DK
Dan Kemppainen
Sat, Mar 6, 2021 9:02 PM
Hi All,
Just to be clear, I am not the person who made the crystals glow blue. I
just noticed some pictures of that happening on the auction site:
https://www.ebay.com/itm/8x-Quartz-Resonator-1000-kHz-Crystal-oscillator-gold-Sonoluminescence-effect-NOS/113862454353
https://www.ebay.com/itm/1x-Quartz-Resonator-1000-kHz-Crystal-oscillator-gold-Sonoluminescence-effect/113874435589
I certainly will not abuse these crystals this way!
As for measurements, I'm trying to take some measurements with the
equipment on hand. Currently, that is an Agilent 33220A signal
generator, and TDS3000B oscilloscope + Active FET Probe.
Years ago I put together a little Excel Macro program that sweeps the
signal generator through a range of frequencies, and measures the
voltage and phase of the signals on the oscilloscope. Basically, the
sampled signals are run through a sine fit routine, which gives very
good estimation of sine amplitude and phase shift (With frequency being
set by the signal generator).
Using this setup, the first try involved making a voltage divider with a
fixed resistor and the crystal. The signal generator was used to drive
signal into the resistor, through the crystal to ground. A standard 10x
probe monitored the signal generator voltage, and the FET probe in
series with a 1K resistor (for more isolation) was used to monitor the
crystal voltage. (The probes were compared before the test, and channel
skew adjusted to zero).
Basically, this is a voltage divider made with a resistor and a crystal.
From this, a frequency response curve was generated. See attached image.
The -3dB and +/-45 deg phase shift points match well. They are also
quite close to the Fs frequency (999,999.800 Hz). Those -3dB points come
out to be 999,990.640 Hz and 999,990.910Hz.
However, I'm a bit concerned that the Q calculated with these numbers is
a bit higher than expected based on what I've read. Running the test
with a smaller series resistor (100 Ohm) results in a lower Q (As would
be expected as the 'load' on the crystal is higher), although even these
numbers are quite high.
In order to try to measure Rs, the voltages of the divider were measured
at Fs, and RS was calculated accordingly (Easy calculation, as phase
shift = 0 deg). This was repeated with several series resistor values
(10, 100, and 1000 Ohm). These tests resulted in Rs = between 4 to 7
ohms (depending on the series resistor).
My concern is, are there any potential pitfalls in this measurement
setup? Is there something that will give more accurate results, given
the equipment on hand? Certainly the Q value seems unreasonably high,
and Rs seems quite low. However, these are large low frequency
resonators (being 25mm in dia.).
Thanks,
Dan
On 3/6/2021 12:00 PM, time-nuts-request@lists.febo.com wrote:
Message: 4
Date: Fri, 5 Mar 2021 16:03:51 -0600
From: Dana Whitlowk8yumdoober@gmail.com
To: Discussion of precise time and frequency measurement
time-nuts@lists.febo.com
Subject: Re: [time-nuts] Old Crystal.
Message-ID:
CADHrwpcb3_9xeeCHg3r30DS7oGq-CKsXYjW4XM=q=DT0Gv5OXA@mail.gmail.com
Content-Type: text/plain; charset="UTF-8"
Blue LEDs under Nixie tubes might have a deeper purpose than appearance-
they can also
help the Nixie tubes get started upon turn-on (especially if they're
getting old). I once stayed
in a hotel room whose light switches had neon indicators to help one find
them in the dark,
and the one near the entrance door was getting awfully marginal. I
happened to have a blue
LED penlight with me, and I found that shining that on the switch face made
a radical
improvement in making the neon indicator keep going, even at a range of >
20 feet. And
this flashlight was no powerhouse either- it was a single LED with no
auxiliary focussing
optics.
Dana
Hi All,
Just to be clear, I am not the person who made the crystals glow blue. I
just noticed some pictures of that happening on the auction site:
https://www.ebay.com/itm/8x-Quartz-Resonator-1000-kHz-Crystal-oscillator-gold-Sonoluminescence-effect-NOS/113862454353
https://www.ebay.com/itm/1x-Quartz-Resonator-1000-kHz-Crystal-oscillator-gold-Sonoluminescence-effect/113874435589
I certainly will not abuse these crystals this way!
