highaltitude.log.20100214

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[01:00] <natrium42> Endeavour, i am going to U,S&A on monday
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[01:01] <Endeavour> Oh yeah?
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[01:01] <natrium42> but to MI, you are in TX rite?
[01:03] <Endeavour> Yep
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[01:21] <MikeMc68> sup ?
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[02:12] <juxta> Ziltro: it's not so bad here ;p
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[02:38] <juxta> natrium42, you about?
[02:38] <natrium42> yep, sup?
[02:43] <juxta> playing around with that design in eagle
[02:43] <juxta> was going to ask your advice - should crystals be as close to the chips as possible?
[02:43] <SpeedEvil> yes
[02:43] <SpeedEvil> to minimise stray capacitance
[02:43] <juxta> cheers SpeedEvil :)
[02:43] <SpeedEvil> Also radiation of clock noise
[02:44] <SpeedEvil> If you care about 'about 20MHz' - it's a lot less critical than 'I need +-25ppm'
[02:45] <juxta> hehe - so long as I can get accurate timing for serial & rtty all is ok :)
[02:45] <SpeedEvil> yeah - that's in the 5000ppm or so range :)
[02:45] <juxta> any idea on where in the eagle libraries I can find a 2 pin male SIL header?
[02:46] <SpeedEvil> Nope, never used it.
[02:46] <Randomskk> conn-something
[02:46] <Randomskk> but
[02:46] <Randomskk> use the sparkfun library
[02:46] <Randomskk> it's got them
[02:46] <Randomskk> and lots of other useful things
[02:46] <juxta> Randomskk, yeah I have the sparkfun library, but I can only find 3-pin or greater
[02:46] <juxta> let me look again..
[02:46] <Randomskk> M02 should exist
[02:47] <juxta> heh, found it :)
[02:47] <juxta> cheers
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[04:23] <juxta> natrium42 - is it worth leaving space for corner mounting holes for a payload do you think?
[04:44] <natrium42> sure, as long as you are not running out of space
[04:47] <juxta> I think I be packing things too tightly
[04:47] <juxta> autoroute is failing to route some wires if I have too many things close together
[04:50] <natrium42> it's much better to do hand routing
[04:50] <natrium42> autorouting ftl
[04:50] <juxta> hmm
[04:50] <juxta> seems rather daunting though
[04:51] <juxta> is autoroute not particularly efficient?
[04:51] <natrium42> yes, but it's not too bad once you do a couple
[04:51] <natrium42> nope, it creates weird routing and more vias
[04:51] <natrium42> most people manual route
[04:52] <natrium42> only very expensive software does OK autorouting with some help
[04:53] <juxta> hrm
[04:53] <juxta> well I guess I should probably settle on a board layout before I start trying to route by hand then :)
[04:54] <natrium42> usually i place the ICs first minimizing the line crossings
[04:54] <natrium42> then place decoupling caps close to ICs
[04:55] <juxta> decoupling caps for the crystals?
[04:55] <natrium42> then route signals and lastly power
[04:55] <natrium42> well, crystal should be placed close to MCU
[04:56] <natrium42> but usually you also want a decoupling cap on each VCC pin of an IC
[04:56] <natrium42> 0.1uF or so
[04:56] <juxta> ah I didn't think of that
[04:56] <juxta> I'll put some on, cheers
[04:57] <natrium42> :)
[04:57] <juxta> my scematic is still somewhat incomplete
[04:58] <juxta> & I'm wondering if I can put components on both sides of a board with eagle light - I dont think I can, but I can just fake it easily enough with through hole components
[04:58] <natrium42> not sure, best to try
[04:58] <natrium42> middle click should switch component to other side while you are moving it
[04:59] <juxta> oh
[04:59] <juxta> it works, excellent
[04:59] <natrium42> cool
[04:59] <juxta> I can move the damn SD card holder which is taking up heaps of space
[05:01] <juxta> any idea where I could find footprints for mpx5100D pressure sensors natrium42?
[05:01] <natrium42> did you check cadsoft's site?
[05:02] <natrium42> although i doubt you'll find those rare components
[05:02] <natrium42> going to need to learn how to create components :P
[05:03] <natrium42> http://www.sparkfun.com/commerce/tutorial_info.php?tutorials_id=110
[05:03] <natrium42> it's not too hard, actually
[05:03] <juxta> natrium42: i just looked on the cadsoft site, they seem to be there - I'll give them a go
[05:04] <juxta> but yes, I should work out how to create components
[05:04] <natrium42> ah, cool
[05:04] <juxta> the other thing I want to try is the 3d renders I've seen kicking around
[05:04] <natrium42> :)
[05:05] <natrium42> eagle3d ftw
[05:05] <juxta> I had a quick look at eagle3d, installed it, but it didnt seem to have any binaries
[05:05] <juxta> that was last night at 3am, so I may have missed something though
[05:06] <juxta> or is it a plugin or something?
[05:06] <natrium42> it's a script that you run from eagle
[05:07] <juxta> ah, well that makes more sense
[05:07] <natrium42> it then creates a pov file that you render with povray
[05:07] <juxta> does it have its own library of components?
[05:07] <juxta> as in 3d models of components
[05:07] <natrium42> yes, the common ones
[05:07] <juxta> ah alright
[05:08] <natrium42> http://www.matwei.de/doku.php?id=en:eagle3d:library
[05:08] <natrium42> you can create new ones, of course
[05:09] <natrium42> it has functions to create IC packages, for example
[05:10] <natrium42> so you could them to add a new chip package, for example
[05:10] <juxta> yeah
[05:10] <natrium42> then there's always photoshop :P
[05:11] <natrium42> photograph the component and overlay it
[05:11] <juxta> does it let you substitute compoents for ones that look alike - ie using little transistors instead of the dallas sensors?
[05:11] <natrium42> yeah, it does
[05:11] <natrium42> there's a special file for a list of your substitutions
[05:11] <juxta> nifty
[05:12] <juxta> I'll have to look into it properly when I get home :)
[05:15] <juxta> natrium42: are you planning any future launches?
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[06:09] <natrium42> juxta, within 1 month
[06:10] <juxta> oh nice
[06:10] <juxta> what're you gonna have onboard?
[06:11] <natrium42> satphone, camera, ntx2, some backup module (spot or cellular)
[06:11] <juxta> satphone?
