Turn your Rigol DS1052E Oscilloscope into a 100MHz DS1102E
in [Design]
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From: Nico Coesel on 6 Apr 2010 18:54 John Larkin <jjlarkin(a)highNOTlandTHIStechnologyPART.com> wrote: >On Mon, 05 Apr 2010 21:08:34 GMT, nico(a)puntnl.niks (Nico Coesel) >wrote: > >>John Larkin <jjlarkin(a)highNOTlandTHIStechnologyPART.com> wrote: >> >>>On Mon, 05 Apr 2010 14:30:50 -0400, Phil Hobbs >>><pcdhSpamMeSenseless(a)electrooptical.net> wrote: >>> >>>>On 4/5/2010 2:23 PM, John Larkin wrote: >>>>> On Mon, 5 Apr 2010 11:17:56 -0700, "Joel Koltner" >>>>> <zapwireDASHgroups(a)yahoo.com> wrote: >>>>> >>>>>> "John Larkin"<jjlarkin(a)highNOTlandTHIStechnologyPART.com> wrote in message >>>>>> news:q90kr5pda1mtti9pea5c7tqmao0u9qvfpi(a)4ax.com... >>>>>>> Rigol is like >>>>>>> someone who used to leave their front door unlocked, until someone >>>>>>> wandered in and stole something, so now they have to lock it. >>>>>> >>>>>> I think it's more like Rigol sells houses, and you bought a two-bedroom house >>>>>> (although you're aware they also sell three-bedroom houses)... and one day you >>>>>> notice (or Dave Jones metnions that) there's another door in your home. >>>>>> There's no lock on that door, no sign on it saying, "keep out!," etc. Your >>>>>> ne'er-do-well liberal democrat son moves back home after flunking out of his >>>>>> liberal studies program at the local college and you get to thinking... having >>>>>> that kid spend his nights in his own room rather than sleeping on the couch in >>>>>> the living room every night would be nice... I wonder what's behind that door? >>>>>> >>>>>> :-) >>>>> >>>>> Not entirely the same. It costs money to build rooms, but it costs >>>>> nothing to enable IP. Both have market value. >>>>> >>>>> But why didn't they do the 50 and even 20 MHz bandwidth limits >>>>> digitally? They have 1G samples/second to work with. There are some >>>>> saturation issues that might be best handled with analog limiting, but >>>>> this *is* a cheap scope. >>>>> >>>>> John >>>>> >>>> >>>>One possible reason is that with an analogue bandwidth limit, signals >>>>that would be aliased get attenuated before sampling. >>>> >>> >>>But it's a 1 GHz sample rate. If it's analog limited to 100 MHz, they >>>can do most anything with it. Decimating won't create aliases, will >>>it? >> >>That depends on the steepness of the input filtering. It will need to >>roll-off more than 48dB not to have any aliasing products at fs/2. I >>doubt they decimate. 2GB/s is a lot to handle by the low cost FPGA >>they use (Altera Cyclone IIRC). I strongly doubt digital realtime >>filtering is feasible. > >Whatever aliases the 100 MHz version has, the 50 MHz mode won't be >much better. My 1052 amazed me by having user-programmable >lowpass/highpass/bandpass filtering. If the FPGA can move 1 Gs/s data, >it shouldn't be hard to implement a simple FIR filter to knock 100 MHz >response down to 50. The filter wouldn't be realtime in the sense that >only display data needs to be filtered, and I suspect displays aren't >updated all that often. Good question. The samplerate is probably variable which may lead to several aliasing issues. I doubt they took care of that. Even a simple FIR filter would require massive FPGA real estate. I suppose the filtering options are performed during post-processing. IIRC correct the memory bandwidth is also an issue. At the highest samplerate the record length is limited to a few KB. -- Failure does not prove something is impossible, failure simply indicates you are not using the right tools... nico(a)nctdevpuntnl (punt=.) --------------------------------------------------------------