As for measurements, I'm trying to take some measurements with the
equipment on hand. Currently, that is an Agilent 33220A signal
generator, and TDS3000B oscilloscope + Active FET Probe.
Years ago I put together a little Excel Macro program that sweeps the
signal generator through a range of frequencies, and measures the
voltage and phase of the signals on the oscilloscope. Basically, the
sampled signals are run through a sine fit routine, which gives very
good estimation of sine amplitude and phase shift (With frequency being
set by the signal generator).
Using this setup, the first try involved making a voltage divider with a
fixed resistor and the crystal. The signal generator was used to drive
signal into the resistor, through the crystal to ground. A standard 10x
probe monitored the signal generator voltage, and the FET probe in
series with a 1K resistor (for more isolation) was used to monitor the
crystal voltage. (The probes were compared before the test, and channel
skew adjusted to zero).
Basically, this is a voltage divider made with a resistor and a crystal.
From this, a frequency response curve was generated. See attached image.
The -3dB and +/-45 deg phase shift points match well. They are also
quite close to the Fs frequency (999,999.800 Hz). Those -3dB points come
out to be 999,990.640 Hz and 999,990.910Hz.
However, I'm a bit concerned that the Q calculated with these numbers is
a bit higher than expected based on what I've read. Running the test
with a smaller series resistor (100 Ohm) results in a lower Q (As would
be expected as the 'load' on the crystal is higher), although even these
numbers are quite high.
In order to try to measure Rs, the voltages of the divider were measured
at Fs, and RS was calculated accordingly (Easy calculation, as phase
shift = 0 deg). This was repeated with several series resistor values
(10, 100, and 1000 Ohm). These tests resulted in Rs = between 4 to 7
ohms (depending on the series resistor).
My concern is, are there any potential pitfalls in this measurement
setup? Is there something that will give more accurate results, given
the equipment on hand? Certainly the Q value seems unreasonably high,
and Rs seems quite low. However, these are large low frequency
resonators (being 25mm in dia.).
Thanks,
Dan
On 3/6/2021 12:00 PM, time-nuts-request@lists.febo.com wrote:
> Message: 4
> Date: Fri, 5 Mar 2021 16:03:51 -0600
> From: Dana Whitlow<k8yumdoober@gmail.com>
> To: Discussion of precise time and frequency measurement
> <time-nuts@lists.febo.com>
> Subject: Re: [time-nuts] Old Crystal.
> Message-ID:
> <CADHrwpcb3_9xeeCHg3r30DS7oGq-CKsXYjW4XM=q=DT0Gv5OXA@mail.gmail.com>
> Content-Type: text/plain; charset="UTF-8"
>
> Blue LEDs under Nixie tubes might have a deeper purpose than appearance-
> they can also
> help the Nixie tubes get started upon turn-on (especially if they're
> getting old). I once stayed
> in a hotel room whose light switches had neon indicators to help one find
> them in the dark,
> and the one near the entrance door was getting awfully marginal. I
> happened to have a blue
> LED penlight with me, and I found that shining that on the switch face made
> a radical
> improvement in making the neon indicator keep going, even at a range of >
> 20 feet. And
> this flashlight was no powerhouse either- it was a single LED with no
> auxiliary focussing
> optics.
>
> Dana
BK
Bob kb8tq
Sat, Mar 6, 2021 10:12 PM
Hi
You need to extract Cm, Lm and Rm ( motional resistance, capacitance, inductance)
for the mode you are looking at. You also need C0. Once you have those you can
come up with Q. Because of the interaction between C0 and the other parameters,
you need to extract them all. ( yes, you could extract Fs and leave out Lm, it’s still
three parameters plus C0).
