Re: [time-nuts] Phase-noise through mixer?

Mixers also have the curious phenomenon of non-reciprocity On 10/17/2016 4:13 PM, Bob Camp wrote: Hi Simple answer is yes. More complex answer gets into things like the noise of the mixer (not just it’s floor), the levels of the signals, noise being coherent rather than non-coherent, AM <->

Re: [time-nuts] notch filter for close in phase noise measurement

On 10/2/2016 12:56 AM, Adrian Rus wrote: Hello list, For those of you interested in phase noise measurement without using fancy/dedicated gear, There is no free lunch here. The crystal has its own intrinsic flicker of frequency noise. You cannot measure below this noise floor. The

Re: [time-nuts] Vintage Quartz Crystal Manufacturing

On 9/25/2016 6:53 AM, Bob Camp wrote: Hi If you dropped in to a crystal manufacturing plant at any point over the next 30 years after that film was made, the styles of dress had changed. The crystal holders had changed. Most of the processes were still the same and some of the gear was

Re: [time-nuts] HP 5065A questions

On 9/25/2016 6:42 PM, Skip Withrow wrote: 1. What the heck is rubidium cell flooding, and how does the TEC in the 5065A fix this problem? None of the -many- rubidium oscillators that I have been inside before has a TEC, and I have never seen the subject addressed. The manual suggests that it

[time-nuts] Hobbyist grade or homebrew temperature testing chamber?

stability. Looking for any ideas, maybe in the "maker" spirit. I think the size I need would be perhaps 1/2 the size of a shoebox. BTW, in case someone has a chamber to sell, let me know... Rick Karlquist N6RK ___ time-nuts mailing list -- time-nut

Re: [time-nuts] DIY VNA design

On 8/21/2016 3:59 PM, Dr. David Kirkby (Kirkby Microwave Ltd) wrote: That said, I don't know why the author is using directional couplers. A bridge is much wider bandwidth. It is more lossy though. In general, a resistive bridge will always require a transformer/180 degree

Re: [time-nuts] DIY VNA design

Another great posting, Attila. When I was with Agilent, we looked at all kinds of simplified network analyzer architectures, and I would have to say the author is really well informed. One issue he doesn't seem to be aware of is that the ADL5801, when driven single ended, has some quirks below

Re: [time-nuts] State of the art of crystal oscillator measurements

On 8/11/2016 3:47 PM, John Miles wrote: Right, I'm speaking specifically of L(f). The device being driven by the oscillator doesn't care about the NF of the driver stage, only what a PN analyzer would measure at the output jack. For any 50-ohm source, the practical L(f) floor is -177

Re: [time-nuts] State of the art of crystal oscillator measurements

Zo doesn't matter for these purposes. dBm works just as well for 75 ohm systems. On 8/11/2016 1:22 PM, John Miles wrote: Remember that L(f) is expressed in dBc/Hz, not dBm/Hz. If it were dBm/Hz, then kT would be the limit. But in dBc/Hz terms, the limit is 177 + the DUT's output power in

Re: [time-nuts] State of the art of crystal oscillator measurements

On 8/11/2016 5:01 AM, Mike Feher wrote: This may be a naive question, but, how can you achieve results that are so close to, and sometimes at further out are below kT? Thanks & 73 - Mike Mike B. Feher, EOZ Inc. kT per see is not the relevant parameter. It is the ratio between kT and

Re: [time-nuts] Oscillator Phase Noise: A 50-Year Review

On 8/5/2016 12:47 PM, Tom Van Baak wrote: Here's a new article, on IEEE's site (and this one's free): "Oscillator Phase Noise: A 50-Year Review", by David B. Leeson http://ieeexplore.ieee.org/stamp/stamp.jsp?arnumber=7464875 It has always irked me that no credit was given to Edson's

Re: [time-nuts] Effect of EFC noise on phase noise

Around 35 years ago, I worked with the guys who designed and manufactured the 10811. There are a couple of things here that don't add up, subject to remembering stuff from a LONG time ago: 1. Back in those days at least, there were vendors who supposedly specialized in providing low noise

Re: [time-nuts] Precision DACs

On 7/25/2016 10:42 PM, Scott Stobbe wrote: dramatically different due to glitching on code transition. That being said, they are kept separate not to confuse sources of error. FWIW: The 5071A has a "home brew" DDS that was designed by the late (and great) Robin Giffard. He used what he

Re: [time-nuts] NCOCXO anyone?

