Empathy List Archives

SW

Skip Withrow

Thu, Nov 10, 2016 12:02 AM

Hello Time-Nuts,

I have been checking out some cesium beam tubes lately and have run into an
interesting one. The tube is a standard HP 05061-6077 unit. There are two
labels on these tubes, one at the end that has a serial number, and the
other large label on the side that has the operating information (and the
serial number). Problem with this tube is the large label is completely
BLANK. It appears that there was never any information on this label. The
source that it came from was pretty closely connected to HP, so it could be
a tube that escaped before testing/characterization.

The nice thing is that it works! Using some random nominal resistors for
the oven temperature I get good beam current. Changing the electron
multiplier voltage also dramatically changes the beam current. I see the 3
peaks around the on-frequency point quite nicely.

So, the question is - how do I determine the operating point of the tube
with no data? I could fire up a known tube and set the beam current for
the same value, but how would the oven temperature vs. electron multiplier
voltage be resolved. I would think that a lower oven temp and higher EM
voltage would give the same beam current as a higher oven temp and lower EM
voltage.

I'm sure the HP did not do any characterization of the tube until it was
all buttoned up. So how did they determine the temperature of the oven?
Just from the value of the internal thermistor?

I suspect the answer is what kind of S/N ratio do I want? If that is the
case then I would be tempted to run at the lowest oven temp and highest EM
voltage that gave me a usable signal - for the sake of tube life.

Any thoughts?

Thanks,
Skip Withrow

Hello Time-Nuts, I have been checking out some cesium beam tubes lately and have run into an interesting one. The tube is a standard HP 05061-6077 unit. There are two labels on these tubes, one at the end that has a serial number, and the other large label on the side that has the operating information (and the serial number). Problem with this tube is the large label is completely BLANK. It appears that there was never any information on this label. The source that it came from was pretty closely connected to HP, so it could be a tube that escaped before testing/characterization. The nice thing is that it works! Using some random nominal resistors for the oven temperature I get good beam current. Changing the electron multiplier voltage also dramatically changes the beam current. I see the 3 peaks around the on-frequency point quite nicely. So, the question is - how do I determine the operating point of the tube with no data? I could fire up a known tube and set the beam current for the same value, but how would the oven temperature vs. electron multiplier voltage be resolved. I would think that a lower oven temp and higher EM voltage would give the same beam current as a higher oven temp and lower EM voltage. I'm sure the HP did not do any characterization of the tube until it was all buttoned up. So how did they determine the temperature of the oven? Just from the value of the internal thermistor? I suspect the answer is what kind of S/N ratio do I want? If that is the case then I would be tempted to run at the lowest oven temp and highest EM voltage that gave me a usable signal - for the sake of tube life. Any thoughts? Thanks, Skip Withrow

BC

Bob Camp

Thu, Nov 10, 2016 12:13 AM

Hi

I would bet that they started as you have with a low oven setting and cranked
it up based on stability data. Once they got to that point, add a bit to have enough
margin on the tube for it to last the rated life.

Since there are multiple quantum “modes” the beam can get into, there may have been a bit of
sweeping involved to keep this separated from that. If so, I suspect that the sweep
procedure is long lost. You are pretty much stuck with the stability check / tweak / stability
check approach.

Bob

On Nov 9, 2016, at 7:02 PM, Skip Withrow skip.withrow@gmail.com wrote:

Hello Time-Nuts,

I have been checking out some cesium beam tubes lately and have run into an
interesting one. The tube is a standard HP 05061-6077 unit. There are two
labels on these tubes, one at the end that has a serial number, and the
other large label on the side that has the operating information (and the
serial number). Problem with this tube is the large label is completely
BLANK. It appears that there was never any information on this label. The
source that it came from was pretty closely connected to HP, so it could be
a tube that escaped before testing/characterization.

The nice thing is that it works! Using some random nominal resistors for
the oven temperature I get good beam current. Changing the electron
multiplier voltage also dramatically changes the beam current. I see the 3
peaks around the on-frequency point quite nicely.

So, the question is - how do I determine the operating point of the tube
with no data? I could fire up a known tube and set the beam current for
the same value, but how would the oven temperature vs. electron multiplier
voltage be resolved. I would think that a lower oven temp and higher EM
voltage would give the same beam current as a higher oven temp and lower EM
voltage.

I'm sure the HP did not do any characterization of the tube until it was
all buttoned up. So how did they determine the temperature of the oven?
Just from the value of the internal thermistor?

I suspect the answer is what kind of S/N ratio do I want? If that is the
case then I would be tempted to run at the lowest oven temp and highest EM
voltage that gave me a usable signal - for the sake of tube life.

Any thoughts?

