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Failed to connect to MySQL: (1203) User howardkn already has more than 'max_user_connections' active connectionsPath: ...!local-1.nntp.ord.giganews.com!Xl.tags.giganews.com!local-3.nntp.ord.giganews.com!nntp.supernews.com!news.supernews.com.POSTED!not-for-mail NNTP-Posting-Date: Tue, 30 Jul 2024 20:31:21 +0000 From: john larkin Newsgroups: sci.electronics.design Subject: Re: "Sampler??" Date: Tue, 30 Jul 2024 13:31:20 -0700 Message-ID: <6iiiajtp5gfqk6ehk8oh5fl7sb2ktlui6u@4ax.com> References: <72gfajl8ke966lsu54bpajpang9dvgmt63@4ax.com> <358iajpkaf41atvvnbq9no9p0uearvu8bk@4ax.com> User-Agent: ForteAgent/8.00.32.1272 MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Lines: 170 X-Trace: sv3-rIV3iKUvnHtnHoODEZE4kZVvLzFBnOvlv5xCZ5xkVo37beA/E7Y5Xbnl9AxxI3JhZ/sq+qP3431Td6k!I85WMxt5swguePECN6i6SpcSVqwYe33RCgMuYeol/Y70Sy7ZTTomve0oR7sBIwz1Y/U/krGKgS1v!agxgJQ== X-Complaints-To: www.supernews.com/docs/abuse.html X-DMCA-Complaints-To: www.supernews.com/docs/dmca.html X-Abuse-and-DMCA-Info: Please be sure to forward a copy of ALL headers X-Abuse-and-DMCA-Info: Otherwise we will be unable to process your complaint properly X-Postfilter: 1.3.40 Bytes: 8881 On Tue, 30 Jul 2024 13:46:06 -0400, Joe Gwinn wrote: >On Tue, 30 Jul 2024 15:13:47 -0000 (UTC), Cursitor Doom > wrote: > >>On Tue, 30 Jul 2024 11:01:17 -0400, Joe Gwinn wrote: >> >>> On Tue, 30 Jul 2024 14:51:10 GMT, Jan Panteltje >>> wrote: >>> >>>>On a sunny day (Tue, 30 Jul 2024 11:20:47 -0000 (UTC)) it happened >>>>Cursitor Doom wrote in >>>>: >>>> >>>>>On Tue, 30 Jul 2024 10:36:51 GMT, Jan Panteltje wrote: >>>>> >>>>>> On a sunny day (Tue, 30 Jul 2024 08:58:35 -0000 (UTC)) it happened >>>>>> Cursitor Doom wrote in >>>>>> : >>>>>> >>>>>>>On Tue, 30 Jul 2024 05:16:24 GMT, Jan Panteltje wrote: >>>>>>> >>>>>>>> On a sunny day (Mon, 29 Jul 2024 09:29:04 -0700) it happened john >>>>>>>> larkin wrote in >>>>>>>> <72gfajl8ke966lsu54bpajpang9dvgmt63@4ax.com>: >>>>>>>> >>>>>>>>>On Mon, 29 Jul 2024 05:19:06 GMT, Jan Panteltje >>>>>>>>> wrote: >>>>>>>>> >>>>>>>>>>On a sunny day (Sun, 28 Jul 2024 21:40:41 -0000 (UTC)) it happened >>>>>>>>>>Cursitor Doom wrote in >>>>>>>>>>: >>>>>>>>>> >>>>>>>>>> >>>>>>>>>>>I still can't see where the 'sampling' bit comes into it. >>>>>>>>>>>AFAICT, there's are two signals into this thing and one signal >>>>>>>>>>>out. The signal from the LHS is passed through a very fast diode >>>>>>>>>>>which generates harmonics from that fundamental. The signal from >>>>>>>>>>>the RHS is unmodified and mixed with the desired harmonic to give >>>>>>>>>>>the necessary output signal which is then filtered to get rid of >>>>>>>>>>>the unwanted mixing products. If that's all correct, as I believe >>>>>>>>>>>it is, >>>>>>>>>>>where does any *sampling* come into it? >>>>>>>>>> >>>>>>>>>>A 'sampler' is fact a non-linear mixer. >>>>>>>>> >>>>>>>>>In the audio world, a "mixer" is a linear summer. >>>>>>>>> >>>>>>>>>In RF, a mixer is usually a multiplier, typically a 4-quadrant >>>>>>>>>diode thing or a Gilbert cell type circuit. Or a 2-quadrant thing >>>>>>>>>like a pentode. Or even a single diode. All do some flavor of >>>>>>>>>multiplying. >>>>>>>>> >>>>>>>>>Some mixers inherently multiply a signal by a square wave, which >>>>>>>>>resembles other multiplier-type things once you lowpass filter the >>>>>>>>>output. That's a "synchronous detector", which we usually do in an >>>>>>>>>FPGA. >>>>>>>>> >>>>>>>>>A sampler is a signal multiplier too. >>>>>>>>> >>>>>>>>>These are all variations on the basic idea of multiplying two >>>>>>>>>signals. >>>>>>>> >>>>>>>> A the word 'mixer' in RF is not the same as a multiplier,, >>>>>>>> Multipliers are like harmonic generating stages say you have a 1 >>>>>>>> MHz distorted sine wave and then a second stage tuned at 3 MHz,.. >>>>>>>> turned to third harmonic. >>>>>>>> >>>>>>>> mamamatical speaking RF mixing is indeed multiplication. >>>>>>>> >>>>>>>> Like Shakepierce once said: >>>>>>>> "What's in a name..." CocaCola wihout coke >>>>>>> >>>>>>>I think in this context, HP is using the term "sampler" to