@RFDave@mastodon.social avatar

RFDave

@RFDave@mastodon.social

EE, RF HW engineer doing what I can on the edge of the Milky Way. He/Him

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jeffjarvis, to random
@jeffjarvis@mastodon.social avatar

Guess what Galloway has to say about DEI https://www.tiktok.com/t/ZTLV4kLE8/

RFDave,
@RFDave@mastodon.social avatar

@jeffjarvis wait I bet he’s a big fan /s

azonenberg, to random
@azonenberg@ioc.exchange avatar

New thread on my big ongoing embedded project since the other one was getting too big.

To recap, this is a pilot project for a bunch of my future open hardware T&M and networking projects, validating a common platform that a lot of the future stuff is going to run on.

The primary problem it's trying to address is that I have a lot of instrumentation with trigger in/out ports, sometimes at different voltage levels, and I don't always have the same instrument sourcing the trigger every time.

So rather than moving around cables all the time and adding splitters, attenuators, amplifiers, etc. to the trigger signals I decided to make a dedicated device using an old XC7K70T-2FBG484 I had lying around.

Of course, as with any project, there was feature creep.

I'm standardizing on +48V DC for powering all of my future projects as it's high enough to move a lot of power but low enough to be mostly safe to work around live. So I needed to design and validate an intermediate bus converter to bring the 48 down to something like 12 for the rest of the system to use.

The FPGA has four 10G transceiver pairs on it. I used one for 10GbE (not that I need the bandwidth, but I was low on RJ45 ports on this bench and had some free SFP drops) and the rest are hooked up to front panel SMA ports (awaiting cables to go from PCB to panel) to generate PRBSes for instrument deskew.

Since I'm pinning out the transceivers and am planning to build a BERT eventually, I added BERT functionality to the firmware as well (still need to finish a few things but it's mostly usable now).

And since I have transceivers and access to all of the scope triggers, it would be dumb not to build a CDR trigger mode as well. That's in progress.

RFDave,
@RFDave@mastodon.social avatar

@azonenberg nice looking assembly. Is that hardline?

Green_Footballs, to random
@Green_Footballs@mastodon.social avatar

Honestly never imagined I’d see a worse president than Richard Nixon.

I was just a sweet summer child then.

RFDave,
@RFDave@mastodon.social avatar

@Green_Footballs So far 😩

RFDave, to random
@RFDave@mastodon.social avatar

@futurebird do you have any idea what is going on here? We’re in Maryland, near Washington DC. I saw this in the early evening, about 6pm or so.

RFDave, to random
@RFDave@mastodon.social avatar

I might have a problem. Not enough time to study, but enough money to buy books.

rasterweb, to random
@rasterweb@mastodon.social avatar

Guys, I think you missed the "y" in that string.

RFDave,
@RFDave@mastodon.social avatar

@rasterweb the plural of “y’all” is “all y’all”

jeffjarvis, to random
@jeffjarvis@mastodon.social avatar

The Times continues to live in 1636, when Harvard was America's only college:
After a Year of Turmoil, Harvard’s Applications Drop https://www.nytimes.com/2024/03/29/us/harvard-applications-admissions.html?pvid=RWapM2i1CUhasuSNLzrqSePl&ugrp=c&smid=tw-share

RFDave,
@RFDave@mastodon.social avatar

@jeffjarvis Harvard, the hedge fund with an educational side hustle.

RFDave, to random
@RFDave@mastodon.social avatar

Anyone recognize this IC Marking? this is from an RF amplifer, and it's one of the final drive transistors. I suspect it's some variant of FET, but I don't recognize the marking.

philpem, to random
@philpem@digipres.club avatar

Sun's out so I've been out in the garden assessing some of the jobs wot need doing. I figured a nice easy one is mounting the wall bracket for the new garden hose (which will nicely get that thing off the floor of the workshop). Catch is, to get to the back garden, I need to extend the garden hose.
Meet the Hozelock connector. Basically universal in British gardens, and knocked off by about a dozen other companies. 🧵

RFDave,
@RFDave@mastodon.social avatar

@philpem yeah, it took me like a week of searching on various store websites to understand how they expect this to work. In the US the vendor seems to be Melnor, and they have the same features. They do have brass ones available, which seem like they would last longer.

there’s also a vendor “orbit“ that has a similar product, but they have big rubber ring around the movable disconnect collar which would disconnect on me when I was using a sprayer so that got tossed

lcamtuf, to random

deleted_by_author

    •
    RFDave,
    @RFDave@mastodon.social avatar

    @lcamtuf honestly, it’s all about the tires.

    RollingStone, to random

    Rudy Giuliani’s legal troubles just keep piling up. https://www.rollingstone.com/politics/politics-news/rudy-giuliani-sued-unpaid-legal-bills-1234827610/

    RFDave,
    @RFDave@mastodon.social avatar

    @RollingStone

    kwf, to random
    @kwf@social.afront.org avatar

    Why is it so hard to get a DC-DC to step 80V down to 13.8V?