On 7/24/2016 6:44 AM, James Flynn wrote: Hal Murray writes: Has anybody put the DAC and all of the analog stuff inside the oven? Seems like an obvious idea so somebody has probably patented it. I am using a 5 MHz custom built design which has everything inside the outer oven

Re: [time-nuts] NCOCXO anyone?

On 7/22/2016 10:15 AM, David wrote: It is too bad voltage control of an oscillator cannot be made ratiometric. Or can it? I have never heard of such a thing. That would remove some of the demands on a low drift reference. That's what we tried to do with the E1938A. A multiplying DAC

Re: [time-nuts] NCOCXO anyone?

On 7/22/2016 2:22 AM, Attila Kinali wrote: Hoi Rick, On Thu, 21 Jul 2016 18:47:24 -0700 "Richard (Rick) Karlquist" <rich...@karlquist.com> wrote: Also in 1996, phase microsteppers were already legacy technology and didn't have a good reputation for spectral purity. Ano

Re: [time-nuts] NCOCXO anyone?

On 7/21/2016 4:56 PM, Nick Sayer via time-nuts wrote: Oh my. That’s a bit more than I was originally considering… What I had in mind was adding a DAC front end to an OCXO so that you could tune the EFC with serial commands rather than analog and calling that a product. 20 years ago when

Re: [time-nuts] Switching transistors, current sources, nonidealties and noise

I vaguely remember seeing designs where a through hole transistor like a 2N5179 had a ferrite bead slipped over the base to keep it stable. Although this works, it degrades the performance of the transistor. I prefer to put a resistor in series with the collector instead of the base. Since the

Re: [time-nuts] buying a time interval counter

On 6/29/2016 10:20 AM, Brooke Clarke wrote: PS Stanford Research is a company founded by physicists and makes some really high quality stuff. In fact some of the products HP/Agilent/Keysight sells are repackaged SR instruments. http://www.prc68.com/I/TandFTE.shtml#SR620 In the old days,

Re: [time-nuts] buying a time interval counter

On 6/29/2016 9:22 AM, Dr. David Kirkby (Kirkby Microwave Ltd) wrote: There is also a Keysight 53230A with a slightly better (20 ps vs 25 ps) single shot resolution. It looks more modern, but I don't know how well they compare. Dave. The 53230A does not offer a 10811 option, but instead

Re: [time-nuts] A little telegraph history, slightly off topic

More off topic: I saw on the history channel a story about a British radio installation in France (IIRC) that was taken over by the Germans, who proceeded to masquerade as British operators, hoping to gather intelligence. The British became suspicious and someone got the bright to append "HH"

Re: [time-nuts] that's really awesome

Probably not necessary on this reflector, but often needed on other reflectors I read: If you are making a legitimate post that is not spam, don't use "teaser" subject lines, etc. that mimic spam messages. Don't post tinyURL links either, no telling what those are. Shouldn't have to say this,

Re: [time-nuts] ADCs for phase noise measurement

On 6/11/2016 6:33 AM, Attila Kinali wrote: Hoi Rick, use a small uC board to interface with the PC. Saving the samples in a wav file and using one of the many FFT tools shouldn't be a problem. This gets even better. The free Pscope software comes with FFT. I don't even need to fool with

Re: [time-nuts] ADCs for phase noise measurement

On 6/11/2016 6:33 AM, Attila Kinali wrote: Hoi Rick, I don't know which phase noise measurement sturcture you are going to use exactly or what your goals are, so I am guessing here a little bit... I'm interested in at least 10-100 Hz offset, 1-1000 Hz offset would be a bonus. Thus audio is

Re: [time-nuts] windows for FFT measurements of phase noise

I remember cobbling together a home brew phase noise system 35 years ago using an HP3582 FFT analyzer. It had several available windows: IIRC: flat top, rectangular, and hamming (hanning? I can never get them straight). Basically, if you are looking for spurs, you need to use the flat top.

