[time-nuts] Hydrogen Maser KIT! Update #1
I'd be tempted to experiment with other methods of bulb coating but the time and effort in disassembly, re assembly and testing is so great that I'm going to use a tried and true method to increase the chances of success! It's definitely NOT just as simple as screwing in a different light bulb and trying again! 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] Hydrogen Maser KIT! Update #1
Chuck, The coating opposite the entrance to the bulb was degraded to the point that it was missing over a large area and the tiny particles of loose Teflon were free to move about in the bulb. (Rolling the bulb you could see a little pile of particles moving about) Since a majority of the hydrogen atoms entering the bulb impact first at the opposite end that would cause a large majority of the atoms in the correct state to be perturbed as well as recombine into molecules. So since the end needed recoating it's best to do the whole thing. Per the question of aqueous dispersions here is an excerpt from Dupont: DuPont Teflon® aqueous dispersions are milky white dispersions of PTFE particles in water, stabilized by wetting agents. 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] Divide by five
You could use a SOIC to DIP adaptor board with a couple logic and FF elements in the "Potato Chip" Family. See: http://www.potatosemi.com/ 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] Hydrogen Maser Kit part 3
Hi everyone, The Maser Kit is progressing. Old Teflon removed, Bulb cleaned, Ion pumps ready to test, and curing oven under construction. Details and PIX at: http://leapsecond.com/corby/maser/index.htm#part3 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] We had 5 of our XL-AK GPS receivers suddenly gained 1 second
Hi, XL-AK GPS receivers suddenly gained 1 second! Anyone encounter this with XL-AK GPS receivers? If so is there any work around to correct this? 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 there.
[time-nuts] HP 5065A questions
Joe, Nice find. Don't worry about the lamp, they VERY seldom fail. Of course there are electronics failures that crop up. What color is your physics package? Blue paint= old style Olive green paint = mid production Silver (no paint) = late production Also can I get your units serial number for my list? With it in the operate mode watch the control voltage and slowly adjust the fine quartz back and forth. If it is indeed locking to the Rubidium the meter should follow your adjustment. I would not worry about the physics package case either, just put some tape across to seal it from heat loss. I can give you some alignment hints if you need them. Corby Dawson cdel...@juno.com ___ 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] Anyone have the source code for XL-AK GPS receivers?
Looking for the source code, can anyone help? 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] HP 5065A questions
Joe, Your unit could be a 916 prefix with the newer physics package and 10811 added as retrofits. Look at the top of the A3 module, what is the series number? Also look at the A9 op-amp module, does it have a Epoxy block op-amp or a transistor can style op-amp? What serial number is penciled in the data log on the front panel that swings open? Last year sold was 1992 and latest serial number prefix was 2816A. With the unit in lock adjust the Oscillator fine freq to mid range and the coarse for a reading of around zero. Red lamp is not stock, the green one probably broke and that was only one they could find! Like Dan said the top cover is covered in holes and is hard to find. If you find a bottom that fits make sure you cover the inside with insulating tape. The original bottom cover has a very thin phenolic insulator covering its inside. The switch Paul mentioned is for the 1Mhz and 100Khz dividers. the rational was that if you had a power hit the clock would stop (the 1Mhz also drives the clock option) making sure you were not using a bogus time. Just leave it in the auto start position! The logic reset button is the one that will turn on the operate light! 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] WWVB receivers obsolete!?
Am I wrong or are all the older WWVB frequency standard receivers obsolete? My understanding was that since the transmitted format changed the receivers wont lock. I asked an eBay vendor about that since they are still asking big bucks. The reply was "Ive heard that before, but certain people still use it, and need replacement for there though it is technically obsolete." I know the ones with internal standards can at least be used as a stand alone Quartz standard but what can you do with ones like the 8163 that have no standard? 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] Morion MV-89 Stability
Has anyone measured the AD of a few Morion MV-89? Wondering how they do from 1 to 100 Seconds. (With a setup able to reach 5X10-13th at those Tau.) 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 there.
[time-nuts] Rubidium cell collection
Hi, I've put my Rubidium cell collection up for sale on eBay! See item # 321676724236 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] HP 5065A with Patek clock on eBay
Hi, I've just listed an HP 5065A on eBay, item # 321719923791 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] Hp 10544A repair
Luca, You can pry out the plastic pins easily. Then remove the thin foam piece. Then if I remember correctly you will have to diagram where each color of wire goes to the edge connector and then unsolder them. Now you can remove the guts, some pressure on the tuning capacitor thru the hole will aid in getting it to slide out. The distortion on the output might be normal. If you just hook scope to it they almost allways look distorted. You have to properly load the output into 1KOhm to get the sine wave. 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] FE-2294B data
Anyone have specs and a pinout for the Frequency electronics FE-2294B oscillator? 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 there.