Bob
On Mar 6, 2021, at 4:02 PM, Dan Kemppainen dan@irtelemetrics.com wrote:
Hi All,
Just to be clear, I am not the person who made the crystals glow blue. I just noticed some pictures of that happening on the auction site:
https://www.ebay.com/itm/8x-Quartz-Resonator-1000-kHz-Crystal-oscillator-gold-Sonoluminescence-effect-NOS/113862454353
https://www.ebay.com/itm/1x-Quartz-Resonator-1000-kHz-Crystal-oscillator-gold-Sonoluminescence-effect/113874435589
I certainly will not abuse these crystals this way!
As for measurements, I'm trying to take some measurements with the equipment on hand. Currently, that is an Agilent 33220A signal generator, and TDS3000B oscilloscope + Active FET Probe.
Years ago I put together a little Excel Macro program that sweeps the signal generator through a range of frequencies, and measures the voltage and phase of the signals on the oscilloscope. Basically, the sampled signals are run through a sine fit routine, which gives very good estimation of sine amplitude and phase shift (With frequency being set by the signal generator).
Using this setup, the first try involved making a voltage divider with a fixed resistor and the crystal. The signal generator was used to drive signal into the resistor, through the crystal to ground. A standard 10x probe monitored the signal generator voltage, and the FET probe in series with a 1K resistor (for more isolation) was used to monitor the crystal voltage. (The probes were compared before the test, and channel skew adjusted to zero).
Basically, this is a voltage divider made with a resistor and a crystal. From this, a frequency response curve was generated. See attached image.
The -3dB and +/-45 deg phase shift points match well. They are also quite close to the Fs frequency (999,999.800 Hz). Those -3dB points come out to be 999,990.640 Hz and 999,990.910Hz.
However, I'm a bit concerned that the Q calculated with these numbers is a bit higher than expected based on what I've read. Running the test with a smaller series resistor (100 Ohm) results in a lower Q (As would be expected as the 'load' on the crystal is higher), although even these numbers are quite high.
In order to try to measure Rs, the voltages of the divider were measured at Fs, and RS was calculated accordingly (Easy calculation, as phase shift = 0 deg). This was repeated with several series resistor values (10, 100, and 1000 Ohm). These tests resulted in Rs = between 4 to 7 ohms (depending on the series resistor).
My concern is, are there any potential pitfalls in this measurement setup? Is there something that will give more accurate results, given the equipment on hand? Certainly the Q value seems unreasonably high, and Rs seems quite low. However, these are large low frequency resonators (being 25mm in dia.).
Thanks,
Dan
On 3/6/2021 12:00 PM, time-nuts-request@lists.febo.com wrote:
Message: 4
Date: Fri, 5 Mar 2021 16:03:51 -0600
From: Dana Whitlowk8yumdoober@gmail.com
To: Discussion of precise time and frequency measurement
time-nuts@lists.febo.com
Subject: Re: [time-nuts] Old Crystal.
Message-ID:
CADHrwpcb3_9xeeCHg3r30DS7oGq-CKsXYjW4XM=q=DT0Gv5OXA@mail.gmail.com
Content-Type: text/plain; charset="UTF-8"
Blue LEDs under Nixie tubes might have a deeper purpose than appearance-
they can also
help the Nixie tubes get started upon turn-on (especially if they're
getting old). I once stayed
in a hotel room whose light switches had neon indicators to help one find
them in the dark,
and the one near the entrance door was getting awfully marginal. I
happened to have a blue
LED penlight with me, and I found that shining that on the switch face made
a radical
improvement in making the neon indicator keep going, even at a range of >
20 feet. And
this flashlight was no powerhouse either- it was a single LED with no
auxiliary focussing
optics.
Dana
Hi
You need to extract Cm, Lm and Rm ( motional resistance, capacitance, inductance)
for the mode you are looking at. You also need C0. Once you have those you can
come up with Q. Because of the interaction between C0 and the other parameters,
you need to extract them all. ( yes, you could extract Fs and leave out Lm, it’s still
three parameters plus C0).
Bob
> On Mar 6, 2021, at 4:02 PM, Dan Kemppainen <dan@irtelemetrics.com> wrote:
>
> Hi All,
>
> Just to be clear, I am not the person who made the crystals glow blue. I just noticed some pictures of that happening on the auction site:
>
> https://www.ebay.com/itm/8x-Quartz-Resonator-1000-kHz-Crystal-oscillator-gold-Sonoluminescence-effect-NOS/113862454353
>
> https://www.ebay.com/itm/1x-Quartz-Resonator-1000-kHz-Crystal-oscillator-gold-Sonoluminescence-effect/113874435589
>
> I certainly will not abuse these crystals this way!
