 pF? I think 30 pF would be marked "300". Someone else may have
a better idea; it's been awhile for me.
No. That's 10X10^3, or 10000pF, .01 uF.

Tom

8. ### colinGuest

i gues it could be just 3pf, although that is i feel rather small even for
am/fm
does it stil work at all? i would try a trimmer or a cap of a few pf or tens
of pf if its next to the tuning cap

and 103 = 0.01uf.

Colin =^.^=

9. ### fpdGuest

The radio used to work, but recently just stopped. A couple "adjustments"
with my hand would get it working again. Now, I can not seem to make the
capacitor "make" any more, so that is why I opened the radio. I'm going to

The radio is powered by four "AA" batteries (6vdc). Anything I might
destroy by using a cap that is too small (10pF)?

Thank you for your help.

No.

11. ### fpdGuest

Well, I put it in parallel with the broken cap. Unfortunately it did not
solve the problem. Must have another broken part nearby - the workmanship
on the inside was ugly to say the least. Batteries and on/off/volume
potentiometer both worked. I will look a little bit more, but for USD 5, I
can get another one with a digital alarm clock (sadly).

Thanks for all the help.