[time-nuts] HP 8620 A B or C Mainframe
Hi everyone, I'm looking for the enclosure, top and bottom panels and inside frames from an HP 8620 A,B, or C. Can be gutted, and all the goodies removed from the front panel. I just need the frame and outsides for a project. (rear heatsink intact if possible.) Anybody have a gutted one I can buy? Thanks, Corby Dawson ___ 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] FIRST AID WHEN YOU BUY AN HP5065A
Also replace C23 and C24 on the A11 board. Even if they read OK, I change them to be safe! 20uf 50V Axial. 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] Indicator lenses for the HP 5065A and 5061A/B
Surplus sales of nebraska has lenses that fit into the 5065A lamp holders. (Also 5061A/B) LMP-RL-180TT (teal- light green) LMP-RL-180YT (yellow) They show a green one also but it's too short. The yellow needs to be filed a bit as the plastic portion that extends into the holder is a tiny bit too fat. 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] MTI 260 Oscillator question.
Hi, I've noticed that there is a soldered area on the top of the module that appears to be covering a hole. Has anyone taken one of these apart, and if so is there a trim cap or pot under this hole to allow adjustment??? Thanks, Corby Dawson ___ 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] Reeeely long term HP 5065A drift rate (13 year!)
I recently had a unit come in for repair that I had sold 13 years ago. The owner never did ANY adjustments on the unit. After the repair (which would not have affected the frequency) and before aligning the unit I decided to check and see how far it had drifted in the 13 years. Did a run against an HP 5071A and the frequency offset is 2.1X10-11th best case and 4.1X10-11th worst case. This gives an average of 1.65X10-12th to 3.15X10-12 per year! Pretty amazing! 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] Reeeely long term HP 5065A drift rate (13 year!)
Yes, same workbench and location! How about some of the 5065A owners helping out in a bigger sample? What I thought is that say on July the 4th a few owners measure their frequency offset to say at least 5X10-12th and then without changing the C-field for a year we could repeat the measurement next year and see what kind of results we get. Units would not have to stay powered on the entire time as long a you give them a day or so to warm up before the measurements. The Independence day 5065A offset club! 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] Reeeely long term HP 5065A drift rate (13 year!)
A few have volunteered for extended tests! Also got some info for a couple others: Unit 1 3.15X10-12/Year 12 years Unit 2 1.53X10-12/Year 13 Years Unit 3 7.12X10-12/Year 7 months so far Spec. is 1X10-11th per Year. 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] Reeeely long term HP 5065A drift rate (13 year!)
Ooops, HP 5065A Spec is 1X10-11 per MONTH not a year as I had in the prior post! 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] HP 3581A question
Hi, I have an HP 3581A and I need to replace the top right hand frequency pot. My unit has a dual pot with a concentric shaft. The only manual I have shows a single pot. If anyone has a manual that shows the dual pot could you let me know the values of the pots? Thanks, Corby Dawson ___ 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] Lamp oven repair info for HP 5065A
Hi, Just thought I'd share some info on repairing a defective HP 5065A lamp oven. These ovens can fail either shorted to the oven cylinder or have interwinding shorts. I have repaired three optical units so far with this failure. The original winding was insulated twisted pair wound directly onto the Aluminum oven cylinder. I used teflon insulated heater wire, Pelican P2332ADVFEP.009BL. It is approx. 5 Ohms/ft. and I use a 50 Ohm length doubled and then twisted tightly. This is then wound onto the oven cylinder which is first covered with a single layer of kapton tape. The original thermistor is replaced with a DigiKey 615-1007-ND. The thermistor MUST be surrounded by heat sink compound. I also install a digiKey TO220 100 degree thermal cutout switch for future protection. It is mounted to the top of the lamp assy. using one of the 3 original mounting screws. The thermistor and heater wires are brought out tie wrapped along the original cable and then soldered to the appropriate pins on the db9 connector. 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] Lamp oven repair info for HP 5065A
The 3 units I have repaired had the original heater wire twisted with around 7 twists per inch. That's what new windings replicated. The teflon insulated wire and the Kapton tape should prevent any further problem! 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] HP10811 vs 00105 OCXO
Luciano, I have found that "selected" 10811 units will offer significantly better short term stability as a stand alone or open loop oscillator over the 105 style oscillator. (Mid parts in 10-13th from 1 to 100 Seconds) However with the 5065A locked the performance will be driven by the loop and both styles will give similar performance. 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] Cavity frequency air filled vs vacuum?