[06:12] <natrium42> yes, iridium
[06:12] <juxta> to be able to ring the payload?
[06:12] <natrium42> going to try downlinking pictures
[06:12] <juxta> ahh nice
[06:12] <juxta> what baud rate would you get from the sat phone? 9600?
[06:12] <natrium42> it's bidirectional, yes
[06:12] <natrium42> but the response time is rediculous
[06:13] <natrium42> ~2 seconds
[06:13] <juxta> ah, not ideal latency, hehe
[06:13] <natrium42> more like 2200-2400 baud
[06:14] <juxta> fair enough - what's the pricing like?
[06:15] <natrium42> 500 minutes cost about $650
[06:15] <natrium42> i got a little under 1000 minutes left
[06:16] <juxta> ah - so it's not the cheapest then, hehe
[06:16] <juxta> have you sent one up before?
[06:17] <natrium42> nope, it's a test launch
[06:17] <natrium42> we'll see how well it works :)
[06:17] <natrium42> just need a lot of redundancy -- it's not cheap to lose
[06:18] <juxta> good point
[06:18] <juxta> esp with the lakes etc around you
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[08:20] <jcoxon> morning
[08:23] <SpeedEvil> morning.
[08:23] Action: SpeedEvil goes back to sleep.
[08:24] <jcoxon> hehe
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[10:07] <MikeMc68> morning
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[10:57] <Laurenceb> hi
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[12:16] <MikeMc68> morning
[12:16] <MikeMc68> well... afternoon
[12:16] <LazyLeopard> Hiya
[12:19] <MikeMc68> Figured out how to use your radio Rick ?
[12:20] <LazyLeopard> Well, some of the basics...
[12:21] <MikeMc68> Shame you didn't get a chance to do some RTTY decoding yesterday
[12:21] <MikeMc68> But sounds like James won't wait too long for a retry - weather conditions permitting
[12:21] <LazyLeopard> It has dozens of menus and options I've not even looked at yet...
[12:22] <MikeMc68> yeah - even my radio which is pretty basic has all kinds of functions i don't understand yet
[12:22] <LazyLeopard> Yeah, it's getting a day when the high altitude winds are blowing south...
[12:22] <LazyLeopard> I'm booked on a foundation licence course end of this month, so that may enlighten me a little...
[12:24] <MikeMc68> yeah i'm probably going to do one myself
[12:24] <MikeMc68> I got the info. booklet from the RSGB
[12:25] <LazyLeopard> A friend over near Swindon managed to go from nowt to full licence in 11 months.
[12:26] <russss> I'm trying to organise a foundation course at the Hackspace if you're interested MikeMc68
[12:26] <MikeMc68> Yeah i see no reason why not if you have the time and inclination to study
[12:26] <MikeMc68> Oh really?
[12:26] <MikeMc68> Got any dates yet?
[12:26] <russss> yeah it's annoying that they don't run them in central London
[12:27] <russss> I only just emailed the RSGB so I am waiting for them
[12:27] <russss> it'll probably be in a month or two when it's a little warmer.
[12:27] <MikeMc68> ok - Yes i'd be interested
[12:27] <russss> I don't think I'm going to have any problem finding enough people
[12:27] <LazyLeopard> Where's hacksspace?
[12:28] <LazyLeopard> In central London?
[12:28] <russss> Islington/Kings Cross at the moment
[12:28] <MikeMc68> http://london.hackspace.org.uk/
[12:28] <LazyLeopard> Right.
[12:28] <russss> we may or may not be moving shortly
[12:29] <MikeMc68> Where to Russs ?
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[12:31] <russss> MikeMc68: oddly enough, the vaults beneath Somerset House
[12:32] <russss> or more correctly beneath Waterloo Bridge
[12:32] <russss> but we haven't confirmed anything for that yet, we're still talking to them but they're busy with London Fashion Week
[12:32] <MikeMc68> ok that will be easier for me to get to for sure
[12:33] <russss> it would be pretty good if we could though.
[12:33] <MikeMc68> Best of luck
[12:33] <MikeMc68> So the course - would it be two day s?
[12:34] <russss> well I don't know how it usually works
[12:34] <russss> the last time I looked into radio license courses it was a totally different system
[12:34] <russss> that was a while ago.
[12:34] <russss> they say it's usually 10-12 hours, so we could do it over a weekend, or two saturdays I guess
[12:35] <russss> lot of it is fairly basic electronics from the looks of things so I wonder if we could do an accelerated version.
[12:36] <russss> (the syllabus is here http://www.rsgb.org/tutors/foundation/)
[12:37] <LazyLeopard> The one in Bromley I'm attending is two Saturdays, two weeks apart.
[12:37] <MikeMc68> 2 weekends sounds sensible
[12:37] <LazyLeopard> ...so it could be done in a single weekend, probably.
[12:38] <MikeMc68> yeah
[12:38] <russss> once I've got some more details I'll try and work out what the most convenient day is
[12:38] <russss> and so on
[12:38] <MikeMc68> OK Thanks russs
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[13:15] <Hiena> ' morning!
[13:18] <Hiena> Well, well, well... Seems the ozone treatment yield the avaited results. Half hour bubbling made peroxide, strong enough to green a copper plate within an hour. Only problem, he lack of efficiency.
[13:21] <MikeMc68> ?
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[13:23] <edmoore> LazyLeopard: re you comment at 12:25, you can compress the lcensing quite a bit further
[13:24] <edmoore> two of us from cusf did the three inside 3 months, excluding the 4 weeks it takes to mark the advanced
[13:24] <Randomskk> you can do it silly fast
[13:25] <Randomskk> if you just take the tests as fast as possible
[13:25] <Randomskk> I did foundation and intermediate on the same evening and advanced at the next opportunity
[13:25] <Randomskk> all said about one month, plus another to get results from the advanced
[13:26] <Randomskk> if you can memorise a few key facts from the book you'll be fine, plus sort out doing the practical exercises for foundation and intermedate
[13:26] <Randomskk> intermediate* even
[13:26] <Randomskk> the pass mark is really low
[13:26] <Randomskk> like 60% for advanced
[13:27] <Hiena> If i not miss a number or two, the total wasted energy for the ozone generation around 4kW which results only 1.6 litre ozone. Guess, due the missaligned reactor pressure only the 10% results peroxide, the others goes to the blow-out valve.
