[time-nuts] Raw phase data of super-5065

Saw the plot in the June 12 post. Pretty much limited by the 3816 up to 10K Seconds. Would be interesting to see a long plot of the two 5065 against each other! Cheers, Corby ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to

[time-nuts] HP5065C or the 5065Jr.

Joe, "What is mounted on top of the 10811?" That is a Clifton Labs Z1 buffer amp. Still made but by another company. Mounted on a small right angle bracket that is mounted using the existing screws on the back of the 10811 adaptor assy. It's input is connected to the 10Mhz out pins of

[time-nuts] Raw phase data of super-5065

Attila, I will send you some raw data. Attached is a combined plot of a recent successful filter installation. Only 20 to 25% of units will be improved with the filter mod. Two things to look for. 1- The short term stability at 1 Sec (Allan Deviation) should drop from the 2X10-12th range down

[time-nuts] how long dues this rubidium standard last for

Paul, I agree with Bob, the small telecom ones to include the Efratom ones have a lifetime that is just a guess at this point. A brand new PRS10 with a warranty and the original owner repair discount would be a good bet, they do however have lamp assy problems unless that has been redesigned.

[time-nuts] HP 5061A and 5061B modules clear out!

Hi, I'm cleaning out a BUNCH of modules from HP 5061A/B. See listing on eBay below. More lots of other modules to follow in groups that will fit into flat rate boxes. If you have specific wants contact me off list! Cheers, Corby

[time-nuts] What does determine the short term stability of an Rb vapor cell standard?

Here is an clip from one of the space qualified ones Bob mentioned. "The RAFS employs classical rubidium gas cell atomic frequency standard principles. It utilizes a physics package with a discrete isotopic filter cell for best stability. The relatively large, cool absorption cell provides

[time-nuts] Replacement Backup Battery for 5065A?

I agree with Bert, I always remove the battery. They will cause grief eventually! Use either in UPS or the separate DC input jack on the rear. One note, if the battery is removed and the battery charge switch is in the position to light the front panel lamp you will degrade the stability of

[time-nuts] Replacement A9 boards for the HP 5065A

Well I hunted up the change pages for the A9. The cap is polycarbonate, the original A9 was polyester. If I can't find the polycarbonate I'll look into the PPS. Cheers, Corby ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to

[time-nuts] Replacement A9 boards for the HP 5065A

Hi, I'm working to make some replacement A9 boards for the HP 5065A to the new style schematic. Will share the Gerber file when done. The integrator capacitor is a 1986 vintage TRW 5.0ufd 50V 10% .42"DX1.0"L axial. Of course it has an HP part number and no manufactures #. Any guess as to what

[time-nuts] Selling Time and Frequency Equipment Or "just saying"

First, full disclosure, I have no vested or financial interest in the 5065A he is selling. Now the 2816A prefix is the last series built so the most modern. The last one I remember on eBay went for OVER $4000.00 Comparing a 5065A to a Cesium (except maybe a working 5071A for the same price)\is

[time-nuts] HP 5065A super

Perrier, The telecom Rubidiums don't leave much meat on the bone for improvements as they sacrificed pretty much everything else to be cheap, small, and low power consumption. Most of these tradeoffs work directly against trying to get better short term stability out of them. Bummer. Cheers,

[time-nuts] Curious, how many t-nuts have 5065A

Hi, My current Tally of "Known" HP 5065A is 120 units! Cheers, Corby ___ 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] The "NAKED" 5065A optical unit

Attila, The Child and oven windings were destroyed pulling the oven cylinders out of the potting. I suppose you could replicate them and try to repot but I'm never going to try! Cheers, Corby ___ time-nuts mailing list -- time-nuts@febo.com To

[time-nuts] The "NAKED" 5065A optical unit

Paul, You do NOT want to take one apart to this level! It's never going to operate again. If you look at the lamp in the PIX you will see a white coil wrapped around the bulb. This is the tank for the 90Mhz drive and it sits cocked at a 45 degree angle. The lamp assy can be removed easily via

[time-nuts] HP 107BR on eBay

Found a cosmetically nice HP 107BR on eBay right now. Hewlett Packard HP 107BR Quartz Oscillator Vintage Cheers, Corby ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and