    RFDave,
    @RFDave@mastodon.social avatar

    @kwf for a switcher, the switch duty cycle is going to be tiny, so hard to design and low efficiency. Try 2 stages with an intermediate voltage rail

    RFDave,
    @RFDave@mastodon.social avatar

    @ren Brian Ibbot over at coverville.com has been doing a covers podcast for years. Excellent stuff

    mattblaze, to DEFCON
    @mattblaze@federate.social avatar

    All the videos for the 2023 main stage are now up (with proper subtitles) on our YouTube channel:

    https://www.youtube.com/@defconvotingvillage/videos

    RFDave,
    @RFDave@mastodon.social avatar

    @mattblaze perfect place for my election judge stipend to end up in!

    jeffjarvis, to random
    @jeffjarvis@mastodon.social avatar

    Lord. David Brooks is on Morning Joe revealing his essential conservatism, lamenting that we're not taught to be nice to each other, as Joe laments the phone replacing the the Constitution and Bible.

    RFDave,
    @RFDave@mastodon.social avatar

    @jeffjarvis I too remember the days when folks weren’t paying attention to where they were walking because they were reading the Bible as they walked.

    RFDave, to random
    @RFDave@mastodon.social avatar

    A friend called this a war crime. I mostly agree with her

    rasterweb, to random
    @rasterweb@mastodon.social avatar

    I’m going to Maryland today. 🦀

    RFDave,
    @RFDave@mastodon.social avatar

    @rasterweb be ready for some heat and humidity 💦💦💦

    bitsavers, to random

    Done with Electronic Design for now, starting on late 80s early 90s EDN. This is going to take a while, most issues are over 300 pages long.
    http://bitsavers.org/magazines/EDN

    The 90s was a fascinating decade. RISC, Fuzzy Logic, Windows eating the world, CPUs going from sub 100MHz to a GHz.

    Oh, and that "web" thing.

    The 20xx's has been "the century of suck"

    RFDave,
    @RFDave@mastodon.social avatar

    @philpem @bitsavers at one point I had 6 or 7 binders full of ripped out articles from EDN and Electronic Design that I was planning on using as reference.

    paulrickards, to retrocomputing
    @paulrickards@mastodon.social avatar

    Who’s going to the VCF/System Source Swap Meet outside of Baltimore next Saturday July 22?

    More info: https://vcfed.org/system-%20source-swap-meet/

    Accessible PDF flyer: https://vcfed.org/wp-content/uploads/2023/05/System-Source-Swap-Meet-Flyer-2023.pdf

    RFDave,
    @RFDave@mastodon.social avatar

    @paulrickards I’m going to try to make it. I’d like to bump up the number of old RPN calculators I’ve got stashed in the basement

    freemo, to random
    @freemo@qoto.org avatar

    so i decided im putting back up my HF antenna, doing it all new! I'm excited.

    RFDave,
    @RFDave@mastodon.social avatar

    @freemo @brouhaha the only thing SWR tells you is how well something is matched to 50ohms. There’s no information about radiating efficiency there.

    jeffjarvis, to random
    @jeffjarvis@mastodon.social avatar

    Subhed: "In a divided country, a clean look and a neutral color palette is the aesthetic comforting communities around the country."
    Oh, come on. The polarization trope ad absurdum.

    The Modern Farmhouse Is Today’s McMansion. And It’s Here to Stay. https://www.nytimes.com/2023/07/07/realestate/modern-farmhouse-suburbs.html?smid=tw-share

    RFDave,
    @RFDave@mastodon.social avatar

    @jeffjarvis there are too many column inches and broadcast hours to fill.

    North, to random
    @North@chaos.social avatar

    I am extremely tired of feeling like shit and the shrinking invisible fence of agoraphobia. I hate that I burned out so hard that I've potentially wrecked my summer after working so hard not to let winter make me crazy. I hate dumping this shit onto strangers' timelines because every other online community has been systematically destroyed. I know I'll get better, because I've done it before, but right now it just fucking sucks.

    RFDave,
    @RFDave@mastodon.social avatar

    @North sending good vibes. Remember to breath.

    jeffjarvis, to random
    @jeffjarvis@mastodon.social avatar

    Times discovers real cause of inflation...
    Companies Push Prices Higher, Protecting Profits but Adding to Inflation https://www.nytimes.com/2023/05/30/business/economy/inflation-companies-profits-higher-prices.html?smid=tw-share

    RFDave,
    @RFDave@mastodon.social avatar

    @jeffjarvis the Bloomberg odd lots podcast had a show on this issue a few weeks ago

    jeffjarvis, to random
    @jeffjarvis@mastodon.social avatar

    They call this news.
    Do Dress Sneakers Belong in the Oval Office? https://www.nytimes.com/2023/05/19/style/do-dress-sneakers-belong-in-the-oval-office.html?smid=tw-share

    RFDave,
    @RFDave@mastodon.social avatar

    @jeffjarvis imagine it they were wearing w tan suit with those shoes 😂

    mcnees, to random
    @mcnees@mastodon.social avatar

    Happy May 19.

    RFDave,
    @RFDave@mastodon.social avatar

    @mcnees TIL there is a Steely Dan day 🎧

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