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Apologies for the delay in responding ¨C I had jury duty today, and was (fortunately) blown out the airlock.? It seems that the moment the attorneys discover you have a technical background and might be somewhat analytical, they have no interest in keeping you.? Anyway¡
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On the crystal ¨C I replaced it (see photo of the new crystal) and all appears to be well.? The original crystal (which I opened to inspect) is a flat sheet sandwiched between two flat electrodes.? The crystal is centered on the electrodes by way of a window in the white plastic piece that¡¯s sandwiched in the middle.? If you test the crystal out of circuit, the resonant frequency will change if you ever-so-slightly move the crystal.? And turning it over or even on its side will definitely alter things.? Put it up to your ear and shake, and it rattles.? I read somewhere that these crystals were designed that way, and in most instances the frequency variation is small enough that it has little to no effect on the intended use.? In other words, it was cheaper and did the job, so that¡¯s the way it was. ?I¡¯m going to run some more out-of-circuit tests to better analyze just how much variation was in that old crystal.? The new one is working fine ¨C no need to remove it and put the original back in.
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73 ¨C Steve, KW4H
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Yes Richard? what I sent is likely? about a permanent shift? in frequency;? it likely does not closely relate to the original posting, but is an aside, closely related to xtal frequency shifts in general. There is no info about where the xtal came from.
I was looking for , and then ran into the xtal stuff
I am interested in your comments, but I have no expertise on this: just interested in learning about what others have run across.
Seems to me the cause of Steve¡¯s? xtal frequency jumping?? remains unclear, at least to me.?
Wonder if Steve got his new xtal and tried it?
73, Don VA3DRL ?
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I suspect this is not a plated crystal but a plain crystal held between plane electrodes on both sides.? ?It seems to me that migrated solder would cause a permanent shift in frequency rather than one that changed with position.? Opening the holder would tell you.? I think the op said he had opened it. I think the crystal is loose in the holder.? It can't be too tight but also should not move around.? One reason the phasing setting changes could be a change in the holder capacitance due to loosness.
-------- Original message --------
From: don Root <drootofallevil@...>
Date: 11/7/22 11:29 AM (GMT-08:00)
Subject: Re: [HallicraftersRadios] SX-110 Crystal Instability
steve
I just ran across this,but but there is not enough info to know if it could be related to your investigation.?
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"This is a BSE SEM image of a quartz crystal that reportedly shifted in frequency. The problem was apparently caused by tin-lead solder on the spring mounts that wicked out onto the silver contact metallization on the crystals, which would be expected to change the mechanical response and therefore the frequency of the crystal."
from ...
don VA3DR
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