[time-nuts] repairing General Technology (Tracor) 304-B rubidium standard

Stewart, Tracor units use a high voltage pulse to start the lamp. You should be able to hear the relay that drives the pulse clicking around every 10 seconds or so until the lamp lights up. Tracor lamp failures are not rejuvinatable (is that really a word). However I have in the past

[time-nuts] Allan deviation and modified Allan deviation

Ok I've been plotting my oscillators for years using Allan Deviation. That way all my records can be compared easily. Is there any advantage to using Modified Allan Deviation? It seems to give a better stability plot but that just seems to be cheating! If I plot both ways what do the

[time-nuts] FTS oscillator sale

Hi, I put up an FTS 1000A/100 oscillator on the eBay. Stability day in the PIX. 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] FTS Oscillator Sale

Sorry here it is! Item number: 321062141056 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] FTS Cesium parts units on eBay

Hi, I've placed a couple FTS 4060 parts units on ebay if anyone has an interest! Thanks, 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

[time-nuts] Some Quartz short term stabilities

Here is an update of measurements of some Quartz short term stabilities. It's interesting to see that the 10811-60111 that some turn their noses up at can turn in excellent stability as well! QUARTZ 1 SEC. 10 SEC. 100 SEC. 1K SEC.

[time-nuts] HP 5065A short term stabilities, update

A few years ago I posted the short term stabilities of some HP 5065A. Here is an updated list with some more results. The 1 sec figures with a * indicate a maximum. The actual 1 sec results for those units will be better. The 1340A unit was exceptional! 1 SEC.

[time-nuts] Set up for short term stability tests on HP 5065A

Tom, My setup consists of: NBS 106B DMTD unit that I have upgraded a bit A selected FTS 1200 as an offset oscillator Berts mini counter RS232 interfaced to a laptop for the 1 sec taus without the * the reference is a cherry picked 10811 for the others as well as the higher taus the reference is

[time-nuts] Rubidium Lamp PIX

Don, The only lamps besides FRS lamps I have had to rejuvinate were HP lamps that the oven had run away on forcing all the Rubidium out into the bulb and coating the walls. The design of most standards insures that the base of the bulb will cool faster than the bulb when turned off thus

[time-nuts] Rubidium PIX

Tom is hosting some rubidium PIX on his http://www.leapsecond.com/ website http://www.leapsecond.com/corby/rb-lamp.htm http://leapsecond.com/corby/5065a-optical/ http://www.leapsecond.com/pages/rb-cells/ Enjoy! Corby ___ time-nuts mailing list --

[time-nuts] ensemble of standards

Also about ensembles, http://www.mksa.deit.univpm.it/biblioteca/sala_tecnica/scaffale_strumenti /Campioni/EPSG070861.pdf This article describes combining 4 HP 5071A standards. Description on page 2 and block diagram in figure 2. Unfortunately no details on the controller are given! It's what

[time-nuts] ensemble oscillators for better stability

Hi, I've been playing around with 2 HP 5065A standards to see if averaging them will give better stability. The results so far are: 1 sec10 sec100 sec unitA1.28-123.83-13 1.33-13 unitB9.31-133.44-13 1.18-13 combined

Re: [time-nuts] ensemble oscillators for better stability

John, Injection locking won't be a problem with the isolation I have in the setup. Azelio, The 1 second results are referenced to a cherry picked FTS 1200 quartz which is better than 3X10-13th at 1 second. The 10 and 100 second results are referenced to an EFOS2 Active Hydrogen maser. After

[time-nuts] HP 5065A optical unit PIX

Merry Christmas everyone! I have taken some PIX of a disassembled HP 5065A optical unit for your pleasure! Tom Van Baak is hosting them at http://leapsecond.com/corby/5065a-optical/ Enjoy ___ time-nuts mailing list -- time-nuts@febo.com To

[time-nuts] noisy varactor diodes

The HP sceme in the patent refers to an array of series and parallel diodes to reduce noise. Just paralleling them does not reduce the noise! The 4 paralleled in the 5065 are to give enough phase deviation for the low modulation level applied. (150mv) The symptom was a fluctuating 2nd

