Hello, I recently acquired a HP5061A and I am attempting to start it but there are some things that are puzzling me. Per the manual I have left the unit plugged in for 24 hours with mode set to CS OFF set to and I have observed the Ion Pump readings go to 0 after about 3 or 4 minutes of first plugging it in. So now I am attempting to power up the tube by switching to Loop open and I can hear another power supply engage. My Ion Pump reading climbs to about 30 after about 10 seconds and then the power supply shuts off. Then I get into a cycle of about 2 seconds on for 10 seconds off with the Ion Pump going between 20-30 or thereabouts. I'm not sure if this is normal and part of the pumping down process. Should I leave it on or keep trying to run it on CS OFF? Am I correct in assuming that with CS OFF the +3500V supply is running and that is what is acting as the Ion Pump to evacuate the tube, and then when I switch to Loop open that also powers up the Cesium Heater and the -2500V supply? I have experience with high power Triodes and Tetrodes where you run the filaments without high voltage to help evacuate the tube so I'm unsure how a tube like this operates. Thank you!

Hi Matt, You're doing everything right. Read Paul's comment about the "crud burst": https://febo.com/pipermail/time-nuts_lists.febo.com/2022-November/106842.html The entire thread will be of interest to you. Search for "5061A HV Supply" in the sorted monthly archive: https://febo.com/pipermail/time-nuts_lists.febo.com/2022-November/subject.html The short answer is it's totally normal for a 5061A to cycle like that if it's been powered off for months or years. Leave it in open loop and once in a while mentally measure the period. You say it's 10 seconds now; it will slowly get faster and faster and eventually finish. The entire process could take many minutes or even many hours; it all depends on how long the tube has been unused. But as long as the cycle slowly gets faster you're all set. /tvb On 2/7/2023 9:39 PM, Matt Krick via time-nuts wrote: > Hello, > > I recently acquired a HP5061A and I am attempting to start it but there are > some things that are puzzling me. > > Per the manual I have left the unit plugged in for 24 hours with mode set > to CS OFF set to and I have observed the Ion Pump readings go to 0 after > about 3 or 4 minutes of first plugging it in. > > So now I am attempting to power up the tube by switching to Loop open and I > can hear another power supply engage. My Ion Pump reading climbs to about > 30 after about 10 seconds and then the power supply shuts off. Then I get > into a cycle of about 2 seconds on for 10 seconds off with the Ion Pump > going between 20-30 or thereabouts. > > I'm not sure if this is normal and part of the pumping down process. > Should I leave it on or keep trying to run it on CS OFF? > > Am I correct in assuming that with CS OFF the +3500V supply is running and > that is what is acting as the Ion Pump to evacuate the tube, and then when > I switch to Loop open that also powers up the Cesium Heater and the -2500V > supply? > > I have experience with high power Triodes and Tetrodes where you run the > filaments without high voltage to help evacuate the tube so I'm unsure how > a tube like this operates. > > Thank you!

Toms right though the last paragraph is a little misleading. In the open position you hear the 2500 V supply. This causes the crud burst and the meter climbs. At 30ua approx the 2500V supply turns off. The Ion pump pumps down and then the 2500V comes back on. The effect. Slowly but surely the 2500 V will stay on longer. When it shuts off the ION pump brings it back down faster. Over some time it simply stays on. The fact that the tube pumped down so fast is amazing if its been off a long time. Regards Paul On Wed, Feb 8, 2023 at 4:57 AM Tom Van Baak via time-nuts < time-nuts@lists.febo.com> wrote: > Hi Matt, > > You're doing everything right. Read Paul's comment about the "crud burst": > > > https://febo.com/pipermail/time-nuts_lists.febo.com/2022-November/106842.html > > The entire thread will be of interest to you. Search for "5061A HV > Supply" in the sorted monthly archive: > > > https://febo.com/pipermail/time-nuts_lists.febo.com/2022-November/subject.html > > The short answer is it's totally normal for a 5061A to cycle like that > if it's been powered off for months or years. Leave it in open loop and > once in a while mentally measure the period. You say it's 10 seconds > now; it will slowly get faster and faster and eventually finish. The > entire process could take many minutes or even many hours; it all > depends on how long the tube has been unused. But as long as the cycle > slowly gets faster you're all set. > > /tvb > > > On 2/7/2023 9:39 PM, Matt Krick via time-nuts wrote: > > Hello, > > > > I