markings on XTALs what do they mean?

On a sunny day (Fri, 27 Aug 2021 18:46:27 +0200) it happened Johann Klammer snipped-for-privacy@NOSPAM.a.net> wrote in <sgb4tg$1mk6$ snipped-for-privacy@gioia.aioe.org>:

Could be 14.3 MHz do you have a shortwave radio? listen for carrier there?

A frequency counter helps too!

20 MHz?

Yea, that is more difficult,

Johann Klammer wrote: ====================

** Why ?????

Likely they are nothing special at all.

Just regular clock frequency X-tals,

..... Phil

<snipped>

Yes, 14.3 MHz is something to do with NTSC, it is (or was) a very common crystal.

Clive Arthur wrote: =================

** Very close to 4 times the color burst frequency. 3.579545 MHz

For a long time the *cheapest* crystal you could buy in stores. Got one in my home brew frequency counter.

..... Phil

Does that have more digits after the three, coz I can not seem to find exactly 14.3M at any distributor.

14.31818 (4*3.579545 )

You should associate the parts with their application. These days, that generally means the ASIC they're tied to. Look up the chip numbers and typical app notes.

RL

On a sunny day (Sat, 28 Aug 2021 16:15:34 +0200) it happened Johann Klammer snipped-for-privacy@NOSPAM.a.net> wrote in <sgdgeh$3ik$ snipped-for-privacy@gioia.aioe.org>:

10 for 4$30 many sellers have these

On a sunny day (Sat, 28 Aug 2021 16:15:34 +0200) it happened Johann Klammer snipped-for-privacy@NOSPAM.a.net> wrote in <sgdgeh$3ik$ snipped-for-privacy@gioia.aioe.org>:

PS I have no idea what you are trying to do, but the probability of such crystals being defective in that application is close to zero. Better tell us what you are doing, and what test equipment and experience you have, multimeter, scope, etc.

Hefty Phase noise onscreen. esp at low resolutions. I guess the caps have gone bad. But while I'm at it I'll just swap the xtals aswell.

On a sunny day (Sat, 28 Aug 2021 18:41:16 +0200) it happened Johann Klammer snipped-for-privacy@NOSPAM.a.net> wrote in <sgdovm$1ocg$ snipped-for-privacy@gioia.aioe.org>:

Hard to tell, most often it is electrolytics, supply filtering.

If you have a scope you can check the ripple voltage, else sometimes you can put one of the same value in parallel, if that helps it was the cap.

Johann Klammer wrote: =======================

** You are watching NTSC color TV ?

Where ?

.... Phil

Why would you touch, let alone replace, something that's almost 100% sure to be working with something that may or may not work?

This kind of thing is why nobody wants to touch a "repair" that someone else has had an unsuccessful go at.

On a sunny day (Sat, 28 Aug 2021 16:58:23 -0400) it happened Spehro Pefhany snipped-for-privacy@interlogDOTyou.knowwhat wrote in snipped-for-privacy@4ax.com:

Anecdote Once had to help somebody repairing TVs. He had one that had been around for ages and did not have color. So I asked: What exactly did you do? He replied: Replaced every component in the color circuit but one! it did not help. So, I asked: Which one did you not replace? He replied: That coil, measured it, it was not interrupted, so put it back. I looked at the circuit diagram and that coil had, in the metal can it was in, a capacitor in parallel (tuned to the color carrier). So soldered out that cap, it had a short! Replaced the cap, customer so happy he finally got the thing back..

10 minutes ;-)

Jan Panteltje wrote: ================

** Nice going.

Only one ever came across a dead, HC49 crystal. In the Rx of a 30MHz radio control receiver.

The Rx was tied to the chassis of a 1/10 scale racing car that used a 3.5cc nitro / methanol 2-stroke engine. The engine revved in the 30,000rpm range

Must have resonated mechanically with the mounting springs of the crystal. Cos when cut open, it was no attached to the springs any more.

..... Phil

On a sunny day (Sat, 28 Aug 2021 23:52:17 -0700 (PDT)) it happened Phil Allison snipped-for-privacy@gmail.com wrote in snipped-for-privacy@googlegroups.com:

I had a big crystal from some surplus army set in my school days that I used for all sorts of experiments. After soldering it in projects many times, one of the wires came lose, so you could turn it. That in turn rotated the little golden wire to a golden surface plating on the actually crystal and it ripped off. Managed to open the crystal and fix it (xtal was about 7 MHz IIRC). Some are even simpler:

You can also modify the frequency of quarts crystal: You can pull those quite far by changing the circuit capacitance too. That is how those quartz PLL circuits work, like for example that in the color carrier locking NTSC and PAL.

And then there are overtone modes:

much more. I have heard, but not confirmed, that real audiophiles can tap a crystal and hear the frequency, just like a tuning fork... ;-)

That's a very poor article. No picture to illustrate how the crystal vibrates on an overtone, nothing about overtone oscillator design, except for the vague 'resonant circuit to amplify the overtone'. The guy even seems to think that 'applying a voltage' is enough to make the crystal oscillate. No hint about the difference between an overtone and a harmonic, either. Pretty much useless.

Jeroen Belleman

On a sunny day (Mon, 30 Aug 2021 14:28:07 +0200) it happened Jeroen Belleman snipped-for-privacy@nospam.please wrote in <sgiisn$1gka$ snipped-for-privacy@gioia.aioe.org>:

It is left to the inteligent reader to guggle for more in depth info. Or read the book I am working on: "The Fart Of Electronics" BTW what happeend to Winfield?

Jan Panteltje wrote: ==================

** ROTFLMFAO !!!

** The posturing, pommy "gong beater" picked up his spherical football and shuffled off home.

Never to return......

..... Phil