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Also, I love that on page 1 of this thread I complained that I’m not doing electronics and that it’s holding me back but now I’m designing PCBs. I’m trying to make a kind of “Megapixie” with everyone’s good mods in. Edit: oh. Well I thought it was page 1 thehustler fucked around with this message at 01:44 on Dec 14, 2019 |
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Dec 13, 2019 21:40
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COOL CORN posted:Just bang out some CW on a 5W QRP rig ya goobers!!! OK! I took some humidity saturated old test equipment and turned it into a shitbox class radio.  modified chinesium forty-9er using the function generator as a very drifty oscillator. LP filter added where the mixer input crystal was. Sounds like poo poo on transmit and has a front end as vast as the Yukon. Works though! dds on order as the function generator uses a oddball op amp triangle wave oscillator that looks like it was originally a tube circuit. It's very temperature dependent. I can swing it 10KHz using a heatgun. With a several hour warmup, stability is +/- 1500Hz. DDS then some better filters then superhet conversion. thehustler posted:I’ve just bought a pixie kit and I’m having fun building it. I was wondering if the supplied transistors, an S8050 and S9018 would be the best NPN transistors to use? Would I get any better performance with a 2N2222 or something? I know I have to think about frequencies as well. use the 8050 as a preamp if you seek more power out. The above junker I built uses an 8050 as a preamp to a 2SD882. I'd personally work on receive/transmit quality before upping the power. Projects beget more projects. Lost another moto comms system to water ingress. $20 baofeng to the rescue. Took the stock headset with the baofeng kit and merged it with an old moto headset.   Send it! thehustler posted:Also, I love that on page 1 of this thread I complained that I’m not doing electronics and that it’s holding me back but now I’m designing PCBs. I’m trying to make a kind of “Megapixie” with everyone’s good mods in. it's a good hobby from this perspective. It pushes you to make your poo poo not suck as the results are right there in your face. cursedshitbox fucked around with this message at 07:06 on Dec 14, 2019 |
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Dec 14, 2019 06:59
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I want to know more about that Rc monster truck with the aperture science wheels
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Dec 14, 2019 18:29
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Jim Silly-Balls posted:I want to know more about that Rc monster truck with the aperture science wheels It's a model I built of the ARES rover from "The Martian"  6 wheel drive, powered by a homebrew 3S 15AH battery that can deliver 120A. The main drive motor is a 775 which you'd find in most cordless drills or power wheels jeeps. It weighs around 20lb and has a payload of 10lb currently. The powertrain can propel this vehicle north of 30mph. It can also drive autonomously. Not very well with a raspberry pi, a Jetson Nano is gonna get dropped in soon. If it can't stay cool I'm going to cnc a waterblock for it, and if i'm going down that hole, might as well get the motor controller and the motor too. It's getting a partial redesign currently to be more usable, and will eventually have some content for this thread with a UHF/VHF radio installation.  Full album here: https://imgur.com/a/r2zueJH The goal of this rover was to design and build a stable hardware platform to learn better software engineering with. In the album there's a 6dof arm that was my first attempt using someone else's work.
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Dec 14, 2019 20:45
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That. owns. Is there video of it?