Re: [time-nuts] Divide by 3

I remember when we first got a prototype 10816 Mini-Rubidium standard working. We put in on of those old paper strip chart recorders (this was circa 1981). We were pretty cocky about how it went straight down the page. You couldn't do that with quartz. When we came back the next day, you

Re: [time-nuts] Divide by 3

On 6/8/2016 9:59 AM, Charles Steinmetz wrote: You can achieve substantially lower jitter (phase noise) with a regenerative divider, which also allows you to divide by 3/2 for a 10MHz output. I've built several like that, and they work extremely well. When I was at Agilent, they developed

Re: [time-nuts] How can I generate a very clean 1 W signal @ 116 MHz ?

On 5/31/2016 3:30 AM, Dr. David Kirkby (Kirkby Microwave Ltd) wrote: Please excuse my ignorance, but how would one lock a 116 MHz 5th overtone crystal oscillator to 10 MHz with no difficulty? Do you have a circuit you share that would give low phase noise, and if so how low? If you

Re: [time-nuts] How can I generate a very clean 1 W signal @ 116 MHz ?

I'm really surprised at all the complicated solutions posted here. A 116 MHz crystal oscillator is not rocket science. Croven Crystals will sell you a custom resonator. The whole circuit is like a dozen components. Rick N6RK ___ time-nuts mailing

Re: [time-nuts] How can I generate a very clean 1 W signal @ 116 MHz ?

On 5/30/2016 4:06 AM, Dr. David Kirkby (Kirkby Microwave Ltd) wrote: I was thinking about designing a 2 m (144-146 MHz) ->HF (28-30 MHz) transverter, using a 116 MHz local oscillator feeding a level 30 mixer. 116 + 28 = 144 116 + 30 = 146 I'm wondering what's the best way to generate 116 MHz

[time-nuts] Wenzel BP-1000 phase noise measurement system

Does anyone have any experience with this system? Rick Karlquist ___ 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] Mystery hp Ovens For Sale

Len Cutler proudly displayed an HP106 in his office. It was one of the examples of Len's philosophy of making the best possible design rather than a "good enough" design. I never heard what happened to it when he passed away. Rick ___ time-nuts

Re: [time-nuts] Get together at IMS?

I'll be there all day Wednesday. I'll try to meet you guys at 5 PM. Rick Karlquist N6RK On 5/22/2016 9:06 AM, Bernd Neubig wrote: Agreed! See you on Wed at 5.00pm at Booth 714 (Dynamic Engineers) -Ursprüngliche Nachricht- Von: time-nuts [mailto:time-nuts-boun...@febo.com] Im Auftrag

Re: [time-nuts] HP5071

On 5/21/2016 11:25 AM, Attila Kinali wrote: I'd give a lot to read the design documents of the 5071. There must be a lot of knowhow and techniques in them. Read papers by me and my colleagues at the 1992 Frequency Control Symposium. There is nothing else in the public domain. What

Re: [time-nuts] GENIUS by Stephen Hawking (PBS TV),

y one (strong) person. It was great to see that this clock is still relevant as it nears its 25th birthday. Rick Karlquist N6RK ___ 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] High rate, high precision/accuracy time interval counter methods

HP/Agilent/Keysight laser interferometers measure at the kind of rates you are talking about and (last time I heard) could divide an interference fringe down to 1/512 of a wavelength. As you say, they definitely use an ASIC with a ring oscillator. Perhaps there is some way you could repurpose

Re: [time-nuts] HP OCXO warmup graphs

with 10544 oscillators. However, they are certainly mechanically compatible. It's entirely possible that a 10544 might work in a 5334B, but the factory never shipped such a configuration. Where would they get 10544's? Rick Karlquist N6RK Project Manager HP 5334B

Re: [time-nuts] HP 5360A History?