>
>
>
> As for measurements, I'm trying to take some measurements with the equipment on hand. Currently, that is an Agilent 33220A signal generator, and TDS3000B oscilloscope + Active FET Probe.
>
> Years ago I put together a little Excel Macro program that sweeps the signal generator through a range of frequencies, and measures the voltage and phase of the signals on the oscilloscope. Basically, the sampled signals are run through a sine fit routine, which gives very good estimation of sine amplitude and phase shift (With frequency being set by the signal generator).
>
> Using this setup, the first try involved making a voltage divider with a fixed resistor and the crystal. The signal generator was used to drive signal into the resistor, through the crystal to ground. A standard 10x probe monitored the signal generator voltage, and the FET probe in series with a 1K resistor (for more isolation) was used to monitor the crystal voltage. (The probes were compared before the test, and channel skew adjusted to zero).
>
> Basically, this is a voltage divider made with a resistor and a crystal. From this, a frequency response curve was generated. See attached image.
> The -3dB and +/-45 deg phase shift points match well. They are also quite close to the Fs frequency (999,999.800 Hz). Those -3dB points come out to be 999,990.640 Hz and 999,990.910Hz.
>
> However, I'm a bit concerned that the Q calculated with these numbers is a bit higher than expected based on what I've read. Running the test with a smaller series resistor (100 Ohm) results in a lower Q (As would be expected as the 'load' on the crystal is higher), although even these numbers are quite high.
>
> In order to try to measure Rs, the voltages of the divider were measured at Fs, and RS was calculated accordingly (Easy calculation, as phase shift = 0 deg). This was repeated with several series resistor values (10, 100, and 1000 Ohm). These tests resulted in Rs = between 4 to 7 ohms (depending on the series resistor).
>
> My concern is, are there any potential pitfalls in this measurement setup? Is there something that will give more accurate results, given the equipment on hand? Certainly the Q value seems unreasonably high, and Rs seems quite low. However, these are large low frequency resonators (being 25mm in dia.).
>
>
> Thanks,
> Dan
>
>
> On 3/6/2021 12:00 PM, time-nuts-request@lists.febo.com wrote:
>> Message: 4
>> Date: Fri, 5 Mar 2021 16:03:51 -0600
>> From: Dana Whitlow<k8yumdoober@gmail.com>
>> To: Discussion of precise time and frequency measurement
>> <time-nuts@lists.febo.com>
>> Subject: Re: [time-nuts] Old Crystal.
>> Message-ID:
>> <CADHrwpcb3_9xeeCHg3r30DS7oGq-CKsXYjW4XM=q=DT0Gv5OXA@mail.gmail.com>
>> Content-Type: text/plain; charset="UTF-8"
>> Blue LEDs under Nixie tubes might have a deeper purpose than appearance-
>> they can also
>> help the Nixie tubes get started upon turn-on (especially if they're
>> getting old). I once stayed
>> in a hotel room whose light switches had neon indicators to help one find
>> them in the dark,
>> and the one near the entrance door was getting awfully marginal. I
>> happened to have a blue
>> LED penlight with me, and I found that shining that on the switch face made
>> a radical
>> improvement in making the neon indicator keep going, even at a range of >
>> 20 feet. And
>> this flashlight was no powerhouse either- it was a single LED with no
>> auxiliary focussing
>> optics.
>> Dana
> <457 Sweep 1K Series.jpg>_______________________________________________
> time-nuts mailing list -- time-nuts@lists.febo.com
> To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
> and follow the instructions there.
