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C radio s: still meaning to hook up some antennas to an sdr and some Linux to a computer to gnuradio some crap
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Dec 23, 2014 06:21
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I put a 1.3ghz video receiver on a helmet do you wanna see
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Dec 23, 2014 06:23
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A Yolo Wizard posted:I put a 1.3ghz video receiver on a helmet do you wanna see yes! holy crap
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Dec 23, 2014 07:31
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Jonny 290 posted:yes! holy crap Really because I asked you three times in irc last week and pasted it in and you never responded  A WIP I STILL NEED TO VELCRO A 2200mah LIPO TO THE OTHER SIDE OF MY HEAD
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Dec 23, 2014 08:48
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Jonny 290 posted:hahaha, this is the most magical experience. love it. same thing happened with my faroudja line quadrupler/deinterlacer. i plugged it in and it went BANG and sparks shot out of the back. an inspection of the interior showed that something blew up well enough that it left no recognizable remains other than a blast mark on the cover panel it works fine 
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Dec 23, 2014 09:17
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A Yolo Wizard posted:Really because I asked you three times in irc last week and pasted it in and you never responded hello is this like a fpv thing, what do you use it with, tell me about it
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Dec 23, 2014 09:37
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did an experiment with a 1:9 long wire balun and a 1 meter steel whip yesterday, it tuned up on all bands except 24 MHz+ where the power supply shut down due to RFI once the SWR started to come down and the radiation increased, considering there's no shielding at all in the supply that's not surprising sensitivity wasn't very good though, but considering it was inside that's not very surprising plan for apartment antenna is to try the largest whip i can get away with and using the railing on the balcony as a ground plane, it's all metal and mounted in concrete so that should work fairly well, i'll need a set of coils to ease matching of the whip at lower frequencies (will be a pretty crazy voltage at the antenna though) little tarhell II looks tempting with the remote controlled coil + length selection, but that costs almost as much as my radio did so it'll have to wait alternate plan it to just string up as much wire as i can and use the 1:9 balun my VHF/UHF antennas also use the railing as a ground plane, so i'll probably need current baluns for all the other gear mounted there to avoid crazy feedline radiation coming back in A Yolo Wizard posted:Really because I asked you three times in irc last week and pasted it in and you never responded what receiver hardware are you using? i know some emcom hams who might be interested in building/buying something like that
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Dec 23, 2014 12:05
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Crankit posted:hello is this like a fpv thing, what do you use it with, tell me about it porn
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Dec 23, 2014 16:53
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A Yolo Wizard posted:Really because I asked you three times in irc last week and pasted it in and you never responded hater! i scroll in irc so hard and my highlight's hosed up. dont weep. thats badass hahaha i love it. longview posted:did an experiment with a 1:9 long wire balun and a 1 meter steel whip yesterday, it tuned up on all bands except 24 MHz+ where the power supply shut down due to RFI once the SWR started to come down and the radiation increased, considering there's no shielding at all in the supply that's not surprising hm ok so apartment dweller, steel railing, typical setup in that situation got it. the mfj-1622 is an option but after you see what it is, you're going to just go build one out of a piece of metal strap and a pvc pipe and a whip, hahah. i would say right now to not even worry about 75/80 meters, and to only casually care about 40. you're just not going to have enough metal out there to get good s/n ratios on 40 meters, especially if the euro broadcasters are partying. really i'd think if you could get the classic 108 inch (2.6ish meters?) CB whip mounted on the balcony either horizontal or at a 45 degree angle, it will be effective on 20 through 10 meters. below that its just not gonna have the radiation resistance for good effeciency even if you can tune it.
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Dec 23, 2014 17:28
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longview posted:did an experiment with a 1:9 long wire balun and a 1 meter steel whip yesterday, it tuned up on all bands except 24 MHz+ where the power supply shut down due to RFI once the SWR started to come down and the radiation increased, considering there's no shielding at all in the supply that's not surprising http://www.readymaderc.com/store/index.php?main_page=product_info&cPath=11_34_44&products_id=1015 There are lots of these on ebay as well I think (as well as ones that do .9-1.3ghz, 2.4, 5.8). I have the 800mw transmitter (which according to some other guy spits out closer to 1-1.75 watts depending on the channel) I thought about gettin a bigger more directional antenna like this or LIKE THIS  but that isn't really necessary for mini quad fpv.Crankit posted:hello is this like a fpv thing, what do you use it with, tell me about it yes I'll show you later moron izzard fucked around with this message at 19:16 on Dec 23, 2014 |
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Dec 23, 2014 19:13
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linear supply is fixed! replaced the old caps with 3x10000µF, we had to mount them with silicone glue to the base plate due to space constraints but these are brand new and much higher quality, inrush did dim the lights a bit but that was mostly due to a somewhat undersized extension cord  the wires were a compromise, but it worked fine at 50W at least, and i added a 100µF/400V switch mode cap to the output to improve load regulation slightly + i couldn't find the 47µ that the schematic indicated was there to begin with. adding a 10000µF to the output seemed risky wrt. stability turns out the raw DC voltage is 24V, my low side regulated design only needed a 16V input for 14V out, but it's not worth the effort to rewire this design just need to add some rubber pads around the chassis to dampen the hum it produces when i get it home
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Dec 23, 2014 22:00
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   pretty sure this is weatherfax or something like that but im not sure what im loving up here seeing as qsstv spit out 3 frames of what looks like 1 frame
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Dec 24, 2014 22:03
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deffo weatherfax. mode set wrong maybe?
