Take this with a grain of salt, but I believe I read somewhere that someone has taken these apart and cleaned them, with good results
I was researching my SX-62? I was reading up on this, but my chrystal seemed ok, so I didn't go any further with it.
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On Nov 2, 2022 6:25 PM, don Root <drootofallevil@...> wrote:
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Steve--Just double checking--? you get the same reaction from 2 different crystals with the same test setup .. I guess you meant that you ?have used these new testers on crystals before ??
is a strange coincidence!! Beats me!!
Now ?a bit more curious.?
De Sergeant Friday ?.. oh.. ?you might not remember Dragnet?
Don VA3DRL
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It¡¯s a new Siglent ¨C no issues and solid.? The scope also a new Siglent.
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Steve ¡ is your sig gen infallible .. just in case¡? still a curious? situation
Don VA3DRL
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The crystal from the SX-71 did the same thing in the test setup, with the signal generator and scope.? For now, I¡¯ve returned the original crystal to the SX-110 and am going through the IF alignment again, but this time with more knowledge about the resonant
frequency.? Want to see where I land and more about the effects of repositioning the radio (on its side, right side up, etc).? The new(er) 455 KHz crystal will be here in a few days ¨C I¡¯ll swap it out then and we¡¯ll see what effect that has, following another
alignment.
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73 ¨C Steve, KW4H
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Steve ¡ doing the same thing in the test setup or in the receiver or both?
I am a curious reader at this time
Don VA3DRL
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Yeah, I ordered a couple of 455 KHz crystals today.? It would be good to have another on hand.?
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FYI, I stumble onto these things because I restore boat anchors (mostly receivers) for educational and historical purposes.? I also write articles for ER magazine, and the extra information is fun and interesting.? Anyway, I¡¯m more likely to remove a component
and test it out of curiosity rather than questioning the design.? The unstable crystal caught me by surprise! ?And just for the heck of it, I pulled a similar crystal out of a SX-71 awaiting restoration and it¡¯s doing exactly the same thing.? Still mulling
that over.
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73 ¨C Steve, KW4H
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I've owned several SX-110's over the years, including the one I used as a Novice back in '67, that was like new I acquired from original owner. Never had any issues with xtal instability. They
all were fairly stable after initial 10-15 min. warmup. Sounds like you need a new xtal.
In a message dated 11/2/2022 1:23:14 PM Eastern Standard Time, reedsteve@... writes:
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On Wed, Nov 2, 2022 at 10:20 AM, Richard Knoppow <1oldlens1@...> wrote:
I am not an expert but think this is not normal.? ?It looks like the crystal holder comes apart.? ?Perhaps cleaning crystal and electrodes will fix it.
-------- Original message --------
From: "KW4H via groups.io" <reedsteve@...>
Date: 11/2/22 9:28 AM (GMT-08:00)
Subject: [HallicraftersRadios] SX-110 Crystal Instability
Attached is a photo of the crystal in my SX-110.? I pulled the crystal to test its resonant frequency using a sig gen and scope, and the darn thing is so unstable it¡¯s driving me loopy.? The resonant frequency can vary (roughly) between 453.700 KHz and 453.800
KHz by simply moving it around, no matter how gently.? Pardon my ignorance, but is that normal for crystals of this vintage?? Is there a reason, operationally in the Hallicrafters, for a crystal to act like this?? Before I order a different (and more stable)
crystal to solder into the circuit, thought I should ask.
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73 ¨C Steve, KW4H
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