recently acquired a HP5061A and I am attempting to start it but there > are > > some things that are puzzling me. > > > > Per the manual I have left the unit plugged in for 24 hours with mode set > > to CS OFF set to and I have observed the Ion Pump readings go to 0 after > > about 3 or 4 minutes of first plugging it in. > > > > So now I am attempting to power up the tube by switching to Loop open > and I > > can hear another power supply engage. My Ion Pump reading climbs to about > > 30 after about 10 seconds and then the power supply shuts off. Then I get > > into a cycle of about 2 seconds on for 10 seconds off with the Ion Pump > > going between 20-30 or thereabouts. > > > > I'm not sure if this is normal and part of the pumping down process. > > Should I leave it on or keep trying to run it on CS OFF? > > > > Am I correct in assuming that with CS OFF the +3500V supply is running > and > > that is what is acting as the Ion Pump to evacuate the tube, and then > when > > I switch to Loop open that also powers up the Cesium Heater and the > -2500V > > supply? > > > > I have experience with high power Triodes and Tetrodes where you run the > > filaments without high voltage to help evacuate the tube so I'm unsure > how > > a tube like this operates. > > > > Thank you! > _______________________________________________ > time-nuts mailing list -- time-nuts@lists.febo.com > To unsubscribe send an email to time-nuts-leave@lists.febo.com >

Hi Matt, I just went through this when resurrecting a 5061A option 4 that was about to be scrapped (Horrors!).  My ion pump power supply was flakey, but after I fiddled with it, I got it to work.  I then saw the same behaviour.  Ultimately, I connected an external supply to the ion pump and left it powered for a few days.  This cleaned (or whatever happens) the tube and I was able to lock it.  FWIW, the supply I connected was about 7 kV.  The label said 3KV, but apparently that was under the rated load.  In any event, I thought I wrecked the whole thing.  I was assured by some time nuts that it was OK, and it was.  It's been running continuously now for about 2 months.  Here's an ADEV plot for fun...   Measured against another opt 4.  Both units have an unknown history, and they are 40 year old tubes, so I consider this a success!  Good enough anyway. Good luck, and keep one hand in your pocket. Jim On 2023-02-08 12:39 AM, Matt Krick via time-nuts wrote: > Hello, > > I recently acquired a HP5061A and I am attempting to start it but there are > some things that are puzzling me. > > Per the manual I have left the unit plugged in for 24 hours with mode set > to CS OFF set to and I have observed the Ion Pump readings go to 0 after > about 3 or 4 minutes of first plugging it in. > > So now I am attempting to power up the tube by switching to Loop open and I > can hear another power supply engage. My Ion Pump reading climbs to about > 30 after about 10 seconds and then the power supply shuts off. Then I get > into a cycle of about 2 seconds on for 10 seconds off with the Ion Pump > going between 20-30 or thereabouts. > > I'm not sure if this is normal and part of the pumping down process. > Should I leave it on or keep trying to run it on CS OFF? > > Am I correct in assuming that with CS OFF the +3500V supply is running and > that is what is acting as the Ion Pump to evacuate the tube, and then when > I switch to Loop open that also powers up the Cesium Heater and the -2500V > supply? > > I have experience with high power Triodes and Tetrodes where you run the > filaments without high voltage to help evacuate the tube so I'm unsure how > a tube like this operates. > > Thank you! > _______________________________________________ > time-nuts mailing list --time-nuts@lists.febo.com > To unsubscribe send an email totime-nuts-leave@lists.febo.com -- Jim Muehlberg Senior Engineer National Radio Astronomy Observatory ngVLA Local Oscillator Lead 1180 Boxwood Estates Rd B-111 Charlottesville, VA 22903-4602 P 434.296.0270 C 434.422.2017

Hi Matt, Just to add another 2c to this thread, I went through roughly the same process Jim describes with my 5061A. I also kept the hot wire ionizer powered on in order to catch any neutral particles which may have been affecting the vacuum. I took some measurements of the process to get a rough "pump curve" which can be seen here: https://docs.google.com/spreadsheets/d/1zsTUAiDZ92Eb-2lID9Hkoe7ByOylcx_LJ3ktGqG_uac/edit?usp=drivesdk Best of luck! -Aiden Sent from my Verizon, Samsung Galaxy smartphone -------- Original message -------- From: Jim Muehlberg via time-nuts <time-nuts@lists.febo.com> Date: 2/8/23 17:34 (GMT-05:00) To: Matt Krick via time-nuts <time-nuts@lists.febo.com> Cc: Jim Muehlberg <jmuehlbe@nrao.edu> Subject: [time-nuts] Re: Attempting to start HP5061A {External} Hi Matt, I