Hi Win,
I looked at the page source and while there is javascript, I see no java apps. Are you sure (ducking) that this is a JAVA issue and not a problem with javascript?
Just asking...
John ;-#)#
All I know is I changed FireFox first, but had to experiment with different versions of Java before having success. I'll try to find time for more experiments, but it'd be nice if someone else could help out. Now only have 9 days left to add stuff to the book, wanted to get some more measurements.
--
Thanks,
- Win
At this point I'd be asking on the mozilla FireFox support forum for assistance. I don't have a windows machine so can't duplicate your environment.
Good hunting!
John :-#)#
I think you are misunderstanding the issue, it is not the tek site that is the problem, it is the webpage running on the instrument that fails with a java issue
You are correct, I did not read the content correctly.
Opps.
John :-#(#
s NPAPI,
And none of
refox_Extensions
the
y
ava
lem
ox
t
I assume Win saw this discussion on forum.tek.com regarding the issue and a possible solution:
----- Re: TSP Express Unable to Launch
Java 8 and newer browsers do not work. Here's what still works...
32-bit browser Firefox ESR (latest version is now 60). Internet Explorer 11.Java Runtime (jre) (32-bit) In addition to one of the above 32-bit browsers, you will also need
32-bit java runtime. Java runtime (x86)versions 6 and 7 both still work. Once java runtime is installed, you need to enable the add-in from your browser. Top----- Re: TSP Express Unable to Launch
You can try delete cache or just run from Java control panel. (images)
-----
Sorry about making the stupid assumption previously...
John :-#(#
Yes, it was Stuart M's answer: to use 32-bit Firefox and 32-bit Java Runtime (jre). But not all 32-bit versions worked, I experimented to find a working set. Once the machine's Java app, in a working Firefox and with a working Java, it didn't try to call Keithley.
--
Thanks,
- Win
Winfield Hill wrote in news:qfqlqh0r3 @drn.newsguy.com:
I'd bet that the reason is that that particular 64 bit java & firefox was default IPV6 and your ISP does not pass the call, hence the rejection.
IPV4 is 32 bit.
So, if you exploreed the setting in the 64 bit version and blocked IPV6 connect hooks, it would fall back to IPV4 and work.
The reason it works now is because 32 bit java is IPV4 only.
I experienced a similar problem 4 years ago and that fixed it.
Seeing the particulars of your problem in this thread and the solution that "worked", I'd almost bet it would work on the 64 bit set if the jave jre setting was changed.
Just to be consistent, all the techniques discussed here measure voltage. You can convert voltage to power with the equation P = E^2/R, but the resulting equations are awkward. From Mogami:
The defining equation for decibels is
A = 10*log10(P2/P1) (dB)
where P1 is the power being measured, and P1 is the reference to which P2 is being compared.
To convert from decibel measure back to power ratio:
P2/P1 = 10^(A/10)
Voltage is more easily measured than power, making it generally more convenient to use:
A = 20*log10(V2/V1) (Z2 == Z1)
The equation for obtaining voltage ratio from dB is
V2/V1 = 10^(A/20)
There are no VNAs with 0.01dB accuracy. An ADC cannot give 0.01dB over a wide range of input signals. A log converter may be able to approach 0.1dB over a wide range of signals if properly calibrated.
The ripple is minimal. You can calibrate it out.
The AD8307 is not trimmed. There are many other factors that determine the log conformity. These can all be calibrated out, providing you can find an accurate step attenuator.
There are no VNAs with an accuracy of 0.01dB. Most are 0.1 to 0.2dB over a very limited amplitude range. The HP 8753D has an uncertainty around 0.1dB from 0 to -60dB, rising rapidly to 5dB at -100dB
You have return loss backwards.
"Return loss is a measure of how well devices or lines are matched.
A match is good if the return loss is high. A high return loss is desirable and results in a lower insertion loss. Return loss is used in modern practice in preference to SWR because it has better resolution for small values of reflected wave."
You want a high return loss. When you are working with 30-40dB return loss, 0.1db accuracy is not important. If you are working with 6dB return loss, half your power is wasted. You have to fix it, so 0.1dB accuracy is meaningless.
You have already calibrated the ripple out. And you are not subtracting two fairly large signals.
Measure the temperature and add a correction factor.
The log converter works at a fixed frequency.
[...]
For example, a 24 bit ADC has a dynamic range of about 100dB, or a ratio of 10**(100/20) = 100,000. That corresponds to 2**17 =
131,072, so the bottom 7 bits of the ADC are just noise and can be thrown away.So let's see what resolution can be obtained at full signal. One bit is 20 * Log(100001/100000) = 8.685e-5dB. That is pretty good. But a VNA has to work over a wide range of amplitudes.
