James Morris
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James Morris
jmorris
I finally bought a USB microscope and wow does it help with reverse engineering RF circuits. Quite an interesting & surreal world down there, too. This is from a 60 GHz wireless backhaul device. The RF wavelength is about 4.5mm.
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James Morris
jmorris
Large discone antenna in Arizona, covers 3-30 MHz. Licensed amateur operators can use this, at the Titan Missile Museum. I didn’t have a radio with me.
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James Morris
jmorris
Collected various bits of 80s surplus over a couple of years and now I can “see” signals from DC to sub-millimeter (300 GHz+), in theory at least. This is a 25 GHz signal.
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James Morris
jmorris
DIY window feed through for running RF cables from inside to outside. You can buy these but I had the parts.
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James Morris
jmorris
@oshpark @kicad Now verified to work with the HMC doubler as expected. Thanks for making this possible! I plugged the laminate specs from your site into a couple of calculators and they were in close agreement, as are the test results. 4-layer is the next step. I'll publish the design & will be presenting the overall project at Microwave Update (MUD) in a couple of weeks.
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James Morris
jmorris
Running make -j32 to build a kernel on my new work workstation. Takes about a minute, in total silence.
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Here's another 3D print project: a mounting bracket for W1GHZ dual-band microwave feed horns (10 GHz + 24 GHz).
https://github.com/xjamesmorris/dual-band-10-24-ghz-feed-mount
#amateurradio #hamradio #3dprinting #rf #microwave
https://github.com/xjamesmorris/dual-band-10-24-ghz-feed-mount
#amateurradio #hamradio #3dprinting #rf #microwave
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@mcdanlj I will look into that, thanks for the tip. This is stainless because it was 3D-printed -- the design is not economically viable to me as a CNC project, and would also then require split block machining and/or EDM. Here it is after sanding (it would be better to mill the end), alongside a surplus piece of WR15 waveguide.
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James Morris
jmorris
Tapping stainless steel with a small diameter bit is a little stressful 😬
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James Morris
jmorris
Published 3D print & model files for a mounting bracket for the Leo Bodnar mini GPSDO device. These are commonly used in VHF+ amateur communications as 10 MHz references for use with timing-critical weak signal modes and for frequency-locking microwave & mmwave equipment.
I'm using the CERN-OHL-W license, which seems best for design files.
https://github.com/xjamesmorris/bodnar-gpsdo-mount
#electronics #hamradio #amateurradio #osh
I'm using the CERN-OHL-W license, which seems best for design files.
https://github.com/xjamesmorris/bodnar-gpsdo-mount
#electronics #hamradio #amateurradio #osh
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James Morris
jmorris
The results are in, with 18 votes. I kind of like bsky but not seeing a critical mass of people in my areas of interest.
If you answered other, please feel free to explain.
In honor of this landslide vote, here's a photo of my latest tinkering: making pipecap filters for an 11 GHz RF multiplier (using the W1GHZ board & design). I'll use brass M3 tuning screws once some arrive from McMaster-Carr, although I'd be interested to see if they are very different to stainless steel. And yes, I had to order them online after not finding any metric brass fasteners locally. Why not use SAE screws? Standard metric screws have much higher TPI, even more than fine-thread SAE. This will provide better mechanical stability & finer tuning, but then again, I'm not building a spaceship here, so 🤷
#hamradio #amateurradio #microwave #rf #nerds #fediverse
RE: https://social.kernel.org/objects/81c8273c-6a3f-43d9-bfc9-673541118280
If you answered other, please feel free to explain.
In honor of this landslide vote, here's a photo of my latest tinkering: making pipecap filters for an 11 GHz RF multiplier (using the W1GHZ board & design). I'll use brass M3 tuning screws once some arrive from McMaster-Carr, although I'd be interested to see if they are very different to stainless steel. And yes, I had to order them online after not finding any metric brass fasteners locally. Why not use SAE screws? Standard metric screws have much higher TPI, even more than fine-thread SAE. This will provide better mechanical stability & finer tuning, but then again, I'm not building a spaceship here, so 🤷
#hamradio #amateurradio #microwave #rf #nerds #fediverse
RE: https://social.kernel.org/objects/81c8273c-6a3f-43d9-bfc9-673541118280
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James Morris
jmorris
Weekend tinkering: finally made enough room for a microscope on my bench and looked at small things. The chip of interest is 0.7mm wide: a ~60 GHz amplifier.
#hamradio #amateurradio #electronics #rf #mmic #microwave #millimeterwave #mmwave
#hamradio #amateurradio #electronics #rf #mmic #microwave #millimeterwave #mmwave
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