[time-nuts] Rakon HSO-14

Hi, Anyone priced a Rakon HSO-14 option 8. It's the Oscilloquartz 8607 option 8 replacement. I'm almost afraid to ask! Cheers, Corby ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to

[time-nuts] Time interval measurement vs dual mixer method

Luciano, I don't know of a commercial version. As you have seen as the two signals move away from close phase coincidence the system noise level will increase. This is because the common offset oscillator noise will only cancel when the phases are closely matching. This is mainly important

[time-nuts] minimalist sine to square

The Efratom/Tektronix PTB-100 took the 10Mhz sine out of the FRK brick, AC coupled it to the input of an 74LS14 biased with a votage divider from +5 to ground. 4 parts! Cheers, Corby ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe,

[time-nuts] Time interval measurement vs dual mixer method

Luciano, Not sure what you mean by "two measures made on the same DUT never coincide". The plotter program takes out wraps which since your phase gain is so large are due to happen. For lower Tau measurements just adjust the phase for close to equal and run shorter plots. These can be spliced

[time-nuts] Some HP 10811 05071-60219 info!

Hi, Attached is a schematic of the changes made to the stock 10811 for use in the HP 5071A. Also while I recently had two of them opened I noticed wavy lockwashers under the nut attaching the tuning capacitor. If you have ever had to open one up to retighten this nut you would wish all of them

[time-nuts] LED replacement screen for 53131A 53132A!!??

Hi, Saw this on the EEVblog and wondered if it could be done for the 53132A?? https://www.eevblog.com/forum/projects/led-display-for-hp-3457a-multimete r-i-did-it-)/ I'd just be happy with 7 segment hi efficiency LEDs and just a few of the annunciators!! Cheers, Corby

[time-nuts] Regarding the improved integrator A9 in the 5065A...

Ulf, The new A9 was only installed in units that had the 10811 installed so HP was not concerned with it working with the 105 oscillator. In the 10811 interface the EFC from A9 goes thru a 316K resistor to a 147K (nominal) resistor to ground. This forms a voltage divider the feed the 10811 EFC

[time-nuts] OFF topic! Iridium 4 launch video

Hi, I've worked at Vandenberg AFB since 1971 and have seen LOTS of launches over those years. I was tracking the Iridium 4 launch so could not go outside and watch. However someone made a video that is just Awesome. https://www.youtube.com/watch?v=UU5KpfOT-_Y You see the rocket come over a

[time-nuts] question about HP 5601a harmonic generator

When working on the A4 assy. the ONLY adjustments you should make are: - Cavity frequency, unscrew locking ring and while looking at the A7 J1 signal or 2nd harmonic reading adjust for max and then lock down. - Attenuator, Unlock with allen, adjust for same, usually pulled all the way out.

[time-nuts] HP5065 - Some OP-Amp, FB and Teflon ...

Here is the schematic of the new style A9. Cheers, Corby___ 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] HP5065 - Some OP-Amp, FB and Teflon ...

Ulf, Forrest is correct. I'd try the LT1793. It's an SOIC but if you are making your own board that would not be a problem. It is $4.87 at DigiKey. Cheers, Corby ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to

[time-nuts] Some more info on the 5065A optical unit

Bob, The cardboard is impregnated with the foam insulation goop and then sealed under the foam layer. It is totally sealed off from any environmental effects. Cheers, Corby ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to

[time-nuts] Some more info on the 5065A optical unit

Made some measurements on a 5065A optical unit. -There are 3 layers in the magnetic shield. -There is about 1/8" of insulation between the outer and middle, and between the middle and inner shields. -The C-field winding is wound on a cardboard form that fits tightly into the inner shield.

[time-nuts] HP 5065A - Some OP-Amp, FB and teflon stand off questions...

