PICAXE is in Space

srnet

Senior Member
You wont pick up the FSK RTTY with a UHF handheld, they dont do LSB\USB mode (yes I knew there is one that does, the TH7)

For the FSK RTTY the Funcube dongle is probably the cheapest option (£125) that will receive it and all you need is some sort of omni directional antenna. The quadrafiler helix is a good one, mine is made from a bit of plastic pluming pipe, some sticks and a wire coat-hanger, see picture.

One of the RTL DVB TV dongles might do the trick, there cheap, £6 off eBay, but it will need a decent low noise amplifier in front of it.
 

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srnet

Senior Member
Last night I had my first chance to pick up some data from $50SAT whilst it was in eclipse (the dark).

Battery has been stabilized at around 3700mV since launch, so during the sun period its getting enough charge to run the beacons and data transmissions once every 73 seconds.

Temperature of satellite -20C

Its on orbit #31 now.
 

MFB

Senior Member
Manuka recommended the Baofeng transceiver but does he, or anyone else, know of a similar performance low cost scanner that can be used for satellite and balloon telemetry reception?
 

srnet

Senior Member
Even just switching on a transmitter
without a licence,
is that legal?
Good idea to get a license, but I cant see what law is being broken if you turn on a receiver that just happens to be capable of transmitting.

Pressing the transmit button would be illegal without a license.
 

srnet

Senior Member
The FSK RTTY from the $5 radio (RFM22B) we are using is proving to be a star performer.

There was a pass over central Europe around 0917 this morning, closest approach was 2224kM.

At an estimated range of 2400kM, I received;

$50SAT,128,,172,,,49,3,,21,145,86,,82,10,3703,*43

Which means all is well.

I am just using an omni antenna with no gain, the mind boggles as to the range you would get with a long 15dB yagi on a tracking setup.
 

kranenborg

Senior Member
Hello srnet,

Most impressive I must say, and an excellent showcase showing what can be done with off-the-shelf technology. Also a very good example of the power of a cooperative and well-documented project. I find it truly amazing what can be done regarding receiving range with a few solar cells and proper storage

Is there any prediction possible regarding satellite lifetime regarding
- components ageing / malfunction?
- orbit change?

Is there something you could reveal about the mppt-technology used? (could not find it in the long thread about the preparations, but maybe you cannot disclose ...)

BR, Jurjen
http://www.kranenborg.org/electronics
 
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MFB

Senior Member
Being unlicensed, I would certainly feel more comfortable operating a scanning receiver. My reasoning about the Baofeng alternative was that if the Chinese can produce low cost tranceivers, maybe they also do good receivers. Regarding the USB dongle approach, it seems there are either very low cost options that lack sensitivity (and need lots of fiddle downloads to set-up) or the excellent FunCube that seems a bit expensive compared with the Baofeng transceiver.
 

JimPerry

Senior Member
kranenborg has exceeded their stored private messages quota and cannot accept further messages until they clear some space
 

srnet

Senior Member
Is there any prediction possible regarding satellite lifetime regarding components ageing / malfunction?
We just dont know, there is very little data (none really) that we could find regarding the radiation durability of standard commercial parts in space.

512 bytes of the PICAXE scratchpad RAM are scanned every minute or so for corruption or changes. One concern is obviously bit flipping from high energy particles which is more likely than normal as the only shielding is the 1/16th Aluminum chassis. So far no bit flips have been detected in the RAM or EEPROM which is also being checked.

- orbit change?
Not even sure if Norad can track it to come up with an initial accurate set of orbit parameters. So orbit changes might be difficult to spot. Its at around 600km altitude, and even though there are big kapton flaps on the antenna the atmospheric drag wont bring it down for a good few years.

What will likely kill it sooner rather than later is the battery, its just a Klic7002 camera battery and cannot be expected to last too long.

Is there something you could reveal about the mppt-technology used? (could not find it in the long thread about the preparations, but maybe you cannot disclose ...)
All the software and electronic designs will be put on the Dropbox site at some point, hopefully next week, we always intended for all the stuff to be open source.

We are using 4 x LTC3105, one for each side of solar panel.

