Path: ...!eternal-september.org!feeder3.eternal-september.org!news.eternal-september.org!.POSTED!not-for-mail From: Bill Sloman Newsgroups: sci.electronics.design,sci.electronics.repair Subject: Re: Favourite Test Equipment Date: Fri, 5 Apr 2024 17:04:22 +1100 Organization: A noiseless patient Spider Lines: 108 Message-ID: References: <9k7j0jlnbhs8qfg5m17pium0835meean83@4ax.com> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Injection-Date: Fri, 05 Apr 2024 06:04:38 +0200 (CEST) Injection-Info: dont-email.me; posting-host="df23da257da9506c79ec203629896d8d"; logging-data="1280960"; mail-complaints-to="abuse@eternal-september.org"; posting-account="U2FsdGVkX18x00ZaOM+Wd3VHbrCeZ+aGgg8H7dJHDkU=" User-Agent: Mozilla Thunderbird Cancel-Lock: sha1:8ephuHYum8wsK5TqITYOOrCibj4= In-Reply-To: Content-Language: en-US Bytes: 6374 On 5/04/2024 2:04 am, John Larkin wrote: > On Thu, 4 Apr 2024 11:56:23 -0000 (UTC), Phil Hobbs > wrote: > >> Klaus Vestergaard Kragelund wrote: >>> On 01-04-2024 09:01, Jan Panteltje wrote: >>>> On a sunny day (Sun, 31 Mar 2024 18:41:18 +0100) it happened Cursitor Doom >>>> wrote in <9k7j0jlnbhs8qfg5m17pium0835meean83@4ax.com>: >>>> >>>>> Hi all, >>>>> >>>>> I'm starting to get a bit fed up with having my test equipment blow up >>>>> just when it's needed. This is the drawback with vintage gear; if it's >>>>> not used frequently then it can go *bang* the next time you switch it >>>>> on. It makes for good practice in repairing stuff, but wastes a lot of >>>>> time which could be better spent doing other things. >>>>> I think it's time I modernised my test gear. I was just wondering if >>>>> anyone has any recommendations they can share. Is there a particular >>>>> piece of test equipment you couldn't live without? Something you're >>>>> particularly impressed with? I'd be interested to know so I can >>>>> perhaps acquire said item and thereby reduce the number of explosions >>>>> I experience. >>>>> >>>>> Thanks, >>>>> >>>>> CD. >>>> >>>> My 10 MHz Trio dual trace analog scope is from 1979 or there about, I >>>> blew up a channal once myself in the first week >>>> when I accidently touched a booster diode in a TV I was repairing with >>>> it, fixed it locating the problem with the other channel. >>>> Later I cracked the graticule when a soldering station fell on it from >>>> the table (scope stands on the ground) >>>> Made a new graticule. >>>> So, and still working perfectly, OK for all things I build with micros. >>>> For RF to about 1.6 GHz I use RTL_SDR USB sticks and the spectrum analyzer I wrote. >>>> and for AC DC measurements I have some made in China digital meters and an analog one. >>>> also a Voltcraft clamp-on meter for current when you do not - or cannot >>>> interrupt things with the meter impedance. >>>> Also have a Voltcraft soldering station. >>>> Blew up one of my digital meters a while back (volts on the resistance >>>> scale) but fixed it again (replaced resistor). >>>> Many other test equipment I designed and build, like amplifiers LF and >>>> RF, SWR meter, radiation meters, gamma spectrometer, >>>> GHz stuff for satelite, transmitters low and very high power, what not, >>>> a frequency converter to use the RTL-SDR sticks and so the spectrum >>>> analyzer on higher and lower frequencies. >>>> Have a SARK100 SWR analyzer too. >>>> Things last forever here... >>>> Scope used on a regular basis.. >>>> RTL-SDR stick 24/7. >>>> Digital meters used every day. >>>> Use my self designed lab power supply every day.. >>>> What more do you need? >>>> Learn to use the stuff, understand what's important, and that is it >>>> When I started in electronics as a kid I did not even _have_ a meter, still stuff worked. >>>> Build my own scope at some point back then when I somehow got the parts >>>> Not much pocket mony as a kid. >>>> UNDERSTAND your systems, what electrons do. >>>> Showing of with boat anchors may impress people, especially the clueless... >>>> But it does not help you one bit. >>>> Anything with an accuracy better than 1 percent in most cases is just >>>> like apes screaming load trying to impress other apes. >>>> >>> >>> Very true about specifically the 1% statement. Sidebar, at an earlier >>> employment, we needed to equip a new lab. Guys wanted GHz scopes. When >>> asked if the ever looked at edges faster than 1ns, no one did. >>> >>> >> >> It’s true that there are a lot of relatively undemanding jobs in >> electronics. You can get on fine with a 200-MHz scope if all you’re doing >> is PIC and Pi and ham radio and analog TV. >> >> It’s also true that you can often make do with what you have—the most >> important test instrument is the one between your ears. >> >> In the before times, doctors were much better with stethoscopes than they >> are now. >> >> But I’d sure prefer a cardiologist who could use tomography and ultrasound >> over the best stethoscope guy. >> >> And it’s a lot easier finding gigahertz oscillations if you aren’t limited >> to a 10-MHz >> scope with scale marks in cuneiform. > > We have a product in development, a new digital delay generator, that > had too many picoseconds of excess, erratic jitter. Turns out that the > 50 MHz LC oscillator squeggs at about 6 GHz, which I guess is my > fault. We found that with a spectrum analyzer, not a scope. > > My new oscillator, using a BUF602 as the gain element, looks good. > Jitter is under 10 ps RMS at 5 usec out, which is great for a > triggered LC. But it's rubbish for a free-running oscillator https://ieeexplore.ieee.org/document/7331424 https://spectrum.ieee.org/for-precision-the-sapphire-clock-outshines-even-the-best-atomic-clocks You need a system architecture that can exploit a free running clock. I came up with one that worked in 1988, and I'm sure that there are others. -- Bill Sloman, Sydney