[time-nuts] 5061A Beam Current question

Pete, The more likely singing offender is the old style A11 oven controller module. It also is off in the Cs off mode so the singing should stop when in that mode. The newer style A11 modules do not sing! Corby ___ time-nuts mailing list --

[time-nuts] Special integration capacitors

I'm selling a few of these cards. See eBay item 321033088669 I also have a quantity of the bath tub style from HP 5061 Cesium standards. (If I remember 5, 8, and 3uf available) Built specially for long time constant integrators. Corby

[time-nuts] Stanford Research SR620

Hi Everyone, I'm selling my SR620 and thought to offer it here first before the eBay. The only problem I know about is an error 3 on power up. This equates to the battery backed up RAM not holding its load. The battery checks good so it's probably the RAM chip itself. You can then select a

[time-nuts] SR620 is sold!

Thanks for the interest the SR620 is sold. Corby Woman is 53 But Looks 25 Mom reveals 1 simple wrinkle trick that has angered doctors... http://thirdpartyoffers.juno.com/TGL3141/50b68d00e6768d0043bast03duc

[time-nuts] My MINI TIC implementation

Attached is a block diagram of how I am using the MINI TIC. I use a wall-wart feeding two DC to DC convertors for the +- 5VDC. The dual one shot IC is an LS221 that drives two LEDS. I used LS14 schmitt triggers on the input as their trigger level closely matched the pulse transformer output of

[time-nuts] Nifty MINI TIC for DMTD work

MINI-TIC for DMTD work Hi Everyone! I've been testing a Miniature 2 channel TIC that Bert Kehren and Juerg Koegel and Richard Mc Corkle have designed. It has 9 digits/Sec. and with a 1HZ offset in the DMTD unit gives a resolution of 1X10-15th at 10 MHz, 2X10-15 with a 5 MHz input, when

[time-nuts] Nifty MINI TIC for DMTD work

As Bert mentioned once the amount if interest is established purchase details will post. We also will post a FAQ for this project. Thanks, Corby The New #34;Skinny#34; Fruit How This Strange 62-Cent African Fruit Is Making Americans

[time-nuts] Confused about Rubidium oscillators

Bob, Rubidium lamps are purpose designed for particular units. However The Efratom threaded ones are mostly interchangeable. I'll see about taking a PIX of a variety of lamps and posting it. Something along the lines of the Rubidium Cell PIX I took at:

[time-nuts] Confused about Rubidium oscillators

Bob, Modern Rubidium units like the PRS10 Have a lamp life of over 20 years (of continuous operation). Vintage HP 5065A units likewise had a very long lamp lifetime. All the other common failures are just in the electronics. The main interest for time nutters is how long will the lamp last in

[time-nuts] Zeeman frequency oddness

After the degauss you should recheck the Zeeman setting, which you did. You also verified the synthesizer frequency is set to the frequency that requires a C-field current high enough to reach 53.53. Since it is running at 48.21 you should increase the C-field setting until the central peak

[time-nuts] Neat Mini ovenized vcxo!

Thought I'd repost this with a different subject line as I think more members will see it now! Found this neat mini Ovenized VCXO on the auction site. Check out item # 310380778466 and the data sheet at: http://www.microcrystal.com/CMSPages/GetFile.aspx?nodeguid=8f7cfa22-c317-

[time-nuts] SR620 VCTCXO replacement

Hi, Check this one out! I think it might work as long as the +5 volts can source the oven current required. Your part was 20ma. This one requires About 250 ma during warmup and between 80 and 130ma afterwards. http://www.ebay.com/itm/310380778466?ssPageName=STRK:MEWNX:IT_trksid=p39

[time-nuts] Two PICTIC II bare boards for sale

Hi, I've had these a while and have decided to sell them. Two bare PICTIC II boards. The version with the 16 pin DIP 74AC175. Take them both for $11.00. (shipping included in USA) Thanks, Corby Woman is 53 But Looks 25 Mom reveals

[time-nuts] Two PICTIC II bare boards for sale SOLD!

