modern oscilloscopes

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https://dl.dropbox.com/u/53724080/SED/LeCrash.JPG


--  

John Larkin         Highland Technology, Inc

jlarkin at highlandtechnology dot com
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Re: modern oscilloscopes
On 2/13/2013 7:05 PM, John Larkin wrote:
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So was there a solution available?

Re: modern oscilloscopes
On Wed, 13 Feb 2013 19:51:00 -0500, bitrex

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Of course. Reboot Windows.


--  

John Larkin         Highland Technology, Inc

jlarkin at highlandtechnology dot com
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Re: modern oscilloscopes

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My Agilent has yet to crash.  I think it's windows CE.

Cheers
  



Re: modern oscilloscopes
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our agilent network analyser is winxp, first time I plugged a
network cable it started the usual windows song,
updates available computer may be at risk , old virus definitions
etc.


-Lasse


Re: modern oscilloscopes
On Wed, 13 Feb 2013 16:56:42 -0800, the renowned John Larkin

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The Tek logic analyzer runs Windows 2000. I had to boot it with a
Linux disk to remove a password that someone installed and forgot..  


Best regards,  
Spehro Pefhany
--  
"it's the network..."                          "The Journey is the reward"
snipped-for-privacy@interlog.com             Info for manufacturers: http://www.trexon.com
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Re: modern oscilloscopes
bitrex wrote:
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   Rigol.
   Linux.


Re: modern oscilloscopes
John Larkin wrote:
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oops.

Jamie


Re: modern oscilloscopes
I have no problems with that.
http://www.seventransistorlabs.com/Images/Tek475_7.jpg

Well,,,

Tim

--  
Deep Friar: a very philosophical monk.
Website: http://seventransistorlabs.com

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Re: modern oscilloscopes
wrote:

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The LeCroy is 4-channels, 6 GHz, 20 Gs/s per channel. It does differential PCI
Express eye diagrams without a trigger, and I mean without *any* trigger.

We eval'd a couple of digital scopes, this one and a 4 GHz Rohde & Schwarz. Both
have a fair amount of ringing on a step or impulse input. Remember when scopes
had beautiful gaussian step response? No more; you can claim another 10% or so
bandwidth in your ads if you peak it up and let it ring.


--  

John Larkin                  Highland Technology Inc
www.highlandtechnology.com   jlarkin at highlandtechnology dot com    

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Re: modern oscilloscopes
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Avalanche pulse into the 475 was always a nice sharp spike more-or-less at  
rated bandwidth (i.e., 2ns across).

My "new" TDS460, (unrelated waveforms)
http://www.seventransistorlabs.com/Images/DCDC_2.jpg
does just the same, except it shows a taller and narrower spike.  Of  
course, with equivalent time sampling, I can crank the timebase up way  
past anything a CRT can do, so it isn't really "narrow" any more.  Think I  
still need another factor of 2 or 4 to see the true form of the spike,  
which isn't bad at all for a 2N3904.
http://www.seventransistorlabs.com/Images/AvalancheGen.jpg

The trigger on the TDS460 is interesting.  It seems to group towards the  
end of a signal burst, as if to emphasize the conditions that occured  
during a loss of signal or something like that.  Not sure just yet how  
they accomplished that, or if it's more or less handy.  It seems to  
produce very stable displays, even in the presence of additive line  
ripple, which is something the newer Teks don't even do.

Tim

--  
Deep Friar: a very philosophical monk.
Website: http://seventransistorlabs.com



Re: modern oscilloscopes [use Wavelet-scaling base functions]
On 14/02/13 04.03, John Larkin wrote:
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...

Hi John

It is probably because that the DAC+lowpass filter use 1/x envelope  
compact supported ortogonal sinc-sampling base functions:
http://en.wikipedia.org/wiki/Sinc_function

Please note that convolution of a signal with a sampling function - is  
equivalent to filter a signal with an appropriate lowpass filter -  
hereafter you can sample at regular intervals and send the sample to a DAC.

