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RF, Microwave, Ham Radio / Re: fake MPF102s from AliExpress
« Last post by graybeard on Today at 10:21:30 pm »My $10 Chinese tester seems to work OK on Ge transistors and diodes.
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RF, Microwave, Ham Radio / Re: fake MPF102s from AliExpress
« Last post by TimFox on Today at 10:19:04 pm »Have you tried Jameco (my usual source for obsolete semiconductors)?
https://www.jameco.com/z/MPF102-Major-Brands-Transistor-MPF102-JFET-N-Channel-TO-92_26403.html?CID=GOOG&gad_source=1&gclid=EAIaIQobChMI5tiM-fflhQMV_0f_AR3FaAF9EAQYASABEgKBevD_BwE
https://www.jameco.com/z/MPF102-Major-Brands-Transistor-MPF102-JFET-N-Channel-TO-92_26403.html?CID=GOOG&gad_source=1&gclid=EAIaIQobChMI5tiM-fflhQMV_0f_AR3FaAF9EAQYASABEgKBevD_BwE
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General Technical Chat / Re: Cable Management
« Last post by edpalmer42 on Today at 10:17:46 pm »I came across an Ikea wire rack for holding stemware glasses at a bar. I mounted it on the end of one of my shelving units and adjusted the width of the slot so that it holds a BNC connector while allowing the cable to slide in. I slid vinyl tubing over the rails so that the cables didn't slide on the chrome rails.
I'm going to build another cable holder. Take a flat piece of wood and mount dowels or threaded rods that are spaced to hold the connectors while allowing the cable to slide between the rods. Put vinyl tubing over the rods and ensure that the tubing sticks out beyond the end of the rod so that if someone bumps into it they hit vinyl tubing rather than the wood or metal rod.
I'm going to build another cable holder. Take a flat piece of wood and mount dowels or threaded rods that are spaced to hold the connectors while allowing the cable to slide between the rods. Put vinyl tubing over the rods and ensure that the tubing sticks out beyond the end of the rod so that if someone bumps into it they hit vinyl tubing rather than the wood or metal rod.
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RF, Microwave, Ham Radio / Re: fake MPF102s from AliExpress
« Last post by Alex Nikitin on Today at 10:16:49 pm »Just curious. Is there anything special about MPF102? Could J304 be a suitable replacement?
Cheers
Alex
Cheers
Alex
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Repair / Re: Mig welder wire feeder controller board not working
« Last post by .RC. on Today at 10:06:07 pm »I have been doing the ear plugs on the wire for quite a few years now. I did at first have those special foam things, but earplugs are much cheaper. I do not so critical structural welds so I do put corrosion inhibitor on the wire as a roll may last quite some time. I cannot say I have had porosity issues because of it.
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Test Equipment / Re: Siglent SDS3000X HD and upgraded SDS1000X HD
« Last post by Martin72 on Today at 10:04:48 pm »I would rather enjoy the fact that there has never been so much “scope” for the money as there is now, instead of brooding about it.
Not so long ago, the 12-bit ADCs used were cited as one of the reasons why the 2000X HD was twice as expensive as the 2000X plus.
Now you can get them in a 500€ model.
Not so long ago, the 12-bit ADCs used were cited as one of the reasons why the 2000X HD was twice as expensive as the 2000X plus.
Now you can get them in a 500€ model.
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Projects, Designs, and Technical Stuff / Re: Reactive Source Resonant Transformer
« Last post by Benta on Today at 09:55:16 pm »Well..,
"This design posses (sic!) the potential to"... do something. Perhaps provide a therapy for AntiVaxxers? Or QAnon followers?
I dunno.
"This design posses (sic!) the potential to"... do something. Perhaps provide a therapy for AntiVaxxers? Or QAnon followers?
I dunno.
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FPGA / Re: Analog video output with FPGA ?
« Last post by Jaunedeau on Today at 09:55:06 pm »Since you mentioned using MCUs (I think?), note that generating RGB video at these resolutions would be plenty feasible with just a RP2040 and its PIO. But given its limited number of GPIOs, you'd probably have to limit the bit depth to something lower.
The PIO is plenty of fun and I'll try playing with PDM on the PIO, but with max overclocking and 4 bit depth per component, I would get only 3 samples per pixel with pwm and 160 px per line... still a bit low for my all grey / alternating black and white pixels problem. I even thought of a dual rp2040 solution with one acting as an SPI ADC, but the stm32g4 (170MHz, requires no external flash, $2.5 for one piece in 64pins package / 52 gpios and has an real datasheet ^^) seems a simpler solution if an R2R ladder + calibration can do the job.
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Test Equipment / Re: SDS800X HD Wanted Features
« Last post by tautech on Today at 09:54:12 pm »How about making the tabs a tiny bit smaller too?Not possible without sacrificing space needed for indication of channel settings.
BW limit, Hidden (but active) etc.
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Beginners / Re: LiPo battery charging problem
« Last post by amyk on Today at 09:53:26 pm »I assume this is a 3s pack? Yes, there are lion cells which are rated at 4.4v full:
https://electronics.stackexchange.com/questions/519625/4-4v-li-ion-polymer-battery
The disadvantage of charging them to less than 4.4v is lower capacity, but the advantage is they'll last longer.
https://electronics.stackexchange.com/questions/519625/4-4v-li-ion-polymer-battery
The disadvantage of charging them to less than 4.4v is lower capacity, but the advantage is they'll last longer.