On a sunny day (Fri, 10 Nov 2023 10:11:44 -0800) it happened john larkin <jl@650pot.com> wrote in <i9sski1c3big5ju6vanl09jkqeq04k7icu@4ax.com>:>On Thu, 09 Nov 2023 14:58:08 -0800, john larkin <jl@650pot.com> wrote: > >>On Wed, 8 Nov 2023 18:12:38 -0500, Phil Hobbs >><pcdhSpamMeSenseless@electrooptical.net> wrote: >> >>>On 2023-11-08 18:08, Phil Hobbs wrote: >>>> On 2023-11-08 14:04, john larkin wrote: >>>>> >>>>> https://www.amazon.com/Fluke-TL81A-Test-Deluxe-Electronic/dp/B000NI2B6A/ref=pd_lutyp_rtpb_sccl_2_1/142-3653234-3875240?pd_rd_w=8wX1f&content-id=amzn1.sym.9c90becd-3e6e-4609-85c5-d4298ba525ad&pf_rd_p=9c90becd-3e6e-4609-85c5-d4298ba525ad&pf_rd_r=W2VAXEFG >>>>> 42ZY2RN15N9V&pd_rd_wg=Tc99b&pd_rd_r=eca67892-4420-4869-8d8e-145a23c7fb1f&pd_rd_i=B000NI2B6A&th=1 >>>>> >>>>> >>>>> Some of their handheld DVMs are over $400. >>>>> >>>> >>>> I paid $275 for an original crispy flavor(*) Fluke 87 in about 1989. >>> >>>I should add that I'm very fond of these DMM probes: >>> >>><https://probemaster.com/8000-series-standard/> >>> >>>Cheers >>> >>>Phil Hobbs >> >>I was just probing a very tight board with a sewing needle. > >Imagine cutting the needle in two, splinting it back together but >bridging the gap with a 950 ohm 0603 resistor, and soldering a coax >center to the top end. You now have a tiny many-GHz 10:1 probe. > >At most signal levels, such probes don't need a ground.At decent signal levels probes do not need to connect either...
Fluke has lost their mind
Started by ●November 8, 2023
Reply by ●November 11, 20232023-11-11
Reply by ●November 11, 20232023-11-11
On Sat, 11 Nov 2023 05:41:10 GMT, Jan Panteltje <alien@comet.invalid> wrote:>On a sunny day (Fri, 10 Nov 2023 10:11:44 -0800) it happened john larkin ><jl@650pot.com> wrote in <i9sski1c3big5ju6vanl09jkqeq04k7icu@4ax.com>: > >>On Thu, 09 Nov 2023 14:58:08 -0800, john larkin <jl@650pot.com> wrote: >> >>>On Wed, 8 Nov 2023 18:12:38 -0500, Phil Hobbs >>><pcdhSpamMeSenseless@electrooptical.net> wrote: >>> >>>>On 2023-11-08 18:08, Phil Hobbs wrote: >>>>> On 2023-11-08 14:04, john larkin wrote: >>>>>> >>>>>> https://www.amazon.com/Fluke-TL81A-Test-Deluxe-Electronic/dp/B000NI2B6A/ref=pd_lutyp_rtpb_sccl_2_1/142-3653234-3875240?pd_rd_w=8wX1f&content-id=amzn1.sym.9c90becd-3e6e-4609-85c5-d4298ba525ad&pf_rd_p=9c90becd-3e6e-4609-85c5-d4298ba525ad&pf_rd_r=W2VAXEFG >>>>>> 42ZY2RN15N9V&pd_rd_wg=Tc99b&pd_rd_r=eca67892-4420-4869-8d8e-145a23c7fb1f&pd_rd_i=B000NI2B6A&th=1 >>>>>> >>>>>> >>>>>> Some of their handheld DVMs are over $400. >>>>>> >>>>> >>>>> I paid $275 for an original crispy flavor(*) Fluke 87 in about 1989. >>>> >>>>I should add that I'm very fond of these DMM probes: >>>> >>>><https://probemaster.com/8000-series-standard/> >>>> >>>>Cheers >>>> >>>>Phil Hobbs >>> >>>I was just probing a very tight board with a sewing needle. >> >>Imagine cutting the needle in two, splinting it back together but >>bridging the gap with a 950 ohm 0603 resistor, and soldering a coax >>center to the top end. You now have a tiny many-GHz 10:1 probe. >> >>At most signal levels, such probes don't need a ground. > >At decent signal levels probes do not need to connect either...DC coupling and amplitude calibration are sometimes nice. I've been toying with going into the probe business, fast stuff, passive resistive and active fet or equivalent. It wouldn't be hard.