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[13:39] <MikeMc68> Hiena are you talking to anyone in here or have you posted in the wrong channel ?
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[13:46] <Hiena> MikeMc68, Just keeping updated the others to know, which time will get our planet yet another funny shaped satellite on orbit. Currently i'm working on a proof of the concept rocket engine and for that i need liquid oxidizer.
[13:51] <MikeMc68> OK - i'm totally confused - but... OK
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[14:21] <LazyLeopard> edmore: Main headache is organising the exams.
[14:21] <LazyLeopard> (Ah. Missed...)
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[15:58] <MikeMc68> Evening
[16:05] <gb73d> hi mike
[16:05] <gb73d> i have fldigis set up and running
[16:12] <MikeMc68> GREAT
[16:14] <gb73d> was looking for a good data prog have multipsk but it wont allow variable shifts on rtty
[16:14] <gb73d> this fldigi is good
[16:15] <gb73d> am looking forward to 27/2 possible launch
[16:18] <MikeMc68> Has James said 27nd is the next attempt?
[16:18] <MikeMc68> 27th
[16:19] <gb73d> possible only
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[17:02] <rjharrison> yo edmoore
[17:02] <edmoore> hello
[17:02] <rjharrison> bit of a disaster yesterday
[17:03] <rjharrison> where you in the field?
[17:03] <edmoore> yep
[17:03] <rjharrison> I felt sorry for jc as he had everything in place for this lauch
[17:03] <edmoore> same
[17:03] <edmoore> not the best outcome
[17:04] <rjharrison> I'm hoping to launch soon
[17:04] <edmoore> cool - what are you launching?
[17:04] <rjharrison> The 3kg is getting older
[17:04] <rjharrison> Icarus II and camera with good wx
[17:05] <rjharrison> Icarus III needs to have the payload built
[17:05] <edmoore> cool
[17:06] <rjharrison> BTW I got into the cambridge repeater using echolink yesterday
[17:06] <rjharrison> had a QSL with Randomskk
[17:17] <rjharrison> edmoore anychance of having a login on the wiki to play with the hourly predictor
[17:18] <edmoore> that won't help
[17:18] <edmoore> the wiki only tells you how to do it, not lets you do it directly
[17:18] <rjharrison> Oh ok Thought it was a weird interface
[17:19] <edmoore> you need a login to the SRCF server, and by policy that is only available to people with a valid CUDN (cam uni data network) login.
[17:19] <rjharrison> Skip that then
[17:19] <edmoore> as to change it you have to edit json files in the directory
[17:19] <edmoore> i can probably change some stuff foor you manually, but at the mo it's still very beta
[17:20] <rjharrison> Any chance of incresing the alt to somehting a bit more realistic
[17:20] <edmoore> rjw is working on the new version of the predictor and that too. some kind of super mega hybrid thangamie
[17:20] <edmoore> only for an hour or too - that alt as currently very specifically set for a launch profile we want to do, and we sort of need it there for reference
[17:20] <rjharrison> 27k is a bit low 33k is more like it
[17:21] <rjharrison> Oh ok
[17:21] <rjharrison> Don't worry then leave it
[17:21] <rjharrison> I'll just keep it in mind
[17:21] <edmoore> will prod rjw to try and get it inot a useful tool for everyone asap
[17:21] <edmoore> into*
[17:22] <rjharrison> no problem
[17:22] <rjharrison> To be fair the standard predicotr is fine using the hourly to predict good chioces
[17:22] <rjharrison> choices
[17:25] <edmoore> the code for the hourly predictor is on the svn too
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[19:02] <gb73d> boy am i pleaed to find this chat room
[19:28] <edmoore> hi gb73d
[19:29] <gb73d> hi this freenode has a lot of sciencee stuff
[19:29] <gb73d> is kewl
[19:29] <gb73d> i been getting into uhf radio monitoring
[19:30] <gb73d> found aabout the LPD channels and 868 mhz lpd stuff
[19:30] <gb73d> this is an application
[19:31] smealum (~smealum@smea.servebeer.com) left irc:
[19:31] <edmoore> lpd?
[19:31] <gb73d> low power devices
[19:31] <gb73d> RF as used in baloon
[19:32] <edmoore> ah cool
[19:32] <edmoore> yes, I beleive one can legally fly 500mW on 868
[19:32] <edmoore> vs 10mW on 434
[19:32] <edmoore> it's just a shame there's not so much amateur equipment on 868
[19:33] <gb73d> yes its illegal for hams to go /air mobile
[19:33] <gb73d> not for lpds tho
[19:33] <gb73d> in uk at least
[19:33] <gb73d> in europe i think hams can use it on ballons
[19:34] <gb73d> in some countries like holland i think
[19:34] <gb73d> ive picked up radio sonde data on 406 mhz
[19:34] <gb73d> once with sonde monitor software
[19:35] <gb73d> i can hear em
[19:35] <gb73d> got altitude readings on the pc till it came down too low and faded out
[19:36] <edmoore> neat
[19:36] <edmoore> so what data do they transmit?
[19:36] <gb73d> i had a massive trip chasing the spirit of knoxville on 10mhz
[19:36] <gb73d> the temps and winds
[19:37] <gb73d> took 3 days to finally hear it , went down of southern eire
[19:37] <gb73d> was so exciting
[19:37] <edmoore> yeah we were all very keen on that here too
[19:37] <edmoore> excellent project
[19:37] <gb73d> want more balloooon fun
[19:37] <edmoore> dan (from SNOX) sometimes comes on ehre
[19:38] <gb73d> yeah they were greate
[19:38] <edmoore> shame we couldn't launch yesterday
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[19:38] <gb73d> yes but it was such a hoot
[19:38] <SpeedEvil> What was the altitude peak yesterday? 4-5m?
[19:39] <edmoore> less than that
[19:40] <edmoore> jame's extended arm
[19:40] <gb73d> i reckon they shu a took it further from the trees before release
[19:40] <gb73d> probly just got carried along by the lower winds
[19:40] <SpeedEvil> Was it a simple case of it being difficult to guage teh right lift?
