[00:12] LazyLeopard (~irc-clien@chocky.demon.co.uk) left irc: Quit: Bye [00:14] jonsowman how are you? [00:15] jasonb (~jasonb@12.201.129.162) left irc: Ping timeout: 260 seconds [00:54] MoALTz_ (~no@92.18.22.82) joined #highaltitude. [00:57] MoALTz (~no@92.18.22.82) left irc: Ping timeout: 246 seconds [01:13] griffonbot (~griffonbo@nessie.habhub.org) left irc: Ping timeout: 252 seconds [01:13] griffonbot (~griffonbo@nessie.habhub.org) joined #highaltitude. [01:13] Action: griffonbot is GriffonBot [http://github.com/ssb/griffonbot] [01:13] Action: griffonbot is following: #ukhas #cusf #atlasballoon [01:13] Action: griffonbot is tracking emails sent to ukhas@googlegroups.com [01:17] Action: SpeedEvil wonders how to get a small quantity of dry gas constantly. [01:17] a nitrogen boil off [01:18] yeah - for that I'd need a dewar. [01:18] Which would be cool. [01:20] yeah [01:21] I think maybe a litre a day or so. [01:21] Which is an annoying quantity. [01:22] yea [01:22] what do you need it for? [01:22] It's to purge a solar panel of water vapour leaking in. [01:24] I'm wondering about a design of solar panel that would cost 40p/kW [01:24] 40p/W@1kW [01:25] ah [01:25] sounds good [01:26] And quite a lot of work though. [01:26] yeah [01:26] like any &D [01:26] R&D [01:27] Not really R&D - more jigsaw. [01:27] http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&item=200621341284&ssPageName=STRK:MEWAX:IT forex [01:28] ah ok [01:29] Lunar_Lander2 (~lunar_lan@p5488283E.dip.t-dialin.net) joined #highaltitude. [01:29] reconnect complete [01:29] :) [01:29] :) [01:33] Lunar_Lander (~lunar_lan@p54A06ACA.dip.t-dialin.net) left irc: Ping timeout: 276 seconds [01:34] lol [01:34] Robot Wars is so great [01:34] Jasperw (~jasperw@93.89.81.29) left irc: Remote host closed the connection [01:39] wolfspraul (~wolfsprau@mimi.q-ag.de) joined #highaltitude. 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[03:24] Lunar_Lander2 (~lunar_lan@p5488283E.dip.t-dialin.net) left irc: Quit: Lunar_Lander2 [03:37] X_ (~X@cpe-67-9-162-158.austin.res.rr.com) joined #highaltitude. [03:40] kf5kwe (~X@cpe-67-9-162-158.austin.res.rr.com) left irc: Ping timeout: 252 seconds [04:50] jasonb (~jasonb@adsl-66-124-73-250.dsl.sntc01.pacbell.net) joined #highaltitude. [05:14] trn (~trn@adsl-065-007-181-160.sip.bct.bellsouth.net) left irc: Quit: trn [05:15] trn (~trn@adsl-065-007-181-160.sip.bct.bellsouth.net) joined #highaltitude. [05:26] kd0mto (~dago@64-121-236-126.c3-0.eas-ubr3.atw-eas.pa.cable.rcn.com) left irc: Quit: AFK, I'm IRL now. [05:44] @jgrahamc: RT @cuspaceflight: Nova 19 / Weasel set a new UK altitude record today at 36.206km! #cusf [http://twitter.com/jgrahamc/status/84134656508821504] [06:03] Darkside (~Darkside@hpavc/darkside) left irc: Ping timeout: 240 seconds [06:10] Darkside (~Darkside@hpavc/darkside) joined #highaltitude. 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[07:46] jasonb (~jasonb@adsl-66-124-73-250.dsl.sntc01.pacbell.net) left irc: Ping timeout: 264 seconds [07:54] Action: Laurenceb_ was looking at beating the arhab altitude record [07:55] looks possible with a very thin zero pressure [07:55] using some of the thin film the indoor plane people use [07:58] SamSilver (2985f42b@gateway/web/freenode/ip.41.133.244.43) joined #highaltitude. [08:16] cuddykid (~acudworth@78.145.196.155) joined #highaltitude. [08:18] morning all [08:18] received an email from the one and only david miller last night saying he will endeavour to get my clearance sorted today :D hope so! [08:22] Laurenceb_ (~Laurence@host86-177-60-70.range86-177.btcentralplus.com) left irc: Ping timeout: 255 seconds [08:23] cuddykid: sounds like you hungry for launch ;-) [08:24] indeed! [08:24] been 2 years waiting haha [08:24] however, I'm not yet equipped with a HABers favourite tool - the chainsaw [08:25] MoALTz_ (~no@92.18.79.191) joined #highaltitude. [08:27] Darkside (~Darkside@hpavc/darkside) left irc: Ping timeout: 240 seconds [08:27] MoALTz (~no@host-92-8-244-182.as43234.net) left irc: Ping timeout: 244 seconds [08:30] shenki (~joel@219-90-212-172.ip.adam.com.au) left irc: Ping timeout: 240 seconds [08:32] cuddykid: I was thinking of getting a pet monkey [08:33] sounds a great idea! [08:34] ooo.. should be able to start getting way off (inaccurate) predictions now for 1st july [08:35] I wish you well for 01 july [08:35] shipit (~shipit@173-228-28-48.dsl.dynamic.sonic.net) left irc: Remote host closed the connection [08:35] my your landing be on solid earth [08:35] nothing wet and nothing tall [08:36] *may [08:36] haha thanks [08:37] afk [08:37] hmm currently looks to be in SE direction... notam will probably say no to that. Last time it was W/SW [08:43] shenki (~joel@219-90-212-172.ip.adam.com.au) joined #highaltitude. [08:51] We need to start making a quadcopter with a live video stream and a pair of shears part of the HAB kit so we can cut out of trees [08:52] lol. Good plan :) [08:52] mixio (~mixio@ppp089210192251.dsl.hol.gr) joined #highaltitude. [08:53] shipit (~shipit@c-67-180-23-104.hsd1.ca.comcast.net) joined #highaltitude. [09:04] mixio (~mixio@ppp089210192251.dsl.hol.gr) left irc: Ping timeout: 240 seconds [09:04] Daviey (~Daviey@ubuntu/member/daviey) left irc: Ping timeout: 246 seconds [09:05] or a quad copter with some sort of winch thing that attaches onto payload (maybe magnetic) to hoist it out lol [09:09] mixio (mixio@79.167.13.14) joined #highaltitude. [09:14] MoALTz__ (~no@92.18.22.233) joined #highaltitude. [09:16] spacekitteh (~TraumaPon@203-214-120-68.dyn.iinet.net.au) left irc: Ping timeout: 244 seconds [09:16] MoALTz_ (~no@92.18.79.191) left irc: Ping timeout: 252 seconds [09:18] Daviey (~Daviey@ubuntu/member/daviey) joined #highaltitude. [09:21] X_ (~X@cpe-67-9-162-158.austin.res.rr.com) left irc: Quit: Leaving [09:24] GW8RAK (~chatzilla@host86-173-140-63.range86-173.btcentralplus.com) joined #highaltitude. [09:33] MoALTz__ (~no@92.18.22.233) left irc: Ping timeout: 258 seconds [09:36] mixio (mixio@79.167.13.14) left irc: Ping timeout: 240 seconds [09:36] mixio (mixio@ppp046177110245.dsl.hol.gr) joined #highaltitude. [09:36] nichrome is what you use for the cutdown mechanisms? [09:39] fsphil (~phil@2001:8b0:34:1:21f:c6ff:fe44:b25b) left irc: Ping timeout: 260 seconds [09:41] perseus (perseus@SDF.ORG) joined #highaltitude. [09:41] fsphil (~phil@2001:8b0:34:1:21f:c6ff:fe44:b25b) joined #highaltitude. [09:44] m1x10 (mixio@ppp046177010206.dsl.hol.gr) joined #highaltitude. [09:45] ping fsphil [09:45] mixio (mixio@ppp046177110245.dsl.hol.gr) left irc: Ping timeout: 260 seconds [09:50] how much gauge is that nichrome wire you use on cutdown mechanisms? [09:52] hello ! [09:53] Received email: Solar Balloonman "[UKHAS] Re: Could this take peroxide? Re: 'Solar Pillow'" [10:10] Darkside (~Darkside@hpavc/darkside) joined #highaltitude. [10:28] mattltm-alt (~mattltm@mail.icm2.org.uk) joined #highaltitude. [10:33] oops almost fried my lassen [10:33] not what I want to happen when I'm close to launch [10:33] plugged connector in wrong way.. rookie error [10:34] m1x10 - I think they use nichrom [10:35] certainly gets ridiculously hot just off a few batteries [10:35] shipit (~shipit@c-67-180-23-104.hsd1.ca.comcast.net) left irc: Remote host closed the connection [10:39] chris_99 (~chris_99@unaffiliated/chris-99/x-3062929) joined #highaltitude. [10:41] Received email: "Re: [UKHAS] Re: Could this take peroxide? Re: 'Solar Pillow'" [10:44] mattltm (~mattltm@mail.icm2.org.uk) left irc: [10:49] hmm you could beat the altitude record with a 1m zero pressure envelope made from OS film [10:49] if the electronics could be made <10grams [10:52] http://www.a2zcorp.us/store/Category.asp?Cguid={CCCB3CBA-6763-499A-8223-DDDBACB0C380}&Category=BuildingMaterials%3ACovering [10:55] futurity (~futurity@212.44.16.158.ip.redstone-isp.net) joined #highaltitude. [10:55] futurity (~futurity@212.44.16.158.ip.redstone-isp.net) left irc: Client Quit [10:57] futurity (~futurity@212.44.16.158.ip.redstone-isp.net) joined #highaltitude. [10:59] pong m1x10 (at work, will be slow :) [11:09] anyone know where to buy nichrome wire (apart from internet)? [11:12] cuddykid: i use 0.125W 10 ohm resistors [11:13] is nichrome the best for making hot wire cutter? [11:13] m1x10 (mixio@ppp046177010206.dsl.hol.gr) left irc: Ping timeout: 252 seconds [11:15] food packaging shops will sell it [11:15] they use nichrome wire for the plastic wrap machines [11:16] mixio (mixio@ppp046177022096.dsl.hol.gr) joined #highaltitude. [11:17] when you buy meat on a polystyrene plate and it covered in a plastic film, they have used a nichrome wire cutter to cut the film [11:17] hi fsphil, i was wondering where to buy the nichrome wire? ebay... ? [11:17] I got mine from Rapid Online [11:18] thanks SamSilver [11:18] got for cutting the payload box, rather than a cut-down device [11:18] just noticed that maplin sell 28swg constantan wire - will that also provide desired hot wire effect? [11:19] Btw, i just found that radiometrix has the TX1 10mw running at 3v3 ! That could make my pcb even smaller and simpler. But i dont have more crystals! [11:19] Hiena (~boreger@81.93.195.181.datatrans.hu) joined #highaltitude. [11:20] all their 10mw modules work at 3.3v [11:20] afaik [11:21] i'd be more inclined to feed the radiometrix module the raw battery voltage [11:21] else you'll be dissipating more heat in your 3.3v regulator, when the radiometrix module could dissipate it instead - it can handle 15v input fine [11:22] good idea [11:22] will the frequency output by the radiometrix module not change with input voltage? [11:22] no [11:22] it has an internal regulator, regulates to 2.8v i believe [11:22] indeed [11:22] chris_99 (~chris_99@unaffiliated/chris-99/x-3062929) left irc: Quit: Leaving [11:22] and if the NTX2 dissipates heat, thats probably a good thing in regards to frequency stability [11:22] though the temperature will vary due to the voltage changes, and this will change the frequency [11:23] it could self-heat iself :-) [11:23] mixio (mixio@ppp046177022096.dsl.hol.gr) left irc: Ping timeout: 252 seconds [11:23] less drift as it gets colder [11:24] less drift as it does not get colder - I get your drift Dark [11:25] it might work [11:25] i've got my mininut boards wired up that way [11:25] we'll see what happens when they fly [11:27] mixio (mixio@ppp079166158074.dsl.hol.gr) joined #highaltitude. [11:36] mixio (mixio@ppp079166158074.dsl.hol.gr) left irc: Ping timeout: 250 seconds [11:36] mixio (mixio@ppp046177100032.dsl.hol.gr) joined #highaltitude. [11:36] what happened to nova19 ? [11:40] G0ATW (51909922@gateway/web/freenode/ip.81.144.153.34) joined #highaltitude. [11:41] landed in a tree [11:47] evil trees [11:48] 3 big sheets of styrofoam have just arrived :D [11:48] need to build a hot wire cutter now [11:49] wrap your soldering iron with aluminium foil to not ruin the tip [11:49] and you got your hot cutter [11:52] ooo.. will