Hi everyone! I'm trying to figure out what change if any to a cavities resonant frequency would be when measured with ambient air pressure and then with a vacuum inside. There will not be any pressure on the cavity when under vacuum as the outside of the cavity will also be at vacuum. The cavity frequency under vacuum will be 1420Mhz + (Maser frequency). 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 there.
[time-nuts] 10811 unsoldered fuse
The fuses in the 10811 are NOT soldered in. The leads are inserted into single pin "sockets" 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] HP 53131A display dim
Anyone know about these displays? If the display is getting dim do I need a new VFD module? 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 there.
[time-nuts] HP 53131A display dim
Hi, Thanks for the replies. Only a couple digits are dim so I guess it must be the VFD? I suppose the only source is to find an otherwise dead unit to strip it out of? 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] HP 5065A battery pack
Any one know how many cells went into the HP 5065A battery packs? 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 there.
[time-nuts] Varactor frequency dividers question
Hi, I'm looking for a copy of the following document. "Parametric frequency divider basics. (technical note )" >From the Microwave Journal Sept 1 1989. Can anyone help? Thanks, Corby Abstract below. >>>Since the introduction of half octave bandwidth microwave frequency dividers and full octave models, parametric frequency dividers have found applications in many microwave systems. General Description The parametric frequency divider is constructed using two varactor diodes in a resonant circuit. These diodes are biased slightly forward under normal operation. The input signal capacitively is coupled into the matching network for the two diodes, where it drives both of the diodes in phase. Due to the modulation of the varactor's capacitance at the input frequency f, a subharmonic resonance is set up in the diode pair at half of the input frequency, f/2. [1] This signal appears across both of the varactor diodes, but at 180[degrees] out of phase with each other. It is possibly, by using a balun connected to both diodes, to cancel the input signal f. However, by observing the signal on one of the diodes in the time domain, it can be seen that balancing is unnecessary. This signal appears as a negative impulse train with a period of f/2, with a positive maximum at the varactor's turn-on threshold voltage of 0.7 V. An electrical schematic diagram of a typical divider is shown in Figure 1. ___ 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] HP 10811
Warren, What is the purpose of "Unseal the internal tuning nut by loosing it ~ 1/2 turn"? And which internal tuning nut are you referring to? 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] Rubidium Frequency Standard
Mike, Luciano is correct. The HP 5065A beats all the others easily. It is not configured however to be disciplined although it can be modified. It's main claim to fame is the excellent short term stability. If all you are after is a long term accuracy standard then any of the others would work. There has been a lot of work done with disciplining the FE-5680 and also temperature controlling its baseplate. Results are very good! Cheers, Corby Dawson ___ 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] Best Rubidium Frequency Standard
Mike, If you are planning to buy "suspect units" with the intent to repair I would steer clear of the PRS10. It is true you can pay for a factory repair but having the schematics and theory of operation only helps for particular repairs. This is because a lot of the alignment parameters are stored in memory and there are no instructions on these alignments and how to store them. An example: I had a unit come in for repair. It had no output. The customer, a professor, said a student applied a large DC to the output. The output is direct from an RF transformer. It burnt open the winding. I thought, how hard can it be? I popped off a good output board from a junker and installed it. I now had an output but the unit would not operate properly. Part of the output go to other circuitry that would need to be aligned to match. No way to do that or store the alignment! Bummer. Luckily the transformer was a metal can type. I opened it up and rewound the tiny wire output coil and that restored the unit to operation. After that I sold my pile of defunct PRS10 units and don't plan to purchase any more. For ease of repair the HP 5065A is first, then the FRKL and H, these have bog standard thru hole circuitry and the manuals are excellent. Another of the worst is the M100 as its cards are conformal coated and the lamp oven assy. is potted! As you mentioned most of the later telecomm units are surface mount and most have some sort of microprocessor involved. 