[19:41] <gb73d> looked inflated ok
[19:41] <gb73d> was good launch , bad position
[19:41] <edmoore> nope, it definitely didn't have enough helium in it
[19:41] <edmoore> it was well away from the trees
[19:41] <gb73d> well dont it expand at height
[19:41] <SpeedEvil> yes
[19:41] <edmoore> that doesn't change anything
[19:41] <SpeedEvil> But the wall pressure of the balloon is - approximately - zero
[19:42] <SpeedEvil> This means that the unbalanced lift at all altitudes stays constant
[19:42] <SpeedEvil> And as the pressure of the air drops as the balloon expands - it means the ascent velocity is also constant
[19:42] <SpeedEvil> (to first order)
[19:42] <edmoore> probably to a second too
[19:43] <gb73d> well in sure they must a measured the He pressure
[19:44] <edmoore> i didn't understand that, what do you mean?
[19:44] <SpeedEvil> This breaks down in the event of slightly underfilled balloons - where the pressure of the balloon walls can pressurise the helium to such an extent that the balloon no longer expands enough as it rises to make up for the decreasing bouyancy due to the displaced air.
[19:44] <gb73d> welll when they put the He in surely they use a measured amount
[19:44] <SpeedEvil> This only happens at altitude though
[19:45] <gb73d> it could have had more
[19:45] <edmoore> gb73d: it's measured by lift usually, i.e. you measure the bouyancy of the balloon, rather than a more direct measurement of the amount of He that goes in
[19:45] <gb73d> i thort that was cos of the pressure
[19:45] <gb73d> it would have taken off quicker with more
[19:45] <gb73d> so maybe shud a put more in
[19:46] <gb73d> mmmm
[19:46] <SpeedEvil> It's hard to measure in a windy field.
[19:46] <edmoore> not pressure, as the pressure is more or less constant
[19:46] <gb73d> it was about as bad as it could get before being untenable
[19:47] <edmoore> the internal pressure of a balloon is so very close to atmospheric that it's very difficult to measure with a useful enough accuracy.
[19:47] <edmoore> indeed, it was a difficult fill in windy conditions
[19:47] <SpeedEvil> Also I suspect it will vary significantly with temperature.
[19:47] <edmoore> for such a low fill anyway
[19:47] <edmoore> of course
[19:48] <edmoore> yeserday it was negative
[19:48] <SpeedEvil> I mean the elastic modulus of the balloon will change.
[19:48] <SpeedEvil> I suppose the only repeatable solution would be a metering valve of some form, or a big tent.
[19:49] <edmoore> big tent is probably the easier solution
[19:49] <edmoore> mass-flow valves that we could easily integrate into the fill system a pretty hard to come by
[19:49] <SpeedEvil> Well - Laurenceb's anemometer thingy... + ...
[19:49] <SpeedEvil> but yes
[19:51] <gb73d> enuff gas to ensure lift off in a given wind
[19:52] <gb73d> lol lot of blowing off involved
[19:52] <edmoore> well, that is often too much gas
[19:53] <edmoore> you're aiming for a specific ascent rate
[19:53] <gb73d> gas yes
[19:53] <edmoore> the amount of wind shouldn't change that
[19:53] <SpeedEvil> edmoore: hmm. I just went into the kitchen, and weight out some tuna for a sandwitch.
[19:53] <gb73d> so they shud a cancelled or at least waited for a lull in the gusts
[19:54] <SpeedEvil> But the weight of He is going to be what - 150g?
[19:54] <edmoore> no lul seemed forthcoming. in retrospect it was right on the edge of launchable conditions
[19:54] <edmoore> we have certainly launched in those kind of conditions before
[19:54] <SpeedEvil> What does the cylinder weigh - 50kg?
[19:54] <edmoore> just got unlucky with the fill
[19:54] <gb73d> well it was worth it to test the procedures
[19:54] <gb73d> u could not do anything about the weather
[19:54] <edmoore> SpeedEvil: 50-100. I think ours are nearer 100. i think the one yesterday was about 25
[19:56] <edmoore> gb73d: indeed, it'll force some thinking about ways of launching in nasty weather
[19:56] <gb73d> yeah there must be a limiting speed thats what the airforce would do
[19:56] <gb73d> mean ground air speed
[19:57] <gb73d> above which not takes offs
[19:57] <edmoore> that's boring :)
[19:57] <gb73d> say 15kts
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[19:58] <gb73d> it helps make a go no go decision
[19:58] <SpeedEvil> http://www.dealextreme.com/details.dx/sku.1164
[19:58] <SpeedEvil> hmm
[19:58] <edmoore> especially when the ground winds are not very signifiant to the overall flight. if you have ideal jetstream conditions, you don't want to miss them just because ground winds aren't that nice
[19:58] <SpeedEvil> that would actually work OK
[19:58] <SpeedEvil> IF the cyl is lighter
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[19:59] <gb73d> yeah but if its gonna only get a horizontal vector you wont penetrate
[19:59] <SpeedEvil> Actually - it's a bit marginal
[20:00] <edmoore> i think you misunderstand how balloons work. It either goes up or it doesnt, the wind doesn't matter
[20:00] <SpeedEvil> There is no wind once it's launched.
[20:00] <gb73d> it becomes entrained in the lower winds and moves laterally and not up
[20:00] <edmoore> yesterday, what went wrong was that the lift from the balloon was less than the weight of the payload.
[20:00] <edmoore> no it doesn't
[20:01] <gb73d> its like chucking it in a river in flood
[20:01] <Randomskk> the upward force doesn't change due to sideways forces
[20:01] <gb73d> yes but the later overcomes the former
[20:01] <edmoore> er...
[20:01] <Randomskk> no, because it doesn't change them at all
[20:01] <Randomskk> there's no correlation
[20:01] <Randomskk> the upward force is unaffected by any amount of sideways force
[20:02] <gb73d> yeah but the vector on the mass is the resulatnt of the two
[20:02] <Randomskk> (except where, say, there's so much sideways force it changes the shape of the balloon and thus the displaced air, reducing the upwards force, but.... that's somewhat tangential)
[20:02] <Randomskk> gb73d: yes, but the vector's component upwards is unchanged
[20:02] <Randomskk> so it will move upwards just as fast
[20:02] <Randomskk> it will also move sideways
[20:02] <SpeedEvil> The above scale - hooked to the cylinder - would give .2m^3 resolution. Which isn't really ideal.