just went through this when resurrecting a 5061A option 4 that was about to be scrapped (Horrors!). My ion pump power supply was flakey, but after I fiddled with it, I got it to work. I then saw the same behaviour. Ultimately, I connected an external supply to the ion pump and left it powered for a few days. This cleaned (or whatever happens) the tube and I was able to lock it. FWIW, the supply I connected was about 7 kV. The label said 3KV, but apparently that was under the rated load. In any event, I thought I wrecked the whole thing. I was assured by some time nuts that it was OK, and it was. It's been running continuously now for about 2 months. Here's an ADEV plot for fun... Measured against another opt 4. Both units have an unknown history, and they are 40 year old tubes, so I consider this a success! Good enough anyway. Good luck, and keep one hand in your pocket. Jim On 2023-02-08 12:39 AM, Matt Krick via time-nuts wrote: > Hello, > > I recently acquired a HP5061A and I am attempting to start it but there are > some things that are puzzling me. > > Per the manual I have left the unit plugged in for 24 hours with mode set > to CS OFF set to and I have observed the Ion Pump readings go to 0 after > about 3 or 4 minutes of first plugging it in. > > So now I am attempting to power up the tube by switching to Loop open and I > can hear another power supply engage. My Ion Pump reading climbs to about > 30 after about 10 seconds and then the power supply shuts off. Then I get > into a cycle of about 2 seconds on for 10 seconds off with the Ion Pump > going between 20-30 or thereabouts. > > I'm not sure if this is normal and part of the pumping down process. > Should I leave it on or keep trying to run it on CS OFF? > > Am I correct in assuming that with CS OFF the +3500V supply is running and > that is what is acting as the Ion Pump to evacuate the tube, and then when > I switch to Loop open that also powers up the Cesium Heater and the -2500V > supply? > > I have experience with high power Triodes and Tetrodes where you run the > filaments without high voltage to help evacuate the tube so I'm unsure how > a tube like this operates. > > Thank you! > _______________________________________________ > time-nuts mailing list --time-nuts@lists.febo.com > To unsubscribe send an email totime-nuts-leave@lists.febo.com -- Jim Muehlberg Senior Engineer National Radio Astronomy Observatory ngVLA Local Oscillator Lead 1180 Boxwood Estates Rd B-111 Charlottesville, VA 22903-4602 P 434.296.0270 C 434.422.2017 _______________________________________________ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe send an email to time-nuts-leave@lists.febo.com

Looking at the inside I believe the unit is from 1980 and had the tube replaced at HP in 1983. The label on the door is pristine and hasn't been used. I'm thinking the last time it may have been in service was no later than 1992. On Wed, Feb 8, 2023, 14:31 paul swed via time-nuts <time-nuts@lists.febo.com> wrote: > Toms right though the last paragraph is a little misleading. > In the open position you hear the 2500 V supply. This causes the crud burst > and the meter climbs. > At 30ua approx the 2500V supply turns off. The Ion pump pumps down and then > the 2500V comes back on. > The effect. > Slowly but surely the 2500 V will stay on longer. When it shuts off the ION > pump brings it back down faster. > Over some time it simply stays on. > The fact that the tube pumped down so fast is amazing if its been off a > long time. > Regards > Paul > > On Wed, Feb 8, 2023 at 4:57 AM Tom Van Baak via time-nuts < > time-nuts@lists.febo.com> wrote: > > > Hi Matt, > > > > You're doing everything right. Read Paul's comment about the "crud > burst": > > > > > > > https://febo.com/pipermail/time-nuts_lists.febo.com/2022-November/106842.html > > > > The entire thread will be of interest to you. Search for "5061A HV > > Supply" in the sorted monthly archive: > > > > > > > https://febo.com/pipermail/time-nuts_lists.febo.com/2022-November/subject.html > > > > The short answer is it's totally normal for a 5061A to cycle like that > > if it's been powered off for months or years. Leave it in open loop and > > once in a while mentally measure the period. You say it's 10 seconds > > now; it will slowly get faster and faster and eventually finish. The > > entire process could take many minutes or even many hours; it all > > depends on how long the tube has been unused. But as long as the cycle > > slowly gets faster you're all set. > > > > /tvb > > > > > > On 2/7/2023 9:39 PM, Matt Krick via time-nuts wrote: > > > Hello, > > > > > > I recently acquired a HP5061A and I am attempting to start it but there > > are > > > some things that are puzzling me. > > > > > > Per the manual I have left the unit plugged in for 24 hours