Empathy List Archives

S

SAIDJACK@aol.com

Wed, Jul 28, 2010 2:07 AM

Hi Scott,

yes the pads are there, you can use the through-hole pad right next to C67
and a standard ground pad for the Thermistor. There will be 10.5V across
the thermistor. Connect the thermistor to your Rb case.

You should be able to connect two 10K Thermistors in parallel to get a good
reading without excessive self-heating of the thermistors, while
generating enough current through them that can be measured by the ADC.

You can check the thermistor current using the meas? command. If the
thermistor is not drawing enough current for the ADC, then simply place a 2.2K
resistor in parallel to it.

The software needs to be enabled to support measuring and applying a tempco
correction, by default I think the boards were shipped with only aging
compensation enabled.

Us the following command to enable tempco correction:

serv:tas 2,288,600,50,0.05

Check the settings with:

serv:tas?

The first number is the mode (0 is all off, 1 is aging only, 2 is aging and
tempco correction). The second number is the memory usage, 288 points in
this case. The third number is the sensing frequency in seconds, so 10
minute intervals in this example. 288 points * 10 minutes is 48 hours of memory.
The fourth number is the maximum phase offset allowed for a sense point,
in this case +/-50ns. The last item is the required frequency error
estimate for a sense point, in this case +/-0.05ppb.

bye,
Said

In a message dated 7/27/2010 17:07:31 Pacific Daylight Time, smace@intt.net
writes:

Said, Did the OEM units (from way back) ship with an open pad for the
thermistor? I thought that wouldn't work unless it was drawing oven
current from the Fury. It would be neat to add some tempco into the mix
instead of just trying to shield it from HVAC cycling. The particular
LPRO-101 that I'm using now, doesn't seem to be as sensitive as others
to temp. I was using a different LPRO originally and when I plotted the
Fury board temp sensor with GPSCON you could see the impact of the
cycling, now with this one you would be hard pressed to pick it out.
The X72 was very sensitive to temp changes, EFC tracked the temp quite
well.

Scott

Hi Scott, yes the pads are there, you can use the through-hole pad right next to C67 and a standard ground pad for the Thermistor. There will be 10.5V across the thermistor. Connect the thermistor to your Rb case. You should be able to connect two 10K Thermistors in parallel to get a good reading without excessive self-heating of the thermistors, while generating enough current through them that can be measured by the ADC. You can check the thermistor current using the meas? command. If the thermistor is not drawing enough current for the ADC, then simply place a 2.2K resistor in parallel to it. The software needs to be enabled to support measuring and applying a tempco correction, by default I think the boards were shipped with only aging compensation enabled. Us the following command to enable tempco correction: serv:tas 2,288,600,50,0.05 Check the settings with: serv:tas? The first number is the mode (0 is all off, 1 is aging only, 2 is aging and tempco correction). The second number is the memory usage, 288 points in this case. The third number is the sensing frequency in seconds, so 10 minute intervals in this example. 288 points * 10 minutes is 48 hours of memory. The fourth number is the maximum phase offset allowed for a sense point, in this case +/-50ns. The last item is the required frequency error estimate for a sense point, in this case +/-0.05ppb. bye, Said In a message dated 7/27/2010 17:07:31 Pacific Daylight Time, smace@intt.net writes: Said, Did the OEM units (from way back) ship with an open pad for the thermistor? I thought that wouldn't work unless it was drawing oven current from the Fury. It would be neat to add some tempco into the mix instead of just trying to shield it from HVAC cycling. The particular LPRO-101 that I'm using now, doesn't seem to be as sensitive as others to temp. I was using a different LPRO originally and when I plotted the Fury board temp sensor with GPSCON you could see the impact of the cycling, now with this one you would be hard pressed to pick it out. The X72 was very sensitive to temp changes, EFC tracked the temp quite well. Scott

SM

Scott Mace

Wed, Jul 28, 2010 2:55 AM

Any particular thermistor you would recommend?

Scott

On 07/27/2010 09:07 PM, SAIDJACK@aol.com wrote:

Hi Scott,

yes the pads are there, you can use the through-hole pad right next to C67
and a standard ground pad for the Thermistor. There will be 10.5V across
the thermistor. Connect the thermistor to your Rb case.

You should be able to connect two 10K Thermistors in parallel to get a good
reading without excessive self-heating of the thermistors, while
generating enough current through them that can be measured by the ADC.