[20:03] <edmoore> gb73d: the wind vector is orthogonal to the lift vector, unless there's some very local witchcraft
[20:03] <edmoore> so it really should not have an affect
[20:03] <gb73d> its the cross product of the two forces
[20:03] <Randomskk> what? no
[20:04] <russss> heh, very local witchcraft
[20:04] <edmoore> are you trolling?
[20:04] <gb73d> only on sunday
[20:04] <gb73d> is party night here
[20:04] <Randomskk> russss: stranger things have happened I imagine
[20:04] <Randomskk> launching into a hurricane is probably not advisable
[20:05] <edmoore> still, a resultant as a cross-product of who forces
[20:05] <edmoore> i didn't realise the balloons had a sufficiently high angular rate as to precess
[20:06] <SpeedEvil> Once it's launched - it rapidly accellerates to the overall air velocity.
[20:06] <SpeedEvil> Any effect from wind is then only windshear
[20:08] <gb73d> windshear thats the term
[20:08] <gb73d> thats what got it
[20:09] <edmoore> I honestly think it was just that it didn't have positive lift, that's all
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[20:13] <RocketBoy> yeah I think it was the process of measurubg the lift - I liked the theory of the gazebo creating a vortex above the balloon while we were measuring it
[20:13] <natrium42> hi all
[20:13] <RocketBoy> its aabout the only explanation I can think of
[20:13] <natrium42> jcoxon, what are the forecasts for next weekend? :)
[20:14] <jcoxon> evening natrium42
[20:17] <jcoxon> i'm not sure - also need to sort logistics for a launch, not sure who is around even if the weather was good
[20:17] <natrium42> gotcha
[20:18] <jcoxon> though i desperate to launch the damn thing - its wasted so many of my weekends now
[20:20] <natrium42> i know the feeling
[20:22] <jcoxon> the payload is in excellent condition
[20:22] <jcoxon> even the antenna + gp wires are still intact
[20:22] <gb73d> did u test the tx at launch ?
[20:23] <natrium42> gb73d, i think the only problem was the underfilling
[20:23] <gb73d> was anyone monitoring it
[20:23] <natrium42> the tx is very proven and reliable
[20:23] <gb73d> wanted to check
[20:23] <gb73d> is worth having a listen on a scanner
[20:23] <jcoxon> gb73d, oh the tx was still going while being dragged
[20:23] <jcoxon> and it had gps lock as well
[20:24] <gb73d> good oh it was on
[20:24] <jcoxon> yup
[20:24] <jcoxon> it was purely that it wasn't going up
[20:24] <natrium42> gb73d, you probably didn't hear it because it was too low
[20:24] <Laurenceb> hello
[20:24] Action: Laurenceb back
[20:24] <gb73d> i wish i was there with the scanner in my car
[20:24] <natrium42> it's only 10mW, so you need LOS...
[20:24] <Laurenceb> natrium42: almost worked out your horizon problem
[20:24] <natrium42> oh cool
[20:25] Action: Laurenceb has about 4 pages of A4
[20:25] <Laurenceb> freaking trigonometery
[20:25] <natrium42> so you think it's more appropriate to do 10 degree horizon?
[20:25] <natrium42> rather than 0 degree?
[20:25] <Laurenceb> SpeedEvil: KADA 852D+ is awesome
[20:25] <edmoore> natrium42: i'd say 5
[20:25] <Laurenceb> natrium42: yes
[20:25] <edmoore> we got badgercub just over the horizon over the summer. 10 is pretty conservative
[20:25] Action: Laurenceb has just been trying some hot air soldering
[20:25] <natrium42> ah
[20:26] <Laurenceb> I really like the automatic cooldown thingy
[20:26] <Laurenceb> and temperature seems fairly accurate
[20:27] <Laurenceb> its actually quite hard to burn your hands
[20:28] <natrium42> yeah, it's surprising how protective human skin is
[20:28] <jcoxon> please don't burn your hands - they are quite sensitive and i'll have to come and fix you!
[20:29] <natrium42> :D
[20:29] <Randomskk> oooh my favourite thing
[20:29] <Randomskk> an email from my supervisor moving my supervision to tomorrow and assigning work for it
[20:29] <Randomskk> at 2030 on sunday
[20:31] <edmoore> sounds about right
[20:31] <gb73d> i know im right
[20:31] <gb73d> lol
[20:31] <edmoore> we had one who set a supervision for 6am on a sunday
[20:31] <Randomskk> the bastard
[20:31] <Randomskk> one of our supervisors wishes our DoS would let him set 6AMs so that he could prevent the rowers from going rowing
[20:32] <gb73d> i foiund the notam covering luanches from the EARS site
[20:32] <gb73d> runs till april
[20:32] <edmoore> sent a stroppy email to my DoS about how we shouldn't pander to these aspergers-ey robots
[20:33] <gb73d> i worked out it would hasve to rise to 3280 ft before i could hear in in Reading
[20:33] <gb73d> about 1km
[20:33] <edmoore> it would have been heading very close to you too
[20:34] <gb73d> yes it was looking great
[20:35] <edmoore> what are you listening with OOI?
[20:36] <gb73d> yaesu vr5000 scanner and hombrew 446mhz ground plane in the loft with a 20 db preamp at the mast head
[20:36] <gb73d> its hot as f
[20:36] <edmoore> the pre-amp sounds nice
[20:36] <edmoore> does that scanner support ssb/
[20:36] <gb73d> im gonna make a 435 hz version for uhf satcoms and ballons
[20:36] <edmoore> ?
[20:36] <gb73d> yep an d has dsp and spectrum scope
[20:37] <edmoore> very nice
[20:37] <gb73d> i can get 100mw satellites
[20:37] <gb73d> i luve it
[20:37] <gb73d> thats y this room is so kool
[20:37] <edmoore> oh wow it's a proper manly scanner
[20:37] <gb73d> fantastic
[20:37] <gb73d> its got italian blood in it it shouts
[20:37] <edmoore> :)
[20:38] <gb73d> my qth is 57m above sea level too
[20:38] <edmoore> we're all major fans of the yaesu 817 here
[20:38] <edmoore> seems to be the radio of choice for tracking and chasing
[20:38] <gb73d> yeah yaesu rocks
[20:38] <edmoore> chasing is a lot of fun
[20:39] <edmoore> a couple of us run icom ic-7000s too
[20:39] <gb73d> yeah its really exciting and also damn hard
[20:39] <gb73d> yeah thats a good rg
[20:39] <gb73d> rig
[20:39] <edmoore> i adore it
[20:40] <edmoore> but not so good for trudging around the field looking for the payload
[20:41] <gb73d> dont give up is the frontier
[20:42] <gb73d> i would help out may be one day
[20:42] <gb73d> is long drive
[20:42] <edmoore> do!