with mode > set > > > to CS OFF set to and I have observed the Ion Pump readings go to 0 > after > > > about 3 or 4 minutes of first plugging it in. > > > > > > So now I am attempting to power up the tube by switching to Loop open > > and I > > > can hear another power supply engage. My Ion Pump reading climbs to > about > > > 30 after about 10 seconds and then the power supply shuts off. Then I > get > > > into a cycle of about 2 seconds on for 10 seconds off with the Ion Pump > > > going between 20-30 or thereabouts. > > > > > > I'm not sure if this is normal and part of the pumping down process. > > > Should I leave it on or keep trying to run it on CS OFF? > > > > > > Am I correct in assuming that with CS OFF the +3500V supply is running > > and > > > that is what is acting as the Ion Pump to evacuate the tube, and then > > when > > > I switch to Loop open that also powers up the Cesium Heater and the > > -2500V > > > supply? > > > > > > I have experience with high power Triodes and Tetrodes where you run > the > > > filaments without high voltage to help evacuate the tube so I'm unsure > > how > > > a tube like this operates. > > > > > > Thank you! > > _______________________________________________ > > time-nuts mailing list -- time-nuts@lists.febo.com > > To unsubscribe send an email to time-nuts-leave@lists.febo.com > > > _______________________________________________ > time-nuts mailing list -- time-nuts@lists.febo.com > To unsubscribe send an email to time-nuts-leave@lists.febo.com >

Measured against another opt 4.  Both units have an unknown history,

I am pleased to report that the unit is Alive and Ticking! After 30 minutes of the cycling my unit stabilized. I have it another 2 hours of CS OFF mode and then started it again this time stable with no cycling. With Loop Open the Beam meter started at 2 and slowly climbed to about 15 after about 20 minutes where I did a rough tune. After another 20 minutes I went with Oper mode and centered the coarse tuning getting a peak meter reading of 34. Pegging control to -50 I then centered the control reading by again tuning coarse and hit the reset button and got the continuous operation to light. I set the clock to my watch and will compare tomorrow On Wed, Feb 8, 2023, 15:22 Aiden Gibson via time-nuts < time-nuts@lists.febo.com> wrote: > Hi Matt, > > Just to add another 2c to this thread, I went through roughly the same > process Jim describes with my 5061A. > > I also kept the hot wire ionizer powered on in order to catch any neutral > particles which may have been affecting the vacuum. > > I took some measurements of the process to get a rough "pump curve" which > can be seen here: > > > https://docs.google.com/spreadsheets/d/1zsTUAiDZ92Eb-2lID9Hkoe7ByOylcx_LJ3ktGqG_uac/edit?usp=drivesdk > > Best of luck! > -Aiden > > Sent from my Verizon, Samsung Galaxy smartphone > > > > -------- Original message -------- > From: Jim Muehlberg via time-nuts <time-nuts@lists.febo.com> > Date: 2/8/23 17:34 (GMT-05:00) > To: Matt Krick via time-nuts <time-nuts@lists.febo.com> > Cc: Jim Muehlberg <jmuehlbe@nrao.edu> > Subject: [time-nuts] Re: Attempting to start HP5061A {External} > > Hi Matt, > > I just went through this when resurrecting a 5061A option 4 that was > about to be scrapped (Horrors!). My ion pump power supply was flakey, > but after I fiddled with it, I got it to work. I then saw the same > behaviour. Ultimately, I connected an external supply to the ion pump > and left it powered for a few days. This cleaned (or whatever happens) > the tube and I was able to lock it. FWIW, the supply I connected was > about 7 kV. The label said 3KV, but apparently that was under the rated > load. In any event, I thought I wrecked the whole thing. I was assured > by some time nuts that it was OK, and it was. It's been running > continuously now for about 2 months. Here's an ADEV plot for fun... > > Measured against another opt 4. Both units have an unknown history, > and they are 40 year old tubes, so I consider this a success! Good > enough anyway. > > Good luck, and keep one hand in your pocket. > > Jim > > On 2023-02-08 12:39 AM, Matt Krick via time-nuts wrote: > > Hello, > > > > I recently acquired a HP5061A and I am attempting to start it but there > are > > some things that are puzzling me. > > > > Per the manual I have left the unit plugged in for 24 hours with mode set > > to CS OFF set to and I have observed the Ion Pump readings go to 0 after > > about 3 or 4 minutes of first plugging it in. > > > > So now I am attempting to power up the tube by switching to Loop open > and I > > can hear another power supply engage. My Ion Pump reading climbs to about > > 30 after about 10 seconds and then the power supply shuts off. Then I get > > into a cycle of about 2 seconds on for 10 seconds off