Ulf, Be careful if you are going to duplicate the new style A9 for use in a chassis that was built for the old style! On the old style chassis one of the resistors is mounted on the rear of the front panel loop switch. This resistor is mounted on the A9 module for the new style chassis. Which

[time-nuts] HP5065A C-field mods and optical unit mods

HP5065A C-field mods and optical unit mods The contribution of the temperature coefficients of the fixed resistors and the pot (which is a 21 turn bulk metal foil 10PPM/Deg C pot) show up as frequency errors as shown for several combinations. Note that the pot does not cover the entire 2X10-9

[time-nuts] HP5065A C-field mods and optical unit mods

Warren, Most all Rubidium standards do not have active current drive. The HP 5065A is the exception. However the mod I installed is not active. The C-field coils are roughly temperature compensated as they are near the cell oven that is regulated. If you check out Poul-Hennings "hacking the

[time-nuts] HP5065A C-field mods and optical unit mods

Attached is the schematic of the C-field supply. Cheers, Corby___ 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] HP5065A C-field mods and optical unit mods

HP5065A C-field mods and optical unit mods In addition to the power supply mods: -removed AC components -power now supplied with an external DC lab grade low noise highly regulated supply. -temperature coefficient of +20 Volt supply adjusted to be below 1PPM/deg C See:

[time-nuts] Resoration of 5065A - continued/old style A7

Ulf, You either should replace the -6010 old style A7 or if building one from scratch build the late style. The new style has a BP filter on the 2nd harmonic that makes the 2nd harmonic reading a better indication. On the old style as you adjust the CF (in open loop) you will see the 2nd harmonic

[time-nuts] HP5065A +20V supply and C-field mods

HP5065A +20V supply and C-field circuit mods I'm doing some more work on the 5065A and thought I'd share the results of a modification (one of several that will be done on this unit). I measured the +20V P/S temperature coefficient and got -13.5ppm per degree C. This equates well with the 1N938

[time-nuts] Machining some aluminum help!

Well I did some research and found my new best friend! If you remember I needed: "I have a square aluminum tube 5" X 5" with a .25" wall it's 8 1/2" long. I need 20 holes in each end tapped for 4/40 and 1/2" deep." This for a Rubidium standard I am working on. I found all about self forming

[time-nuts] HP5061B Versus HP5071 Cesium Line Frequencies

Donald, Will look forward to seeing your Allan Deviation plots before and after. That will be the only way to verify your modification will make any improvement. I suspect the improvement at a few seconds will degrade it at other Tau. Cheers, Corby

[time-nuts] HP5061B Versus HP5071 Cesium Line Frequencies

Donald, HP changed from 12.631771.6 Mhz to 12.631772.5 Mhz in the later days. The Zeeman frequency changed to correspond from 42.82Khz to 53.53Khz. The 5071A uses a Zeeman frequency of 39.949Khz. I believe they liked the stability a bit more at the different C-field current. Either way will

[time-nuts] Machining some aluminum help!

Thanks everyone. Not looking for a redesign, just figuring out how to get the holes drilled and tapped. I have come up with a scheme that looks promising and will let you know how it goes. The enclosure only has to hold +.1PSI of dry nitrogen without leaking. It will have a pressure sensor

[time-nuts] Machining some aluminum help!

Well that generated a lot of advice and thanks for it! I think I might do it myself and go with a 1/2" hole depth and 1/4" threaded depth. I'll get some of that Aluminum Tap magic, some new taps and new drill bits. Good idea about drilling the end plates first and drilling thru to match. Between

[time-nuts] Machining some aluminum help!

Hi, I have a square aluminum tube 5" X 5" with a .25" wall it's 8 1/2" long. I need 20 holes in each end tapped for 4/40 and 1/2" deep. This is for a Rubidium project. The local machine shop want's $360.00 Anyone have a machining setup that could do the work a bit cheaper? If not I'll

[time-nuts] HP5061B Square Wave Modulation Evaluation

Attached is a plot showing the measured floor of the sine wave loop in the 5061A/B and also in the 5065A, along with plot of an HP 5061B with a high performance tube. The tube is the limiting factor. As you can see the margin provided by the current design is substantial. Also if you look at

[time-nuts] FTS Ramsey cavity

A friend asked me a while ago why the FTS Cesium tubes were so light. Since they were designed from the beginning to fit in a 5.25" high chassis that cut quite a bit of the weight. However a large amount of weight was saved by using a Ramsey cavity that was not milled from a massive block of

[time-nuts] Cesium oven and filament PIX

Attached is a PIX showing (CW from top left) the: >ionizer filament >Oven filaments (STD oven) >standard oven assy >high perm oven assy The HiPerf oven filament is the sealed spiral wound tube on the face of the oven. The posts on the top edge of the ovens is the connection to burn a hole in

[time-nuts] HP5061B Peak to Valley Ratios

Donald, I agree with John, remove the gearing gizmo from the 10811 assy. the adjust hole lines up any way so no need to drill a hole. you just need a long insulated tuning tool. Also agree that a quick indication of tube operation can be seen if the beam current rises when the mod is turned off.