You can check the thermistor current using the meas? command. If the
thermistor is not drawing enough current for the ADC, then simply place a 2.2K
resistor in parallel to it.

The software needs to be enabled to support measuring and applying a tempco
correction, by default I think the boards were shipped with only aging
compensation enabled.

Us the following command to enable tempco correction:

serv:tas 2,288,600,50,0.05

Check the settings with:

serv:tas?

The first number is the mode (0 is all off, 1 is aging only, 2 is aging and
tempco correction). The second number is the memory usage, 288 points in
this case. The third number is the sensing frequency in seconds, so 10
minute intervals in this example. 288 points * 10 minutes is 48 hours of memory.
The fourth number is the maximum phase offset allowed for a sense point,
in this case +/-50ns. The last item is the required frequency error
estimate for a sense point, in this case +/-0.05ppb.

bye,
Said

In a message dated 7/27/2010 17:07:31 Pacific Daylight Time, smace@intt.net
writes:

Said, Did the OEM units (from way back) ship with an open pad for the
thermistor? I thought that wouldn't work unless it was drawing oven
current from the Fury. It would be neat to add some tempco into the mix
instead of just trying to shield it from HVAC cycling. The particular
LPRO-101 that I'm using now, doesn't seem to be as sensitive as others
to temp. I was using a different LPRO originally and when I plotted the
Fury board temp sensor with GPSCON you could see the impact of the
cycling, now with this one you would be hard pressed to pick it out.
The X72 was very sensitive to temp changes, EFC tracked the temp quite
well.

Scott

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Any particular thermistor you would recommend? Scott On 07/27/2010 09:07 PM, SAIDJACK@aol.com wrote: > Hi Scott, > > yes the pads are there, you can use the through-hole pad right next to C67 > and a standard ground pad for the Thermistor. There will be 10.5V across > the thermistor. Connect the thermistor to your Rb case. > > You should be able to connect two 10K Thermistors in parallel to get a good > reading without excessive self-heating of the thermistors, while > generating enough current through them that can be measured by the ADC. > > You can check the thermistor current using the meas? command. If the > thermistor is not drawing enough current for the ADC, then simply place a 2.2K > resistor in parallel to it. > > The software needs to be enabled to support measuring and applying a tempco > correction, by default I think the boards were shipped with only aging > compensation enabled. > > Us the following command to enable tempco correction: > > serv:tas 2,288,600,50,0.05 > > Check the settings with: > > serv:tas? > > The first number is the mode (0 is all off, 1 is aging only, 2 is aging and > tempco correction). The second number is the memory usage, 288 points in > this case. The third number is the sensing frequency in seconds, so 10 > minute intervals in this example. 288 points * 10 minutes is 48 hours of memory. > The fourth number is the maximum phase offset allowed for a sense point, > in this case +/-50ns. The last item is the required frequency error > estimate for a sense point, in this case +/-0.05ppb. > > bye, > Said > > > > > In a message dated 7/27/2010 17:07:31 Pacific Daylight Time, smace@intt.net > writes: > > Said, Did the OEM units (from way back) ship with an open pad for the > thermistor? I thought that wouldn't work unless it was drawing oven > current from the Fury. It would be neat to add some tempco into the mix > instead of just trying to shield it from HVAC cycling. The particular > LPRO-101 that I'm using now, doesn't seem to be as sensitive as others > to temp. I was using a different LPRO originally and when I plotted the > Fury board temp sensor with GPSCON you could see the impact of the > cycling, now with this one you would be hard pressed to pick it out. > The X72 was very sensitive to temp changes, EFC tracked the temp quite > well. > > > Scott > _______________________________________________ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > >

D@

Don @ True-Cal

Wed, Jul 28, 2010 4:18 PM

Said,

I would like to take advantage of the Fury TempCo capabilities when using an Rb. I have been looking for the thru-hole pad which you say is next to C67 but I can't find a C67. Consider that I am over 60 and eyesight is challenged but I have found C68 with nearby pads. Can you give us some additional components nearby to zero in on this allusive component. Thanks!

