Mystery Component

I took apart an old NOAA weather radio (it wasn't much use anymore) and I found some great stuff inside (lots of resistors, capacitors, tunable inductors, NPNs). I found something inside, though, and I don't what it is. It says: 16.2020 UNI 82-J Sorry, its big. My camera is 14 MP. Anyone?

Looks like a crystal. Probably 16.2020MHz.

Is there any way I could test it? (the freq.)

Big pictures - You have a PC? Use Microsoft Office Picture Manager to Crop & then Resize down to 640 x 480 type size. Have been doing that with mine also, too many megapixels in cameras these days.

I did a little googling, found this application note that looks simple to implement.

http://www.fairchildsemi.com/an/AN/AN-340.pdf

There are numerous ways to test the crystal… but nearly all of them probably involve things you don’t have.

  1. You need to make it oscillate
  2. You need to not load it down so you need to amplify the signal
  3. You need to measure it:
    a) a frequency meter is probably the easiest
    b) A oscilloscope would do it too
    c) There are things called “crystal checkers” but they usually just say “it oscillates”

Maybe you should just plop it in you junk box for later.

The chance of it being a Crystal? I’d say 100% The chance of it being 16.2020 MHZ? I’d say 95% or better. Chances of it working? How carefully did you remove it?

Testing crystals can get complicated. Check this out: http://jvgavila.com/other/Crystal_Test_Set.pdf

Though you can make an oscillator with just one TTL GATE: http://www.ee.washington.edu/circuit_archive/circuits/F_ASCII_Schem.html#ASCIISCHEM_009

Since 16.202MHz is almost within 1% of 16MHz, couldn't this crystal just be tested with an Arduino?

I have built 3 "severino" type boards... the DIY single sided serial board that is shown in the Arduino web site.

1 has a 16MHZ crystal just like on the production board (mini) as mentioned by Richard.

1 has a 16MHZ crystal rescued from something I can't remember (junk box part)

1 has a 16MHZ ceramic resonator.

All work just fine.

So could you re-use that part and have success... maybe. Your timings might be a little off... and you might get some issues with serial transfers... but a little experimentation should not stop you. Try it and see if it works.

Worst case: It doesn't work so you need to place an order with Mouser or Farnell.

It doesn't need to be 16MHz to test with Arduino

You know what I meant. With no need to change any settings, and be able to communicate with the board. I wouldn't have suggested this method if the crystal was 14MHz, for example, although a sketch burnt into the chip could have run. But then, how would you tell the frequency?

There was a recent discussion about making a 1MHZ output clock- check, run that simple sketch, see how fast it actually runs. Or try the inverter circuits that have been posted here.

I don't have an oscilloscope, so I'll just put it in the junk box.\ About the oscilloscope, though: Could I snip a mic plug and use a sound-editing program as the oscilloscope? Like this: http://www.ledametrix.com/oscope/index.html I have audacity, which should work. Maybe I could figure out the frequency using that??

Sound card scopes have limited range, certainly not up on the MHz. You'd have to divide it down a few times to get something in the capturable range. If you have a little money, check out dpscope.com, nice little USB o'scope for $89. Assembly required, nice little project. Good for 20 MSample/sec.

Richard,
I am just trying to be helpful.
I just suggested to a beginner (probably) a method to verify, the easiest possible way (without oscilloscope or extra circuitry) that a crystal is indeed about 16MHz.
Although I don’t “seem to be comprehending”, I know from experience that Arduino can work with any crystal you throw at it, “as long as it is within the specified range” (0 to 20MHz?).

This sound card scope works well for audio.

http://www.sillanumsoft.org/

I used while debugging a tube amp to figure out where the output noise was coming from - turned out to be power supply related, spikes from diodes getting amplified in the high gain stages.

Free download, works well. Had a microphone in front of the speaker.

Sorry, its big. My camera is 14 MP.

Show-off :)

The Gimp is your friend: it does a great job of scaling down and compressing pictures. And it's easy to learn the minimal subset of its bewildering array of features that you need. Just remember to do a "save as" to preserve the original while you're figuring out the settings you need.

I just downloaded & installed, took a while at 40+MB for the program & help. Now to find the 'correct blurry picture' button ...