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Dec 24, 2014 22:14
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Palace of Hate posted:
I'm seeing line art goatse
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Dec 25, 2014 04:36
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A Yolo Wizard posted:yes I'll show you later  shoulda got a frame with a longer top
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Dec 27, 2014 02:42
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is that a WASD keyboard? how do u like it? also keep us updated on that b/c im doing something similar but my buddy bagged out and im shouldering the whole thing.
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Dec 27, 2014 04:15
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A Yolo Wizard posted:
ok this still doesnt actually tell us what in the gently caress you've built just tell us the goddamn details don't be weird and evasive as if yospos might disapprove who gives a poo poo we're all nerds so show us the cool nerd stuff 
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Dec 27, 2014 05:18
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SO DEMANDING posted:ok this still doesnt actually tell us what in the gently caress you've built well to me it looks like a quadrotor drone with a fancy sort of antenna on it
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Dec 27, 2014 05:19
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i think it's a cloverleaf antenna that produces circularly polarised radiowaves
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Dec 27, 2014 05:52
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SO DEMANDING posted:ok this still doesnt actually tell us what in the gently caress you've built its a mini quad running a 1.3ghz vtx and a 433mhz uhf rx. I just finished assembling it and have to set up all the controls and then tune it and poo poo. i got my longer cord this week so I'll hopefully have this poo poo done next week. I have to install a groundstation communication module thing on my phantom this weekend and get my photogrammetry thing setup.
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Dec 27, 2014 09:32
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anyone else ever think sstv signals sound like a tree full of angry robot squirrels    also reccomend linux sstv software that isnt qsstv
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Dec 28, 2014 19:37
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14.230 is busy today 
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Dec 28, 2014 20:49
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Your TV looks like poo poo, twiddle the bunny ears
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Dec 28, 2014 22:31
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Bloody posted:Your TV looks like poo poo, twiddle the bunny ears      
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Dec 28, 2014 22:42
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Bloody posted:Your TV looks like poo poo, twiddle the bunny ears just for you I left the vfo on the digital channel for a while         digital mode dogs  reggo slow scan                         im thinkin ill do something to twit these on the tweeter automatically or something while leaving it run all the time switching between the channels based on signal strength
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Dec 30, 2014 03:40
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im 595 op james
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Dec 30, 2014 04:48
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Palace of Hate posted:im thinkin ill do something to twit these on the tweeter automatically or something while leaving it run all the time switching between the channels based on signal strength would
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Dec 31, 2014 05:34
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https://www.youtube.com/watch?v=teaxWYRH9A4
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Jan 1, 2015 00:58
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Jonny 290 posted:how did you connect it, did you run coax? i already have a coax run through my house so i'm just using that for now. two cable joins and a pre-amp, possibly more because i don't know what's in the wall. i also have some coax i will use if i do set it up outside which would leave me with one join and the pre-amps. so right now it's: - antenna - coax (6' or so) - pre-amp - joiner (i.e. wall plate) - more coax (40' or so) - joiner - even more coax (20' or so) - tv i've also been trying it with the pre-amp between the coax and the tv and that works but not quite as well i'm using the same setup to test inside and outside. i think my eavetroughs are interfering outside, but when i go further from the house it gets even worse, maybe due to neighbouring buildings e: this is all rg6 coax Cold on a Cob fucked around with this message at 22:09 on Jan 1, 2015 |
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Jan 1, 2015 22:04
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i did some adjustments on my TS-850SAT, I don't have a good signal generator so I couldn't do the sensitivity adjustments but I did all the band pass filter and DC/AF adjustments VCO voltages were slightly off so had to break out the precision trimmer tools 20 MHz master oscillator was slightly out of spec after warming up, adjusted it to around 1 Hz (spec is +-50), but I have a ~0.5 ppm TCXO module on order that will eliminate the need for adjusting that ever again nice thing about the 850 and probably all newer radios is the master time base is used to synthesize all the other frequencies in the radio, so no need to adjust hundreds of free running beat oscillators like I had to in the old FT-747GX, upgrading the 20 MHz reference automatically makes the radio run spot on frequency in all modes RF band pass filters were apparently adjusted by the dealer last year but I don't think they did a particularly good job, there's three sets of tunable filters for 40, 20 and 15 meters, all of them were tuned lower than the adjustment manual calls for so when I tuned from 7499 to 7500 (switching from the 7-7.2 MHz filter to the general 7.5-14 MHz filter) the noise on the input would go up around 20 dB here's my solution for putting a center frequency marker on the display of my old SA  a DDS generator tuned to the center frequency called for with a small antenna placed around the measurement point  worked out alright, no appreciable difference going between filter sets and no loss in sensitivity, all the filters were wide enough that they could easily overlap the other bands E: oh, and three pages in it calls for doing a power on test:  longview fucked around with this message at 00:16 on Jan 2, 2015 |