Reply by ●November 11, 20232023-11-11
On Sunday, November 12, 2023 at 2:21:01 AM UTC+11, John Larkin wrote:> On Sat, 11 Nov 2023 05:41:10 GMT, Jan Panteltje <al...@comet.invalid> > wrote: > >On a sunny day (Fri, 10 Nov 2023 10:11:44 -0800) it happened john larkin > ><j...@650pot.com> wrote in <i9sski1c3big5ju6v...@4ax.com>: > > > >>On Thu, 09 Nov 2023 14:58:08 -0800, john larkin <j...@650pot.com> wrote: > >> > >>>On Wed, 8 Nov 2023 18:12:38 -0500, Phil Hobbs > >>><pcdhSpamM...@electrooptical.net> wrote: > >>> > >>>>On 2023-11-08 18:08, Phil Hobbs wrote: > >>>>> On 2023-11-08 14:04, john larkin wrote: > >>>>>> > >>>>>> https://www.amazon.com/Fluke-TL81A-Test-Deluxe-Electronic/dp/B000NI2B6A/ref=pd_lutyp_rtpb_sccl_2_1/142-3653234-3875240?pd_rd_w=8wX1f&content-id=amzn1.sym.9c90becd-3e6e-4609-85c5-d4298ba525ad&pf_rd_p=9c90becd-3e6e-4609-85c5-d4298ba525ad&pf_rd_r=W2VAXEFG > >>>>>> 42ZY2RN15N9V&pd_rd_wg=Tc99b&pd_rd_r=eca67892-4420-4869-8d8e-145a23c7fb1f&pd_rd_i=B000NI2B6A&th=1 > >>>>>> > >>>>>> > >>>>>> Some of their handheld DVMs are over $400. > >>>>>> > >>>>> > >>>>> I paid $275 for an original crispy flavor(*) Fluke 87 in about 1989. > >>>> > >>>>I should add that I'm very fond of these DMM probes: > >>>> > >>>><https://probemaster.com/8000-series-standard/> > >>>> > >>>>Cheers > >>>> > >>>>Phil Hobbs > >>> > >>>I was just probing a very tight board with a sewing needle. > >> > >>Imagine cutting the needle in two, splinting it back together but > >>bridging the gap with a 950 ohm 0603 resistor, and soldering a coax > >>center to the top end. You now have a tiny many-GHz 10:1 probe. > >> > >>At most signal levels, such probes don't need a ground. > > > >At decent signal levels probes do not need to connect either... > > DC coupling and amplitude calibration are sometimes nice. > > I've been toying with going into the probe business, fast stuff, passive resistive and active fet or equivalent. It wouldn't be hard.It might not look hard to John Larkin, who is happy to ignore the parallel capacitance of inductors. People who think more rigorously might see more potential problems. -- Bill Sloman, Sydney
Reply by ●November 12, 20232023-11-12
On a sunny day (Sat, 11 Nov 2023 07:20:17 -0800) it happened John Larkin <jl@997PotHill.com> wrote in <so6vki18mna03t03sfg0s6i2tfp4ulkcf1@4ax.com>:>On Sat, 11 Nov 2023 05:41:10 GMT, Jan Panteltje <alien@comet.invalid> >wrote: > >>On a sunny day (Fri, 10 Nov 2023 10:11:44 -0800) it happened john larkin >><jl@650pot.com> wrote in <i9sski1c3big5ju6vanl09jkqeq04k7icu@4ax.com>: >> >>>On Thu, 09 Nov 2023 14:58:08 -0800, john larkin <jl@650pot.com> wrote: >>> >>>>On Wed, 8 Nov 2023 18:12:38 -0500, Phil Hobbs >>>><pcdhSpamMeSenseless@electrooptical.net> wrote: >>>> >>>>>On 2023-11-08 18:08, Phil Hobbs wrote: >>>>>> On 2023-11-08 14:04, john larkin wrote: >>>>>>> >>>>>>> >>>>>>> https://www.amazon.com/Fluke-TL81A-Test-Deluxe-Electronic/dp/B000NI2B6A/ref=pd_lutyp_rtpb_sccl_2_1/142-3653234-3875240?pd_rd_w=8wX1f&content-id=amzn1.sym.9c90becd-3e6e-4609-85c5-d4298ba525ad&pf_rd_p=9c90becd-3e6e-4609-85c5-d4298ba525ad&pf_rd_r=W2VAXE >>>>>>> FG >>>>>>> 42ZY2RN15N9V&pd_rd_wg=Tc99b&pd_rd_r=eca67892-4420-4869-8d8e-145a23c7fb1f&pd_rd_i=B000NI2B6A&th=1 >>>>>>> >>>>>>> >>>>>>> Some of their handheld DVMs are over $400. >>>>>>> >>>>>> >>>>>> I paid $275 for an original crispy flavor(*) Fluke 87 in about 1989. >>>>> >>>>>I should add that I'm very fond of these DMM probes: >>>>> >>>>><https://probemaster.com/8000-series-standard/> >>>>> >>>>>Cheers >>>>> >>>>>Phil Hobbs >>>> >>>>I was just probing a very tight board with a sewing needle. >>> >>>Imagine cutting the needle in two, splinting it back together but >>>bridging the gap with a 950 ohm 0603 resistor, and soldering a coax >>>center to the top end. You now have a tiny many-GHz 10:1 probe. >>> >>>At most signal levels, such probes don't need a ground. >> >>At decent signal levels probes do not need to connect either... > >DC coupling and amplitude calibration are sometimes nice. > >I've been toying with going into the probe business, fast stuff, >passive resistive and active fet or equivalent. It wouldn't be hard.Yes, at lower frequencies OK. But at several GHz even sticking / touching a needle in the circuit will change everything depending on needle length for example (part of wavelength, reflections etc). Amplitude measurements OK at 50 Ohm output. For DC on a RF point probe with high value resistor (several kOhm SMD) to a cheap meter with high input impedance... Just whatever you encounter. Sure an interesting project, could make some money. I was testing earplugs, need really good ones playing while not freaking everybody out with mistakes I make... The new Sennheiser sound terrible.. the very old ones are great The new ones are 50 dollars or more I think,.... Do not even fit my ears. So crap sells. I did frequency sweeps to test the output of about 10 different earplugs I have laying about... Oh man... some are like filters missing whole parts of the audio spectrum. Could be fakes? https://arstechnica.com/gadgets/2023/11/sparse-innards-of-25-counterfeit-airpods-pro-revealed-by-ct-scans/ I have not tested any Apple ones, have no Apple stuff, way too expensive. only have real apples and apple pies mmmm! All those super HiFi things, whatever a fool likes to pay...