that work well?! [11:53] I don't see why not, I used the same trick to cut some plastic sheets, make sure only that the foil is tightly wrapped [11:53] G0ATW (51909922@gateway/web/freenode/ip.81.144.153.34) left irc: Ping timeout: 252 seconds [11:54] mmm [11:54] for foam you want a thin cutter [11:54] a soldering iron won't work so well [11:54] MoALTz__ (~no@92.18.22.233) joined #highaltitude. [11:54] you want a very clean edge [11:55] best way is to use some nichrome wire, about 30cm or so, and put 12v or so across it [11:55] Darkside: can an old power supply be used for the 12V (from mains) [11:56] careful of the fumes [11:56] depends ont eh current draw i guess [11:56] the power supply needs to be able to deliver few A [11:56] less wire length, more current draw, and higher chance of burning out the wire [11:56] you don't want it red hot [11:57] you don't even need rectification, a plain transformer is sufficent [11:57] ok, will see what's lying around [11:57] trying to find a picture of the cutter i use [11:57] are the fumes toxic? guess they're not healthy! [11:58] hm, never had to deal with fumes [11:58] i dont think the cutter i used got hot enough to burn the foam, just melt it [11:59] they cause cancer in california, if you know what i mean [11:59] I get you laurenceb ;) ! [11:59] so does everything [12:00] an alternative option may just be using a saw to get rough shape then sanding? [12:01] ruku (ruku@phy226apc19.umbc.edu) joined #highaltitude. [12:01] I used a saw - but it's very difficult to make a perfectly straight cut [12:01] my payload box wasn't really a box [12:01] #highaltitude: mode change '+o jonsowman' by ChanServ!ChanServ@services. [12:01] though maybe that's just me :) [12:02] Topic changed on #highaltitude by jonsowman!jonsowman@kryten.hexoc.com: Welcome to #highaltitude - discuss anything to do with high altitude projects (balloons, gliders, etc) www.ukhas.org.uk [12:02] #highaltitude: mode change '-o jonsowman' by ChanServ!ChanServ@services. [12:02] I'm not good at making things [12:02] using a hot wire really is the best option [12:02] GeekShadow (~Antoine@reactos/tester/GeekShadow) joined #highaltitude. [12:03] indeedy [12:03] but it involves making the cutter :) [12:03] worth it tho [12:03] very useful to have a hot-wire cutter [12:03] cant find the damn pic... [12:04] i had a good pic of the cutter in operation somewhere.. [12:04] don't worry darkside :) [12:04] upu's pic is great - http://ava.upuaut.net/wp-content/uploads/2010/09/IMG_4820.jpg [12:05] yep thats a good way of doing it [12:05] we had nichrome wire streched between the ends of a bent piece ov PVC pipe [12:05] pf* [12:05] of* [12:05] so we moved the cutter, not the foam [12:05] but upu's cutter would work really well too [12:06] interesitng blue foam [12:07] jcoxon shohuld add his nano payload here: http://www.arhab.org/records/records/records/lpayload.html [12:09] mixio (mixio@ppp046177100032.dsl.hol.gr) left irc: Ping timeout: 240 seconds [12:10] man, 89 grams [12:10] thats nute [12:10] nuts* [12:10] what did it have in it tho [12:12] Upu (~Upu@ubn.upuaut.net) left irc: Read error: Connection reset by peer [12:12] Upu (~Upu@ubn.upuaut.net) joined #highaltitude. [12:14] priyesh (~priyesh@cpc21-nmal17-2-0-cust75.croy.cable.virginmedia.com) left irc: Read error: Operation timed out [12:16] mixio (mixio@ppp046177103007.dsl.hol.gr) joined #highaltitude. [12:17] priyesh (~priyesh@cpc21-nmal17-2-0-cust75.croy.cable.virginmedia.com) joined #highaltitude. [12:21] prolly just gps, battery and transmitter [12:21] mm [12:21] something like that would be good with a little uart camera [12:21] my