with the Ion Pump > > going between 20-30 or thereabouts. > > > > I'm not sure if this is normal and part of the pumping down process. > > Should I leave it on or keep trying to run it on CS OFF? > > > > Am I correct in assuming that with CS OFF the +3500V supply is running > and > > that is what is acting as the Ion Pump to evacuate the tube, and then > when > > I switch to Loop open that also powers up the Cesium Heater and the > -2500V > > supply? > > > > I have experience with high power Triodes and Tetrodes where you run the > > filaments without high voltage to help evacuate the tube so I'm unsure > how > > a tube like this operates. > > > > Thank you! > > _______________________________________________ > > time-nuts mailing list --time-nuts@lists.febo.com > > To unsubscribe send an email totime-nuts-leave@lists.febo.com > -- > > Jim Muehlberg > Senior Engineer > > National Radio Astronomy Observatory > ngVLA Local Oscillator Lead > > 1180 Boxwood Estates Rd B-111 > Charlottesville, VA 22903-4602 > P 434.296.0270 > C 434.422.2017 > _______________________________________________ > time-nuts mailing list -- time-nuts@lists.febo.com > To unsubscribe send an email to time-nuts-leave@lists.febo.com > _______________________________________________ > time-nuts mailing list -- time-nuts@lists.febo.com > To unsubscribe send an email to time-nuts-leave@lists.febo.com >

Measured against another opt 4.  Both units have an unknown history,

Great to hear and with a reading I see in the pix you included thats a nice tube. Appears to be 38?? Granted the beam current isn't absolute. I have a unit with 0 beam current and it still locks and is consistent with the other CS units. Regards Paul WB8TSL On Thu, Feb 9, 2023 at 1:42 AM Matt Krick via time-nuts < time-nuts@lists.febo.com> wrote: > I am pleased to report that the unit is Alive and Ticking! > > After 30 minutes of the cycling my unit stabilized. I have it another 2 > hours of CS OFF mode and then started it again this time stable with no > cycling. > > With Loop Open the Beam meter started at 2 and slowly climbed to about 15 > after about 20 minutes where I did a rough tune. > > After another 20 minutes I went with Oper mode and centered the coarse > tuning getting a peak meter reading of 34. Pegging control to -50 > > I then centered the control reading by again tuning coarse and hit the > reset button and got the continuous operation to light. > > I set the clock to my watch and will compare tomorrow > > On Wed, Feb 8, 2023, 15:22 Aiden Gibson via time-nuts < > time-nuts@lists.febo.com> wrote: > > > Hi Matt, > > > > Just to add another 2c to this thread, I went through roughly the same > > process Jim describes with my 5061A. > > > > I also kept the hot wire ionizer powered on in order to catch any neutral > > particles which may have been affecting the vacuum. > > > > I took some measurements of the process to get a rough "pump curve" which > > can be seen here: > > > > > > > https://docs.google.com/spreadsheets/d/1zsTUAiDZ92Eb-2lID9Hkoe7ByOylcx_LJ3ktGqG_uac/edit?usp=drivesdk > > > > Best of luck! > > -Aiden > > > > Sent from my Verizon, Samsung Galaxy smartphone > > > > > > > > -------- Original message -------- > > From: Jim Muehlberg via time-nuts <time-nuts@lists.febo.com> > > Date: 2/8/23 17:34 (GMT-05:00) > > To: Matt Krick via time-nuts <time-nuts@lists.febo.com> > > Cc: Jim Muehlberg <jmuehlbe@nrao.edu> > > Subject: [time-nuts] Re: Attempting to start HP5061A {External} > > > > Hi Matt, > > > > I just went through this when resurrecting a 5061A option 4 that was > > about to be scrapped (Horrors!). My ion pump power supply was flakey, > > but after I fiddled with it, I got it to work. I then saw the same > > behaviour. Ultimately, I connected an external supply to the ion pump > > and left it powered for a few days. This cleaned (or whatever happens) > > the tube and I was able to lock it. FWIW, the supply I connected was > > about 7 kV. The label said 3KV, but apparently that was under the rated > > load. In any event, I thought I wrecked the whole thing. I was assured > > by some time nuts that it was OK, and it was. It's been running > > continuously now for about 2 months. Here's an ADEV plot for fun... > > > > Measured against another opt 4. Both units have an unknown history, > > and they are 40 year old tubes, so I consider this a success! Good > > enough anyway. > > > > Good luck, and keep one hand in your pocket. > > > > Jim > > > > On 2023-02-08 12:39 AM, Matt Krick via time-nuts wrote: > > > Hello, > > > > > > I recently acquired a HP5061A and I am attempting to start it but there > > are > > > some things that are puzzling me. > > > > > > Per the manual I have left the unit plugged in for 24 hours with mode > set > > > to CS OFF set to and I have observed the Ion Pump