They just sold! Thanks everyone. Corby Woman is 57 But Looks 27 Mom publishes simple facelift trick that angered doctors... http://thirdpartyoffers.juno.com/TGL3141/5086e65285d0c66524b86st01duc

[time-nuts] Adjusting HP 5065A frequency

Edgardo, You do use the C-field adjust to put a 5065A On frequency. The Factory values are a moot point after all these years! Just incrementaly adjust the c-field control in small steps while observing the frequency comparison. The only thing that might happen is that you reach one end of the

[time-nuts] Efratom FRK and M100 question

It's been a few years since I really dug into the FRK and M100 but I do remember this particular common problem. You power the unit up and after the normal warm up period it locks and stays locked. Then if you cycle the power the Lamp refuses to light. Has anyone figured out the most likely cause

[time-nuts] Efratom FRK and M100 question

Bill, When plugged in cold and after the lamp starts I can cycle the power and the lamp will re-ignite up to about 4 minutes into the warmup. After that the lamp won't start. Maybe the lamp heater is set too hot or the lamp oscillator is heat sensitive? Corby

[time-nuts] GWBasic at 57600 Baud WORKS!

I got my dinosaur up and healthy again. The code Ed Moxon suggested worked great with some monor tweaks to my program. 10 'run gwbasic com port at high baudrate by poking divisor latch 100 OPEN COM1:9600,N,8,1 AS 1 '9600 is 115200/12, so latch is now 12 110 UBASE = h3f8: LCR=UBASE+3 'uart i/o

[time-nuts] 57600 baud rate with Basic???

Hi, I'm currently using a GWBasic program at 9600 Baud to get 1 second T.I. data (12 digits) from an SR620 counter, display the reading , put the reading into a file, name the file sequentialy, and either save or delete the file via a function key. I'm switching to a new counter that outputs at

[time-nuts] 5071A Cs oven

Hi, Cs depletion in modern tubes is a real failure mode! However some competing modes are: Ion pump failure (whiskers or high impedance shorts) High Cs backround level (Gettering saturation) Oven or ionizer filament failure (More common on older HP units with the AC excitation, (think of those

[time-nuts] Wenzel oscillator question

Hi, I have a Wenzel oscillator that I don't remember where I got it. I think I removed it from an instrument as it has a sticker on it labeled A3A1. It's a model 500-09802D 5Mhz oscillator with 2 BNC and one SMA connectors, a ground pin and 3 other pins. The label indicates +15 and +20VDC.

[time-nuts] FTS Datum 1000B for sale

This unit has one 5Mhz and one 10Mhz output. See the data sheet at: http://www.gigatest.net/datum/1000b-r2.pdf Thanks, Corby Woman is 53 But Looks 25 Mom reveals 1 simple wrinkle trick that has angered doctors...

[time-nuts] 10514B mixer terminations for DMTD

Hi, For DMTD work 50 ohms is usually not optimum. In the NBS design they used an effective 500 Ohms. You want to optimize for the highest amplitude. (Generally) A network of capacitor(s) and resistor(s) is usually the best way to terminate. Corby

[time-nuts] FTS 1000B oscillator for sale

Hi, I put an FTS 1000B oscillator on sale at eBay see item # 320980495168 if you are interested. I will also be selling several FTS1000A in the near future. Thanks, Corby Dealing With Incontinence Learn About This Medical Condition.