[20:42] <gb73d> could be done
[20:42] <gb73d> maybe on a nice day
[20:42] <edmoore> in the mean time, being a listener for the distributed listener is a really awesome thing to do
[20:43] <edmoore> and will give you an excuse to build a wee yagi :)
[20:43] <gb73d> 100% on that
[20:43] <gb73d> yes have plans for a helix and other ants
[20:43] <edmoore> the distributed listener is, I think, one of the most fun things to come from this community
[20:44] <gb73d> thhe ground plane is a n connector with brass rod welded to it
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[20:44] <Lunar_Lander> hello
[20:44] <gb73d> on the end of rg313
[20:44] <Lunar_Lander> hi jcoxon
[20:44] <jcoxon> hey Lunar_Lander
[20:44] <gb73d> good to mee t you all
[20:44] <Lunar_Lander> sorry that I wasn't here
[20:44] <Lunar_Lander> I had a sudden appointment
[20:45] <natrium42> moin Lunar_Lander
[20:45] <jcoxon> Lunar_Lander, oh don't worry - the launch failed :-(
[20:45] <jcoxon> so there wasn't anything to follow
[20:45] <jcoxon> which reminds me
[20:45] <Lunar_Lander> hi natrium42
[20:45] #highaltitude: mode change '+o jcoxon' by ChanServ!ChanServ@services.
[20:45] <Lunar_Lander> what exactly happened?
[20:46] <jcoxon> messed up judging lift so didn't actually take off - just dragged a long way so we had to stop the flight
[20:46] <Lunar_Lander> oh ok
[20:46] <Lunar_Lander> btw, look at this: http://img19.imageshack.us/img19/2115/balloon3.png
[20:46] <jcoxon> Lunar_Lander, yup - but you don't want to mess with the Canadian Air Authorities - they are mean
[20:47] <Lunar_Lander> ah ok
[20:47] <jcoxon> you'd struggle to get permission to launch from there
[20:47] <Lunar_Lander> yeah
[20:47] <Lunar_Lander> the launch would lead into nothing anyway
[20:47] <jcoxon> would need to permission from a member of government
[20:47] <Lunar_Lander> yeah
[20:47] <Lunar_Lander> and the track looks like it would go to nowhere
[20:48] <jcoxon> Lunar_Lander, you need to check out Hysplit
[20:48] <russss> yeah that's pretty close to the north atlantic tracks, heh
[20:49] <Lunar_Lander> interesting website
[20:50] <jcoxon> that will allow you to do very good predictions on floating
[20:50] <Lunar_Lander> yeah
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[21:04] <Lunar_Lander> will there be a second attempt?
[21:04] <jcoxon> oh yes
[21:05] <jcoxon> soon!
[21:05] <Lunar_Lander> cool
[21:06] <gb73d> i see the txer is nbfm - can u send rtty using nbfm ?
[21:06] <gb73d> by just sending the tones on a nbfm carrier
[21:06] <gb73d> as audio
[21:06] <gb73d> suppose it would work
[21:07] <russss> the computer modulates the FM transmitter to actually send SSB
[21:07] <gb73d> can it be made to simulate ssb
[21:07] <russss> so the resultant signal isnt actually FM at all, it's SSB
[21:07] <russss> it's a cunning hack
[21:07] <fergusnoble> hi all
[21:07] <gb73d> i see
[21:08] <jcoxon> hey fergusnoble
[21:08] <gb73d> will stick to ssb on the rig tho
[21:08] <gb73d> am a little worried about doppler shift and the rx stability on ssb
[21:08] <gb73d> never tried rtty with it before
[21:09] <gb73d> might be hard to keep tuned
[21:09] <gb73d> have 20hz steps minimum
[21:09] <fergusnoble> gb73d: you can send rtty over fm, its called AFSK modulation, but the performance is worse than "proper" fsk on SSB
[21:09] <gb73d> i might have to feed it into the icom at 10.7 mhz and ssb it there
[21:10] <fergusnoble> or rather it degrades less well as SNR goes down
[21:10] <gb73d> i seee afsk yes
[21:10] <gb73d> yes its that ssb is ok lower signals
[21:11] <gb73d> will see fldidg has afc too that might work
[21:12] <SpeedEvil> see http://www.motivatedphotos.com/?id=37803
[21:12] <SpeedEvil> err
[21:12] <SpeedEvil> not that
[21:12] <SpeedEvil> http://wiki.ukhas.org.uk/guides:tracking_guide
[21:12] <SpeedEvil> this outlines the way 'we' do it
[21:12] <SpeedEvil> Another way of looking at it is the SSB reciever is just used as a downconverter, sampling the RF into an audio IF
[21:13] <Lunar_Lander> xD on the soccer pic
[21:13] <SpeedEvil> Sorry - I thought it was called beginner - so I just copied off the first completed URL on firefox
[21:14] <SpeedEvil> which gets populated by random clicks by titles.
[21:14] <gb73d> tnx fer that site have bookmarked it
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[21:16] <eam52> not sure if this is a colloquy bug or not, but works fine through irssi. odd
[21:16] <fergusnoble> hi ed
[21:16] <jcoxon> that is odd
[21:16] <eam52> yo
[21:16] <jcoxon> yay - i earnt 17p yesterday from google adsense - should help to offset costs :-p
[21:16] <russss> heh
[21:16] <fergusnoble> dont spend it all at once
[21:18] <eam52> test
[21:18] <jcoxon> eam52, test received
[21:18] <eam52> " /nick " isn't working for me either
[21:18] <eam52> oh well
[21:18] <eam52> my colloquy is full of cobwebs
[21:19] <gb73d> that motivated photos is good too
[21:21] <eam52> which motivated photos?
[21:21] <gb73d> the site posted before
[21:21] <eam52> probably missed it
[21:23] <SpeedEvil> jcoxon: http://www.tesco.com/superstore/xpi/9/xpi53541119.htm
[21:24] <jcoxon> SpeedEvil, ballast?