EB
ed breya
Sat, Mar 6, 2021 10:42 PM
Haha - interesting pictures. It looks like they really do glow, but I
doubt it's from anything the crystal element is doing - it and the mount
structure may just serve as the electrodes for a gas discharge lamp. If
the envelope is filled with some relatively "inert" gas or mixture,
instead of vacuum, then you have a discharge lamp. Using say, dry
nitrogen or krypton (common fillers, I think), you may get the bluish
color at some conditions. If you excite it with high enough AC voltage
at limited current, it will strike and run.
I doubt that the crystal would be mechanically damaged unless you could
somehow apply the excitation at "exactly" the resonant frequency, but
I'd think it would become no good as a normal crystal anymore, since
various things could deposit onto or depart from the surface, affecting
the resonance and Q. If the voltage is high enough that it arcs over and
ruins the connections, that's another story. The voltage will at least
be limited by the gas. If the current is allowed to get too high, then
the whole thing will be shot.
Ed
Haha - interesting pictures. It looks like they really do glow, but I
doubt it's from anything the crystal element is doing - it and the mount
structure may just serve as the electrodes for a gas discharge lamp. If
the envelope is filled with some relatively "inert" gas or mixture,
instead of vacuum, then you have a discharge lamp. Using say, dry
nitrogen or krypton (common fillers, I think), you may get the bluish
color at some conditions. If you excite it with high enough AC voltage
at limited current, it will strike and run.
I doubt that the crystal would be mechanically damaged unless you could
somehow apply the excitation at "exactly" the resonant frequency, but
I'd think it would become no good as a normal crystal anymore, since
various things could deposit onto or depart from the surface, affecting
the resonance and Q. If the voltage is high enough that it arcs over and
ruins the connections, that's another story. The voltage will at least
be limited by the gas. If the current is allowed to get too high, then
the whole thing will be shot.
Ed
DW
Dana Whitlow
Sat, Mar 6, 2021 11:18 PM
Re: light producing crystals-
If you view https://en.wikipedia.org/wiki/Sonoluminescence
you'll learn that this is not the explanation for the blue glow
seen in the crystals. Sonoluminescence involves collapsing
tiny bubbles in liquids driven by high power acoustic fields.
I think it's safe to assume that these crystals are not liquid filled.
I agree with what Ed just sent, with the added comment that the
"gas" may just be residual from an imperfect vacuum (as all
vacuums are).
Dana
On Sat, Mar 6, 2021 at 3:26 PM Dan Kemppainen dan@irtelemetrics.com wrote:
Hi All,
Just to be clear, I am not the person who made the crystals glow blue. I
just noticed some pictures of that happening on the auction site:
https://www.ebay.com/itm/8x-Quartz-Resonator-1000-kHz-Crystal-oscillator-gold-Sonoluminescence-effect-NOS/113862454353
https://www.ebay.com/itm/1x-Quartz-Resonator-1000-kHz-Crystal-oscillator-gold-Sonoluminescence-effect/113874435589
I certainly will not abuse these crystals this way!
As for measurements, I'm trying to take some measurements with the
equipment on hand. Currently, that is an Agilent 33220A signal
generator, and TDS3000B oscilloscope + Active FET Probe.
Years ago I put together a little Excel Macro program that sweeps the
signal generator through a range of frequencies, and measures the
voltage and phase of the signals on the oscilloscope. Basically, the
sampled signals are run through a sine fit routine, which gives very
good estimation of sine amplitude and phase shift (With frequency being
set by the signal generator).
Using this setup, the first try involved making a voltage divider with a
fixed resistor and the crystal. The signal generator was used to drive
signal into the resistor, through the crystal to ground. A standard 10x
probe monitored the signal generator voltage, and the FET probe in
series with a 1K resistor (for more isolation) was used to monitor the
crystal voltage. (The probes were compared before the test, and channel
skew adjusted to zero).
Basically, this is a voltage divider made with a resistor and a crystal.
From this, a frequency response curve was generated. See attached image.
The -3dB and +/-45 deg phase shift points match well. They are also
quite close to the Fs frequency (999,999.800 Hz). Those -3dB points come
out to be 999,990.640 Hz and 999,990.910Hz.
However, I'm a bit concerned that the Q calculated with these numbers is
a bit higher than expected based on what I've read. Running the test
with a smaller series resistor (100 Ohm) results in a lower Q (As would
be expected as the 'load' on the crystal is higher), although even these
numbers are quite high.