The internals of the satellite are very sparten, two 40mm x 40mm PCBs, one is the processor and radio board, the other is the maximum power point controller & battery charger.

Attached is a picture of the processor/radio board that is whizzing around above our heads.
 

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hippy

Technical Support
Staff member
It was a genuine, and pertinent question.

http://stakeholders.ofcom.org.uk/enforcement/spectrum-enforcement/law

I've got my licence, but for others, it's still worth checking.
A very good question. From the link -

Section 8 of the 2006 Act forbids the installation or use of wireless telegraphy equipment (radio) ... unless an appropriate licence has been obtained from Ofcom, or there are Regulations in force exempting it from the licensing requirements.
Much radio apparatus is therefore exempted from licensing, including ... apparatus capable only of reception
My reading of that is you cannot legally install or use equipment which can transmit on licensed bands without a licence. Even if only listening. Even if only transmitting on a license exempt band.

If it's receive-only equipment you are fine ( though there may be other restrictions on listening to certain frequencies ).
 

kranenborg

Senior Member
kranenborg has exceeded their stored private messages quota and cannot accept further messages until they clear some space
Box emptied, open for new messages ...Tks for signalling /Jurjen

Srnet, thanks for the reference to the LTC3105 controller, from the manufacturer info I understand that it is a DC step-up converter that accepts single solar cell input voltage levels (minimum voltage level for converter startup is 0.245 V, where a single cell already gives 0.5 V at moderate illumination level) and includes mppt functionality, very useful therefore for small solar powered picaxe projects (there have been several discussions on this forum on how to build mmpt's. Will take one myself and experiment with it one day)

/Jurjen
 
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Paix

Senior Member
@Eclectic, M3 are old hat now, M6 for the last year and more!

@MFB get yourself a licence. With just half a brain, you would have to struggle to fail the Foundation examination and it starts to open up a lot of possibilities.

I have just got a 400mW 5.8GHz FPV type tx/rx. 25mW permitted in UK, but 400W as a licenced radio amateur (10W for Foundation licencees) bottom three of eight channels fall into the Amateur allocation. That makes me legal as long as I ident properly and that's good enough for me. 5.8GHz Bandplan? tut!
Bottom six 2.3GHz wifi channels also fall into the Amateur allocation. It gives me a potential playground to test things in the spirit of self training and experimentation. I'm sure that SRNET made good use of his licence when range checking.

The other thing is that for generally receiving satellite signals, you really need a receiver that has an SSB capability. FM tends to be channelised so tuning is likely to be an issue and doesn't realise the sensitivity offered by CW/SSB due the BFO/CIO and the much narrower bandwidth possible.

The three launches in November have netted some 41 amateur satellites to listen for across a large swathe of spectrum. More than enough to excite anyone I would have thought. What an early Christmas present and Eagle2 ( $50Sat ) is up there head and shoulders above the best, punching well above it's weight - but them I'm biased!
 

srnet

Senior Member
Srnet, thanks for the reference to the LTC3105 controller, from the manufacturer info I understand that it accepts singe solar cell input voltage levels and includes mppt functionality
Thats correct, and they work rather well.

They can also be used to directly charge a battery, we have them set to limit output voltage to 3.9V, which is then connected to the Lithium Ion battery. Voltage limited charging is not the best way to charge a Lithium battery, but we are charging a fair bit under the normal maximum charge voltage (4.1v) so it should be OK.

The MPPT was the work of one of the US members of the team, I did the software and the processor\radio board and the third member did the engineering and flight model assembly and testing, plus the forward error correction code used to transmit the FEC data packet.
 
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papaof2

Senior Member
Need to check on the definitionof "operating" where you are. In the US, "operating" a transmit-capable device means transmitting, in the same sense as "operating" a motor vehicle. Anyone can sit behind the wheel and rev the engine. The license is only required when you put it in gear and start moving.
 

MFB

Senior Member
Thanks for the advise Paix and I my well try for the licence. However, I would still welcome advice on any suitable low cost (Chinese) UHF receivers. My be manuka can recommend something?
 

srnet

Senior Member
Here is a graphic of some of the distance tests I did to establish some base data for the RFM22 performance. The long blue line is the route of the 40km test.

