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FWIW I bought an 8648C w/ opt 1E5 for under $1k delivered. Very nice clean instrument which should meet most or all of my needs.

I also received an email from AD today which might be relevant. They have a new part in volume production, the ADF4371. I'm sure there is a significant amount of programming required to turn this into a bench instrument. But the eval board set is under $1K and the specs are *very* impressive. It's clearly worth a close look if you want to go above 4 GHz.

I have been stunned at what you can buy now in the form of an OEM eval board. If you require a broad range of capability, a commercial instrument is generally a better choice. But if you need to do a narrow range of tasks and are competent writing software You can get the same performance for 10% or less of the price. That's pretty cool in my book.

Reg

On Thu, Mar 21, 2019 at 05:09 PM, Reginald Beardsley wrote:

You can get the same performance for 10% or less of the price. That's pretty cool in my book.

That is awesome definitely.? Especially, even more exiting is if a decent board can be made in an even more cost effective module even without all the features like has been done with the older AD chips that can be bought really cost effectively on eBay.?

Reminds me of a great presentation of an application of the ADF4355.? ?

I'll have to look into what the ADF4371 upgrade modularized system looks like sometime... with mixing and harmonics filtering... seems like wow!? Way cool!?

On Thu, Mar 21, 2019 at 11:21 PM, jafinch78 . wrote:

even more exiting is if a decent board

Entry error typo due to excitement: "...even more exciting is if a decent board..."??

My initial awareness of the AD eval boards was through a QEX feature article about a 16 bit 100 MHz BW direct sampling SDR built using an AD eval board and a Zed board for ~$1K BoM.

I signed up to get ADs email PR releases and have been blown away by what they are making.

Someone on EEVblog did an extensive evaluation of a Chinese board with a very nice AD part. Unfortunately, I don't recall the part. But the conclusion was the board was crap. I am hoping someone will do some OSHW designs so one is not at the mercy of the Chinese. A set of Gerbers would be fantastic.

Take a look at this part:



Owon is using it in the XDS2102A which is available on Amazon for $400 delivered. The aesthetics and UI are terrible, but it will collect 20 Mpts of 12 bit data at 500 MSa/s. The part is $80 in 100+ and $111 in singles.

I'm working on developing a FOSS DSO FW stack for Zynq and Cyclone V parts. I have *no* FPGA experience and it is quite different from DSP on a general purpose CPU. So lots to learn before it's complete. I just started reading "VLSI DSP Systems" by K.K. Parhi. The EE lexicon is very different from the geophysical lexicon, but except for minor notational differences the math is familiar. My primary concern is word length effects. In seismic we just switch to double precision if word length is an issue.

Because memory BW is critical to seismic DSP you are forced to deal with the CPU at register transfer level to get good performance. So my main concern about doing the work is the quality of Vivado and Quartus. I have lots of scars from $100K/seat exploration software.

A bit off topic, but we are all T&M junkies around here.

On 3/22/19 7:08 AM, Reginald Beardsley via Groups.Io wrote:

I am hoping someone will do some OSHW designs so one is not at the mercy of the Chinese. A set of Gerbers would be fantastic.
Take a look at this part:

Owon is using it in the XDS2102A which is available on Amazon for $400 delivered. The aesthetics and UI are terrible, but it will collect 20 Mpts of 12 bit data at 500 MSa/s. The part is $80 in 100+ and $111 in singles.

I can make a board layout with open editing tools -- I have even used my own footprint for QFN48 packages with good results fabbing. Anyone else on the list interested in supporting that effort with cash up front?

I'm working on developing a FOSS DSO FW stack for Zynq and Cyclone V parts. I have*no* FPGA experience and it is quite different from DSP on a general purpose CPU.

So, is the Zynq and Cyclone V plan using the HMCAD1520 also?

The Zynq and Cyclone effort is aimed at hijacking COTS DSOs. I'm skeptical that one can build HW to the same price point. The motivation is I'm fed up with crappy FW. Even at $20K the FW is crap on the Keysight and R&S instruments I've tried. The only reason I ever looked at those was a 1/2 price deal from Keysight on demo units with full warranty, etc on an MSOX3104T.

The logic behind this is fairly simple. With the low parts count, there are simply not very many possible choices for connecting the ADC to the FPGA. And with the ARM cores one should be able to do a lot of snooping by installing some additional software.

I'd love to have an SMA input HMCAD1520 in a shielded box with PMOD connectors for connecting to a Zybo Z7-20.

A primary goal of mine is to be able to do stackable math operations on the live data the way the LeCroy DDA-125/LC684DLX does.

If you design a board I'll certainly buy a couple boards cash up front.

Is an extender card a fairly simple task? I want one for my Tek 11801 so I can service it and more particularly so I can investigate replacing the 1.4 ps jitter timebase clock with a sub ps chip. There is no component level information on the scope, so the only option is to probe it with my DDA-125 using a GPSDO reference input. My thinking is to make a small board with the new clock ], locate the clock lines, cut the traces and hook in the new chip.

The 11801 has been very difficult to find data for. I finally found an original user manual and service manual on eBay. Everything online was for later variants and clearly different from what I have. I've asked about an extender card on TekScopes, but nothing useful has come up yet.