readings go to 0 > after > > > about 3 or 4 minutes of first plugging it in. > > > > > > So now I am attempting to power up the tube by switching to Loop open > > and I > > > can hear another power supply engage. My Ion Pump reading climbs to > about > > > 30 after about 10 seconds and then the power supply shuts off. Then I > get > > > into a cycle of about 2 seconds on for 10 seconds off with the Ion Pump > > > going between 20-30 or thereabouts. > > > > > > I'm not sure if this is normal and part of the pumping down process. > > > Should I leave it on or keep trying to run it on CS OFF? > > > > > > Am I correct in assuming that with CS OFF the +3500V supply is running > > and > > > that is what is acting as the Ion Pump to evacuate the tube, and then > > when > > > I switch to Loop open that also powers up the Cesium Heater and the > > -2500V > > > supply? > > > > > > I have experience with high power Triodes and Tetrodes where you run > the > > > filaments without high voltage to help evacuate the tube so I'm unsure > > how > > > a tube like this operates. > > > > > > Thank you! > > > _______________________________________________ > > > time-nuts mailing list --time-nuts@lists.febo.com > > > To unsubscribe send an email totime-nuts-leave@lists.febo.com > > -- > > > > Jim Muehlberg > > Senior Engineer > > > > National Radio Astronomy Observatory > > ngVLA Local Oscillator Lead > > > > 1180 Boxwood Estates Rd B-111 > > Charlottesville, VA 22903-4602 > > P 434.296.0270 > > C 434.422.2017 > > _______________________________________________ > > time-nuts mailing list -- time-nuts@lists.febo.com > > To unsubscribe send an email to time-nuts-leave@lists.febo.com > > _______________________________________________ > > time-nuts mailing list -- time-nuts@lists.febo.com > > To unsubscribe send an email to time-nuts-leave@lists.febo.com > > > _______________________________________________ > time-nuts mailing list -- time-nuts@lists.febo.com > To unsubscribe send an email to time-nuts-leave@lists.febo.com

Measured against another opt 4.  Both units have an unknown history,

The Beam I current rose up to 45 and the front panel clock was 40 minutes slow since last night but I'm going to reset it and keep an eye on it, might of just been a glitch in the Matrix. On Thu, Feb 9, 2023 at 1:00 PM paul swed <paulswedb@gmail.com> wrote: > Great to hear and with a reading I see in the pix you included thats a > nice tube. > Appears to be 38?? Granted the beam current isn't absolute. > I have a unit with 0 beam current and it still locks and is consistent > with the other CS units. > Regards > Paul > WB8TSL > > On Thu, Feb 9, 2023 at 1:42 AM Matt Krick via time-nuts < > time-nuts@lists.febo.com> wrote: > >> I am pleased to report that the unit is Alive and Ticking! >> >> After 30 minutes of the cycling my unit stabilized. I have it another 2 >> hours of CS OFF mode and then started it again this time stable with no >> cycling. >> >> With Loop Open the Beam meter started at 2 and slowly climbed to about 15 >> after about 20 minutes where I did a rough tune. >> >> After another 20 minutes I went with Oper mode and centered the coarse >> tuning getting a peak meter reading of 34. Pegging control to -50 >> >> I then centered the control reading by again tuning coarse and hit the >> reset button and got the continuous operation to light. >> >> I set the clock to my watch and will compare tomorrow >> >> On Wed, Feb 8, 2023, 15:22 Aiden Gibson via time-nuts < >> time-nuts@lists.febo.com> wrote: >> >> > Hi Matt, >> > >> > Just to add another 2c to this thread, I went through roughly the same >> > process Jim describes with my 5061A. >> > >> > I also kept the hot wire ionizer powered on in order to catch any >> neutral >> > particles which may have been affecting the vacuum. >> > >> > I took some measurements of the process to get a rough "pump curve" >> which >> > can be seen here: >> > >> > >> > >> https://docs.google.com/spreadsheets/d/1zsTUAiDZ92Eb-2lID9Hkoe7ByOylcx_LJ3ktGqG_uac/edit?usp=drivesdk >> > >> > Best of luck! >> > -Aiden >> > >> > Sent from my Verizon, Samsung Galaxy smartphone >> > >> > >> > >> > -------- Original message -------- >> > From: Jim Muehlberg via time-nuts <time-nuts@lists.febo.com> >> > Date: 2/8/23 17:34 (GMT-05:00) >> > To: Matt Krick via time-nuts <time-nuts@lists.febo.com> >> > Cc: Jim Muehlberg <jmuehlbe@nrao.edu> >> > Subject: [time-nuts] Re: Attempting to start HP5061A {External} >> > >> > Hi Matt, >> > >> > I just went through this when resurrecting a 5061A option 4 that was >> > about to be scrapped (Horrors!). My ion pump power supply was flakey, >> > but after I fiddled with it, I got it to work. I then saw the same >> > behaviour. Ultimately, I connected an external supply to the ion pump >> > and left it powered for a few