Dear Ulrich,
Now you taught me something useful, that the SC-cut has inherent less
noise than AT-cut. Many thanks.
Indeed, measuring below 1 Hz starts to be challenging as environmental
aspects chimes in. I assume you ovenize your crystals, to make use of
the turn-over point.
Even for ovens, (wind)shielding to reduce thermal stress turns out to be
helpful. Some toss their oscillators into thermal flasks too. As always,
a myriad off issues creep up as you push the noise down and want to
verify it. Thermal mass has proven useful in many ways. There was a nice
paper from NIST where they used water-bottles to stabilize WWVB.
Cheers,
Magnus
On 07/18/2015 11:52 AM, KA2WEU--- via time-nuts wrote:
Good morning,
the AT Cut is inherently noisier then the SC cut but the SC has some
spurious resonances modes. Measurements below 1 Hz are very tricky as the
oscillator must be (more or less) insulated from hum, infrared (heater) . Here
I
am still struggling .
Ulrich N1UL
In a message dated 7/17/2015 9:59:55 P.M. Eastern Daylight Time,
[email protected] writes:
He doesn't mention that that crystal is used in New Horizons:
http://www.bliley.com/products/crystals-precision-standard/vacuum-sealed/
Nice. I have a similar crystal from Valpey-Fischer, 5 MHz 5th overtone
AT-cut (as opposed to your 3rd overtone SC-cut). I would be interested
in what you would use for an oscillator circuit.
David N1HAC
On 7/17/15 4:27 PM, paul swed wrote:
Ulrich,
Nice picture. What are you doing with the crystal? I have several older
crystals that are nice but have never done anything with them.
Regards
Paul
WB8TSL
On Thu, Jul 16, 2015 at 6:02 PM, KA2WEU--- via time-nuts
<[email protected]
wrote:
I am working with this ...... amazing device, Ulrich N1UL
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