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XTAL parameters for measurement receiver

EB4APL
 

Hi,

I forgot to mention that the crystals were really cheap when I bought them in a local store which is not very well supplied.

I don't know why this frequency was selected for the MS but it might be due to its abundance.  I don't know for what they are supposed to be.

73 de Ignacio EB4APL


El 06/06/2016 a las 2:55, 'Steve Dick' sbdick@... [PHSNA] escribió:
 

Thanks very much Ignacio. Really appreciate the data.
“Digital Steve”, K1RF
 
Sent: Sunday, June 05, 2016 2:02 PM
Subject: Re: [PHSNA] XTAL parameters for measurement receiver [1 Attachment]
 
 

Hi,

I have measured a bunch of 12 crystals that I bought for the MR, I attach the results.

73 de Ignacio EB4APL


El 05/06/2016 a las 13:47, sbdick@... [PHSNA] escribió:
 

If anyone has measured crystal parameters for the 3276.8 KHz crystals used in the measurement receiver (ECS part number ECS-32-17-1X) I would appreciate it (Rs, Lm, Cm, Q). I was thinking of buying a bunch of extras for making some experimental filters. I'm particularly interested in the Rs or Q that people are seeing.  The Rs looks fairly high from the data sheet at 120 ohms which is typical for low cost crystals.  Have your crystals been running at the high end for the ESR or are they really much better?  (or if you have Q values that would be helpful)

Thanks,
"Digital Steve", K1RF



Posted by: sbdick@...


Nick Kennedy
 

​In order to use things I had on hand, I used crystals at around 5.2 MHz for my measurement receiver. The actual frequency chosen isn't really critical.

73-

Nick, WA5BDU​

 

Hi,

I forgot to mention that the crystals were really cheap when I bought them in a local store which is not very well supplied.

I don't know why this frequency was selected for the MS but it might be due to its abundance.  I don't know for what they are supposed to be.

73 de Ignacio EB4APL



Steven Dick
 

Hi Nick.
I have measured many a crystal with the PHSNA and crystal test fixture including samples of 12MHz(q=92000 to 135,000), 20MHz (Q=15,000-31,000), and 40 MHz (Q=2534 to 58,000). Most of them are not very good. The Q's are not too bad for the posted data on the 3.28 MHz crystals at around 120,000.  I posted a schematic in the K1RF folder for a narrow band CW crystal filter using the 3.28 MHz crystals.  It is about 410 Hz at 3dB down, 502Hz at 6dB down.  I may just build it. Simulated in LT Spice. I also posted the LT SPICE file