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] 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, unless your lab swings tens of degrees will you really see it? Short term stability scales with cell size and is also proportional to the design temperature. Also separate filter and resonance cells perform better than an "integrated" cell. The 5065A cell is the largest available today and the 66 degree C is the lowest temp around these days. The 5065A cell also has a temperature regulated stem to stabilize the Rubidium level. These combine to give a typical STS of 1.5X10-13 at a Tau of 100 Seconds. Unfortunately as others have noted, it is easily the most expensive Rubidium standard out there. A few members are looking into improving the tempco and I hope testing the barometric pressure performance. 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] 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 oven that stays on all the time. 10811A units are better performers. 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] 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 function and the counter will function fine. (It loads the factory defaults from ROM) I have been using it for over a year this way in the time interval mode with no problems. I can email a set of pictures to intrerested parties. It has an SC10 oscillator inside. (I plotted its short term stability and can provide it with the PIX.) Includes an original factory manual with schematics. I'm asking $975.00 + shipping for it. Questions welcome! Thanks, Corby Dawson cdel...@juno.com Woman is 53 But Looks 25 Mom reveals 1 simple wrinkle trick that has angered doctors... http://thirdpartyoffers.juno.com/TGL3141/50b66e51b19b76e51555dst02duc ___ 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] 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 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] 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 OVERSTOCK ipads: $30.93 Get 32GB Apple iPad for as low as $30.93. Limit 1.Day. Grab yours Now! http://thirdpartyoffers.juno.com/TGL3141/50b7b8504921c3850534ast04duc ___ 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] 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@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
[time-nuts] Noisy Varactor diodes
The vertical is 50Mv/cm and the horizontal is 1ms/cm The diode is connected to + 20VDC and then to a 20K resistor to ground. The scope is across the resistor. This simulates the in-circuit situation. 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] 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 harmonic meter reading and coresponding fluctuations at the A7 TP2 test point. John I could not see the info you refered to? 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] 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 unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
[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 8.95-133.09-13 8.95-14 Each unit was adjusted for equal amplitude into a resistive power combiner and also adjusted so their phase was coincident prior to starting the plots. The main problem was getting their relative frequencies close enough so that there was no drift during the measurements. Not a trivial accomplishment for the 100 sec tau! I'm thinking now of a way to loosely lock the phase of one unit to the other to simplify the setup. One different idea I had that I'd like some feedback on: If I take both units into a double balanced mixer, then take the resulting 10MHz and divide it back to 5MHz would I get the same improvement? This method would be much simpler! Happy New Year! Corby Dawson ___ 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.
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 the first post I cobbled together a mixer/divider and ran some plots and unfortunately you don't get better stability! Bummer, that would have made it a lot simpler. I'm going to look into locking one to the other via the C-field control. I have disciplined several FRK and M100 via the C-field before so I know it will work. 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] 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 collecting the Rubidium back into the base. The FRS was not quite as good in this respect! If upon inspection you can see Rubidium anywhere but down in the very base of the bulb you can use a heat gun to force it back into the base. I sit the bulb so the base is sitting on something to heat sink it and then ply the heat gun around the top of the bulb until all the visible Rubidium is off of the bulb proper. On an HP unit you can just leave the bulb mounted on its board to use as the heat sink. Here is a link to an excellent description of FRS lamp repair. Corby http://www.n4iqt.com/efratom8084008/eeratom_model_frs_lamp_assembly_repai r.pdf ___ 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] 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@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