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Dec 14, 2019 20:54
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Jim Silly-Balls posted:That. owns. have a few videos from right after the build, If it comes along over xmas break i'll get some updated content. not using autonomy in these. It's limited to about 3/8 speed. https://www.youtube.com/watch?v=d6xReD0ZyvA https://www.youtube.com/watch?v=CP9fZM4ivok https://www.youtube.com/watch?v=ypeDZib6yLg At full tilt it'll need some software to work with its steering system (think GM's quadrasteer and how its implemented) The donkeycar software its running is designed for small 4 wheeled vehicles indoors on a track. It'll do L2 or L3 autonomy on the pi. I've altered their software to make it work for this vehicle which has naturally caused some instabilities. The purpose of their software was to test the hardware. After xmas break I'm going to upgrade it to a Jetson and scratch write new software. The software and some electronics ideas are: L4/L5 autonomy using classifiers, slam, etc. give it a gps coord and it will sort the rest out using 4 cameras and onboard sensors. Give it a perimeter and it will explore the area using its cameras and sensors. direct control from *anywhere*. Preferably off cellular networks as it likely won't have cell coverage. Think UHF/VHF short range to HF long range. (it will have a local outstation that's yet to be built) Self protection via polling various sensors to avoid driving into poo poo and damaging the vehicle. Think of how back up sensors work in the automotive industry. Lidar or ultrasonics will work good for this purpose without the need to run a classifier on the GPU. high speed stability using onboard IMUs. It only has one brake and one motor so torque vectoring can't be done. With front and rear steering some hysteresis can be done. All 3 differentials are stock open diffs, probably gonna leave it that way. Inductive charging, screw having a barrel jack. The BMS needs an upgrade for this too, which by then I should know how to implement it. Quickly attachable and configurable I/O for adding peripherals like a spherical cameras, metals detector, sample collecting using a 4dof arm. (my husband is working on the I/O that goes on it at the same time I'm working on the platform) It's mainly designed to function in the desert and to explore abandoned mines without needing a tow. If I can build the software so to not be a nearly meter long roomba that drives by braille it'll work fine in most mines of the southwest. An awesome future project would be to launch drones from it to explore vertical mine shafts.
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Dec 14, 2019 22:37
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That is sick and I know this isnt the thread for it but I find that massively interesting
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Dec 14, 2019 22:56
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I bought the RX package from DXpatrol (QO-100) and i am finally having a stable good experience. Here i saw somebody having fun on the narrow band 
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Dec 20, 2019 17:50
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Hi amateur radio thread! I've been wanting to get into this for a few years now but haven't had the motivation. I have the technician study book. I've ready online from numerous people to just take the test and figure everything out afterwards. However, I've taken some sample tests and those questions are pretty hard for me. Should I just go through the book cover to cover a few times or is there another strategy you guys used? The book is quite long. Any advice for getting my license?
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Dec 20, 2019 23:03
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Pennywise the Frown posted:Hi amateur radio thread! make an account at qrz.com and repeatedly take the practice tests until you get 80 or better consistently
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Dec 20, 2019 23:59
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Same except hamstudy.org
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Dec 21, 2019 00:29
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Please do not post the url for my culinary academy
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Dec 21, 2019 03:01
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I used the app on my iphone. The one Roy Watson made. I also read though this: https://www.kb6nu.com/study-guides/ Take long shitter breaks at work, and take a few section quizzes on the phone.
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Dec 21, 2019 03:25
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DevNull posted:Take long shitter breaks at work, and take a few section quizzes on the phone. haha I did that exact thing as well, also with watson's app on android. I mentioned qrz rather than hamstudy because I feel like it's more responsive and I mean you're gonna end up with an account there anyway e: study for tech and general at the same time and do those in one shot. then study for extra the same way (it's question pool is about the same size as those two put together) and go back and take that one. d0s fucked around with this message at 05:32 on Dec 21, 2019 |
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Dec 21, 2019 05:29
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yeah don't fail to sit the General if you pass tech. You have to wait till they grade your tech to know if you can attempt, but if you passed, go for it. There's literally no downside besides another 40 mins of your time, and you might walk away with those sweet HF creds.
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Dec 21, 2019 05:36
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Progressive JPEG posted:Same except hamstudy.org Same except hamexam.org. (seriously , either of those are fine)
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Dec 21, 2019 05:46
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Ok, I have the kb6nu study guide open in a tab that I'll check out throughout the day and I signed up at hamstudy.org (sorry just picked one of the 3). I'll start taking exams here and there until I get up to 80. I guess I have some work to do now.
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Dec 21, 2019 06:45
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as far as I can tell (correct me if I'm wrong) those sites don't give you instant feedback when you get a question right/wrong and instead grade you at the end. this can be either better or worse for you depending on how you learn but I liked seeing it in real time on qrz. on the other hand if you're trying to simulate the actual test day that's exactly what you don't want. e: I also was not using any other book, relying only on either my knowledge or the feedback from the test itself to learn the right answers. if you're also using a book the hamstudy/exam tests would be better d0s fucked around with this message at 00:53 on Dec 22, 2019 |
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Dec 22, 2019 00:50
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d0s posted:as far as I can tell (correct me if I'm wrong) those sites don't give you instant feedback when you get a question right/wrong and instead grade you at the end. HamStudy has a mode where you get instant feedback with the right answer as well as some rationale that you can use to learn or hunt down why it's the right answer. License Prep question myself, aside from memorizing the entire pool, what's a good resource for studying for Extra? I've been a General for way too long and want to remedy the situation.