A better sampling is with Wavelet-scaling base functions - many  
biortogonal og ortogonal Wavelet-scaling functions exists. There exist  
Wavelet-scaling functions that is exponentially mathematically compact  
supported in both the time and frequency function space:


Moving at Wavelet speed:
Wavelet modulation can help squeeze more out of existing networks:
http://web.archive.org/web/20020612210638/www.cedmagazine.com/ced/2001/0601/06g1.htm
Quote: "...
Figure 1: Steep stop-bands
...
The stop-band of Wavelet modulation is in excess of 40 dB than the  
stop-band of Fourier-based modulation techniques such as DMT and OFDM  
[implicitly using sinc-functions!]. This property provides many  
advantages over existing modulation techniques:
...
* Greater resistance to noise and interference opens up the whole pipe:  
only noise directly in the sub-band is of issue
* Easier equalization: equalization only need cover the sub-band
* Longer symbol time greatly increases microreflection immunity
* Less-noise polluting: wasted side band energy is not emitted
* Excellent separation and isolation of sub-bands
* No need for external filters.
...
The data rate of a downstream wavelet channel is 170 Mbps, equivalent to  
1024 QAM or 10 bit per Hertz per second modulation density.
..."

-

Wavelets 101 - Wavelets for Dummies (Non-Mathematicians):
http://web.archive.org/web/20020218141428/www.rainmakertechnologies.com/tech/WaveletU_101.html

Wavelets 201 - QAM OFDM Wavelets - A Relative Performance Comparison:
http://web.archive.org/web/20020626180705/www.rainmakertechnologies.com/tech/WaveletU_201.html
Quote: "...
Comparison Table
..."


-

INTRA overview:
http://web.archive.org/web/20020815081947/www.rainmakertechnologies.com/tech_archives/tech_doc_int_ovr.html
Quote: "...
The modem modulation method called INTRA (INformation TRAnsformations)  
is based on Wavelet Theory. With INTRA, the data-rate for networks can  
be increased by a factor of 2 to 4 over the current state-of-the-art for  
LANs and MANs based on simulations. INTRA modems can achieve this  
remarkable performance at very low cost.
...
The receiver for one channel is shown as a Surface Acoustic Wave Filter  
(SAW) followed by one comparator. There is no A/D converter or DSP in  
this INTRA receiver.
...
Each wavelet extends over several symbol [= a Wavelet scaling function  
sample] periods. If the wavelets are orthogonal they are uncorrelated so  
there is no interference from other wavelets. Thus there is no  
Inter-Symbol Interference (ISI) and no Adjacent-Channel Interference  
(ACI). Wavelets can be generated and received by matched transversal  
(FIR) digital filters. Simulations show this all-digital design has no  
spurious response.
...
The correlation process-gain of INTRA provides an inherent immunity to  
interference that is comparable to the jamming rejection of a  
conventional spread spectrum system, except that INTRA does not spread  
the spectrum. Conventional spread-spectrum wastes bandwidth in order to  
obtain this immunity to interference. INTRA does not expand the  
bandwidth with a spreading function --- in fact, INTRA spectra can  
overlap due to the properties of wavelets so it is more bandwidth  
efficient than any other modulation. INTRA's immunity to interference  
comes by spreading symbols in time rather than frequency, and since the  
time waveforms of wavelets can also overlap there is no penalty in  
data-rate.
..."

Tech archives INTRA Introduction:
http://web.archive.org/web/20021021013925/www.rainmakertechnologies.com/tech_archives/tech_doc_int_int.html
Quote: "...
Figure 1
...
[Instead of a comparator use use a flash-DAC - then you have a Wavelet  
scaling function sampled the analog signal:]
In the illustration, the receiver uses an analog SAW filter and  
comparator to correlate the received waveform with the known wavelet  
shape. Here the sign of the correlation determines if a 1 or a 0 was  
received.
..."

http://web.archive.org/web/20021021014520/www.rainmakertechnologies.com/tech_archives/tech_doc_int_p1.html
Quote: "...
The receiver's matrices contain the time-reversed wavelets so that the  
receiver's vector-filter computes the correlation between each  
orthogonal wavelet and the received signal to recover the DATA vectors.  
This is in fact the textbook form of an optimal MAP (Maximum Apriori  
Probability) receiver. Not only is INTRA an optimum receiver in this MAP  
sense, but it also has the following six very powerful features:

1. It can be self-equalizing by applying any adaptive equalization  
algorithm (i.e. LMS) to the vector filter matrices in the same manner as  
FSE.

2. Interference is suppressed, since the symbols are recovered by  
correlation.

3. FIR vector filtering (Tx or Rx) can be done in the analog domain with  
SAWs or CCDs, so no D/A or A/D converter or DSP is required at high rates.