Thanks,
Skip Withrow

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

Hi I would bet that they started as you have with a low oven setting and cranked it up based on stability data. Once they got to that point, add a bit to have enough margin on the tube for it to last the rated life. Since there are multiple quantum “modes” the beam can get into, there may have been a bit of sweeping involved to keep this separated from that. If so, I suspect that the sweep procedure is long lost. You are pretty much stuck with the stability check / tweak / stability check approach. Bob > On Nov 9, 2016, at 7:02 PM, Skip Withrow <skip.withrow@gmail.com> wrote: > > Hello Time-Nuts, > > I have been checking out some cesium beam tubes lately and have run into an > interesting one. The tube is a standard HP 05061-6077 unit. There are two > labels on these tubes, one at the end that has a serial number, and the > other large label on the side that has the operating information (and the > serial number). Problem with this tube is the large label is completely > BLANK. It appears that there was never any information on this label. The > source that it came from was pretty closely connected to HP, so it could be > a tube that escaped before testing/characterization. > > The nice thing is that it works! Using some random nominal resistors for > the oven temperature I get good beam current. Changing the electron > multiplier voltage also dramatically changes the beam current. I see the 3 > peaks around the on-frequency point quite nicely. > > So, the question is - how do I determine the operating point of the tube > with no data? I could fire up a known tube and set the beam current for > the same value, but how would the oven temperature vs. electron multiplier > voltage be resolved. I would think that a lower oven temp and higher EM > voltage would give the same beam current as a higher oven temp and lower EM > voltage. > > I'm sure the HP did not do any characterization of the tube until it was > all buttoned up. So how did they determine the temperature of the oven? > Just from the value of the internal thermistor? > > I suspect the answer is what kind of S/N ratio do I want? If that is the > case then I would be tempted to run at the lowest oven temp and highest EM > voltage that gave me a usable signal - for the sake of tube life. > > Any thoughts? > > Thanks, > Skip Withrow > _______________________________________________ > 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.

PS

paul swed

Thu, Nov 10, 2016 12:14 AM

Skip
Not the expert but as you say the lower oven temp means higher em and visa
versa.
Funny you mention no writing in some document or ebay pixs I saw the same
thing a tube with no details. So that now makes 2 instances of no marking.
My non-professional 10 cents put a tube in you know. Set EM to some beam
current level.
Replace using the same temp resistor if it the beam current goes up lower
the oven temp.
Regards
Paul
WB8TSL

On Wed, Nov 9, 2016 at 7:02 PM, Skip Withrow skip.withrow@gmail.com wrote:

Hello Time-Nuts,

I have been checking out some cesium beam tubes lately and have run into an
interesting one. The tube is a standard HP 05061-6077 unit. There are two
labels on these tubes, one at the end that has a serial number, and the
other large label on the side that has the operating information (and the
serial number). Problem with this tube is the large label is completely
BLANK. It appears that there was never any information on this label. The
source that it came from was pretty closely connected to HP, so it could be
a tube that escaped before testing/characterization.

The nice thing is that it works! Using some random nominal resistors for
the oven temperature I get good beam current. Changing the electron
multiplier voltage also dramatically changes the beam current. I see the 3
peaks around the on-frequency point quite nicely.

So, the question is - how do I determine the operating point of the tube
with no data? I could fire up a known tube and set the beam current for
the same value, but how would the oven temperature vs. electron multiplier
voltage be resolved. I would think that a lower oven temp and higher EM
voltage would give the same beam current as a higher oven temp and lower EM
voltage.

I'm sure the HP did not do any characterization of the tube until it was
all buttoned up. So how did they determine the temperature of the oven?
Just from the value of the internal thermistor?

I suspect the answer is what kind of S/N ratio do I want? If that is the
case then I would be tempted to run at the lowest oven temp and highest EM
voltage that gave me a usable signal - for the sake of tube life.

Any thoughts?

Thanks,
Skip Withrow

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.

Skip Not the expert but as you say the lower oven temp means higher em and visa versa. Funny you mention no writing in some document or ebay pixs I saw the same thing a tube with no details. So that now makes 2 instances of no marking. My non-professional 10 cents put a tube in you know. Set EM to some beam current level. Replace using the same temp resistor if it the beam current goes up lower the oven temp. Regards Paul WB8TSL On Wed, Nov 9, 2016 at 7:02 PM, Skip Withrow <skip.withrow@gmail.com> wrote: > Hello Time-Nuts, > > I have been checking out some cesium beam tubes lately and have run into an > interesting one. The tube is a standard HP 05061-6077 unit. There are two > labels on these tubes, one at the end that has a serial number, and the > other large label on the side that has the operating information (and the > serial number). Problem with this tube is the large label is completely > BLANK. It appears that there was never any information on this label. The > source that it came from was pretty closely connected to HP, so it could be > a tube that escaped before testing/characterization. > > The nice thing is that it works! Using some random nominal resistors for > the oven temperature I get good beam current. Changing the electron > multiplier voltage also dramatically changes the beam current. I see the 3 > peaks around the on-frequency point quite nicely. > > So, the question is - how do I determine the operating point of the tube > with no data? I could fire up a known tube and set the beam current for > the same value, but how would the oven temperature vs. electron multiplier > voltage be resolved. I would think that a lower oven temp and higher EM > voltage would give the same beam current as a higher oven temp and lower EM > voltage. > > I'm sure the HP did not do any characterization of the tube until it was > all buttoned up. So how did they determine the temperature of the oven? > Just from the value of the internal thermistor? > > I suspect the answer is what kind of S/N ratio do I want? If that is the > case then I would be tempted to run at the lowest oven temp and highest EM > voltage that gave me a usable signal - for the sake of tube life. > > Any thoughts? > > Thanks, > Skip Withrow > _______________________________________________ > 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. >

time-nuts@lists.febo.com

Need some wisdom from the cesium beam tube gurus out there