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Dec 22, 2019 03:58
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Zaepho posted:HamStudy has a mode where you get instant feedback with the right answer as well as some rationale that you can use to learn or hunt down why it's the right answer. Ah thanks for clearing that up, I didn't really explore the site much. For extra just get into it and do practice tests and stuff just like with tech and general, I didn't find it too hard and I'm not an engineer or anything. I'm an electronics technician for a company that makes specialized test equipment used on cell antenna towers so I guess I'm used to a lot of the terminology and the electronics specific stuff but I mostly just crammed the answers. It took me maybe a week of an hour a day taking practice tests on my PC and using watson's app on my phone when I could. you'll feel like you're making no progress at all first then the scores will start to shoot up, once you're making passing scores continue to take the practice test for a few more days to be sure you haven't missed anything
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Dec 22, 2019 05:09
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I don't (appear to) have aprs coverage. Are there any other packet networks that are worth trying? I can hit a voice 2m repeater network nearby, what other things are likely to be around? I took my APRS setup to the family cabin and its -completely- dead. I didn't get a decodable packet. My outgoing packets didn't hit an igate either. (same setup at home is getting solid APRS traffic) I know there is an igate ~30 miles away, would I be likely to succeed if I built a yagi and tried again? Rolling plains of the midwest aside. Also, my NanoVNA-H arrived, and I gotta say this thing kicks rear end for the price. Its awesome to have feedback other than SWR. Looking forward to getting into the magic of building filters with this thing too. edit: tech currently. general in the next month or two hopefully. horse_ebookmarklet fucked around with this message at 06:38 on Dec 22, 2019 |
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Dec 22, 2019 06:36
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I was wondering why hamstudy.org wasn't connecting from here in NZ, looked like it was down all day On a lark I try hopping onto a VPN so that it looks like I'm connecting from USA and suddenly the page loads fine. Switched over to Australia and it works fine from there too Gotta keep all the kiwi hackers out I guess
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Dec 22, 2019 09:03
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horse_ebookmarklet posted:I don't (appear to) have aprs coverage. Are there any other packet networks that are worth trying? I can hit a voice 2m repeater network nearby, what other things are likely to be around? What's your antenna setup like? I couldn't decode a single thing with a large mobile antenna indoors (save for one weird night when propagation was insanely good) but once I put a comet GP-3 on a 20 foot mast outside they flooded in, now I run a 24/7 igate with pretty great coverage: 
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Dec 22, 2019 09:39
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I tried to check into a net on America link yesterday but after hours of check ins I gave up .
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Dec 22, 2019 12:53
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Partycat posted:I tried to check into a net on America link yesterday but after hours of check ins I gave up . Huge digital nets can be a drag, no fun waiting to speak when you're checkin #39 and the list is only at #7. 
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Dec 22, 2019 16:44
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d0s posted:What's your antenna setup like? I couldn't decode a single thing with a large mobile antenna indoors (save for one weird night when propagation was insanely good) but once I put a comet GP-3 on a 20 foot mast outside they flooded in, now I run a 24/7 igate with pretty great coverage: I'm using a Yaseu HT with a srh77ca standing outside. A mast and real antenna are a bit out of the budget at the moment. I was thinking a tape measure yagi or (jpole? dipole?) hanging from some trees. This location is fairly remote and without internet.
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Dec 22, 2019 17:28
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horse_ebookmarklet posted:I'm using a Yaseu HT with a srh77ca standing outside. Yeah you probably don't need a $100 antenna, just get something up high and you should be good. Anything like that will be a dramatic improvement over a HT antenna
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Dec 22, 2019 23:07
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horse_ebookmarklet posted:I'm using a Yaseu HT with a srh77ca standing outside. I've been pretty impressed with the DBJ-2 antenna. https://countycomm.com/products/dual-band-roll-up-antenna-government-pack Laid out flat indoors I could clearly pick up one of the SSTV transmissions from the ISS on a crappy Baofeng. If you decide to go with something like a yagi, keep in mind that they're directional by design, which means you'll both get it up into the trees and get it into the correct orientation, which sounds like a pain.