[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 I'd like to do to two or more HP 5065A Anyone know what they did in the controller? 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] 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. 10 SEC. 100 SEC. 1K SEC. -- HP 5065A Spec. <5.0-12 <1.6-12 <5.0-13 <5.0-13 -- 940-3.51-12 1.02-12 2.43-13 1.00-13 2432A1.40-12 6.06-13 3.31-13 3.28-14 2340A1.66-12 7.09-13 2.93-13 6.54-14 2640A1.16-12 4.06-13 1.23-13 2.10-14 2816A1 1.04-12 3.89-13 2.40-13 3.37-14 TESTER 1.15-12 7.40-13 3.66-13 7.54-14 RB09 5.50-12 1.00-12 3.00-13 3.00-13 RB02 9.00-13 3.00-13 1.00-13 6.00-14 RB12 2.00-12 4.00-13 1.10-13 5.10-14 TVB2 1.17-12 4.80-13 1.50-13 7.80-14 TVB1 1.13-12 3.32-13 1.13-13 5.10-14 2816A2 *2.62-12 1.09-12 4.12-13 1.10-13 2816A3 1.38-12 5.93-13 2.51-13 7.81-14 1532A 1.8 -12 8.0 -134.0 -13 2432A1 1.4 -12 4.5 -131.6 -13 2816A4 8.0 -13 3.2 -131.1 -13 RB34 *2.10-12 4.5 -131.15-13 2816A5 1.04-12 3.50-13 8.15-14 2816A6 *2.16-12 4.50-13 1.15-13 2740A *2.07-12 4.05-13 1.01-13 1340A9.45-13 3.31-13 9.60-14 2432A2 1.02-12 3.43-13 1.03-13 2432A3*2.01-12 4.11-13 1.25-13 ___ 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] 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 the EFOS2 Active Hydrogen Maser + the odd cables attenuators etc. I think that's about it! 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 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. >> >> 10811-601096.11-12 2.52-12 8.78-12 >> 10811-601091.65-12 1.91-12 9.79-12 >> 10811-601091.65-12 1.99-12 1.11-12 >> 10811-601095.47-12 1.16-12 2.38-12 >> 105 STYLE #T 7.60-13 2.01-12 3.94-12 >> 10811-601111.27-12 2.65-12 1.93-12 >> 105 STYLE #2 1.14-12 1.57-12 2.26-12 >> 105 STYLE #3 1.31-12 1.58-12 2.68-12 >> 10811-601113.04-12 5.54-12 1.47-12 >> 105 STYLE #4 1.38-12 3.49-12 4.84-12 >> 10811-601092.05-12 2.89-12 3.24-12 >> 10811-601111.36-12 1.17-12 1.75-12 >> 105 STYLE #5 1.14-12 2.09-12 2.51-12 >> FTS 1200 #17.14-13 1.48-12 1.92-12 >> 10543A2.86-11 1.05-11 1.63-11 >> 10544A4.08-12 2.95-12 7.79-12 >> 10811-601111.24-12 2.10-12 2.09-12 >> 10811-601111.48-12 1.59-12 1.54-12 >> 10544A1.89-12 2.99-12 5.01-12 >> 105 style #6 2.88-12 2.88-12 7.37-12 >> 105 style #7 9.69-13 2.30-12 3.49-12 >> 10544-60511 8.20-13 2.11-12 2.51-12 >> Piezo clone 2.57-12 2.23-12 2.17-12 >> 5060Aosconly 4.04-12 5.94-128.42-12 1.30-11 >> 10811-60111 2.59-12 3.87-12 5.77-12 >> 105 STYLE 8 8.0-13 2.0-12 9.0-12 >> 10811- 2.0-12 1.0-12 2.5-12 >> 10811- 1.5-12 2.5-12 3.0-12 >> 10811- 2.2-12 2.5-12 3.4-12 >> 10811- 2.1-12 2.0-12 3.3-12 >> 10811- 1.8-12 1.4-12 5.0-12 >> 10811- 2.0-12 2.0-12 3.2-12 >> 10811-601201.3-12 1.3-12 1.2-12 >> 10811- 2.0-12 1.8-12 2.8-12 >> Motorola DOXO 1.05-12 1.0-121.03-12 *** "CHERRY PICKED" units ** FTS 1200 #2 2.99-13 4.30-13 7.69-13 8.65-13 ** FTS/datum 1000B 8.69-13 1.15-12 9.20-13 ** FTS 9110 6.50-13 2.68-13 3.90-13 ** Datum 1115C6.88-13 5.83-13 9.34-13 ** 10811-601096.22-13 6.43-13 3.66-13 ** 10811-601095.25-13 4.20-13 6.78-13 ** 10811-601117.60-13 7.80-13 7.15-13 ** 10811-601112.16-12 4.89-13 1.24-12 ** 10811-601116.02-13 3.11-13 3.46-13 -- -60109spec 2.50-125.00-12 1.00-11 -- -60111spec <1.00-12* * -- 10811Aspec 5.00-12 5.00-12 1.00-11 ___ 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 there.
[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] 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 differences mean? 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 there.
[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 installed Efratom lamps into some 304D units. 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 1000A oscillator on the bay
Hi, See my FTS oscillator I'm selling. item number 321080604271 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.
Re: [time-nuts] LTC6957 Low Phase Noise Buffer/Driver
"Very high gain front end. It's a saturating amp rather than a comparator." Wonder how it would work as a DMTD front end? 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] HP 5065A change sheets
Hi Everyone, Does anyone have the change sheets that apply to the prefix 2816A. I only have the one that covers up to prefix 2740A. 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 there.
[time-nuts] HP5065B !!!
OK, that was just to get your attention! What do you call a modified HP 5065A that can give you an Allan Deviation of 4X10-13 @ 1 Second and 6X10-14 @ 100 Second? I call it the "SUPER" HP 5065A. Any of these links will get you to the document describing it. Have a look and see what it's all about! Enjoy, Corby http://leapsecond.com/corby/Super-5065A-Project.pdf or http://leapsecond.com/corby/superproj10.docx or http://www.febo.com/pages/HP5065A_SUPER for ___ 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] HP 5065B !!!
Brook, It's all done with mirrors! No lenses. A reflector at the lamp end and a tapered mirror at the photocell end. I'll see if I can post an outline drawing. 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] laser locking
Attila, When researching ways to improve the 5065A (AKA the SUPER 5065A) I considered using a laser. However the long term operation is hard to optimize. Tuning the laser is a combination of temperature and current to select the proper line. (and optics if you use a grating tuning) It's cumbersome at best even if you don't lock the laser to a Rubidium cell. Since I was able to get performance better than any published Rubidium standard using the regular RF excited lamps I decided "why go the Laser route?" Note this performance is better than the laser pumped experimental models in the literature. I'm sure once the diode technology becomes mature enough to be reliable you will start seeing them in commercial standards. Until then it is just fun to play with but not very sensible for reliable operation. Corby Dawson ___ 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] hp5065b !!!