[time-nuts] HP5061B Ion Current

Things to be careful about! "I think the final vacuum improvement can be achieved more quickly if the cesium oven is on." The outgassing in a tube that has been off for an extended time is almost all from the oven filaments and the ionizer filament. The metal surfaces are virtual "sponges" and

[time-nuts] HP5061B Ion Current

If you cannot get the ion current below 50ua or so after a week at 5kV then you are out of luck. Most likely you have resistive deposits on the ion pump insulator. If you can get the tube to give a decent SN at those levels then you can run with the alarm circuit bypassed. I have run tubes a

[time-nuts] Optical Cesium or maybe Cesium "light"!

Looks like Oscilloquartz is getting ready to sell this commercially! Will give the 5071A a run for the money! Reliability should go way up as: -No electron multiplier -No ionizer filament -No state selection magnets Also all the fiddley bits (laser diodes and photodetectors) are external to the

[time-nuts] Need HP 5061A setup help

Skip, If you are setting against GPS then you are done. For most applications either Zeeman frequency- synthesizer setting will be fine. What the Zeeman adjust lets you do is set the frequency (via the C-field) to within the accuracy specs for the instrument without having to use another

[time-nuts] Antique precision timing device without electronics

Very cool! Thanks for sharing. You could probably use any of the large vintage neon bulbs to replace the missing lamp. Cheers, Corby ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to

[time-nuts] Early 5065A

Pete, That is a VERY early unit. Those early ones did not have the TED device. I have only seen one unit with an earlier SN! Ohm the lamp oven windings to the threaded post protruding from the end of the optical unit. (should be open) Also check across the oven winding (50 Ohm) If the

[time-nuts] Install a 5061A/B tube into a 5071A!

Well I thought that would get your attention! It's not quite as simple as that, however it CAN be done. First you need a good "mini" tube scavenged out of a 5061A/B. These smaller diameter tubes HP made for 5061A/B replacements are essentially a 5071A tube with different connectors. Then you

[time-nuts] Hp5061 Cesium Zeeman adjustment

Paul, The Zeeman frequency you use depends on what synthesizer frequency your unit is set for. Either 48.82Khz or 53.53Khz. See: https://www.febo.com/pipermail/time-nuts/2008-July/032378.html The Zeeman coil is close to a short. You set the amplitude to the spot that gives you the best look at

[time-nuts] HP5065A Rubidium questions: some progress

Scott, The resistor should be 12 Ohms nominal, I'd try installing a 12 Ohm and see what happens. The lamp should light within 10 seconds or so of applying power. If you have a spectrum analyzer you can place a loose wire close to the lamp assy and see the approx 120Mhz signal if it's

[time-nuts] HP5065A Rubidium question

Scott, If you pull the SMB lamp connector off of the chassis jack you can Ohm out between the center pin and shield. Try both polarities of the leads. If the 1330 Ohm resistor is good you should read around 3330 Ohms. This is the sum of the 1330 and a 2000 Ohm resistor. The 12 Ohm (selected)

[time-nuts] Have done some more cutting on the Cs beam tube

Hi, The tiny coil inside the beam path is the low frequency coil used for DC testing of the tube. The tube shown is a standard performance tube and has no degaussing coil. The flat windings on top of the shield are the C-field winding. The high performance cavity is even "prettier". You can

[time-nuts] HP 5061A Cesium Beam Std

David, I would let it set on the peg in Cs off mode for a fewdays. It can take a long time for some tubes. An external HV supply can also be tried if it does not come down in a few days. If it does come down turn the switch to operate to turn the filaments on. The ion pump should peg again,

[time-nuts] HP 5061A/B Cesium tube conundrum

I've been doing some work on testing some HP 5061A/B tubes and came across something that's not making any sense! The R11 and R12 values marked on the tubes for use with the new style A11 are supposed to reflect a parallel value that is 10X larger than the thermistor reading. This to agree with

[time-nuts] HP 5062C Service Manual

Dick, The AC connector used depends on if the unit is an option 010 or not! Regular unit MS3106-14S-5S Option 010 MS3126F14-12S Service manual PN is 05062-90029 Cheers, Corby ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to

[time-nuts] EFOS Maser turns 34!