payload is 35g without batteries... [12:21] or antenna [12:22] i'm betting it will be around 150g after boxing [12:22] use bubblewrap instead of a box? [12:22] heh [12:22] im gonna use very lightweight foam for the box [12:22] hadie was 510g, most of that was the canon camera [12:22] my main concern is the antenna [12:22] i'm thinking of just using a wire dipole [12:23] I think the box was about 100g or so [12:23] and have the wire running up the payload line [12:23] radials will mean more reinforcing of the box, and more weight [12:24] if I get it out of the tree I must weigh the individual bits [12:24] a wire antenna on the cord would be perfect [12:24] a dipole should work well enough [12:24] i mean, it worked on HF >_> [12:24] one out either side of the payload [12:24] vertical dipole too [12:25] problem there will be making a balun for it [12:25] as 1/4 wave of wire will be anoying to deal with [12:26] could the transmitter be made to connect directly to a balanced antenna? [12:26] well the output is unbalanced [12:27] lengh of the matching 1/4 wave will be 200/(4*144) right? [12:27] due to 66% c [12:27] mixio (mixio@ppp046177103007.dsl.hol.gr) left irc: Ping timeout: 240 seconds [12:27] so about 35cm [12:27] thats a shitload of wire to have sitting in a payload [12:27] coax* [12:29] actually, the other option is to hang a j-pole off it [12:30] i may as well make a payload with a SMA connector on the outside of it, heh [12:33] mixio (mixio@ppp046177085026.dsl.hol.gr) joined #highaltitude. [12:36] that conductive thread that sparkfun sell might make a good antenna wire [12:36] though maybe not at -40c [12:38] Ava is 850g [12:39] nah [12:39] maybe not a dipole then [12:39] matchint is gonna be too hard [12:39] what you after Darkside ? [12:39] unless i just do the dodgy air-core choke method [12:39] Upu: lightweight 2m antenna [12:39] ah ok [12:39] sure, i could use a 1/4 wave monopole with ground plane [12:39] base station one ? [12:39] nah [12:39] priyesh (~priyesh@cpc21-nmal17-2-0-cust75.croy.cable.virginmedia.com) left irc: Read error: Operation timed out [12:39] for payload [12:40] oh [12:40] i've donw a 1/4 wave monopole with ground plane radials before [12:40] but it means a lot of reinforcement is needed, especially with the 50cm ground plane radials [12:40] guy from the club recommended 1/4 wave but use copper tape as the ground plane [12:40] 50cms ? [12:40] 144MHz [12:41] ah of course yes [12:41] sorry thought you meant 434Mhz [12:41] have fun with that :) [12:41] we've done it before: http://projecthorus.org/wp-content/uploads/2011/01/DSC_2710.jpg [12:41] but that payload had a lot of reinforcement inside, and even then it broke on landing [12:41] not sure I'd want that coming down at me [12:41] yup [12:41] so i was thinking a vertical dipole [12:42] but then you need a balun, and the standard 1/4 wave matching stub is going to be heavy [12:42] http://ava.upuaut.net/files/antenna.jpg [12:42] that was my first stab at 434 [12:42] going to be redesigned for next launch [12:42] Copper tape ground plane [12:42] juxta's 434MHz payload has something similar [12:43] You're not UK based are you ? [12:43] priyesh (~priyesh@cpc21-nmal17-2-0-cust75.croy.cable.virginmedia.com) joined #highaltitude. [12:43] nope, australia [12:43] Yeah we don't have this issue as we're not actually allowed to transmit on 2meters in the air [12:43] i was thinking of making the payload box as small as possible, and just having an SMA connector on the outside of it [12:43] 5/8's ? [12:44] and have a j-pole antenna hanging down [12:44] I think I'm going to have a light weight frame on Ava2 with insulation