The short line is a test carried out by some guy called Marconi, but as you can see he did not get very far.
 

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MPep

Senior Member
1st thing first, SRNET => WELL DONE. What a feat.

@ Paix:
I'll get a TLE into Orbitron for a daytime look when I have a moment. Enjoy!
Where do you get the TLE from? I've used Orbitron before, for tracking Iridium satellites, and works very well too.
Just not quite sure which TLE file to check for $50SAT.

MPep
 

srnet

Senior Member
The first set of TLEs to be used, which were accurate, were available at the location mentioned in the first post ..................

Norad have just released the latest radar tracking, and everyone is trying to work out which one is which;

http://celestrak.com/NORAD/elements/tle-new.txt

It might take a few days to work out which is which.
 
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manuka

Senior Member
Kranenborg: Good to see you active, & again many thanks for your hospitality during our June Uppsala visit!

MFB: Numerous high quality Chinese VHF/UHF sets cheaply abound, but the FM/NBFM Baofeng UV-5R is (presently) considered the best bang for buck -their ~US$40-50 landed price makes them almost disposable. Refer UK outlet Sinotel. They're not perfect however,with their keyboard manual programming especially a pain -although CHIRP software & the USB programming cable makes setup a breeze !

The receiver is very sensitive but some users report significant RX desensing in urban areas with strong nearby signals. This may especially be an issue with high gain external antenna (which can readily be connected via a BNC-SMA adapter).Although I prefer "Big 3" Japanese sourced Ya-Ken-Com (Yaesu/Kenwood/Icom) offerings,they're far more costly. My UV-5R has run a treat & it handles all manner of local VHF & UHF ham, UHF-CB, ISM & marine freqs. to great effect.

Stan (ham ZL2APS since 1967)
 

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eclectic

Moderator
Kranenborg: Good to see you active, & again many thanks for your hospitality during our June Uppsala visit!

MFB: Numerous high quality Chinese VHF/UHF sets cheaply abound, but the FM/NBFM Baofeng UV-5R is (presently) considered the best bang for buck -their ~US$50 landed price makes them almost disposable. They're not perfect however,with manual programming especially a pain -CHIRP & the USB cable essential!

Although the receiver is very sensitive some users report significant RX desensing in urban areas with strong nearby signals. This may especially be an issue with high gain external antenna (which can readily be connected via a SMA-BNC adapter).Although I prefer a Japanese sourced "Ya-Ken-Com" (Yaesu/Kenwood/Icom) my UV-5R has run a treat & it handles all manner of local VHF & UHF ham, UHF-CB, ISM & marine freqs. to great effect.

Stan (ham ZL2APS since 1967)
Transceiver?

See posts 45, 46, 52 and more.
 

manuka

Senior Member
CHIRP has simple "receive only" options to lock out transmission on channels. I've not explored this in depth (as being a ham I wished transceiver features), but the UV-5R unit (at least) can be totally transmit inhibited.

Such receive only sets can only be made 2 way when (re)config. via the programming cable & CHIRP.
 

Paix

Senior Member
@Mpep, source of TLE is spacetrack.org a USAF facility in New York. sign up for an account, but be aware that they work office hours, so if you have a password problem on a weekend then you will maybe have to wait until Monday morning for a reply.

A few years ago TLE info to Celestrak dried up for a while due to regulatory changes. It's been good again for several years, but the source is spacetrack.org. Take your pick basically whichever is easiest.

How do you find your TLE, get a whole bunch and search for the Norad catalogue number of the satellite. As SRNET has said, these get allocated when the tracking has positively identified the separate entities deployed from the launch vehicle.
Here is a breakdown of the TLE format. Sometimes a satellite may have different names, ie: Delfi-3A DO-64 if in doubt, find the Norad catalog/satellite number from line 1 field 2 and search for that data in a mass download if necessary. Edit and pop the ones you are interested into a file and point Orbitron at it. Not the best way perhaps, but sometimes the categorisation is difficult to ascertain.