[time-nuts] FE 5680A Warning

Hi Folks, I played with a few of these that came off the cut up board you describe. The ones I had put out 1PPS ONLY! Internally they ran at 8.xx Mhz that divided down to the 1 Hz. I was able to engineer a tiny add-on board using very small 10Mhz crystals and made them put out 10Mhz. By the

[time-nuts] Long term storage of HP5065A Rb frequency standard

Hi, Here is a post I made years ago on the subject. There was a typo and a correction post that changed the resistor value to 5 Ohms, it is corrected here also. First take a look at the leapsecond.com website. Click on various lab reports and then rb-cells. You will see pictures of rubidium

[time-nuts] HP 5061 zeeman frequency experiance

The HP spec for an end of life tube is a main peak of 8.5 nanoamp when measured at the SMA output jack terminated directly into a high impedance voltmeter. Use the meters input impedance and Ohms law to determine the current. However this value is where the tube stability starts to fall below the

[time-nuts] HP 5065a Rb ref update and question on time scale

When manufacturing the cells for the 5065A receiver package it was not feasable or cost effective to try and make each cell exactly on frequency. With the sythesizer designed the way it was all thay had to do was make sure that cells would fall within the 0 to +1000X10-10th range. That way they

[time-nuts] HP 5065a Rb ref update and question on time scale

Paul, The time scale selection is to match the offset in each particular receiver section and thus put it on frequency. Once there you can use the chart to determine offsets from the value you use. The synthesizer setting by virtue of how its designed does not allow one digit changes! You have

[time-nuts] HP5065A digital clock info

Hi, The clock chip is a National MM5313N, it is also the one used in the digital clock for the HP 5061A. Schematics were in the update pages for the older manuals and in the manual for the newer ones. Corby Dawson 60-Year-Old Mom

[time-nuts] Mystery Passive Maser Update 4

Update 4 of the Mystery Passive Maser Project is now available at: http://www.leapsecond.com/maser/ Enjoy! Corby Dawson 60-Year-Old Mom Looks 27 Mom Reveals Free Wrinkle Trick That Has Angered Doctors!

[time-nuts] ERC-130 INFO

Skip, I do have a manual around here somewhere but it has no schematics. It's just a basic spec. and info. The main info is that is composed of a +15VDC linear supply, A 10Mhz buffer card to deliver 1VRMS into 50 ohms and an FE5650A rubidium module. Corby Dawson

[time-nuts] Mystery Maser Project

Hi Everyone, I'm working on a vintage passive Hydrogen maser that is undocumented and missing a bunch of the electronics. I am working on getting it up far enough to see if I can get Maser action and if so will then work on the rest of the electronics. Tom Van Baak is hosting the blog on his

[time-nuts] HP 5065A low serial numbers

Hi Everyone, A while ago I posted for anyone with a 5065A that had a 2816A prefix serial number to try and determine the last HP 5065A sold. Now I'd like to know what the earliest SN anyone has seen. The current winner is SN 0940-00203. If anyone knows of an earlier or similar vintage please

[time-nuts] SR620

The downloaded manuals from SRS don't have the schematics, but if you buy a paper manual from them you get the schematics. (At least for the PRS10 and SR620) Corby Globe Life Insurance $1* Buys $50,000 Life Insurance. Adults or

[time-nuts] Datum 1111C oscillator/4040A Cesium

I picked up the guts of a Datum 4040A cesium standard on eBay. I am at the point of wanting to test the Datum C quartz oscillator that was part of it. Does anyone know what the power supply voltage is? There is also a nice 9Ghz SMA packaged Macom RF amp that I'd like to know the power

[time-nuts] Garage built Rubidium standard

The RB-87 isotope used in Rubidium standards is radioactive, but at such a slight activity level that special procedures and shielding must be used to measure it. Any chunk of granite, including your fancy kitchen counters, far outshines RB-87 as a radiation source! A garage built Rubidium

[time-nuts] RS XSRM Rubidium

This link shows the light from a rubidium spectral lamp. Its appearance is quite similar to the rubidium lamps used in various rubidium standards. There can be a slight bluish cast also, especially at low temperatures as the lamp warms up. I'm not familiar with the RS but depending on the

[time-nuts] 10544 TCXO used in H/P 5245L counter

Hi, I have a copy of the retrofit pages that went with the 10544A install for the HP 5245A. There were LOTS of these installed in the 5245 series after the original oscillators started failing. Give me a day or so to hunt it up and I'll share it. It has the schematics of the interface board.

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