On 4/13/2016 12:28 PM, Pete Lancashire wrote: that even with a $10K price they sold, either Bill or Dave were advised to cancel the project due to its growing cost and complexity but decided to keep it going in that HP would learn about designing with logic. I have an internal HP logic design

Re: [time-nuts] HP 5360A History?

This product came out in the early '70's when I was working for Boeing. The company bought several and they were very popular. This was an amazing advance for the time, to be able to measure short term stability so easily. This was before HPIB, so you couldn't easily connect a counter to a

Re: [time-nuts] Where does the source time for GPS come from?

On 4/12/2016 3:16 PM, Michael Wouters wrote: evaluations (for accuracy) to finally get its best estimate of what one second is. Each participating lab is then told what the difference between its clock and UTC is. USNO participates in UTC and keeps within tens of ns of UTC. It might also

Re: [time-nuts] high rev isolation amps

On 3/30/2016 8:18 AM, Tim Shoppa wrote: There's a real beauty to many of the NIST designs - using topology and jellybean parts to achieve the performance, rather than selected devices. Tim N3QE If only this were true. Authors at NIST have consistently told me that the conditions of

Re: [time-nuts] high rev isolation amps

Nothing has come to my attention in the last 35 years that is superior for buffer amplifiers to the simple cascade of grounded base transistors as described by numerous NBS/NIST papers. The chain usually starts with a common emitter (with emitter degeneration resistor), which is an even older NBS

Re: [time-nuts] Spectrum Analyzer Specifications

exotic. Bob On Mar 24, 2016, at 12:25 AM, Richard (Rick) Karlquist <rich...@karlquist.com> wrote: On 3/23/2016 3:56 PM, Bob Camp wrote: and standard covered. If you want to do spurs, spend $40 and build a phase noise test set that will drive the sound card on your PC. Lots of c

Re: [time-nuts] Spectrum Analyzer Specifications

On 3/23/2016 3:56 PM, Bob Camp wrote: and standard covered. If you want to do spurs, spend $40 and build a phase noise test set that will drive the sound card on your PC. Lots of choices …. Bob Any documentation on this $40 phase noise test set? Rick N6RK

Re: [time-nuts] When does NIST change to DST?

On 3/13/2016 10:39 AM, Nick Sayer via time-nuts wrote: Our WWVB clock switched way, way early last night - like 20:00 or so (PST). but that clock hasn’t exhibited any whacky behavior as long as I can remember. Same here with my clock. Rick ___

Re: [time-nuts] quartz thermometers

Does anyone have a documented way to do this? I asked the original designers of the 10811 (Burgoon and Wilson) about this a few years ago and they couldn't remember what the circuit mods were. I got hold of their lab notebooks and it wasn't in there either. What I remember them telling me 35

Re: [time-nuts] PLL book 3rd edition

On 3/8/2016 10:11 AM, jimlux wrote: Or is subject to export controls because of the specific application. While you could probably "generalize" it to get out from under export controls, that's a lot of work. Ulrich and Rick raise interesting points: The people who really know about this

Re: [time-nuts] PLL book 3rd edition

On 3/8/2016 3:18 AM, ka2...@aol.com wrote: Good Morning, technically you are correct, most buy what they find and live with a compromise. But companies like mine, R, test equipment , need superior performance and many parts which we need, we have made by foundries. Numerically controlled

Re: [time-nuts] PLL book 3rd edition

I know for me, I mainly use the "synthesizer on a chip" IC's from Analog Devices/Hittite and National. Their data sheets and ap notes serve as the "textbook". I'm not sure there will be much call going forward for a book on fundamentals that explains how to design synthesizers from first

Re: [time-nuts] HP 10544A Repair

On 3/1/2016 4:13 AM, Bob Camp wrote: Is it worth getting it super close? Probably not without a temperature test setup. Bob Right. It is entirely possible that if you did a temperature test in an environmental chamber, you would find that you could get a better tempco by adjusting oven