"Copper has a quite high temperature expansion, so could you servo that via the cavity temperature ?" To answer, both Copper and Aluminum cavities use the temperature setting to coarse tune the cavity. Fine tuning is via Varactor diode and modern Masers do servo "Auto-tune" the cavity to reduce

[time-nuts] EFOS2 MASER turns 34!

Tim, The EFOS2 uses an Aluminum cavity! So machining would be easier than Copper! The complete manuals with schematics are on Tom's Leapsecond.com site. Making a homebrew Maser was bandied about a few years ago on TimeNuts. Cheers, Corby ___

[time-nuts] EFOS2 MASER turns 34!

Happy Birthday EFOS2 Maser! The EFOS2 active hydrogen Maser at my place just turned 34 years old! Pretty impressive reliability. It is an Oscilloquartz Maser, they are now called T4 Science. I know a guy in Norway that bought the refurbished EFOS3 Maser last year directly from T4 Science! It is

[time-nuts] HP5062C Chassis available

Hi, I have Seven HP5062C chassis collected over the years. Not sure how many tubes are installed (I can check) or their condition. I'm pretty sure most of the quartz oscillators are missing but I see two sitting by the pile. Might be a very few modules missing. Most of the top and bottom covers

[time-nuts] Mystery hp Oven UPDATE

Back in June I picked up the mystery oven assy that turned out to be the oscillator assy. of an HP 106A. Since then I have repaired it and another 106B oscillator assy for a friend. My oscillators main problem was that one of the inner oven windings was open. Just for testing I installed an array

[time-nuts] HP53131A RS232 question ANSWERED!!!

Thanks to a reply from Angus the 53131A is sending data every sample now!!! "Something to check - in the 'Utility' menu, if the HP-IB is set to 'Talk' rather than a numeric address, it does just what you describe and only sends data every few seconds. Angus. Thanks Corby

[time-nuts] HP53131A RS232 question

Scott, Tried reversing connections and the count goes from 4ms to 900+ms which is correct. update goes from about 3 seconds to about 5 seconds with them switched. So the connections were correct with the 4ms reading. Found out that the RS232 is talk only so it would not need any commands or

[time-nuts] HP53131A RS232 question

I've tried all the parameters and the update rate still drops to about once every 3 seconds when I turn print on! You still see the 1pps strobing the input channels every transition even with print on. I was using just pins 2, 3 and 5 on the rs232 and switched to a "full" cable with no

[time-nuts] HP53131A RS232 question

I reconfigured for TI with +.7V level 50Ohm and I get a good count. With a TI of around 43milliSec between two 1pps signals the display is updating every second. However if I turn print on the display update slows way down and no longer displays consecutive counts! I know I had this working

[time-nuts] HP53131A RS232 question

Hi, I have not played with my 53131A RS232 for a couple years and have a question. I want to configure it to "talk" to Hyperterminal so I can log some readings. I did the 5 items to configure it: HW pacing (disabled) print on baud rate (19200) parity SW pacing (none) with a 5Mhz input I only get

[time-nuts] Maser Hydrogen supply (was Swagelok and metric tubing question)

The EFOS2 has a small (approx. 4" X 10") aluminium compressed gas bottle. I fill it to about 450PSI and it lasts about 3 years. Most modern Masers use Hydride supplies like the Hydrostik I'm working to install. They can last up to 10 years. This all predicated that you have no leaks! Cheers,

[time-nuts] Swagelok and metric tubing question

Well it's been an education! First finding out how to identify if the Swagelok fitting is Metric by sight and now how carefully the tubing has to be made to use compression fittings! I just went ahead and got the short section from McMaster Carr. Want to make sure it's right if I'm at 400+ PSI