In order to try to measure Rs, the voltages of the divider were measured
at Fs, and RS was calculated accordingly (Easy calculation, as phase
shift = 0 deg). This was repeated with several series resistor values
(10, 100, and 1000 Ohm). These tests resulted in Rs = between 4 to 7
ohms (depending on the series resistor).
My concern is, are there any potential pitfalls in this measurement
setup? Is there something that will give more accurate results, given
the equipment on hand? Certainly the Q value seems unreasonably high,
and Rs seems quite low. However, these are large low frequency
resonators (being 25mm in dia.).
Thanks,
Dan
On 3/6/2021 12:00 PM, time-nuts-request@lists.febo.com wrote:
Message: 4
Date: Fri, 5 Mar 2021 16:03:51 -0600
From: Dana Whitlowk8yumdoober@gmail.com
To: Discussion of precise time and frequency measurement
time-nuts@lists.febo.com
Subject: Re: [time-nuts] Old Crystal.
Message-ID:
<CADHrwpcb3_9xeeCHg3r30DS7oGq-CKsXYjW4XM=q=
Content-Type: text/plain; charset="UTF-8"
Blue LEDs under Nixie tubes might have a deeper purpose than appearance-
they can also
help the Nixie tubes get started upon turn-on (especially if they're
getting old). I once stayed
in a hotel room whose light switches had neon indicators to help one find
them in the dark,
and the one near the entrance door was getting awfully marginal. I
happened to have a blue
LED penlight with me, and I found that shining that on the switch face
a radical
improvement in making the neon indicator keep going, even at a range of >
20 feet. And
this flashlight was no powerhouse either- it was a single LED with no
auxiliary focussing
optics.
Dana
Re: light producing crystals-
If you view https://en.wikipedia.org/wiki/Sonoluminescence
you'll learn that this is not the explanation for the blue glow
seen in the crystals. Sonoluminescence involves collapsing
tiny bubbles in liquids driven by high power acoustic fields.
I think it's safe to assume that these crystals are *not* liquid filled.
I agree with what Ed just sent, with the added comment that the
"gas" may just be residual from an imperfect vacuum (as all
vacuums are).
Dana
On Sat, Mar 6, 2021 at 3:26 PM Dan Kemppainen <dan@irtelemetrics.com> wrote:
> Hi All,
>
> Just to be clear, I am not the person who made the crystals glow blue. I
> just noticed some pictures of that happening on the auction site:
>
>
> https://www.ebay.com/itm/8x-Quartz-Resonator-1000-kHz-Crystal-oscillator-gold-Sonoluminescence-effect-NOS/113862454353
>
>
> https://www.ebay.com/itm/1x-Quartz-Resonator-1000-kHz-Crystal-oscillator-gold-Sonoluminescence-effect/113874435589
>
> I certainly will not abuse these crystals this way!
>
>
>
> As for measurements, I'm trying to take some measurements with the
> equipment on hand. Currently, that is an Agilent 33220A signal
> generator, and TDS3000B oscilloscope + Active FET Probe.
>
> Years ago I put together a little Excel Macro program that sweeps the
> signal generator through a range of frequencies, and measures the
> voltage and phase of the signals on the oscilloscope. Basically, the
> sampled signals are run through a sine fit routine, which gives very
> good estimation of sine amplitude and phase shift (With frequency being
> set by the signal generator).
>
> Using this setup, the first try involved making a voltage divider with a
> fixed resistor and the crystal. The signal generator was used to drive
> signal into the resistor, through the crystal to ground. A standard 10x
> probe monitored the signal generator voltage, and the FET probe in
> series with a 1K resistor (for more isolation) was used to monitor the
> crystal voltage. (The probes were compared before the test, and channel
> skew adjusted to zero).
>
> Basically, this is a voltage divider made with a resistor and a crystal.
> From this, a frequency response curve was generated. See attached image.
> The -3dB and +/-45 deg phase shift points match well. They are also
> quite close to the Fs frequency (999,999.800 Hz). Those -3dB points come
> out to be 999,990.640 Hz and 999,990.910Hz.