Re: [time-nuts] HP 10544A Repair

On 2/28/2016 7:01 AM, Bob Camp wrote: Hi It’s not an electrical issue as much as a heat issue …. Before you start, consider that you will be doing something like: Move trimmer 1 turn CW Wait 10 minutes read frequency Move trimmer 1 turn CW wait / read Move trimer 1/2 turn CCW wait / read

Re: [time-nuts] HP 10544A Repair

If you replaced the thermistor with an exact replacement, then you shouldn't need to change the pot. If you didn't replace the thermistor with an exact replacement, then you should carefully measure the resistance of the pot as you found it. (I hope you did not fool with it already.) From the

Re: [time-nuts] HP Reliability

On 2/14/2016 11:20 AM, William H. Fite wrote: They don't wonder; they know very well. But they're stuck. Consider oscilloscopes. Why pay for a Keysight or Tectronix or LeCroy or, God forbid, a Rohde & Schwarz when, for the vast majority of applications, a Rigol will give you everything you

Re: [time-nuts] HP Reliability

A few clarifications: Before 1999, HP had a Medical Division that made equipment you saw in hospitals and a Scientific Instrument Division that made chemical analysis equipment used in medical laboratories (and also other laboratories). IIRC, both began as acquisitions. The Agilent spin off in

Re: [time-nuts] Calibration procedures - what is normal?

On 2/12/2016 12:14 PM, Joseph Gray wrote: I sent my HP 3457A in for cal. I should be getting it back next week. I won't mention where I sent it, but it wasn't Keysight (I don't like that name). I recently changed the SRAM battery and purposely did not I left Agilent just before the split, but

Re: [time-nuts] HP Equipment Running Hot as Heck...

logic analyzer model that HP engineers referred to as the "logic furnace" because it ran so hot. Rick Karlquist N6RK On 1/27/2016 4:22 PM, Burt I. Weiner wrote: Don, Something to be careful of... Be sure the mains voltage switch is set properly. I had a HP-3336A that ran hot like that. L

Re: [time-nuts] HP5370B & HP5345B Front-End IC Redesign Effort

people on time nuts are interested in this board. David was one of the best engineers in the history of the Santa Clara division and the fact that the 5370 lives on is a testimony to how far ahead of its time the design was, some 40 years ago. Rick Karlquist N6RK HP Santa Clar

Re: [time-nuts] what is acceptable harmonic content & level for a 10Mhz standard?

, the harmonics are down over 80 dB. Rick Karlquist N6RK ___ 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] low noise multiplication to 100 MHz

going to be tough to replace a 100 MHz OCXO by multiplying. You have the additional problem that 100 MHz is not a power of 2 multiplication. I think you're stuck waiting for your OCXO's. Rick Karlquist N6RK On 1/21/2016 6:43 AM, jimlux wrote: My tiny 100 MHz low noise OCXOs are unexpectedly

Re: [time-nuts] New Member + Basic Questions

, I had the chance to discuss this product with various engineers who were involved in its development. It frankly wasn't one of the better products in the line. It has a high broadband noise floor. The follow on product, the 8662, is MUCH better. No comparison. Rick Karlquist N6RK

Re: [time-nuts] Divider circuit for Rubidium Standard

for the multistage zero crossing detectors discussed on this forum many times. Rick On 1/10/2016 2:24 AM, Attila Kinali wrote: Hi Rick, On Sat, 9 Jan 2016 14:45:43 -0800 "Richard (Rick) Karlquist" <rich...@karlquist.com> wrote: This circuit is very similar to one that was champione

Re: [time-nuts] DMTD - analog multiplier vs. diode mixer ?

y were non players in terms of phase noise. I still think I would do that even if I had to do over 25 years later. Rick Karlquist N6RK ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo

Re: [time-nuts] Divider circuit for Rubidium Standard

or any other ones discussed. It's disappointing to see this published by an otherwise excellent outfit like Wenzel. The modifications make sense IMHO. I suspect that the 2N3906's are good for two reasons: the low f-t reduces noise bandwidth and the high current gain reduces noise current. Rick

Re: [time-nuts] DMTD - analog multiplier vs. diode mixer ?