[21:24] <SpeedEvil> 17p
[21:24] <jcoxon> oh right, thanks :-)
[21:25] <Lunar_Lander> they have Tesco in the Czech Republic too btw :P
[21:25] <gb73d> thats value
[21:25] <jcoxon> celebratery soup!
[21:28] <gb73d> is basically tomato puree
[21:28] <SpeedEvil> gb73d: Some of their stupidly reduced stuff is OK.
[21:28] <SpeedEvil> Got 40 cans of baby sweetcorn@5p
[21:29] <gb73d> would stop u starving
[21:29] <gb73d> some bargains tho
[21:29] <SpeedEvil> Stir-fried, with a little vinegar, sugar, and soy, it's quite nice.
[21:30] <eam52> i could murder a pizza
[21:30] <gb73d> mmm supper
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[21:34] <eam52> is webchat.freenode.net working for anyone?
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[21:35] <jcoxon2> yup
[21:35] <eam52> this is very odd
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[21:35] <eam52> oh, it works for me in safari
[21:35] <eam52> praps a chrome bug
[21:36] <Lunar_Lander> jcoxon what do you think about Stirling engines?
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[21:36] <jcoxon> Lunar_Lander, in what context?
[21:36] <edmoore_> that's better
[21:37] <Lunar_Lander> well
[21:37] <Lunar_Lander> I once heard that they wanted to try one on the ISS
[21:37] <Lunar_Lander> and maybe it could be a power source on the atlantic cruise or so
[21:37] <gb73d> cheers see ya next sunday prob
[21:37] gb73d (gb73d@80-42-30-75.dynamic.dsl.as9105.com) left irc:
[21:38] Nick change: edmoore_ -> edmoore
[21:38] #highaltitude: mode change '+o edmoore' by ChanServ!ChanServ@services.
[21:38] <edmoore> right. test
[21:39] <jcoxon> yup
[21:39] <edmoore> cool thanks
[21:39] <edmoore> was having user permission problems
[21:39] Topic changed on #highaltitude by jcoxon!jcoxon@host86-156-36-88.range86-156.btcentralplus.com: Welcome to #highaltitude - discuss anything to do with high altitude projects (balloons, gliders, etc) www.ukhas.org.uk, wiki.ukhas.org.uk
[21:40] #highaltitude: mode change '-o edmoore' by ChanServ!ChanServ@services.
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[21:40] <jcoxon> edmoore, apparently we went up to 54users yesterday
[21:40] <edmoore> wow
[21:40] <edmoore> that's a record
[21:40] <edmoore> half a tonne
[21:41] <Lunar_Lander> but I would also think that any Stirling engine would probably too heavy
[21:42] <edmoore> Lunar_Lander: i'm not sure from where you would extract the thermal gradient you need to run it
[21:42] <edmoore> i can see in space that you could have one end pointing at the sun and the other to space, but i'm not sure that would hold nearly so well in the atmosphere
[21:43] <jcoxon> bbl
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[21:43] <Lunar_Lander> yeah, truw
[21:43] <Lunar_Lander> *true
[21:44] <Lunar_Lander> we'd need to know how much convection there is at 1% atmosphere
[21:45] <russss> well you've still got to orient it too
[21:45] <russss> and if you're doing that then is it any better than PV?
[21:46] <Lunar_Lander> yeah
[21:46] <Lunar_Lander> and there is the weight
[21:46] <Lunar_Lander> and moving parts
[21:46] <Lunar_Lander> is PV for photovoltaics?
[21:47] <russss> yeah
[21:47] <Lunar_Lander> yes
[21:47] <russss> I mean, theoretically it's more efficent, right? But on balloons and in space, you've also got massive weight considerations
[21:47] <russss> (also, batteries work fine ;)
[21:47] <Lunar_Lander> solar cells would probably be much better in a performance/weight calculation
[21:47] <Lunar_Lander> yeah ;)
[21:48] <edmoore> a little big ago, henry did a few napkin sums and concluded that up to about 2 weeks duration, batteries make sense, then after that, PV
[21:48] <Lunar_Lander> ah ok
[21:48] <edmoore> it was on the old private transatlantic forum, and i'm not sure where that's gone, but it might be interesting to have a look at his working if you're thinking about doing this
[21:48] <Lunar_Lander> but what I saw from the tracks is, that the Atlantic might be doable in two days
[21:48] <edmoore> s/forum/wiki
[21:48] <Lunar_Lander> yeah
[21:49] <Lunar_Lander> I think Transaltlantic is one day in the far future ;)
[21:49] <Lunar_Lander> but it is always important to learn new things
[21:51] <edmoore> yes - pv things would be an awesome way to experiment
[21:52] <russss> presumably NASA's long-duration floaters use PV
[21:52] <edmoore> yep
[21:53] <edmoore> eg BLAST
[21:55] <edmoore> right, gtg
[21:55] Nick change: edmoore -> edmoore|away
[21:56] <russss> that's a big payload.
[21:56] <Lunar_Lander> yeah
[21:56] <Lunar_Lander> or CREAM too
[21:56] <Lunar_Lander> or SUNRISE
[21:56] <Lunar_Lander> my Uni was short of making a radiation sensor for SUNRISE
[21:56] <Lunar_Lander> but then the contract didn't work out
[21:59] <Laurenceb> grr stupid horizon equation
[21:59] <Laurenceb> its turned into a horrible mess
[22:00] <SpeedEvil> :)
[22:00] <Lunar_Lander> physics Laurenceb?
[22:00] <SpeedEvil> Are you trying to work out if a line between the balloon and a ground station intersects the earth spheroid?
[22:00] <SpeedEvil> Or something more complex
[22:01] <Laurenceb> trying to calculate radio horizon
[22:01] <SpeedEvil> including elevation data?
[22:01] <Laurenceb> so if your horizon is 10 degrees above hozizontal say
[22:01] <Laurenceb> and balloon is at altitude a
[22:01] <Laurenceb> what is the visable range
[22:02] <RocketBoy> the radio horizen is normally over the visable horizon
[22:02] <SpeedEvil> I assume you want to assume non-zero altitude.
