[time-nuts] 5 x 2 x 3 = 30 MHz
KA2WEU at aol.com
KA2WEU at aol.com
Sun Jul 19 08:19:48 EDT 2015
Good morning,
That is too close for my taste. For long term stability, 1 Hz and less the
transistor has more influence then considered . It is a pity that this
group does not address this topic.More to come. I am supervising a PhD
dissertation and it became clear that that is an issue
Ulrich N1UL
In a message dated 7/19/2015 8:12:44 A.M. Eastern Daylight Time,
radio.n9xr at gmail.com writes:
I am attaching a file showing the schematic for the trap used in a
Colpitts
oscillator which will look like 58pF at 5MHz and will be inductive at
5.5MHz. So something like this can be used in place of a pair of one of
the split capacitors at ~56pF loading the crystal.
Jerry N9XR
On Sat, Jul 18, 2015 at 11:59 AM, Magnus Danielson <
magnus at rubidium.dyndns.org> wrote:
> 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,
>> n1hac at dartmouth.edu 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
>>>
>> <time-nuts at febo.com
>>
>>> wrote:
>>>>
>>>> I am working with this ...... amazing device, Ulrich N1UL
>>>> _______________________________________________
>>>> time-nuts mailing list -- time-nuts at febo.com
>>>> To unsubscribe, go to
>>>> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
>>>> and follow the instructions there.
>>>>
>>>> _______________________________________________
>>> time-nuts mailing list -- time-nuts at febo.com
>>> To unsubscribe, go to
>>>
>> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
>>
>>> and follow the instructions there.
>>>
>>
>> _______________________________________________
>> time-nuts mailing list -- time-nuts at febo.com
>> To unsubscribe, go to
>> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
>> and follow the instructions there.
>>
>> _______________________________________________
>> time-nuts mailing list -- time-nuts at febo.com
>> To unsubscribe, go to
>> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
>> and follow the instructions there.
>>
>> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to
> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
>
> and follow the instructions there.
>
_______________________________________________
time-nuts mailing list -- time-nuts at febo.com
To unsubscribe, go to
https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.
More information about the time-nuts
mailing list