on it [12:44] mm [12:45] im currently thinking of making a foam box, with some kind of reinforcement for a sma connector on the outside [12:45] ideally i want the payload to be re-usable [12:46] all my payloads so far have been damaged beyond repair on landing [12:46] is that bad to use a rechargable 9v li-on battery on space? [12:47] i dunno how li-ions go at low temps [12:47] i know lipo's freeze [12:47] Why don't you transmit at 434Mhz Darkside ? [12:47] Upu: because we want to do some high speed APRS experiments on UHF [12:47] ok [12:47] 9600 baud APRS [12:48] and the 2m modules i've got ordered do 100mw :-) [12:49] mixio http://trs-new.jpl.nasa.gov/dspace/bitstream/2014/13702/1/00-0068.pdf [12:50] The Limits of Low-Temperature Performance of Li-Ion Cell [12:50] The results of electrode and electrolyte studies reveal that the poor low-temperature (<-30'C) performance of Li-ion cells is ma... etc [12:51] anyway, im thinking of using a slim-jim style 2m antenna made from balanced line [12:51] 9600 baud over fm? [12:51] fsphil: yeah [12:51] high output power on the TX probably [12:51] a few watts [12:52] does anyone do that already? [12:52] yep [12:52] there are high speed UHF APRS networks around the place [12:52] jasonb (~jasonb@adsl-66-124-73-250.dsl.sntc01.pacbell.net) joined #highaltitude. [12:52] I've seen the 9600 option on my radios but I don't actually know what it does [12:53] we figure if we can get 9600 baud down from a payload, it opens up lots more experiments [12:54] I could send an image down in 10 seconds :) [12:54] heh [12:54] well, thats one idea [12:55] very low bitrate video [12:55] but in effect we'd have a flying digipeater [12:55] so we'd be able to have data links between the chase vehicles [12:55] and experiment with APRS-based cutdown, etc [12:55] aah two-way link [12:55] yep [12:55] flying digipeater [12:56] running our own APRS network [12:56] you could transmit fairly good digital voice over 9600 baud [12:56] its packet based tho [12:56] true [12:56] actual rate and latency would be pretty bad [12:56] yeah [12:56] but man, you could do some cool stuff via it [12:57] i'd have a local tap into the APRS packet stream, on the payload [12:57] Darkside: but in effect we'd have a flying digipeater <- I read that as flying diapers, was disappointed after re-reading :( [12:57] so you could wire up other payloads to it, and have them send packets down, for images, etc [12:58] that could be arranged BrainDamage [12:58] moisture protection for the electronics? :p [12:58] BrainDamage: send $450 + diapers, and we'll fly them, and retrieve them [12:58] wait, make that $600, just to be safe [12:58] >_> [12:59] yeah, no [12:59] aww [13:18] mixio (mixio@ppp046177085026.dsl.hol.gr) left irc: Ping timeout: 258 seconds [13:19] Dan-K2VOL (~Adium@74-143-44-42.static.insightbb.com) joined #highaltitude. [13:39] Anyone here an analog guru? [13:40] Action: SpeedEvil wishes people would just ask questions. [13:40] Or wander over to ##electronics. [13:41] pointless questions are irritating just as much there tought [13:42] ruku sorry, doesn't seem like it [13:43] so if you type jeri ellsworth into google, the first suggested search made me lol [13:43] I'm not as interested as getting my question answered as meeting people... [13:43] IRC channels aren't just for Q and A right? >_>; [13:44] so true [13:44] I mean I could just say... what happens if I run my op amp off of a 5 V and 5.25 V supply, will that cause a ground voltage (0 V) through a unity gain amp to drift? [13:44] (ie: 0.25 or something...) [13:44] Part of the probelm is - your question is meaningless (the initial