>
> However, I'm a bit concerned that the Q calculated with these numbers is
> a bit higher than expected based on what I've read. Running the test
> with a smaller series resistor (100 Ohm) results in a lower Q (As would
> be expected as the 'load' on the crystal is higher), although even these
> numbers are quite high.
>
> In order to try to measure Rs, the voltages of the divider were measured
> at Fs, and RS was calculated accordingly (Easy calculation, as phase
> shift = 0 deg). This was repeated with several series resistor values
> (10, 100, and 1000 Ohm). These tests resulted in Rs = between 4 to 7
> ohms (depending on the series resistor).
>
> My concern is, are there any potential pitfalls in this measurement
> setup? Is there something that will give more accurate results, given
> the equipment on hand? Certainly the Q value seems unreasonably high,
> and Rs seems quite low. However, these are large low frequency
> resonators (being 25mm in dia.).
>
>
> Thanks,
> Dan
>
>
> On 3/6/2021 12:00 PM, time-nuts-request@lists.febo.com wrote:
> > Message: 4
> > Date: Fri, 5 Mar 2021 16:03:51 -0600
> > From: Dana Whitlow<k8yumdoober@gmail.com>
> > To: Discussion of precise time and frequency measurement
> > <time-nuts@lists.febo.com>
> > Subject: Re: [time-nuts] Old Crystal.
> > Message-ID:
> > <CADHrwpcb3_9xeeCHg3r30DS7oGq-CKsXYjW4XM=q=
> DT0Gv5OXA@mail.gmail.com>
> > Content-Type: text/plain; charset="UTF-8"
> >
> > Blue LEDs under Nixie tubes might have a deeper purpose than appearance-
> > they can also
> > help the Nixie tubes get started upon turn-on (especially if they're
> > getting old). I once stayed
> > in a hotel room whose light switches had neon indicators to help one find
> > them in the dark,
> > and the one near the entrance door was getting awfully marginal. I
> > happened to have a blue
> > LED penlight with me, and I found that shining that on the switch face
> made
> > a radical
> > improvement in making the neon indicator keep going, even at a range of >
> > 20 feet. And
> > this flashlight was no powerhouse either- it was a single LED with no
> > auxiliary focussing
> > optics.
> >
> > Dana
> _______________________________________________
> time-nuts mailing list -- time-nuts@lists.febo.com
> To unsubscribe, go to
> http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
> and follow the instructions there.
>
MF
Mike Feher
Sat, Mar 6, 2021 11:52 PM
During WWII the Germans had crystals that glowed at resonance. Some place I
have about a dozen of them on different frequencies. These were mainly used
for calibration purposes, much like in our ARC-5 transmitters that utilized
a crystal and a magic eye tube. About 55 years ago I had an old German radio
guy tell me about crystals that glowed. I thought he was crazy. Turns out he
was right. 73 - Mike
Mike B. Feher, N4FS
89 Arnold Blvd.
Howell NJ 07731
848-245-9115
-----Original Message-----
From: time-nuts time-nuts-bounces@lists.febo.com On Behalf Of ed breya
Sent: Saturday, March 6, 2021 5:42 PM
To: time-nuts@lists.febo.com
Subject: Re: [time-nuts] Old Crystal.
Haha - interesting pictures. It looks like they really do glow, but I doubt
it's from anything the crystal element is doing - it and the mount structure
may just serve as the electrodes for a gas discharge lamp. If the envelope
is filled with some relatively "inert" gas or mixture, instead of vacuum,
then you have a discharge lamp. Using say, dry nitrogen or krypton (common
fillers, I think), you may get the bluish color at some conditions. If you
excite it with high enough AC voltage at limited current, it will strike and
run.
I doubt that the crystal would be mechanically damaged unless you could
somehow apply the excitation at "exactly" the resonant frequency, but I'd
think it would become no good as a normal crystal anymore, since various
things could deposit onto or depart from the surface, affecting the
resonance and Q. If the voltage is high enough that it arcs over and ruins
the connections, that's another story. The voltage will at least be limited
by the gas. If the current is allowed to get too high, then the whole thing
will be shot.