days. This cleaned (or whatever happens) >> > the tube and I was able to lock it. FWIW, the supply I connected was >> > about 7 kV. The label said 3KV, but apparently that was under the rated >> > load. In any event, I thought I wrecked the whole thing. I was assured >> > by some time nuts that it was OK, and it was. It's been running >> > continuously now for about 2 months. Here's an ADEV plot for fun... >> > >> > Measured against another opt 4. Both units have an unknown history, >> > and they are 40 year old tubes, so I consider this a success! Good >> > enough anyway. >> > >> > Good luck, and keep one hand in your pocket. >> > >> > Jim >> > >> > On 2023-02-08 12:39 AM, Matt Krick via time-nuts wrote: >> > > Hello, >> > > >> > > I recently acquired a HP5061A and I am attempting to start it but >> there >> > are >> > > some things that are puzzling me. >> > > >> > > Per the manual I have left the unit plugged in for 24 hours with mode >> set >> > > to CS OFF set to and I have observed the Ion Pump readings go to 0 >> after >> > > about 3 or 4 minutes of first plugging it in. >> > > >> > > So now I am attempting to power up the tube by switching to Loop open >> > and I >> > > can hear another power supply engage. My Ion Pump reading climbs to >> about >> > > 30 after about 10 seconds and then the power supply shuts off. Then I >> get >> > > into a cycle of about 2 seconds on for 10 seconds off with the Ion >> Pump >> > > going between 20-30 or thereabouts. >> > > >> > > I'm not sure if this is normal and part of the pumping down process. >> > > Should I leave it on or keep trying to run it on CS OFF? >> > > >> > > Am I correct in assuming that with CS OFF the +3500V supply is running >> > and >> > > that is what is acting as the Ion Pump to evacuate the tube, and then >> > when >> > > I switch to Loop open that also powers up the Cesium Heater and the >> > -2500V >> > > supply? >> > > >> > > I have experience with high power Triodes and Tetrodes where you run >> the >> > > filaments without high voltage to help evacuate the tube so I'm unsure >> > how >> > > a tube like this operates. >> > > >> > > Thank you! >> > > _______________________________________________ >> > > time-nuts mailing list --time-nuts@lists.febo.com >> > > To unsubscribe send an email totime-nuts-leave@lists.febo.com >> > -- >> > >> > Jim Muehlberg >> > Senior Engineer >> > >> > National Radio Astronomy Observatory >> > ngVLA Local Oscillator Lead >> > >> > 1180 Boxwood Estates Rd B-111 >> > Charlottesville, VA 22903-4602 >> > P 434.296.0270 >> > C 434.422.2017 >> > _______________________________________________ >> > time-nuts mailing list -- time-nuts@lists.febo.com >> > To unsubscribe send an email to time-nuts-leave@lists.febo.com >> > _______________________________________________ >> > time-nuts mailing list -- time-nuts@lists.febo.com >> > To unsubscribe send an email to time-nuts-leave@lists.febo.com >> > >> _______________________________________________ >> time-nuts mailing list -- time-nuts@lists.febo.com >> To unsubscribe send an email to time-nuts-leave@lists.febo.com > >

Measured against another opt 4.  Both units have an unknown history,

Matt that would indeed be odd that the clocks off by that huge amount. If you manually adjusted the 5061 by the manual, its possibly set it to the wrong peak. There are 3 peaks. The center is the highest. But even if you were on one of the side peaks its not a 40 minutes offset. So maybe a glitch. Especially if everythings been off a long time. Lock light still green? Regards Paul On Thu, Feb 9, 2023 at 11:34 PM Matt Krick <dcflux@gmail.com> wrote: > The Beam I current rose up to 45 and the front panel clock was 40 minutes > slow since last night but I'm going to reset it and keep an eye on it, > might of just been a glitch in the Matrix. > > On Thu, Feb 9, 2023 at 1:00 PM paul swed <paulswedb@gmail.com> wrote: > >> Great to hear and with a reading I see in the pix you included thats a >> nice tube. >> Appears to be 38?? Granted the beam current isn't absolute. >> I have a unit with 0 beam current and it still locks and is consistent >> with the other CS units. >> Regards >> Paul >> WB8TSL >> >> On Thu, Feb 9, 2023 at 1:42 AM Matt Krick via time-nuts < >> time-nuts@lists.febo.com> wrote: >> >>> I am pleased to report that the unit is Alive and Ticking! >>> >>> After 30 minutes of the cycling my unit stabilized. I have it another 2 >>> hours of CS OFF mode and then started it again this time stable with no >>> cycling. >>> >>> With Loop Open the Beam meter started at 2 and slowly climbed to about 15 >>> after about 20 minutes where I did a rough tune. >>> >>> After another 20 minutes I went with Oper mode and centered the coarse >>> tuning getting a peak meter reading of 34. Pegging control to -50 >>> >>> I then