Bob, The new style A3 uses the same input and slighly modified output stages from the original. The multiplication from 5 to 60 Mhz is done entirely different. I have two scans that copy the schematic but they are way big in size. I'll experiment and try to make them small enough to email. 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] HP 5065B!!! New A3
Hi, The New style A3 is in mainframes with SN prefix 2644A and above and has series 2644 on its label. I'll see about getting the schematic and theory page posted where everyone can access it. 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] hp5065b !!!
Mark, >Hi, while?skimming some articles I found re GPS satellites, I found some references to?certain buffer gasses in Rb cells working much better?with optical filters than others.??? Can you reference the article? The enhanced performance with optical filters can usually be tied with particular Lamp buffer gases, which are separate from the buffer gases in the Rb cells. Enhancement can be obtained with any mix of gases in the Lamp but some mixes are better than others. 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] AD9830 DDS question
Hi, I'm trying to program an AD9830 DDS chip removed from an FE rubidium unit. I have done it in the past with no problem. However now when I go the AD website and try to use the device configuration assistant it faults out saying internet explorer has a problem with the page and it closes. If I use Firefox the page comes up and I can enter frequencies but the code words section stays empty! Any ideas? Is there a version of this program I can download and run locally? 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 there.
[time-nuts] AD9830 DDS question
Well I've also tried it on a kindle and still can't get the code words! BillWB6BNQ steered me to this alternate page and it works! HooRay! Thanks! http://designtools.analog.com/dtDDSWeb/dtDDSMain.aspx ___ 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] HP 5065A with Patek Philippe analog clock coming up for sale
Thought I'd give a "heads up" concerning a nice HP 5065A that I will be offering for sale in the near future. It has the Patek Philippe analog clock and is in pretty good condition. Fully checked out and aligned! Plot against a Hydrogen Maser looks great and beats the original HP specs handily. Comes with a full 90 day warranty. Contact me off-list and I can provide the plot and some PIX to interested parties. SN prefix is 1320A and includes the power cord and rack ears. Price is $4150.00 which includes shipping in the CONUS. Cheers! Corby Dawson ___ 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] HP 5360A question
Hi, I have a 05360-60051 circuit board from an HP 5360A that I'm scrapping. I just need the HP part number of the transformer on the board to see if I can use it in another project. Can anyone help? 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] HP 10811 variants for sale
Hi, I'm going through my collection of 10811 variants and listing them on ebay over the next couple months. Two 10811B are listed now. Watch user ID corbymite. Cheers, Corby Dawson ___ 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] optically excite a quartz crystal?
After reading about how the BVA oscillators avoid the problems of "on crystal" electrodes I was wondering if anyone has tried to optically excite a quartz crystal in an oscillator? (Use a modulated laser to drive the bare crystal, and a photodetector setup to detect and provide feedback?) Seems like it might work. Any comments? 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] PRS10 rubidium on eBay
Hi, I'm selling a nice PRS10 on eBay if anyone is interested. With manual and schematics. Works great! Cheers, Corby Dawson ___ 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] PRS10 rubidium on eBay
John, I believe that the unit referred to is a Tracor 308A. I no longer look to play with the Tracor units (304 308 600 900) as their performance does not merit putting a lot of work into them. Thanks for the heads up however! The eBay # for the PRS10 is 321402060170 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] STEL 1175 vice 1173
Hi, I found two PLCC STEL 1175 in a rack mounted synthesizer I have. I'd be willing to sell the chips. Would they work? 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] Caveats on Allan Deviation with ultra stable oscillators
Recently I have been testing some Quartz oscillators with exceptional stability. (low parts in 10-13th) I've noticed something that jumped out at these performance levels! Normally I test oscillators on a DMTD system with either an ultra stable Quartz or a Hydrogen Maser reference. On these latest oscillators at the longer Tau (>100sec.) the Quartz versus Quartz data shows much better performance than the Quartz versus Maser! What is happening (I think) in this case is that both Quartz units have exceptionally low and similar ageing. This similar ageing rate masks the true stability performance at longer Tau. The Maser data (with no effective ageing in this case) reveals the true stability at the longer Tau! Cheers! Corby Dawson ___ 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] HP 105/5061/5065 oscillator interface boards
Hi, I'm looking to see if anyone has any 10811 oscillator interface boards to spare? Two boards and a frame that accepts the 10811 and outputs 5Mhz. Used in the HP 105 5061A/B and 5065A. Interested in the whole thing with oscillator or just the two boards or just the bigger rectangular board with the SMB connectors on it. Anybody have these in their pile of boards for a reasonable price? Thanks! :) Corby Dawson ___ 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] Caveats on Allan Deviation with ultra stable oscillators
Hi, I usually don't use drift removal as I want to see the effects of drift! The effects of oscillators locking together are very apparent on both the phase and AD plots when using a DMTD system. There was no indications of such locking! My point was that if you are measuring ultrastable Quartz oscillators against each other the AD at the higher Tau will not reflect the true stability of the oscillators. Only a Maser or high performance Rubidium (HP5065A) will reveal the true behavior. 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] Ulrich Plotter
Hi, When I print an Allan deviation plot from Ulrich's Plotter program the box with the values gets superimposed on the chart and the top 5 or so values get chopped off! Anybody know how to correct this? 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 there.