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Jan 2, 2015 00:13
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the greybeards on 14.230 are getting saucy today more: http://imgur.com/a/mGg2X
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Jan 2, 2015 00:35
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had lunch with some grandpas and my girlfriend left with this 
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Jan 2, 2015 20:56
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congrats! (and btw that's enough to dox u in like 3 days when it hits ULS, edit out city)
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Jan 2, 2015 20:58
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Jonny 290 posted:congrats! (and btw that's enough to dox u in like 3 days when it hits ULS, edit out city) w/e my old username is plenty
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Jan 2, 2015 20:59
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hahah true
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Jan 2, 2015 21:01
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Cocoa Crispies posted:had lunch with some grandpas and my girlfriend 
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Jan 2, 2015 22:42
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ok i realized i *have* to buy an oscilloscope because i need to govern the YOS beacon to like 5 milliwatts or something like that, and the only way that I can really see to do that is to set power into a resistor load and watching volts on the scope and doin math. i'm not buying a microwattmeter or whatever crazy lab poo poo for a $20 joke project but im not gonna get FCC'd either
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Jan 3, 2015 00:10
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now you have the chance to pick up some nice power detector ICs! The AD8307 covers a huge dynamic range and even comes in a DIP package, at 5mW you could easily sink the entire output power into a detector so that dynamic range will be useful since the measurements will be valid even with 40-60 dB of attenuation from the output into the detector then you just build a simple feedback loop to control average or peak power as needed and adjust it with a scope! hell, if you get a linear in volts converter you could probably use that control loop to do AM directly sort of like how you do FM by modulating the VCO directly effectively wasted a bunch of time today, but it was fun and ideologically proper: it started with a dremel and the T/R board in the TS850:   after soldering a SMA connector to the copper and strapping the antenna output over to the centre pin, I added a right angle SMA, semi rigid cable, some more grinding on the metal shielding that goes over the filter unit, I ended up with this:  finally i can sleep well at night, that horrid UHF connector is gone, replaced by a glorious N connector this may seem pointless, and it mostly is, but once I've replaced all the UHF connectors on my gear I can stop keeping UHF cables and plugs around in favour of N and SMA N connectors are far superior to the shielded banana plug design, so all my HF, VHF, UHF and eventually SHF gear can use the same set of cabling as needed, and mated N connectors are weatherproof so I don't have to tape up every single connector that's exposed to a light drizzle/humidity/occasional beer spills N connectors are slightly inferior to UHF at very low frequencies and high power (afaik just DC resistance), but the highest power I have right now is 100W, when I move up to kW amps I'll find some other fancy connector to use there next upgrade might be a separate RX antenna input, and I'm going to replace the old glass envelope GDT that protects the input with a modern GDT from Bourns, a solid 15x upgrade in rated current with improved specs all around longview fucked around with this message at 01:24 on Jan 3, 2015 |
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Jan 3, 2015 01:19
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nice work, yeah I have dreams of replacing all my stuff and standardizing on N for full-size and SMA for rx/mini lines, but then I look at the back of my antenna tuner and start doing checkbook math and enhhhhhhhhh
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Jan 3, 2015 01:22
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a real downside to SMA for that job is that it's loving huge compared to the other connectors in the radio (those horrible plug in connectors that always develop bad joints and are impossible to replace) I think these were silver plated, gonna have to clean them all some day because they look pretty nasty ideally I'd have used SMB but i don't have any of those around and they effectively require crimping tools making them a pain to make in a hurry also technically skirting the limits of rated power for a SMA and RG 405, trouble is they're only rated for 1 GHz and up, the breakdown voltage is still the same as RG-58 so should be fine plus the old interconnects don't look like they're any better gotta save up for my next big connector order, total is up to around $500 but it'll give a very nice stockpile of N and SMA connectors, a stupid amount of adapters for N, SMA, UHF and BNC, and semi rigid cable, then I need to think about getting a roll of RG-213
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Jan 3, 2015 01:35
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