Now let's try 60 db down. That is 1/1000 of the original, which is
100000/1000 = 100. One bit is 20 * Log(101/100) = 8.642e-2dB, or 0.08642dB.So we haven't reached -60dB, and you have already blown your 0.01dB goal.
The reason the log converter is so much better is because it distributes the entire dynamic range over a series of identical stages. Each stage has to carry only a small part of the dynamic range, then it transfers the load to the next stage.
It is much easier to get a single stage to function well over a small range, than to try to do it all in one swoop, like the ADC approach.
And guess what! Some parts of a VNA and a spectrum analyzer are very similar. So if you can get a VNA to work well, you have already made a good section of a spectrum analyzer. You will, of course, want wider frequency range, better image rejection, lower spurs, better bandwidth control, and so on.
Or make it a modular approach and switch the needed sections to whichever function in use at the moment. But keep these things in mind as you develop your plans.
Comments and corrections are welcome.
[...]Steve Wilson wrote in news:XnsAA8519102E8F3idtokenpost@
69.16.179.23:
Shouldn't that be "devices AND their connection lines"?
I mean doesn't the transmission line become part of the entire output transducer and its impedance and return loss.
ie from the "output jack all the way to the tip of the antenna".
AD8302 has a phase output, and relative amplitude. They only work if the two input signals are within 30dB of each other, so not good for a VNA with anything like a useful dynamic range (without PGAs ahead anyhow).
Clifford Heath
The AD8302 has only 60dB log range. Useless for VNA applicaations. There are much better devices available.
I apologise, the first one I looked up was 0.04dB at best:
This depends on what you mean by "wide".
Yes, but calibrating it requires for example a stepped attenuator, with fine steps known to be more accurate than that. I'm not saying you couldn't make such an attenuator, but you'd probably need a good VNA to calibrate that attenuator. So you might as well just use the good VNA that you already had, and if it came from any of the leading VNA manufacturers, it won't use a log-amp inside.
By the way, did you know that the phase shift of log amps (the ones with an output that you can measure the phase of) varies with the input amplitude? Figuring out how to calibrate that out really well ... you could use a good VNA!
Minimal, but not good enough to compete with alternative solutions. You can indeed calibrate it out, but that is harder than alternative solutions.
Haha, yes, and all you need to make one of those is a good VNA!
I did once design a transmitter with a 2GHz stepped attenuator to control the output power, and we trimmed the prototypes of those with an Agilent PSA. It had no trouble correcting the attenuator steps to within
0.03dB. I expect it could have measured it much more accurately, but I didn't put in enough resolution into the chip to correct it better than that, as there was no need. By the way, like most modern spectrum analysers, the PSA uses an ADC, not a log-amp, to measure amplitude.Ok point taken, commercially available VNAs are typically not good to
0.01dB, but bearing in mind the age of the 8753, one would hope to do better than 0.1dB these days, and starting with a log-amp is not the easy way to do that. [snip] Yes, please omit / add minus sign as appropriate. I think anyone familiar with actually measuring it will know what I meant.True, but my point was, that sometimes there is no option to avoid using a test fixture with cables, and that might have significant loss between the VNA and your device. And sometimes the connector on your cable will have worse than 20dB return loss (so mag(S11)>-20dB for clarity!), right at the VNA port. Potentially, the signal into the receiver that measures reflected power will be mostly from the imperfections in the connectors, and only a very small change in the signal reaching the receiver will depend on the device under test. So, even to measure the 30-40dB return loss with an uncertainty of 1dB will require much better than 1dB accuracy (when measuring differces in power levels) in the receiver inside the VNA.
If you are making something by the million a week, and if the cheapest way to make it results in a 6dB return loss, and it works, and if your customer will happily pay for that but they won't pay for 5.5dB, then you'd better measure it, and you won't want to waste much of your margin on crappy test gear.
Only with heroic effort.
Sometimes you are. You could make a specialised VNA that can only measure certain amplitudes, but I wouldn't want one. When you compute A/R, for certain magnitudes of A/R the ripples will all line up and everything will be nice, but for other magnitudes of A/R they will not line up and it will not be so nice.
You can do that, but it is not a single factor. Every hump and wobble of the transfer function could move sideways, get deeper or shallower etc.
I'm not saying you can't do it, I'm just saying that I wouldn't want to.
Ok, it was not clear to me that you had realised that you need a mixer.
Ok, now it is clear to me that you do realise that you need a mixer.
Commercial VNAs use more than one ADC sample to estimate the amplitude. If you do that, and if there is some noise (or deliberately-added dither) then you can measure signals rather smaller than the least significant bit of the converter.
It is interesting to see how they did it in the old HP instruments, and to imagine how much better you could do with modern components:
Yet none of the best VNAs use one.