Ed
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During WWII the Germans had crystals that glowed at resonance. Some place I
have about a dozen of them on different frequencies. These were mainly used
for calibration purposes, much like in our ARC-5 transmitters that utilized
a crystal and a magic eye tube. About 55 years ago I had an old German radio
guy tell me about crystals that glowed. I thought he was crazy. Turns out he
was right. 73 - Mike
Mike B. Feher, N4FS
89 Arnold Blvd.
Howell NJ 07731
848-245-9115
-----Original Message-----
From: time-nuts <time-nuts-bounces@lists.febo.com> On Behalf Of ed breya
Sent: Saturday, March 6, 2021 5:42 PM
To: time-nuts@lists.febo.com
Subject: Re: [time-nuts] Old Crystal.
Haha - interesting pictures. It looks like they really do glow, but I doubt
it's from anything the crystal element is doing - it and the mount structure
may just serve as the electrodes for a gas discharge lamp. If the envelope
is filled with some relatively "inert" gas or mixture, instead of vacuum,
then you have a discharge lamp. Using say, dry nitrogen or krypton (common
fillers, I think), you may get the bluish color at some conditions. If you
excite it with high enough AC voltage at limited current, it will strike and
run.
I doubt that the crystal would be mechanically damaged unless you could
somehow apply the excitation at "exactly" the resonant frequency, but I'd
think it would become no good as a normal crystal anymore, since various
things could deposit onto or depart from the surface, affecting the
resonance and Q. If the voltage is high enough that it arcs over and ruins
the connections, that's another story. The voltage will at least be limited
by the gas. If the current is allowed to get too high, then the whole thing
will be shot.
Ed
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BN
Bernd Neubig
Sun, Mar 7, 2021 8:36 AM
Hi,
in general you are right. But for a 1 MHz crystal it is fair to assume the XC0 is much higher than the crystal impedance around the series resonance. Therefore, in good approximation you can consider the crystal like a series resonance R-L-C circuit in the vicinity of series resonance. C0 can be measured separately with a conventional R-L-C- meter far-off resonance.
This is the basis of the evaluation I have described, which needs only three frequencies. And it is sufficient to use this method up to about 30 ~ 50 MHz without significant loss of accuracy.
For higher accuracy the real and imaginary part of the admittance can be used. Theoretically this allows to determine the four parameters at 2 suitable frequencies. Unsing three frequencies gives you already some additional degree of freedom (accuracy).
The latter method is described in some of my publications and found is standardized in IEC standard 60444-5.
Bernd
----- Bob kb8tq wrote-----
You need to extract Cm, Lm and Rm ( motional resistance, capacitance, inductance) for the mode you are looking at. You also need C0. Once you have those you can come up with Q. Because of the interaction between C0 and the other parameters, you need to extract them all. ( yes, you could extract Fs and leave out Lm, it’s still three parameters plus C0).
Bob
Hi,
in general you are right. But for a 1 MHz crystal it is fair to assume the XC0 is much higher than the crystal impedance around the series resonance. Therefore, in good approximation you can consider the crystal like a series resonance R-L-C circuit in the vicinity of series resonance. C0 can be measured separately with a conventional R-L-C- meter far-off resonance.
This is the basis of the evaluation I have described, which needs only three frequencies. And it is sufficient to use this method up to about 30 ~ 50 MHz without significant loss of accuracy.
For higher accuracy the real and imaginary part of the admittance can be used. Theoretically this allows to determine the four parameters at 2 suitable frequencies. Unsing three frequencies gives you already some additional degree of freedom (accuracy).
The latter method is described in some of my publications and found is standardized in IEC standard 60444-5.
Bernd
----- Bob kb8tq wrote-----
You need to extract Cm, Lm and Rm ( motional resistance, capacitance, inductance) for the mode you are looking at. You also need C0. Once you have those you can come up with Q. Because of the interaction between C0 and the other parameters, you need to extract them all. ( yes, you could extract Fs and leave out Lm, it’s still three parameters plus C0).
Bob