Hand held FM transceivers by definition have a weak front end and will easily be swamped/overloaded by close by strong frequencies if using an external antenna that is well up in the clear or a high gain antenna. They aren't designed for it.
 

manuka

Senior Member
They aren't designed for it.
Of course! However they're a great "get ya feet wet" tool, especially in quiet RF areas, perhaps with a simple Yagi. I've regularly heard beacons & transmissions of assorted satellites on just rubber duckie fitted ham handhelds - OSCARs (Orbital Satellte Carrying Amateur Radio) have been active since the early 1960s,with FUNcube-1 (AO-73) a typical modern launch. It went up on the same mass launch as your $50sat/Eagle2.

Thought:Aside from your TLE set (Two Line Element) is there any chance that tracking data can be more graphically organised? The resources at => www.n2yo.com/space-station/ really enthuse & educate youngsters!
 

srnet

Senior Member
Aside from your TLE set (Two Line Element) is there any chance that tracking data can be more graphically organised? The resources at => www.n2yo.com/space-station/ really enthuse & educate youngsters!
Not sure what your suggesting here.

There are a couple of web sites that do on-line tracking, but that will have to wait for the orbits to be confirmed.

Anyone that wants to track the orbit based on the current set of orbit parameters can install one of several (free) PC programs that will take the TLEs.
 

MFB

Senior Member
Thanks for the advise Manuka. A Baofeng transceiver and USB cable have now been added to my Santa list.
 

srnet

Senior Member
$50SAT has just been heard from the UK as it passed over Krakow in Poland.

Its due directly overhead of Reading in the UK at around 11:18, so you stand a good chance of hearing it on a handheld (outdoors !), start listening on 437.510Khz at around that time. See picture..

Check on 437.505Mhz and 437.500Mhz as the pass progresses, there is a period of about 6 minutes when it can be heard.
 

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eclectic

Moderator
$50SAT has just been heard from the UK as it passed over Krakow in Poland.

Its due directly overhead of Reading in the UK at around 11:18, so you stand a good chance of hearing it on a handheld (outdoors !), start listening on 437.510Khz at around that time. See picture..

Check on 437.505Mhz and 437.500Mhz as the pass progresses, there is a period of about 6 minutes when it can be heard.
For the Morse illiterate (me and others),what are we listening for?

And, as a re-cap, USB or LSB?

e
 

srnet

Senior Member
See post#1, there is a recording of typical FM audio (the Morse callsign beacons) at that Dropbox location.

The FSK RTTY goes out LSB, see page 16 of the communications document at the same location.
 

manuka

Senior Member
UNISAT-5
1 10000U 13325.30958333 .00066391 00000-0 78737-2 0 00001
2 10000 097.8055 037.9628 0031909 207.6761 327.4099 14.84238859000010
Srnet: Yes-I'm aware of programs than have long assisted (even DOS era),but was hoping someone was already on to it! Naturally the orbit will have to first settle down, but some early pointers would be welcomed. I'm following FUNcube /AO-73 at N2YO in fact-it may well be still in the same release cohort as the $50sat ?

FWIW many folks I've pointed sat. tracking to over the decades tend to glaze over with numbers. Most however REALLY take an interest when they can see the graphical screen path & then (at least) hear a "Doppler" influenced beacon. Naturally SEEing the bird (even if possible) is a dawn/dusk/clear sky activity,although mega enthralling when the likes of ISS actually pass overhead as predicted. Stan.

MFB: Great - you'll have a ton of fun I'd say. They come with charger- get a SMA-BNC adapter & "glove" protective case too perhaps?
 

srnet

Senior Member
$50SAT heard on a FT60 handheld and Baofeng handheld at around 11:20 in Cradiff.

The signal is weak, but the transmitter is only 100mW and it was 730km away .......
 

srnet

Senior Member
I'm following FUNcube /AO-73 at N2YO in fact-it may well be still in the same release cohort as the $50sat
Funcube was in the same release, but the data on the N2Y0 (for Funcube-1) is not right, wrong orbit and wrong launch date.

