[Milsurplus] LF & HF Crystal Tester prelim comments

[Brooke Clarke]

Hi Hue:

It depends on what you're trying to do.
Crystal activity meters just confirm that the crystal oscillates.
https://prc68.com/I/Xam.html
Crystal Impedance Meters measure key parameters.
https://prc68.com/I/CrystalImpedanceMeters.html

-- 
Have Fun,

Brooke Clarke
https://www.PRC68.com
http://www.end2partygovernment.com/2012Issues.html
axioms:
1. The extent to which you can fix or improve something will be limited by how well you understand how it works.
2. Everybody, with no exceptions, holds false beliefs.


> Date: Fri, 23 Aug 2019 21:05:57 +0000
> From: Hubert Miller <Kargo_cult at msn.com>
> To: Military Surplus Mail List <milsurplus at mailman.qth.net>, tetrode
> 	<tetrode at googlegroups.com>
> Cc: "nwvrs at googlegroups.com" <nwvrs at googlegroups.com>
> Subject: [Milsurplus] LF & HF Crystal Tester prelim comments
> Message-ID:
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> 	
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>
> So I bought online for very little money one of those LF, HF crystal testers with readout.
>
> It arrived remarkably quickly. It is quite a small unit and arrives in a little mailing bag. In fact, when I received the bag,
>
> I thought it only would contain a couple transistors I had ordered elsewhere.
>
> The thing is really only intended for tiny crystals with wire leads.
> To test anything else, I think we need to attach the smallest alligator clips to very short leads and wire to the tester's
>
> tiny crystal test socket.
>
> I found:
>
> It does not at all like any test leads to your crystal that are anything long. It will not "read" the crystal.
>
> I think it needs good, strongly active crystals. I seem to recall that some that my dipmeter resonated, when tested on
>
> this machine, did not show anything.
> Maybe it has trouble with crystals with a higher than usual series resistance?
>
>
>
> It did however measure a couple of those WWII FT-241  LF crystals.
>
>
>
> It also proved its worth to me in short order. I had a bunch of crystals marked  453.5 that I bought from some boat - radio
>
> surplus lot. Oh boy, I thought, a bunch of 453.5 kHz rocks I can use either with a mechanical filter or as single - crystal
>
> selectivity near the common IF freq. Well, they all tested on this device as in the 16 MHz range. I don't get the 453.5 marking
>
> and I'm pretty sure they weren't intended for 453.5 MHz use, but I'm not positive. More likely I think they were for 1970s -
>
> 1980s crystal controlled SSB boat radios. Now one less thing to save.
>
>
>
> However, the ( gradual ) search for the ideal crystal tester goes on.
>
> -Hue
>
>