4. Fractional bits per vector coordinate can be assigned according to SNR.

5. Since vector-filtering is a convolutional modulation, a receiver  
Viterbi Algorithm might provide error-correction without sending parity  
at the transmitter. (This is a potential theoretical breakthrough since  
conventional Trellis Coded 6.Modulation (TCM) sends parity, which wastes  
transmitted entropy and therefore lowers the potential data rate near  
the Shannon Limit.)

6. Vector-filters can be used for compression-less networking, a new  
concept described in PART 2.
..."



Technology Frequently Asked Questions:
http://web.archive.org/web/20021210004156/www.rainmakertechnologies.com/tech_archives/tech_faq.html
Quote: "...
Rainmaker Technologies? Wavelet modulation for CATV cable modems has  
zero computational complexity in both the transmitter and receiver.
...
Q7. Does Rainmaker?s equalization method provide immunity to upstream  
interference?

A. While equalization helps, immunity to interference is an intrinsic  
feature of Rainmaker Technologies? wavelet modulation due to the gain  
realized during the receiver?s correlation processing.
...
Q14. Does Rainmaker recommend interleaved block codes for Forward Error  
Correction Coding?

A. This may not be necessary because Rainmaker Technologies? solution  
has correlation processing gain.
...
Q15. Can Rainmaker provide more details about immunity to RF Interference?

A. Rainmaker Technologies? wavelet cable modem is immune to interference  
in the sense that the error rate is still good. Rainmaker Technologies?  
solution doesn't look at individual samples. Instead, it compares wave  
shapes (correlates) over many samples for each symbol. It suppresses  
interference because non-Gaussian interference doesn't have the same  
wave shape as a wavelet. Rainmaker Technologies? solution has a gain in  
Signal-to-Interference Ratio (SIR) in the receiver.
...
Q16. What else can Rainmaker Technologies? wavelet modulation do?

A. Calculations show that Rainmaker Technologies? solution should  
dramatically improve the data rate of wireless and twisted pair links  
compared to the current state-of-the-art.
..."

/Glenn

Re: modern oscilloscopes [use Wavelet-scaling base functions]

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scopes
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so
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DAC? What DAC?


--  

John Larkin         Highland Technology, Inc

jlarkin at highlandtechnology dot com
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Re: modern oscilloscopes [use Wavelet-scaling base functions]

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Hey John,

When you changed out the flash memory in the SD-24 sampling head what did  
you need to do to initialize the new memory?

Thanks,
tm  


Re: modern oscilloscopes [use Wavelet-scaling base functions]
wrote:

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We copied the data from a good flash chip from another head, before we
installed it.  

https://dl.dropbox.com/u/53724080/SD-24/SD24_2.JPG

I think we hacked in a socket, too.





--  

John Larkin         Highland Technology, Inc

jlarkin at highlandtechnology dot com
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Re: modern oscilloscopes [use Wavelet-scaling base functions]

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Do you still have the image and can you still program those devices? I have  
a sampler with a bad flash.

Thanks



Re: modern oscilloscopes [use Wavelet-scaling base functions]
wrote:

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I think we have the image, and I could always pull the one that's
socketed... if I can figure out which one it is. I'll ask Jonathan; he
actually did it.

Our B&K USB programmer can read and write these things.


--  

John Larkin         Highland Technology, Inc

jlarkin at highlandtechnology dot com
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Re: modern oscilloscopes [use Wavelet-scaling base functions]

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tm,

It's a 93C46.
Give this one a try: https://home.comcast.net/~spam_gobbler/SD24.bin

Re: modern oscilloscopes [use Wavelet-scaling base functions]

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Thanks JW. Strange but that bin file is only 128 bytes. The 93C46 is a 1k  
device, right? I think the biggest problem with changing the chip is the  
self test fails on a bad check sum then everything halts. Hopefully John can  
burn one for me sometime.

I did find some parts on ebay and have ordered some. Meantime, I will  
install a good machined pin socket.

Regards,
tm


Re: modern oscilloscopes [use Wavelet-scaling base functions]

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Yup it's 1Kb, not 1KB. So 128 bytes is correct. The one I posted will get
rid of your checksum error, but I think the cal constants may be stored in
there as well, perhaps John may know better. Anyway If John can't program
it for you, just give me a shout on the Tekscopes list and we can set
something up...



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