Regards...
Don
----- Original Message -----
From: SAIDJACK@aol.com
To: time-nuts@febo.com
Sent: Tuesday, July 27, 2010 9:07 PM
Subject: Re: [time-nuts] Fury - Rubidium

Hi Scott,

yes the pads are there, you can use the through-hole pad right next to C67
and a standard ground pad for the Thermistor. There will be 10.5V across
the thermistor. Connect the thermistor to your Rb case.

You should be able to connect two 10K Thermistors in parallel to get a good
reading without excessive self-heating of the thermistors, while
generating enough current through them that can be measured by the ADC.

You can check the thermistor current using the meas? command. If the
thermistor is not drawing enough current for the ADC, then simply place a 2.2K
resistor in parallel to it.

The software needs to be enabled to support measuring and applying a tempco
correction, by default I think the boards were shipped with only aging
compensation enabled.

Us the following command to enable tempco correction:

serv:tas 2,288,600,50,0.05

Check the settings with:

serv:tas?

The first number is the mode (0 is all off, 1 is aging only, 2 is aging and
tempco correction). The second number is the memory usage, 288 points in
this case. The third number is the sensing frequency in seconds, so 10
minute intervals in this example. 288 points * 10 minutes is 48 hours of memory.
The fourth number is the maximum phase offset allowed for a sense point,
in this case +/-50ns. The last item is the required frequency error
estimate for a sense point, in this case +/-0.05ppb.

bye,
Said

In a message dated 7/27/2010 17:07:31 Pacific Daylight Time, smace@intt.net
writes:

Said, Did the OEM units (from way back) ship with an open pad for the
thermistor? I thought that wouldn't work unless it was drawing oven
current from the Fury. It would be neat to add some tempco into the mix
instead of just trying to shield it from HVAC cycling. The particular
LPRO-101 that I'm using now, doesn't seem to be as sensitive as others
to temp. I was using a different LPRO originally and when I plotted the
Fury board temp sensor with GPSCON you could see the impact of the
cycling, now with this one you would be hard pressed to pick it out.
The X72 was very sensitive to temp changes, EFC tracked the temp quite
well.

Scott

time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Said, I would like to take advantage of the Fury TempCo capabilities when using an Rb. I have been looking for the thru-hole pad which you say is next to C67 but I can't find a C67. Consider that I am over 60 and eyesight is challenged but I have found C68 with nearby pads. Can you give us some additional components nearby to zero in on this allusive component. Thanks! Regards... Don ----- Original Message ----- From: SAIDJACK@aol.com To: time-nuts@febo.com Sent: Tuesday, July 27, 2010 9:07 PM Subject: Re: [time-nuts] Fury - Rubidium Hi Scott, yes the pads are there, you can use the through-hole pad right next to C67 and a standard ground pad for the Thermistor. There will be 10.5V across the thermistor. Connect the thermistor to your Rb case. You should be able to connect two 10K Thermistors in parallel to get a good reading without excessive self-heating of the thermistors, while generating enough current through them that can be measured by the ADC. You can check the thermistor current using the meas? command. If the thermistor is not drawing enough current for the ADC, then simply place a 2.2K resistor in parallel to it. The software needs to be enabled to support measuring and applying a tempco correction, by default I think the boards were shipped with only aging compensation enabled. Us the following command to enable tempco correction: serv:tas 2,288,600,50,0.05 Check the settings with: serv:tas? The first number is the mode (0 is all off, 1 is aging only, 2 is aging and tempco correction). The second number is the memory usage, 288 points in this case. The third number is the sensing frequency in seconds, so 10 minute intervals in this example. 288 points * 10 minutes is 48 hours of memory. The fourth number is the maximum phase offset allowed for a sense point, in this case +/-50ns. The last item is the required frequency error estimate for a sense point, in this case +/-0.05ppb. bye, Said In a message dated 7/27/2010 17:07:31 Pacific Daylight Time, smace@intt.net writes: Said, Did the OEM units (from way back) ship with an open pad for the thermistor? I thought that wouldn't work unless it was drawing oven current from the Fury. It would be neat to add some tempco into the mix instead of just trying to shield it from HVAC cycling. The particular LPRO-101 that I'm using now, doesn't seem to be as sensitive as others to temp. I was using a different LPRO originally and when I plotted the Fury board temp sensor with GPSCON you could see the impact of the cycling, now with this one you would be hard pressed to pick it out. The X72 was very sensitive to temp changes, EFC tracked the temp quite well. Scott _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.

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Re: [time-nuts] Fury - Rubidium