one) [13:44] Do you for example consider a guru someone who knows ohms law? [13:45] Or are you looking for detailed discussion of shot-noise in transistors, and its relation to transistor geometry. [13:45] ruku: It depends on how the circuit is set up. [13:45] How so Speed? [13:45] In general - opamps totally ignore the supply rail voltage - with the caveats that the inputs or outputs may not work quite up to them. [13:46] They depend on the input voltages, and the reference voltages of the circuit. [13:46] That being, rail to rail amp or not? [13:46] yes [13:46] Dutch-Mill (3e2d7a74@gateway/web/freenode/ip.62.45.122.116) joined #highaltitude. [13:46] The reference voltages may or may not be altered by changes in vcc [13:46] What would be the statistic that describes how non-equal supply voltages affect operation? [13:47] They almost don't. [13:47] For a rail-rail opampp [13:47] The only difference is that the output current varies near the supply rails, and possibly with supply voltage too. [13:48] I remember a 741 acting funny on me... (granted, it was a 741...) I had it set up 5V and ground, and it wouldn't unity buffer a signal. [13:48] But in the ideal case, where feedback is applied and the circuit is properly designed, that does not matter, as you're always below that limit [13:48] 741 is not rail-rail [13:48] It will not work with the inputs within 3v(?) of the positive rail. [13:48] Maybe it's 2 [13:48] nickolai89 (~nickolai@c-98-221-21-20.hsd1.nj.comcast.net) joined #highaltitude. [13:48] Ah. So if perhaps I was using 15 and 0, I'd be ok for anything 3 to 12? [13:49] Theoretically... [13:49] yes [13:49] Or 0-9 [13:49] Hmm. [13:50] http://www.national.com/mpf/LM/LM741.html#Overview [13:50] The reason I'm asking is I'm using a Murata DC/DC to take 3.3 Lithiums to +/- 5 to do some signal work. [13:50] Look at the datasheet [13:50] Page 2 - bottom. [13:50] 'input voltage range' [13:50] You mean you won't look at it for me? ;~; [13:50] Action: ruku kids. <3 [13:51] This is specified at +-15V - the worst-case input range is specified as +-12 - that is 3V from the supply rails [13:52] There are nicer ones with graphs though [13:53] LM358 - say [13:53] http://www.national.com/profile/snip.cgi/openDS=LM358 [13:53] Bottom of page 3, and note 7 on page 5 [13:54] Input range is from V- to V+ - 1.5V [13:54] And it's got a graph on page 5 of input voltage range vs supply voltage [13:57] nickolai89 (~nickolai@c-98-221-21-20.hsd1.nj.comcast.net) left irc: Quit: Leaving [13:58] Dan-K2VOL: lmao [13:59] kd0mto (~dago@64-121-236-126.c3-0.eas-ubr3.atw-eas.pa.cable.rcn.com) joined #highaltitude. [13:59] Laurenceb :-P [13:59] Action: SpeedEvil has IR sensor. [13:59] google needs an anti nerd mode [13:59] "no your not going to get laid" [14:00] if you hit that result [14:00] hahahha [14:02] "google has detected you are a basement dwelling loser" [14:09] so has any of you guys ever seen a Focused Ion Beam milling and depositing metals? [14:09] it's pretty darn fantastic: http://www.youtube.com/watch?v=3MUOj7-n8po&feature=player_embedded [14:10] I'm trying to get one for work [14:17] Heh... [14:19] I'm knee deep in the failed charcoal fuel experiment. But the results promising. Better feeder and high voltage gas chamber will make it better. [14:23] wolfspraul (~wolfsprau@mimi.q-ag.de) joined #highaltitude. [14:25] mmmm? [14:26] smea (~smealum@85-171-206-227.rev.numericable.fr) joined #highaltitude. [14:45] http://spacefellowship.com/Forum/viewtopic.php?f=52&t=12087&sid=929a19f0b81a6c1d842acb783ba3891d [14:45] never saw that happening [14:47] perseus (perseus@SDF.ORG) left irc: Quit: leaving [14:52] Received