[22:02] <SpeedEvil> Which makes it a bit harder
[22:02] <Laurenceb> yes
[22:03] <Laurenceb> so receiver at altitude a and transmitter at altitude b
[22:03] <SpeedEvil> Anyway. draw a line from the balloon tangent to the earth sphere
[22:03] <RocketBoy> there is an appoximate formula around which gives the distance - frequency dependant
[22:03] <Laurenceb> then the receiver has a horizon that is angle h above horizontal
[22:03] <SpeedEvil> if the reciever is above this line - it can recieve
[22:03] <Laurenceb> whats the range
[22:03] <Laurenceb> thats what I'm trying to work out the equation for
[22:04] <Laurenceb> and its a pain
[22:04] <SpeedEvil> Err
[22:04] <SpeedEvil> If the reciever is beyond the intersection point, and above the line, it can recieve.
[22:04] <RocketBoy> tis increadably simple geometry
[22:04] <SpeedEvil> if it's before teh intersection point, it can recieve always
[22:04] <Laurenceb> I'm trying to work it out with cosine rule
[22:05] <Laurenceb> Rocketboy: yes
[22:05] <Laurenceb> but for some reason I cant work it out
[22:05] <SpeedEvil> Draw it out on paper
[22:05] <Laurenceb> probably screwed up a sign somewhere or something
[22:05] <Laurenceb> yes
[22:06] <Laurenceb> its just a triangle, side lenghts d,radius_earth,radius_earth+altitude
[22:06] <SpeedEvil> Do you understand how to go from 3d to 2d?
[22:06] <Laurenceb> d is the maximal range
[22:06] <Laurenceb> its reducable to a 2D problem
[22:07] <Laurenceb> the angle between the radius_earth and d sides of the triangle is 90degrees+h
[22:07] <SpeedEvil> That is lat/lon/alt pair to a 2d representation of the problem sliced through the centre of the earth and the 2 points
[22:07] <Laurenceb> where h is the elevation
[22:07] <Laurenceb> yes
[22:07] <Laurenceb> then cosine rule I think
[22:07] Action: Laurenceb works it out of paper
[22:09] <natrium42> http://en.wikipedia.org/wiki/Horizon
[22:10] <SpeedEvil> I was pondering something based on SRTM
[22:12] <SpeedEvil> http://en.wikipedia.org/wiki/Fresnel_zone - get the SRTM data. For each point of SRTM data under the line between the balloon and the reciever - compute the fraction the terrain clears the frensel zone by.
[22:12] <RocketBoy> anyway - like i said the radio horizen is further than the visable horizen: http://radarproblems.com/chapters/ch04.dir/ch04pr.dir/c04p3.dir/c04p3.htm
[22:12] <SpeedEvil> multiply all these fractions together
[22:13] <SpeedEvil> Err
[22:13] <SpeedEvil> there is no f term there
[22:13] <RocketBoy> I was wrong
[22:14] <SpeedEvil> During the 1940s
[22:14] <RocketBoy> I imagine its still the same
[22:14] <SpeedEvil> Sure.
[22:15] <SpeedEvil> For radar in the frequencies used in the 40s
[22:16] <RocketBoy> yeah like 40MHz and up - by the end of the war RADAR was using magnatorns at 100s of MHZ
[22:17] <RocketBoy> I think you will find a f componet in other texts - with it being streight line by light frequencies
[22:18] <SpeedEvil> during hte 40s it varied a _lot_ - which is why I was questioning the lack of f
[22:21] <RocketBoy> When I tracked BH3 the signal was visable (but not decodable) when the payload was over the visable horized (so I calculated)
[22:22] <russss> in most cases I guess there'll be enough vegetation/buildings to obscure it up to at least +5 degrees or so
[22:31] <Lunar_Lander> I once read a little book on international satellite TV
[22:31] <Lunar_Lander> and there was a Russian station on a satellite parked at 80°E
[22:32] <Lunar_Lander> and there was a guide on how to build some kind of a dish tower to point the dish at that very low elevation
[22:38] <russss> heh
[22:38] <Laurenceb> oh got it
[22:39] <Laurenceb> doh
[22:39] Action: Laurenceb fails
[22:39] <Laurenceb> d=r(sqrt(c^2+a(2r+a)/r^2)-c)
[22:39] <Laurenceb> where c=cos(90+h)
[22:40] <Laurenceb> r=radius_earth a=altitude of balloon
[22:40] <Laurenceb> d is the line of sight distance
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[22:43] <RocketBoy> you can to it with square and squareroot too
[22:45] <RocketBoy> slant height = SQRT((rad+h)^2-rad^2) where rad is earth radius
[22:58] <RocketBoy> put my spreadsheet for this on the wiki http://ukhas.org.uk/communication:lineofsight
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[23:01] <Laurenceb> http://www.analog.com/en/amplifiers-and-comparators/operational-amplifiers-op-amps/ad8571/products/product.html
[23:01] <Laurenceb> yummy
[23:04] <Laurenceb> 5nV/C bias drift thats insane
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[23:11] <Lunar_Lander> good night
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[23:17] <jcoxon> ping fergusnoble edmoore|away
[23:18] <fergusnoble> hey
[23:18] <fergusnoble> whats up?
[23:18] <jcoxon> the cusf LP seems to be broken
[23:18] <jcoxon> well its using pretty old GRIB data from 12/2/10
[23:23] <fergusnoble> ok, ill have a quick look
[23:30] <jcoxon> fergusnoble, thanks, its no hurry - just thought i'd point it out
[23:30] <jcoxon> night all
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[23:30] <fergusnoble> night
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[23:48] <MikeMc68> evening
[23:51] <LazyLeopard> Hi Mike.
[23:51] <MikeMc68> Hi Rick
[23:51] <MikeMc68> Just got back from Cheshire
[23:52] <MikeMc68> Slightly better journey coming back than going - going was 8.5 hours - coming back was 5 hrs 15 mins
[23:52] <MikeMc68> that should be 4 hrs 15 mins
[23:53] <SpeedEvil> Laurenceb: yeah.
[23:53] <SpeedEvil> opamps have got a _LOT_ better.
[23:53] <SpeedEvil> Being able to get a 1uV vos opamp that's under a dollar - in volume - ....
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[23:54] <RocketBoy> nights
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[23:59] <LazyLeopard> G'night
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[00:00] --- Mon Feb 15 2010