From: Joel Koltner on 6 Apr 2010 19:30 Hi Keith, <krw(a)att.bizzzzzzzzzzzz> wrote in message news:vlcnr55rtcv3g0vih6gasa7hcbv5sn4pip(a)4ax.com... > Might be beneficial. Fortunately we have a pretty good toe-hold in the > market > now. A year ago, not so much. Do you guys worry much about 2.4GHz getting awfully crowded in the near future? Or do you figure that with all the whitespace devices out there, DTV, and the FCC wavering on just what is and isn't legal for wireless mics and intercoms anyway, UHF looks just as bad? Joerg was pointing out to me recently that DTV stations today can be assigned adjacent channels and you just end up with a "wall of RF," without the large unoccupied channels you used to get with analog TV wherein frequency coordinators would often find *their* channels for wireless mics and intercoms.. This model: http://www.hme.com/pro850.cfm ... appears to address the problem by having a super-wide tuning range (470-698MHz). It's kinda an interesting design -- older FM technology, but just about every feature you could have without going to full-up digital... and the IRDA link between a belt pack and a PDA for configuration is kinda novel, I suppose -- but I wonder how much use it actually gets? Their "competitive matrix" (http://www.hme.com/collateral/PRO850_vsBTR800.pdf) comparing it with the venerable Telex BTR800 system is a little silly though... kinda like comparing a 2010 Camaro car to a '64 Mustang and dinging the Mustang for not having anti-lock brakes or airbags. :-) > "Why doesn't it support ____? I said we needed ____. Didn't you read my > email? No, I don't keep copies of all my emails." > > Me: "I do." Exactly. :-) ---Joel
From: krw on 6 Apr 2010 21:11 On Tue, 6 Apr 2010 16:30:41 -0700, "Joel Koltner" <zapwireDASHgroups(a)yahoo.com> wrote: >Hi Keith, > ><krw(a)att.bizzzzzzzzzzzz> wrote in message >news:vlcnr55rtcv3g0vih6gasa7hcbv5sn4pip(a)4ax.com... >> Might be beneficial. Fortunately we have a pretty good toe-hold in the >> market >> now. A year ago, not so much. > >Do you guys worry much about 2.4GHz getting awfully crowded in the near >future? Or do you figure that with all the whitespace devices out there, DTV, >and the FCC wavering on just what is and isn't legal for wireless mics and >intercoms anyway, UHF looks just as bad? Not too much in the market we're in. We do have other plans but the 2.4G band is nice because it's world-wide (more or less and the less part is easily manageable). >Joerg was pointing out to me recently that DTV stations today can be assigned >adjacent channels and you just end up with a "wall of RF," without the large >unoccupied channels you used to get with analog TV wherein frequency >coordinators would often find *their* channels for wireless mics and >intercoms.. This model: http://www.hme.com/pro850.cfm ... appears to address >the problem by having a super-wide tuning range (470-698MHz). It's kinda an >interesting design -- older FM technology, but just about every feature you >could have without going to full-up digital... and the IRDA link between a >belt pack and a PDA for configuration is kinda novel, I suppose -- but I >wonder how much use it actually gets? I haven't looked seriously at their offerings. I should. IRDA? Why not BlueTooth. ;-) Disclaimer: I *hate* BlueTooth. Our big seller into the rental market is configuration over Ethernet. It makes the thing a *lot* easier to set up than the arcane menus on the tiny LCD. >Their "competitive matrix" (http://www.hme.com/collateral/PRO850_vsBTR800.pdf) >comparing it with the venerable Telex BTR800 system is a little silly >though... kinda like comparing a 2010 Camaro car to a '64 Mustang and dinging >the Mustang for not having anti-lock brakes or airbags. :-) We used the BTR800 (I think that's the model) in the high-end sports product line until they bit the bullet and decided to do the engineering themselves (before my time). I still see them in the older units that come back each year for service. >> "Why doesn't it support ____? I said we needed ____. Didn't you read my >> email? No, I don't keep copies of all my emails." >> >> Me: "I do." > >Exactly. :-) I never ran into this problem when I worked for IBM. Everything was specified down to the smallest detail[*]. The workbooks were something to behold (easily tens of man-years in some of them). [*] with the exception for the first generation crypto coprocessor key management - they didn't know what they wanted, just how it was to work.