email: Oliver de Peyer Astrobiologist "[UKHAS] Strange satellite modem certification? Comparison with GlobalStar?" [14:53] wolfspraul (~wolfsprau@mimi.q-ag.de) left irc: Quit: leaving [14:54] Laurenceb interesting [14:55] Received email: Oliver de Peyer Astrobiologist "[UKHAS] Insurance" [15:03] anyone in here operate a business? [15:06] yeah [15:06] I own my own business [15:13] I operate a business as well [15:13] a small business though [15:17] http://spacefellowship.com/Forum/viewtopic.php?f=52&t=8610&sid=929a19f0b81a6c1d842acb783ba3891d&start=45 [15:17] what are these guys smoking [15:18] Rocket fuel? [15:18] 100kft quadcopter wtf [15:20] something slightly less insane: i was just looking at the numbers for a 42Km zero pressure balloon- you could do it with a 1m radius envelope made from OS film - rc plane covering [15:20] Never read Daniken? [15:20] easish way to take the arhab altitude record [15:20] Hiena: no [15:21] He wrote Biblical multirotor spacefaring helicopter. [15:21] oh dear [15:22] http://www.daniken.com/e/index.html [15:23] Action: Laurenceb facepalm [15:24] 42km zp? 1m I assume you mean 1 mile radius [15:24] :-P [15:24] Okay. Seems, all set for the onboard test the charcoal fuel system, except i have no car avail. Guess untill that i'll prepare a water cooled feeder. [15:25] Dan-K2VOl: no 1m [15:25] OS film is 0.5um thick [15:25] easily doable, but you need a tracking package thats <10grams [15:25] thats the tricky bit... unless you make the envelope larger [15:26] CUSF made a ~2.5m radius or something balloon by hand [15:26] but that amount of OS film would start to get expensive [15:26] and itd be easy to rip everything [15:28] Ugh [15:29] yeah its not trivial - cusf were looking at tubes [15:30] but it _could_ be done on a tabletop [15:32] from what we've seen with the zps, when they get small it seems that the open vent hole is a problem [15:33] I think we're going to change to a spring-disc vent like the japanese used on their trans-pacific ones [15:33] so you make it smaller [15:33] interesting [15:33] making it smaller just resulted in envelope rupture in the UTARC/SNOX test flights [15:33] i see [15:34] well aiming for altitude is a slightly different problem [15:34] We theorized that gusts of wind/turbulence cause a 'breathing' action of the balloon that's not significant on a large zp [15:34] But loses a lot of helium on a small one - considering the helium and air homogeneously mix in the envelope when air is introduced [15:35] yeah [15:35] maybe less of a problem for an altitude attempt [15:36] Action: SpeedEvil wonders about simple optical tracking. [15:36] Launch on a clear night, and ahve a LED strobe. [15:36] Follow with scopes. [15:37] yeah [15:37] less accurate maybe [15:37] Why would you bother to use a small zp for an altitude attempt? Seems a lot more work than latex [15:37] Not that much [15:37] but gps is heavy [15:37] Against the background of stars [15:37] hard to do gps for <10 grams [15:37] fsa03 is 10g [15:37] but you need power and radio as well [15:37] still i guess 20g is possible [15:37] Oh just get Jodrell bank involved [15:38] and thatd still make the envelope tabletop sized [15:38] aye true, but you could trim down an ntx2 so it weighs less [15:38] 42km is 3g/m^3 [15:38] solder directly to pins on avr so no pcb needed [15:38] those are nice weights for superpressure envelopes too [15:38] Magnitude 4 star is 0.9nW/m^2 - a 1W pulse from a LED over a hemisphere is that bright over a billion square meters - or 12km range [15:39] And mag 4 is quite bright [15:39] Easily naked eye [15:39] depends where you live [15:39] True. [15:39]