[time-nuts] Swagelok and metric tubing question

Bob, That's the cheapest I have been able to find it. I'll probably go that route with the expensive version as it's specified for compression. I know the original setup mixes copper and stainless but I have read that is not recommended??? Cheers, Corby

[time-nuts] Swagelok and metric tubing question

This sound off topic but it's for a Hydrogen Maser modification! The EFOS2 Maser is running low on Hydrogen and this time rather than refill the compressed gas bottle I'd like to install a Hydrostik in its place. I have obtained all the fittings I need but have hit a snag! I need a few short

[time-nuts] Need some wisdom from the cesium beam tube gurus out there

Skip, The easiest way to determine the oven resistor values for an unmarked tube is to directly measure the oven temperature and select a resistance to set it at the temperature you want. Your tube is a STD tube so I'd set it at 90 degrees C. Take a thermocouple meter and thermocouple and cut the

[time-nuts] Corby Dawson Super 5065a work can I use a miniature Rubidium

Anton, To answer both questions: You can use a Laser in place of the Rubidium lamp, however assuming the problem is the lamp it would be cheaper to buy several LPRO units to scavenge for a replacement lamp. How did you determine it's the lamp that is dead? Using a Laser is more complicated

[time-nuts] Rare HP clock

I have worked on these and the electronics is almost always working, or easily repaired. The mechanical can cause problems depending on how much "time" it has on the clock mechanics. No XTAL in these as the drive is external. The case is hermetic and has dessicant inside. Cheers, Corby Dawson

[time-nuts] COTS cesium standard physics package life

Ruslan, Yes you can conserve tube life my operating in the Cs off mode (for 5061A and B). This mode still powers the ion pump and helps maintain the vacuum. If the tube is exposed to high temperatures for a long period the Cesium will slowly escape the oven assy. and reduce the life of the tube.

[time-nuts] Adjusting nominal frequency of FTS 1200-100 OCXO?

Christopher, The only way is to open the oscillator up and reselect the capacitor they used to set it on frequency. I've done it once or twice long ago, not easy to do! I have a 1200 with the same problem however it does tune to 1Hz low so I use it as the offset oscillator for my DMTD unit!

[time-nuts] HP 3010Axxxxx oscillator

Perry, The 3010A prefix identifies that date it was made. It should also have a 10811A marking. The resistor value is for applications needing precise EFC. Usually found in HP 5065A, 5061A, and 5061B. If it also has a 60109 marking it has slightly better short term stability at one Tau.

[time-nuts] Some interesting HP5071A design information

Hi, I've had this booklet for quite a few years and whenever someone posts about the HP5071A I think of sharing it. Finally got around to scanning it and Tom VanBaak was kind enough to host it on his website. It's at http://leapsecond.com/corby/5071comb.pdf Enjoy! Corby Dawson

[time-nuts] More FE405B data

Hi, I posted an AD plot of a good FE405B back on Jun 7th. A plot just completed today after an additional month of running is essentially the same. I did however measure the aging rate and it is currently 1.15X10-11th per day! Cheers, Corby ___

[time-nuts] Spin exchange tuning

Ole, Spin exchange tuning for a classic (non-autotuned) Maser is performed to put the cavity to the frequency that corresponds to the point that eliminates the frequency shift caused by changes in the Hydrogen flux. This enhances the short term stability at short time scales. This tunes the

[time-nuts] Anyone have an HP5060A sitting around?

Hi, I need a couple resistance readings at the A11 oven controller jack. Does anyone have one available that they could measure for me? Cheers, Corby ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to

[time-nuts] HP5065A Super upgrade

Herbert, If you find my original post and also look at the HP5065B info on leapsecond. com you will find that the pre/post performance is closer to that listed below. I belive Luciano missread the plots! Cheers, Corby Dawson Typical ADEV improvement Seconds BeforeAfter 1

[time-nuts] Some FE405B data

Attila, All oscillators are not the same! Although I find the yield to be better for the FE405B than say the 10811 some are duds like the top trace in Toms data, some are very good like the bottom trace, and some are even better, my plot. I've been very impressed by the 405B performance as I