centered the control reading by again tuning coarse and hit the >>> reset button and got the continuous operation to light. >>> >>> I set the clock to my watch and will compare tomorrow >>> >>> On Wed, Feb 8, 2023, 15:22 Aiden Gibson via time-nuts < >>> time-nuts@lists.febo.com> wrote: >>> >>> > Hi Matt, >>> > >>> > Just to add another 2c to this thread, I went through roughly the same >>> > process Jim describes with my 5061A. >>> > >>> > I also kept the hot wire ionizer powered on in order to catch any >>> neutral >>> > particles which may have been affecting the vacuum. >>> > >>> > I took some measurements of the process to get a rough "pump curve" >>> which >>> > can be seen here: >>> > >>> > >>> > >>> https://docs.google.com/spreadsheets/d/1zsTUAiDZ92Eb-2lID9Hkoe7ByOylcx_LJ3ktGqG_uac/edit?usp=drivesdk >>> > >>> > Best of luck! >>> > -Aiden >>> > >>> > Sent from my Verizon, Samsung Galaxy smartphone >>> > >>> > >>> > >>> > -------- Original message -------- >>> > From: Jim Muehlberg via time-nuts <time-nuts@lists.febo.com> >>> > Date: 2/8/23 17:34 (GMT-05:00) >>> > To: Matt Krick via time-nuts <time-nuts@lists.febo.com> >>> > Cc: Jim Muehlberg <jmuehlbe@nrao.edu> >>> > Subject: [time-nuts] Re: Attempting to start HP5061A {External} >>> > >>> > Hi Matt, >>> > >>> > I just went through this when resurrecting a 5061A option 4 that was >>> > about to be scrapped (Horrors!). My ion pump power supply was flakey, >>> > but after I fiddled with it, I got it to work. I then saw the same >>> > behaviour. Ultimately, I connected an external supply to the ion pump >>> > and left it powered for a few days. This cleaned (or whatever happens) >>> > the tube and I was able to lock it. FWIW, the supply I connected was >>> > about 7 kV. The label said 3KV, but apparently that was under the >>> rated >>> > load. In any event, I thought I wrecked the whole thing. I was >>> assured >>> > by some time nuts that it was OK, and it was. It's been running >>> > continuously now for about 2 months. Here's an ADEV plot for fun... >>> > >>> > Measured against another opt 4. Both units have an unknown history, >>> > and they are 40 year old tubes, so I consider this a success! Good >>> > enough anyway. >>> > >>> > Good luck, and keep one hand in your pocket. >>> > >>> > Jim >>> > >>> > On 2023-02-08 12:39 AM, Matt Krick via time-nuts wrote: >>> > > Hello, >>> > > >>> > > I recently acquired a HP5061A and I am attempting to start it but >>> there >>> > are >>> > > some things that are puzzling me. >>> > > >>> > > Per the manual I have left the unit plugged in for 24 hours with >>> mode set >>> > > to CS OFF set to and I have observed the Ion Pump readings go to 0 >>> after >>> > > about 3 or 4 minutes of first plugging it in. >>> > > >>> > > So now I am attempting to power up the tube by switching to Loop open >>> > and I >>> > > can hear another power supply engage. My Ion Pump reading climbs to >>> about >>> > > 30 after about 10 seconds and then the power supply shuts off. Then >>> I get >>> > > into a cycle of about 2 seconds on for 10 seconds off with the Ion >>> Pump >>> > > going between 20-30 or thereabouts. >>> > > >>> > > I'm not sure if this is normal and part of the pumping down process. >>> > > Should I leave it on or keep trying to run it on CS OFF? >>> > > >>> > > Am I correct in assuming that with CS OFF the +3500V supply is >>> running >>> > and >>> > > that is what is acting as the Ion Pump to evacuate the tube, and then >>> > when >>> > > I switch to Loop open that also powers up the Cesium Heater and the >>> > -2500V >>> > > supply? >>> > > >>> > > I have experience with high power Triodes and Tetrodes where you run >>> the >>> > > filaments without high voltage to help evacuate the tube so I'm >>> unsure >>> > how >>> > > a tube like this operates. >>> > > >>> > > Thank you! >>> > > _______________________________________________ >>> > > time-nuts mailing list --time-nuts@lists.febo.com >>> > > To unsubscribe send an email totime-nuts-leave@lists.febo.com >>> > -- >>> > >>> > Jim Muehlberg >>> > Senior Engineer >>> > >>> > National Radio Astronomy Observatory >>> > ngVLA Local Oscillator Lead >>> > >>> > 1180 Boxwood Estates Rd B-111 >>> > Charlottesville, VA 22903-4602 >>> > P 434.296.0270 >>> > C 434.422.2017 >>> > _______________________________________________ >>> > time-nuts mailing list -- time-nuts@lists.febo.com >>> > To unsubscribe send an email to time-nuts-leave@lists.febo.com >>> > _______________________________________________ >>> > time-nuts mailing list -- time-nuts@lists.febo.com >>> > To unsubscribe send an email to time-nuts-leave@lists.febo.com >>> > >>> _______________________________________________ >>> time-nuts mailing list -- time-nuts@lists.febo.com >>> To unsubscribe send an email to time-nuts-leave@lists.febo.com >> >>