-phile here :-) but it is probably the worst for phase noise, compared to the saturating logic types. Rick Karlquist N6RK ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts

Re: [time-nuts] DMTD - analog multiplier vs. diode mixer ?

n inductor. A true noiseless current source. Again no OTS IC's are designed this way. You would have to homebrew the whole mixer from discretes. Rick Karlquist N6RK ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.c

Re: [time-nuts] DMTD - analog multiplier vs. diode mixer ?

of extra noise. IMHO, they only make sense in low performance applications where the lack of transformers is important or in DC coupled applications. The only time I have used an analog multiplier IC was in Costas loop to demodulate QPSK from weather satellite. It needed to be DC coupled. Rick

Re: [time-nuts] Phase noise from Allan Deviation ?

easure flicker noise on crystals that were not installed in an oscillator, and then install them in an oscillator and the ADEV turned out to be what was predictable from the phase noise. It really works! Rick Karlquist N6RK ___ time-nuts mailing list -

Re: [time-nuts] GPSDO and oscillator steering - EFC vs DDS schemes?

ure in my 1995 paper look really attractive. The Griffin can generate any frequency, but if you only need a very narrow band of frequencies, all that capability goes to waste. Rick Karlquist N6RK (now retired from Agilent/Keysight) On 12/8/2015 8:32 AM, Attila Kinali wrote: Moin, I've been

Re: [time-nuts] Phase microstepper designs?

will make a come back :-) Rick Karlquist N6RK ___ 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] modern electronics education/jobs (was:

On 11/12/2015 1:01 PM, William Schrempp wrote: has failed. I hear old machinists complaining about new machinists who can't drill a hole if the drill-press isn't computer-controlled. And in my work, nurse education, I see students who can't be bothered to learn how to take a manual

Re: [time-nuts] Time syncing WiFi routers using FM radio

d to be centrally synchronized, as was common in the 1960's. These were not connected in any way to the "most accurate clock on the west coast" and were frequently off by several minutes and were not even consistent among themselves. So the joke was that we had both the most accurate clo

Re: [time-nuts] Low noise quartz crystal oscillator by Bruce Griffiths

Driscoll wrote a lot about oscillators over the years. I couldn't find anything specific to discontinuous operation. Do you have a titel of a paper related to this? What Driscoll was talking about was self limiting in a transistor. That is discontinuous operation, although Driscoll doesn't

Re: [time-nuts] Low noise quartz crystal oscillator by Bruce Griffiths

for minimum beta and Ft at 20 mA, which is the start up condition due to the ALC being at full gain. It has a special HP part number, so you wouldn't know this just looking at the parts list. Rick Karlquist N6RK ___ time-nuts mailing list -- time-nuts@febo.com

Re: [time-nuts] Low noise quartz crystal oscillator by Bruce Griffiths

Do you have a specific URL for "hacking oscillators"? I can't find it on Rubiola's web site. Rick On 10/28/2015 1:32 PM, Gerhard Hoffmann wrote: Am 28.10.2015 um 19:22 schrieb KA2WEU--- via time-nuts: This oscillator seems to have been more a frequency standard then a noise standard. Today's

Re: [time-nuts] Low noise quartz crystal oscillator by Bruce Griffiths

On 10/28/2015 10:38 AM, Hal Murray wrote: rich...@karlquist.com said: The 2N5179 in the 10811 is selected for minimum beta and Ft at 20 mA, which is the start up condition due to the ALC being at full gain. It has a special HP part number, so you wouldn't know this just looking at the parts

Re: [time-nuts] Low noise quartz crystal oscillator by Bruce Griffiths

On 10/26/2015 9:15 PM, Bruce Griffiths wrote: The 10811A ocxo uses an oscillator of this type albeit with a lower crystal current, an overtone crystal. However the output stages spoil the PN floor..Cascaded transformer coupled CB stages are somewhat quieter. Bruce That's right. Burgoon