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Dec 22, 2019 23:40
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Zaepho posted:License Prep question myself, aside from memorizing the entire pool, what's a good resource for studying for Extra? I've been a General for way too long and want to remedy the situation. I used hamtestonline a few years back. It was paid, like $20 iirc. I had also used them for the tech (pre Hamstudy.org days) and I really like it, but their extra 'course' was pretty much just brute memorization. Studied about 2 months before taking the test. I skipped the math parts because I hate math, and got 49/50 on the test. What have I done with my extra? Other than getting a sweet 1x2 call and some VE sessions, gently caress all.
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Dec 23, 2019 05:28
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I'm sorta enjoying tracking down RFI in my house. Its nice to actually determine what the problem is, but then fixing it is turning out to be a pain. I have a raspberry pi connected to a monitor via HDMI. 1920x1080 @ 60Hz works out to a ~148.5Mhz pixel clock, and its got a bunch of harmonics. Using 3 ferrite cores I was able to suppress the harmonics and knock down the fundamental, but now I have a solid signal hanging out just outside of band. Annoying but workable. I've got better hdmi (with ferrites) cables on order. Seems like the direction I'm headed is every cable in the office has cores on it?
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Dec 23, 2019 06:17
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Yeah, bite the bullet and buy one of the big 50 packs or whatever. that reminds me to buy another load of ferrite, thx.
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Dec 23, 2019 18:49
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It’s been a couple years since the last ferrite haul but I remember getting trays of big honkin fair-rite brand ones from arrow.com for way cheaper than I could find anywhere else at the time. Keep the trays they come in because they’re great for storage. That said I do remember some specific ones being slightly cheaper on kf7p.com (whose outdoor access panels are amazing btw)
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Dec 23, 2019 20:41
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Progressive JPEG posted:kf7p.com (whose outdoor access panels are amazing btw) 100% agree. I had one on my old barn, and will put one on the new one as soon as it and the tower have been built.
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Dec 23, 2019 23:06
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Looking for a HF rig and the IC7300 is on sale right now for $900 after rebates. Its very hard to say no to a price like that... I think know the answer to this next question, but I am going to ask it anyway. How badly do I need a proper RF ground if I'm first getting into this? The ground is frozen, I can't drive a rod in. I probably can't resist throwing my old monitoring antenna up in a tree. I can disconnect everything and pull down the antenna when not in use.
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Dec 30, 2019 04:52
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horse_ebookmarklet posted:The ground is frozen, I can't drive a rod in If you can't do it properly frozen you probably can't do it properly period. Here's the trick: rent a hammer drill. You don't even need a bit. Just put your 6' ground rod in the chuck and watch it disappear into the ground.
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Dec 30, 2019 05:39
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I've driven them by hand before, and I can definitely do it in the spring, but right now its frozen 24 inches down. The hammer drill is a really good idea, I'll give that a shot.
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Dec 30, 2019 08:43
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Motronic posted:If you can't do it properly frozen you probably can't do it properly period. Do you mean rotary hammer?
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Dec 30, 2019 10:43
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Progressive JPEG posted:Do you mean rotary hammer? Yeah, sorry - that's exactly what I mean. horse_ebookmarklet - frozen soil that you can otherwise get through when it's not all that hard. That was kinda my point. It's the rocks and hardpan that get you. If you can drive a rod fine in the summer you can make it through the first - how deep does it freeze there? - by hand probably.
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Dec 30, 2019 17:00
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Just chuck it on the ground and piss on it
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Jan 1, 2020 22:10
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So I recently bought a bigger jeep and I'm looking at antenna mount options. The tire carrier it came with has this accessory mast on top which they suggest using for antennas.  Is this a good / bad idea? I'm just planning on running a VHF/UHF setup and was thinking of something like a comet SBB-5NMO up ontop of that mast. I'm a noob with antenna setups but its listed as a "ground independent" antenna. Does that mean I don't need to have a good ground for it ?
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Jan 2, 2020 00:50
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