As I mentioned above, even spectrum analysers, that in the olden days did use log amps, nowadays use ADCs to measure the IF instead. Even if you don't care about being able to demodulate fancy digital signals, and don't care about getting rid of the log conformity errors of log amps, there are other advantages:
The main problem I see with trying to make a combined spectrum analyser and VNA is that the requirements are conflicting: You care a lot about rejecting arbitrary unwanted frequencies in a spectrum analyser, so usually you will want a tracking YIG filter as a preselector, or always up-convert to a first IF higher than your highest supported input frequency. Both of these approaches are likely to make the response drift (especially in phase) more than you would want for a VNA, where you don't need the preselection filter because the only large signals present are from the VNA itself. Also, the spectrum analyser needs a good input attenuator with lots of range, whereas you could probably get away with little or no built-in facility for input attenuation on a VNA. Also any decent VNA should have 4 receivers at least (two per port, and at least 2 ports), yet all but one of these would be wasted in the spectrum analyser mode.
I say build two separate instruments, and optimise each one properly.
Maybe, but the point was, with a proper browser calling a proper Java to execute the Java code (after doing the simple stuff with Javascript), no web call is made. Had the web call gone through, it still wouldn't have worked, because when I finally did get that far, all I got was a message from Tek, in the instrument-action screen, saying to setup a ticket, which I did, but heard nothing back.
There is no web access at all going on now.
--
Thanks,
- Win
Winfield Hill wrote in news: snipped-for-privacy@drn.newsguy.com:
You keep saying 'proper'. As I said, the SETTING in the 64 bit jave jre version is the problem. With the setting right, it works. whether it makes an internet call or not.
So maybe it is a 32 bit only thing for an older instrument not hitting the web as you say. Maybe it will not even run the 64 bit implementations.
But it has been an IPV6 problem in the past and IPV6 is not fully embraced by the most important element... the ISP.
It is more secure so should be implemented all over the place, but apparently got neglected because those ISPs felt that "what we have works" Not broke don't fix. Where in fact, if they are too lazy to set it up right, *they* are the broke part.
OK, I'll try to find time to try that, thanks.
--
Thanks,
- Win
Great idea, but since I normally run my SMUs from their front panels, I have no idea when it happened, some time in the last five years, maybe. I'm even not 100% sure on which of my computers I last had successful operation.
--
Thanks,
- Win
Long ago I calibrated a DLVA/digitizer combination to about 12 bits using the ring-down of a crystal oscillator. You have to drive the crystal gently enough that there are no significant nonlinear loss contributions, and take the oscillator part out of the circuit during the ring-down. I used PIN diode switches, but nowadays I'd probably use a pHEMT for that job.
A garden-variety 80-MHz crystal will ring down by about 1 dB/ms, which is a very convenient rate.
Cheers
Phil Hobbs
-- Dr Philip C D Hobbs Principal Consultant ElectroOptical Innovations LLC / Hobbs ElectroOptics Optics, Electro-optics, Photonics, Analog Electronics Briarcliff Manor NY 10510 http://electrooptical.net http://hobbs-eo.com
Aren't you measuring Q?
Lecture 21: Decay of Resonances
It would seem you have to measure at a much higher frequency than the crystal to get an accurate indication of the ringdown. This may mean sampling at several hundred MHz. Was there accurate samplers available then? 12 bits is one part in 4096, or 0.00212dB per bit.
Why not use a precision step attenuator? HP has been checking precision step attenuators for a long time. A graph on page 12 shows +/- 0.004dB error at 60dB and 30MHz:
Calibration of Precision Step Attenuators
It would appear you were beating HP with your method. That is quite some achievement!
I didn't have one in the drawer, and there was no budget for it. Plus I'd have had to be super careful about return loss and so forth. My scheme did the calibration effectively with the DUT attached, so all that stuff cancelled out.
I built a 60-MHz amplitude/phase digitizer as part of my interferometric confocal microscope back in my mid-twenties. The calibrator was a lot more complicated than the digitizer--it had two sources whose relative phase could be walked in 1-degree steps via a pulse-swallowing counter, and the aforementioned crystal ring-down amplitude calibrator. The digitizers ran at 50 kS/s, so 1-dB per millisecond was a very convenient number for calibrating.
The microscope is discussed in
and the amplitude/phase digitizer is at .
I needed to get some data so I could graduate, so I didn't build yet another calibrator to check the first one, but the gizmo was pretty stable considering what it was, and the deconvolution algorithm worked very nicely--the data came out very smooth even on very small scales.
Cheers
Phil Hobbs
-- Dr Philip C D Hobbs Principal Consultant ElectroOptical Innovations LLC / Hobbs ElectroOptics Optics, Electro-optics, Photonics, Analog Electronics Briarcliff Manor NY 10510 http://electrooptical.net http://hobbs-eo.com
ElectronDepot website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.