mean >>>>>>>something which 'sniffs' a small amount of a signal for testing >>>>>>>purposes. Like a few turns of wire around a transmission line will >>>>>>>'sniff' a small sample of what's going on in the line. >>>>>>>Where I went wrong was rigidly thinking HP meant 'sampling' in the >>>>>>>manner a sampling oscilloscope works. That's what threw me. I tend to >>>>>>>interpret things very literally. :( >>>>>> >>>>>> Would be nice to see a real circuit diagram of that thing. >>>>>> What is the model / type number? >>>>>> I am curious. >>>>>> So far I have been able to find circuits for most stuff I came across >>>>>> with google. >>>>> >>>>>It's the HP8566B - a very well known lab-grade analyser of the day >>>>>which many RF designers still use. There is a *ton* of service info on >>>>>this model online. However, I have not been able to see a *proper* >>>>>schematic for the "sampler" in the A11A5 board which is where the issue >>>>>is. >>>> >>>>OK, thank you, I will google a bit.. >>>>I got the user manual now: >>>> https://elektrotanya.com/ >>hp-8566b_spectrum_analyzer_100hz-2.5ghz_2-22ghz_usr- >>programming_1984_sm.pdf/download.html#dl >>>>Then trouble shooting manual part 1 >>>> https://xdevs.com/doc/HP_Agilent_Keysight/ >>HP%208566B%20Troubleshooting%20&%20Repair%20Vol.%201.pdf >>>>Seems to have at least some circuits (just a quick look) >>>>and part 2 >>>> https://xdevs.com/doc/HP_Agilent_Keysight/HP%208566B, >>%208568B%20Troubleshooting%20&%20Repair%20Vol.%202.pdf >>>>also has some circuits I will have a look at the hundreds of pages, will >>>>take some time. >>>>I presume you have these? >>>>Took 10 seconds to find with google >>>> >>>>OTOH my 1.4 GHz RTL_SDR sticks cost 30 dollies($$) or so, >>>> https://www.ebay.com/p/22032165355?iid=335019807057 >>>>I can use a 5 dollies($$) satellite LNB as down mixer to go from 10 to >>>>12 GHz to say 1 GHz (modified a LNB for xtal locked to Rubidium >>>>reference) >>>>Also build a small downmixer so it can see 2.4 GHz too Plenty free >>>>spectral display programs online for it, >>>>I wrote my own: >>>> https://panteltje.nl/panteltje/xpsa/index.html >>>>it also has an 'harmonic' button to look for the next harmonic when you >>>>select a carrier... >>>>The latest version has some more stuff and runs on Raspberry Pi.. >>>>The RTL_SDR sticks can even receive GPS signals... >>>> https://panteltje.nl/pub/run_50_outside_2728000.gif uses this guys >>>> software<; >>>> http://michelebavaro.blogspot.nl/2012/04/spring-news-in-gnss-and-sdr- >>domain.html >>>> >>>>For 100 Hz to 20 kHz a PC soundcard or maybe USB audio stick (as I use >>>>for my Raspberry) >>>>and there are several audio programs with spectrum display >>>> >>>>There are so many possibilities... >>> >>> HP always put the theory notes in the HP Journal, so I'd suggest >>> searching there for the HP8566B, in the issues around when the >>> instrument was first introduced. >> >>This analyser is well over 30 years old, so whatever's gone wrong is most >>likely age-related and wouldn't have come to light for many years. >>Fortunately there's a lot of info out there - *if* you can find it! > >On the lack of a schematic, I did dig into how it worked many years >ago, and as I recall it was based of some fancy abuse of a slotted >rectangular waveguide which supported various orthogonal modes - this >cannot be described by any lumped-parameter circuit. > >Try this: > >US4647795A, Travelling wave sampler, Agoston Agoston, Beaverton, Oreg. >Tektronix, Inc., Beaverton, Oreg. granted 3 March 1987. > >. > >It does have schematics, in a manner of speaking. > >Joe Gwinn I have an old HP sampling plugin that uses a machined block slotline structure. 3 GHz bandwidth as I recall. https://www.dropbox.com/scl/fo/3h4fvsfdh2youfd4kuolk/AIapB4g1x0BYRNXRIrAsrO8?rlkey=q5v7llkkk6yagr2w7h4c4kq8k&dl=0 Agoston has a patent for a similar metal-block slotline sampler, but as far as I know Tek never manufactured it. The SD-series samplers were hybrids. https://www.dropbox.com/scl/fo/dnejszdktyc70se6frcdo/AM4vWFFsXPPF4Tw2ZeEm6m8?rlkey=xm82mhqn5mnrlv3l9j0pebj29&dl=0