[time-nuts] Need help with transformer core
I'm trying to built a DC to DC from an existing schematic for a frequency standard I'm working on. The transformer core is identified as an Indiana General F1152-1-6 The Dc to Dc is running at 22Khz and maybe 20 Watts. Can't find any info that would allow me to decide on a proper substitute. Anybody out there have any data on this? 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 there.
[time-nuts] Need help with transformer core
Thanks for the inputs everyone, One of the direct replies got me the data I needed! Alex, I'd like to by it that way, but A 24VDC input 3700VDC output at 4ma does not seem to be available! 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] Lambda power supply data
Hi, Anybody have the mechanical data for mounting a Lambda LRS-54M-24 power supply? It has to be the M type. I believe there are 6 holes on the bottom and I need to know the spacing of the holes. BTW thanks again for all the DC to DC converter info! Cheers, Corby Dawson ___ 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] FRK/M100 Lamps for sale!
Hi, I have a small quantity of good used FRK/M100 lamps I am getting rid of. Offering here prior to eBay. $45.00 each which includes shipping in USA. Contact me off list. 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] Hydrogen Maser KIT!
Well, I bet that got your attention! My Hydrogen Maser "kit" arrived recently. It's a surplus Sigma Tau VLBA-112 with an unknown physics package problem that has had its power supply modules, RF receiver modules, synthesizer and cavity servo tuning modules, and a couple other "bits" removed for spares. Also it has been opened up to the level that the storage bulb could be removed. (Magnetic shields, insulation, and bell jar removed) The two main problems (so far, fingers crossed) are that the palladium silver purifier/leak valve is missing (along with the Hydrogen supply bottle), and that the storage bulb coating looks to be shot. I've been tracing the power supply wiring and design, and should be able to replace the missing stuff easily. Minor problems are fabricating connectors for the ion pumps, replacing one missing oven control module, and finding a Perkin Elmer pump controller (150ma) for a reasonable price. Once the bulb and purifier problems are cured the major efforts will be: -to reassemble the cavity, shields, and bell jar. -bakeout and pumpdown the ion pumps (in isolation) -bakeout and pumpdown the system. -stabilize the ovens and initiate the Hydrogen discharge. Then if oscillation can be achieved the RF system can be built. Replacing the Automatic cavity tuning will come last as it's not needed for basic operation. I plan to add a relay on the input of the EFOS2 Maser that lives here. This will allow the EFOS RF systems to be utilized for testing before having to build up the new receiver. This will be a LONG term effort and I will share the progress as I go along. Some info: Copper cavity loaded with Quartz dielectric cylinder and Quartz bulb. Cavity Q (loaded) 36000 Line Q approx 1.6X10+9 Drift < 5 parts in 10-15 per day (Auto tuner on) Temperature sensitivity < 1 X 10-14 per degree C `Weight 525 pounds (including backup battery) Tom has kindly posted some PIX at: http://leapsecond.com/corby/maser/ You might want to look at the old posts about homemade Hydrogen Masers starting back in Aug 29 2010. 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] capacitors for oven controller
Hi, I'm working to replicate an oven controller and the schematic I have states to check the leakage resistance of the .01uf integration capacitor at 50 degrees C. That is the oven temperature. What would be considered good at that temperature and how would I measure it? Also what type capacitor to use? Polycarbonate??? 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 there.
[time-nuts] any 4hv.org members here?
Hi, Any time-nuts also 4hv.org members. 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] locking oscillators - an increase in power and/or stability ?
Hi, I came across this phenomena when transmitting with two 5KW transmitters via separate parabolic antennas to a satellite. If the phase of the TXs was correct the received signal at the satellite was 6db hotter! I thought at the time that it was due to the power adding in the voltage mode. For instance if you take a 1volt signal into 1 ohm you get 1 amp and 1 watt. but if you take two 1volt signals and add them to produce a 2 volt signal then you get 2 amps and 4 watts. Not sure if my logic is correct but the phenomena is real! 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] locking oscillators - an increase in power and/or stability ?