Re: [time-nuts] Low noise quartz crystal oscillator by Bruce Griffiths

ase buffer stages. There are various NBS/NIST papers where several grounded base stages are cascaded. I did this in the HP 10816 rubidium standard. It is good to see time-nuts learning about oscillator circuit by building them. Rick Karlquist N6RK ___

Re: [time-nuts] 10811 unsoldered fuse

The thermal fuse plugs into pin sockets. It cannot be soldered for the obvious reason that the solder would melt it...at 109 degrees as it is marked. My suggestion would be to jumper it out of the circuit. Rick Karlquist N6RK On 10/19/2015 12:31 PM, Dimitri.p wrote: How common is it to find

Re: [time-nuts] HP Panel colors

There used to be a color at HP called mint gray FWIW. Rick On 8/13/2015 1:58 AM, tim...@timeok.it wrote: I am interested in knowing the exact name or number of the colors used by HP for the HP5065A front panels. ___ time-nuts mailing list --

Re: [time-nuts] how to find low noise transistors

OTOH, the other cure for high base spreading resistance is to simply parallel multiple devices. This avoids the bad side effects you mention. The other key noise parameter in a BJT is RF current gain, and this cannot be cured by any circuit design tricks. Rick Karlquist N6RK On 7/23/2015 8:29

Re: [time-nuts] how to find low noise transistors

On 7/24/2015 11:58 AM, Brooke Clarke wrote: Hi Charles: Does hFE (DC) have much relevance to this? Would hfe (AC) be the important one? Only insofar as DC current gain is an upper bound on AC current gain. If your operating frequency is less than f-sub-t divided by beta, then DC current

Re: [time-nuts] how to find low noise transistors

between base spreading resistance and (beta)(r-sub-e). If base spreading resistance is high, you make r-sub-e high by reducing collector current. Equation f. states that doing that will increase optimum source resistance. Rick Karlquist N6RK ___ time

Re: [time-nuts] how to find low noise transistors

yourself. Putting negative feedback around the transistor can alleviate this by reducing upconversion of noise. Rick Karlquist N6RK ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts

Re: [time-nuts] Close in phase noise of microwave VCOs

On 6/20/2015 6:25 AM, Jim Lux wrote: This makes a good case for the 30dB/decade very close in Somewhat had asked about how close in the 30 dB/decade is good for. There is a reference about this issue. The book Edson: Vacuum Tube Oscillators has what I believe is the first published

Re: [time-nuts] Close in phase noise of microwave VCOs

On 6/20/2015 1:16 PM, Alex Pummer wrote: Actually a YIG, even standalone has very good phase noise performance, as long as the tuning current is quite, once upon the time HP made some cheaper version of the 856x-es spectrum analyzers [ perhaps that was the 95xx ] they had the first LO just

Re: [time-nuts] Close in phase noise of microwave VCOs

On 6/17/2015 11:36 PM, Attila Kinali wrote: Do you have any recomendation, where an ordinary engineer could read up on this topic? Attila Kinali There is always Floyd Gardners, Phase Lock Techniques. However, a better tutorial would be the one written by HP's Dieter

Re: [time-nuts] Close in phase noise of microwave VCOs

On 6/18/2015 1:20 PM, Magnus Danielson wrote: The trick is to convert the 2nd degree loop to a 3rd degree loop, which then allows for a 12 dB/oct slope, to counteract the 9 dB/oct slope. No this is not correct. A very conventional Type 2 loop, where the loop filter consists of an integrator

Re: [time-nuts] Close in phase noise of microwave VCOs

, and even magnetic fields from power transformers, as well as load pulling and thermal drift. Making microwave oscillators that can be used open loop (especially inexpensive ones) is definitely a lost art. It died with the HP8640 sig gen. Rick Karlquist N6RK