From: Joel Koltner on 6 Apr 2010 21:50 Hi Keith, <krw(a)att.bizzzzzzzzzzzz> wrote in message news:81mnr59g2ua9t74p151se2r76sn0qb9b5t(a)4ax.com... > Not too much in the market we're in. We do have other plans but the 2.4G > band > is nice because it's world-wide (more or less and the less part is easily > manageable). That's is somewhat compelling. > I haven't looked seriously at their offerings. I should. IRDA? Why not > BlueTooth. ;-) Disclaimer: I *hate* BlueTooth. I don't know how long those Pro850's have been on the market, but I wouldn't be surprised if it's the better chunk of a decade now, and I remember that back around the turn of the century IRDA was still looking pretty attractive (it was quite cheap to implement too, especially if you only wanted the slower 115.2kbps version), whereas of course today it's become very nichey and is rapidly dying off (although those guys on eBay will sell you USB to IRDA adapters for <$10 still). Bluetooth doesn't work nearly as well as it should, although I do like it for listening to music from a PC and of course as a phone headset, mainly because there aren't really that many other real standards to choose from for those functions. Oh, and it's useful for tethering your laptop to your phone to use as a modem. > Our big seller into the rental market is configuration over Ethernet. It > makes the thing a *lot* easier to set up than the arcane menus on the tiny > LCD. Agreed; we've had discussions about whether or not a base station even needs to be able to fully configure everything through a tiny LCD, given that at the $10k+ price levels we're talking about here adding a $300 netbook into the mix with a 10" 1024x600 LCD is nothing. Nevertheless, at present the thinking seems to be that full (or almost full) configuration through through a tiny LCD is still desirable. > We used the BTR800 (I think that's the model) in the high-end sports product > line until they bit the bullet and decided to do the engineering themselves > (before my time). Yep, that's the thing with the BTR800s -- they're long in the tooth and lacking many features, but what they do they do well and people just like them. I've heard of some guys who were trying out HME DX100's since they really wanted the smaller form factor but went back to BTR800s based on what they found to be better usability and audio quality. Basically the BTR800 is largely the standard that you and I are both trying to displace. :-) Too bad you have some years worth of a head start amd appear to be rather successful! :-) ---Joel
From: JosephKK on 6 Apr 2010 22:22
On Tue, 6 Apr 2010 17:05:18 +0800, "Andrew" <anbyvbel(a)yahoo.com> wrote: >"JosephKK" <quiettechblue(a)yahoo.com> wrote in message >news:l1dlr5l8r4opslaecuhtbhtmn3sd9o8ien(a)4ax.com... >On Tue, 6 Apr 2010 10:05:09 +0800, "Andrew" <anbyvbel(a)yahoo.com> wrote: > >>"JosephKK" <quiettechblue(a)yahoo.com> wrote in message >>news:ci4lr5p8s2pak1fn1g696jbmlgkacm831b(a)4ax.com... >>On Sun, 4 Apr 2010 21:46:48 +0800, "Andrew" <anbyvbel(a)yahoo.com> wrote: >> >>>"Greegor" <greegor47(a)gmail.com> wrote in message >>>news:58f64e6b-2884-4b4c-bbea-60f45949dfba(a)j21g2000yqh.googlegroups.com.... >>> >>>> The usual presumption for different prices is that >>>> different COSTS are involved. >>> >>>Wrong. >>>Supply - demand + goverment intervention. >>>Nothing more, nothing less. >> >>= Dreamer. You should use less wild and crazy drugs though, too much >>= wild hallucination. >> >> >>Haven't you noticed "government intervention part" mentioned above? >> >>Point being "cost" does not make any difference. After the product is >>manufactured "cost" is a lost money anyway. All you can do is to attempt to >>sell for as much compensation as you can. >> >>"Cost" affects the decision to manufacture or not to manufacture the >>particular products. >> >>= Show me a true Adam Smith style market. There hasn't been one in the >>= USA for over a century and a half. >> >>There has not been one ever, AFAIK. However it does not matter. > > >== Bog, have you never heard of per unit costs? Part of which is called >BOM? > >See above, i can repeat it one more time. > >"Cost" affects the decision to manufacture or not to manufacture the >particular products." > >Price is the result of negiotiation between the seller and the buyer, ant >not the pure function of cost. >You will sell with a huge profit if you can or with a huge loss if it is the >only way to recover at least some of the cost. You are too damn scattershot to follow. A proper direct answer was required, you gave many other things instead. Go away until you can give a straight answer. |