The best way of tracking it for now is to use the TLEs I have given, and at some point the various web sites will update, as and when the orbits are confirmed.
 

Paix

Senior Member
Eclectic said:
For the Morse illiterate (me and others),what are we listening for?
As SRNET has said, there is an MP3 available via the link at post #1. If it sounds like morse, a steam train, bleeps or warbling data then variously you may have it. Morse wise, it's a variety of idents :) but not strictly so!

Eclectic said:
And, as a re-cap, USB or LSB?
Most definitaly USB in my book. Why? Because the signal is arriving from the high end of the spectrum and enters the band pass filter as a higher tone that is likely audible. Using LSB then when appearing on the margin of the bandpass filter, any audio is at near to zero beat and so inaudible for the best part of in the order of 200 to 250Hz, so I would tend to set watch on USB for best opportunity.

Manuka said:
Thought:Aside from your TLE set (Two Line Element) is there any chance that tracking data can be more graphically organised? The resources at => www.n2yo.com/space-station/ really enthuse & educate youngsters!
Orbitron is a good graphic representation. The track and footprint can be shown and, to me, there is nothing quite as impressive as the edge of the footprint touching your location on the display and the bird breaks silence. Sorry, but TLEs themselves are what they are, a shorthand data representation of position parameters in a circular geometry terms, drag and other statistics at the epoch. Understanding the terms themselves is both interesting and educational in themselves. An introduction into a new world, Apogee, Perigee, Right Ascension, Inclination, Eccentricity and Release Cohort (Thanks Manuka); to mention a few.
An indication that this is a very different and exciting way of thinking and representation. I wish to God that I fully understood some of those terms usefully. An introduction to the fact that mapping, even on earth uses a variety of standard models to represent best adjusted guesses of an imperfect world in a consistent and better understandable way. It's all about new concepts.
My theory is that concepts are accommodated, not leaned. One becomes familiar as a by product of exposure..

MFB said:
Thanks for the advise Manuka. A Baofeng transceiver and USB cable have now been added to my Santa list.
As long as you expect the USB cable to be used for programming your raido then you are OK. I would hate you to confuse USB (Universal Serial Bus) with USB (Upper SideBand). Unlikely but worth mentioning as there are neophites out there and it's worth making the distinction when bringing radio and computers together that the one acronym has two meanings. And, NO, not a good reason for adopting LSB . . . :)
= = =
A lot of opinion from me. Not intended to be at all argumentative and I accept that my explanations may not always be as elegant as they should be, but I do hope that most of what I speak of has some relevance.

Technically we live in exciting times and just how to best infect our youth with the bug is frankly a little beyond me personally.
 

srnet

Senior Member
The signal reception levels from $50SAT, of the FM Morse, are about what was expected, both by calculation and by listening tests on a couple of Cubesats.

ITUPSAT1, that has a 300mW FM Morse beacon and SWISSCUBE, that has a 100mW CW beacon.

I note this morning that I received the $50SAT FM beacon better on my cheapie Baoefng than I did on my Yaesu FT60, I will check at some point why that should be so.

At the same time I was listening on two handhelds my brother was yielding my FT817 and a 7 element yagi;

http://www.arrowantennas.com/arrowii/440-7ii.html

The beacon was heard very clearly.

I have been monitoring the Funcube situation, and why one website seems to have incorrect information on Funcube, I do not know, but that is for the Funcube team to deal with. Whilst Funcube was on the same launch as $50SAT, I have noticed the orbit is different which is why I have not given it as an example recently. I saw a comment that it was detected in the UK 'around 11:35' this morning, at which point $50SAT was 38degress below the horizon and 8000km away. The timings I have given for Unisat5 and $50SAT, and the TLEs, seem about correct.

If anyone wants to setup a web site displaying the $50SAT orbit in real time using the TLEs given, then I wont mind.
 

srnet

Senior Member
What's the best time estimates for the next few passes?
e
I will probably later today or tomorrow put the 5 day prediction list on the Dropbox.

Until then, you could load up Orbitron and see the pretty pictures on screen.

Goes over Lands End about 10:15 tonight, approaching from the South.
 
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