Re: [time-nuts] Close in phase noise of microwave VCOs

On 6/17/2015 8:22 AM, Jim Lux wrote: I'm looking for some representative data for inexpensive microwave VCOs (in the 2.5-6 GHz range, in general). Not in a locked loop situation, If you are working up to 2.5 GHz, you can get a low power chip for $2 from Analog Devices that has a VCO and

Re: [time-nuts] Modulation Domain Analysis

That's interesting. I worked for the HP Santa Clara Division from 1979 until just before it was closed in 1998. I forget who invented MDA at SCD, but it was hyped like it was some new concept and I never heard anything about the HP9540. Many times someone would come to me and ask me about some

Re: [time-nuts] Using CPLD/FPGA or similar for frequency divider

The counter only had to run at ~50 MHz, on account of our mode locked laser ran at that frequency. I don't remember what the CPLD was rated at. Rick On 6/5/2015 8:19 PM, Hal Murray wrote: rich...@karlquist.com said: I used a CPLD in a 900 GHz (that's right 900 GHz) optical sampling scope

Re: [time-nuts] Using CPLD/FPGA or similar for frequency divider

ahead carry, etc. I cleaned up the timing with conventional logic, so I don't know what the jitter of the CPLD was. We needed jitter in the low fs, so I am sure the CPLD was not OK without cleaning up, but then that was a lunatic fringe project. Rick Karlquist N6RK On 6/2/2015 6:13 AM, David C

Re: [time-nuts] Nature: Hyper-precise atomic clocks face off to redefine time

and Boulder (~5000 feet). Rick Karlquist N6RK On 6/3/2015 12:18 AM, Hal Murray wrote: Nice picture: A strontium-ion optical clock housed at the National Physical Laboratory in Teddington, UK. Over the past decade, various laboratories have created prototype optical atomic clocks, which use

Re: [time-nuts] Divider circuit for Rubidium Standard

to square up 80 MHz for the DDS board. You are exactly right: put in a huge sinewave obtained by good old fashioned analog anplifiers and let the 74AC do its thing. 80 MHz is pretty much flat out for a 74AC series. The 80 MHz came from a 10 to 80 MHz multiplier running from the 10811. Rick

Re: [time-nuts] Divider circuit for Rubidium Standard

as squarers are not as bad as comparators, but are much noisier than 74AC. Rick Karlquist N6RK Rick Karlquist N6RK ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow

Re: [time-nuts] Divider circuit for Rubidium Standard

On 5/8/2015 2:19 PM, Bob Camp wrote: On May 7, 2015, at 11:09 AM, Attila Kinali att...@kinali.ch wrote: On Wed, 06 May 2015 18:09:03 -0700 Richard (Rick) Karlquist rich...@karlquist.com wrote: A standard input on a frequency counter is not a very demanding thing in the hierarchy

Re: [time-nuts] Divider circuit for Rubidium Standard

On 5/6/2015 3:24 PM, Bob Camp wrote: Hi A standard input on a frequency counter is not a very demanding thing in the hierarchy of TimeNut signals. You can drive any of them with some pretty simple logic gate based circuits. No need to spend a lot of money. Bob Logic gate, yes.

Re: [time-nuts] Divider circuit for Rubidium Standard

circuit. This will give you worse performance than just about anything else, but it may be good enough anyway. Rick Karlquist N6RK ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts

[time-nuts] OT: PDF editing (was: Re: Ultra High Stability Time Base Options for 53132A)

On 5/4/2015 5:25 PM, J. L. Trantham wrote: Charles, Thanks for the help. I need to learn how to add text to .PDF documents. Go to: www.tracker-software.com and download (for free): PDF-Xchange viewer. Rick Karlquist N6RK ___ time-nuts

Re: [time-nuts] HP5328A HP5328B option 040

HP also sold voltmeters, they could always buy a voltmeter from our voltmeter division. There are a bunch of reasons why the 5328B would lose a feature that the 5328A had, but the point is that this doesn't break any rule. Rick Karlquist N6RK ___ time

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