Came across this. Might be relevant. Cheers, Corby http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19930008868.pdf a) Greater than 100% power combining efficiencies have been realized as predicted. This implies that the output power from the combiner is typically greater than the sum of the power available from individual devices. ___ 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] Efratom FRT-H Lamp removal and supply schematic
Sebastion, Let the unit warm up for 10 minutes, then power down and then try the lamp removal. It turns CCW to remove. Use a BIG screwdriver! 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] Efratom FRT-H Lamp removal and supply schematic
Sebastion, Try swapping the lamps and see if the loosing lock problem follows the lamp! 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] Hydrogen Maser KIT! Update #1
See the link for the latest progress! http://www.leapsecond.com/corby/maser/ 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] Hydrogen Maser KIT! Update #1
Coating the bulb with Teflon involves coating the inside with a Teflon liquid aqueous dispersion, letting it dry, and then curing it in an oven at 380 to 400 degrees C for around 30 minutes while circulating dry air through the bulb. A little bit intricate but doable. Main concern is getting the bulb surface absolutely clean before coating. A hydrofluoric acid rinse is a must! 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] 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 Woman is 57 But Looks 27 Mom publishes simple facelift trick that angered doctors... http://thirdpartyoffers.juno.com/TGL3141/504e086166b5d861761ast02duc ___ 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 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. What You May Be Able To Do About It http://thirdpartyoffers.juno.com/TGL3141/504e3033a73e530333744st02duc ___ 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 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... http://thirdpartyoffers.juno.com/TGL3141/504f5abe5d8c55abe7bc0st02duc ___ 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] 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. Does anyone know the pinout showing which pins are the power pins? Also is the SMA an EFC input? Thanks, Corby Woman is 53 But Looks 25 Mom reveals 1 simple wrinkle trick that has angered doctors... http://thirdpartyoffers.juno.com/TGL3141/5066169a41cae169a1648st03duc ___ 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] 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 neat light bulbs with the magnet inside where the filament jumps all over the place, less drastic mechanical flexing caused the filaments to eventually fail due to fatigue.) Slow leaks ruining the vacuum Running the Cs with the ovens off as described WILL delay some of these failures, (it's recommended that the ion pump remain energized however) A 5071A tube could be installed into a 5061A (with proper adaptors) but why? Later HP 5061A and 5061B "mini" tubes with the same diameter as the 5071A tubes can be installed into the 5071A with some caveats and proper adaptors. Corby Woman is 53 But Looks 25 Mom reveals 1 simple wrinkle trick that has angered doctors... http://thirdpartyoffers.juno.com/TGL3141/506df1798baa27179062fst04duc ___ 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] 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 57600 Baud (9 digits). Is there a version of Basic I can use that would support that 57600 Baud rate? Thanks, Corby Woman is 53 But Looks 25 Mom reveals 1 simple wrinkle trick that has angered doctors... http://thirdpartyoffers.juno.com/TGL3141/507462c97549762c919e3st02duc ___ 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] 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 address, 3f8 for com1, 2f8 com2 120 X=INP(LCR):X=X+128:OUT LCR,X 'set uart DLAB bit 130 OUT UBASE,2 'uart divisor latch lowbyte, 115200 gets divided by this 140 X=X-128: OUT LCR,X 'reset DLAB for normal op 400 'fetch strings 410 LINE INPUT#1, C$ 420 PRINT C$; 430 GOTO 410 As per the "dinosaur" I have run thousands of Allan Deviation plots over the years, taking data from my SR620 with a GWBasic program running in an old laptop mounted in a docking adaptor in my timing rack. (the dinosaur) The program when run assigns the next sequential file # which it writes to disk as well as printing it to the screen. If you push the S key it closes the file on the disk and stops the program. If you push the D key it deletes the current file and decrements the file number so that you can reuse it the next time. The computer is allways up and ready to go. Since I did not want to tear out and replace the hardware the fix Ed helped with was the way to go! Now I can hook up my new counter that works at 57600 Baud to replace the SR620! Hope this can help someone else! Corby Woman is 53 But Looks 25 Mom reveals 1 simple wrinkle trick that has angered doctors... http://thirdpartyoffers.juno.com/TGL3141/50806c60edb926c602194st01duc ___ 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] 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 C-field pot before getting to the frequency you want. If that is the case you will need to set the synthesizer switch to the next value in the chart. (either up or down depending on which way you ran out of room.) Then start over with the c=field adjustment. If you switch the synthesizer setting you will need to remove power momentarily to reset the synthesizers lock indication circuit. Otherwise pushing the logic reset button to get the green light wont work. Corby Woman is 53 But Looks 25 Mom reveals 1 simple wrinkle trick that has angered doctors... http://thirdpartyoffers.juno.com/TGL3141/5081da95575015a951151st02duc ___ 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.