[time-nuts] Divide by 3

The FE405B AD plot I recently posted used a simple (non 50% duty cycle) divide by 3 using a 74ls74 and 74ls02 (if I remember correctly). I used the HP board from the pair used in the 5065A or 5061A/B. The existing 74ls74 was piggy backed with the 74ls02 and connections made with tiny wire. The

[time-nuts] THE Original Time Interval Counter

Well, This is probably not the original but I remember using one "in the day" Corby___ 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] Some FE405B data

Attached here is a long term AD plot of an FE405B. Stays in the 10-13ths all the way up to 10,000 seconds! This unit has only been operating for about 2 weeks. In a month I'll repeat this plot and also include the aging rate. I have found that these oscillators exhibit less drift than most

[time-nuts] Goodie for British Timenuts!!!

Hi, Saw this while trolling for goodies! http://www.mullardmagic.co.uk/racal-ma259-frequency-standard-ra17-ra117-r af-navy-goldfinger-james-bond-ra1218-ra1772-ra1792-ma50-ra181 RACAL MA259 FREQUENCY STANDARD FROM 1965 Looks neat Cheers, Corby

[time-nuts] HP 106a oscillator connectors question

Thanks for all the info. They are the 1/4-32 (S-93 compatible) Microdot !!! I ordered a double ended cable and will cut it in half to give me the two connections I need (5Mhz out and EFC in). Cheers, Corby ___ time-nuts mailing list --

[time-nuts] HP 106a oscillator connectors question

Well the checkout of the 106A oscillator section is going well. I ran it for 6 hours and the outer oven came down OK, will have to wait until I can do a longer attended run for the inner oven as it takes 8 1/2 hours per the manual to come down! This unit was not built with the fine adjust via an

[time-nuts] Mystery hp Ovens For Sale

Got an email from someone who has the main unit! Found out that the assy. is from an O-451A/U. Possibly coast guard. It is supposedly a double ovened unit. Does anyone have any info on it? Cheers, Corby ___ time-nuts mailing list --

[time-nuts] Mystery hp Ovens For Sale

Peter, Thanks for the heads up! I purchased both units and they arrived yesterday. I was worried for a moment as the HP106 assy. also had an HP107 part number on a label on the side. I realized that it was too big in diameter to fit a 107 but wonder why HP put that label on it??? Carefully

[time-nuts] HP5065A environmental sensitivities

Angus, The M100 barometric data data is attached, the FRK should be the same. Not sure what the time constant would be however. So those units at least should have repeatable performance as far as Barometric pressure is concerned. Not sure about any of the other smaller units. Cheers,

[time-nuts] HP5065A environmental sensitivities

Angus, The HP 5065A has a fairly open path from atmosphere to the cells as far a barometric pressure is concerned. Response is rapid to a change. The mechanism is "oil-canning" of the windows on the ends of the cell. Depends on diameter of the cell, thickness of the windows, and stiffness of

[time-nuts] HP5065A environmental sensitivities

Nice data Wulf. Once I finish reducing the temp effects I'll post a couple long term AD plots with and without the Barometric pressure compensation and with and without the temperature modifications. Will be interesting to see what kind of difference I get. Cheers, Corby

[time-nuts] HP5065A environmental sensitivities

Luciano. Hi, 1) it is difficult to read the frequency value on the plot. Can you specify? The plot is averaged to get the signal out of the noise, The P-P calibration offset on the left allows you to estimate the deviation of the other parts of the plot. The short term stability of the 5065A at

[time-nuts] HP5065A environmental sensitivities

HP 5065A Environmental sensitivity First here is a comparison between the specified sensitivities of various Rubidium units. Barometric per mbar Temperature per degree C HP 5065A6.3X10-14 1.6X10-12 M100 FRK

[time-nuts] HP 5360A History?

The oscillator used in the 5360A is the same one used in the early 105A, the 5061A and the 5065A. I just call them the 105 style oscillator. They have a 115 volt thermoswitch controlled fast warmup heater that is set to switch out once it gets close to the set point of the proportional controller

[time-nuts] HP 5065A repair

I'm changing the topic from best rubidium frequency standard for this post. Most repairs I make to the 5065A run well below $250.00, sometimes as low as $100.00. A "crazy bad" repair might run $400.00 or so but out of over 50 repairs only two needed that level of help. As far a tempco goes,

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