May 2011 - Amsat-dc (INACTIVE)

Re: SimSat on Facebook
by Pat Kilroy 28 Sep '11

28 Sep '11

Hi Steve, I'm sorry for the confusion. Thank you for helping me figure out this Facebook operation. Even when using the FB "Help" feature, I cannot discern clearly the difference between the FB Group and the FB Page options. I started with creating a Group, and then later created a Page. But last night I deleted the Group (long story) in favor of giving the Page an opportunity to incubate. Here are my requirements, and maybe you and others can comment: I want it to be public but we want to know who is in the membership, and allow folks to post photos, videos, data/telemetry/documents, all in good taste and relevant to our high-altitude balloon experiments, Amateur Satellite efforts, educational training opportunities, fellow- ship, and community outreach goals. I want it to be totally separate from my personal Facebook page which is, to me, mostly an immediate family thing. It would be nice to have an e-mail "broadcast" capability there too, like for rain scrubs on flight day. (It will be more dynamic than the Web page, which will be used for verbose announcements, displaying key results, reposit important reference documents, publish diagrams/documents, archive stuff and serve to allow the logging of our "history.") So, do these "specs" suggest we need a Group or a Page? Thoughts? For now, I believe the correct URL, as long as it may be, is: https://www.facebook.com/pages/SimSat/190820480964810?sk=wall although I hope we can shorten it soon. Once we get this Facebook tool stable then I will update the simsat.net site. I am open to suggestions. Thanks, Pat N8PK -----Original Message----- From: Stephan Greene [mailto:ks1g04@gmail.com] Sent: Monday, May 9, 2011 10:19 PM To: pat(a)patkilroy.com Cc: amsat-dc(a)amsat.org Subject: Re: [amsat-dc] Re: SimSat on Facebook This it? https://www.facebook.com/pages/SimSat/190820480964810 (forget how I found it) Or this: https://www.facebook.com/home.php?sk=group_209591802406934 ? Might want to add a link on the Simsat web page. To find the 2nd link, I did a search for Simsat (bringing up a ton of people from various parts of the world) then clicked on groups. What I assume is the school group is the 1st link that's listed. What I think is the AMSAT-dc group (I sent a join request) is the 2nd. 73 Steve KS1G On Mon, May 9, 2011 at 4:00 PM, Pat Kilroy <pat(a)patkilroy.com> wrote: That MIGHT be a Page, and NOT a Group from the Facebook perspective. Just search the string "simsat" (without the quotes) once you are logged on to your own page in FB. Hope this helps. 73 de N8PK. -- ----------------------------------------------------------------------------------------------------------------- Steve Greene ks1g04(a)gmail.com <kay ess one gee zero four>@gmail.com -----------------------------------------------------------------------------------------------------------------

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Re: SimSat on Facebook
by Pat Kilroy 09 May '11

09 May '11

That MIGHT be a Page, and NOT a Group from the Facebook perspective. Just search the string "simsat" (without the quotes) once you are logged on to your own page in FB. Hope this helps. 73 de N8PK.

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Space Day News Please
by JoAnne Maenpaa 09 May '11

09 May '11

Hello everyone, If you were at the Space Day at the National Air and Space Museum this past weekend could you send me a brief description of your participation and impressions/thoughts of the event? I'd like to put an ANS bulletin together congratulating AMSAT and participants. The event, AMSAT display, and ARISS contact looked great on N4HY's photos on facebook. If you took photos please send them in as high resolution as you have (no need to shrink them) and a caption for the photo. A link to accessible storage will work as well, and I'll download them. These will be for the AMSAT Journal. Send photos as attachments to k9jkm(a)comcast.net Thanks! -- 73 de JoAnne K9JKM k9jkm(a)amsat.org Editor, AMSAT News Service

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SimSat on Facebook
by Pat Kilroy 09 May '11

09 May '11

WE ARE STARTING a group on Facebook.com for the SimSat project and the PICetSat high- altitude balloon flight experiments coming this summer and fall. You are invited to join! If you are on FB and want to follow all the action posted by our group members then go to your Facebook page, search for the SimSat Group, then click a request to join. Easy! And, of course, we will still post announcements and archive data at http://simsat.net as always but it just won't be quite as dynamic, especially on flight days. Cheers, Pat Kilroy, N8PK Maryland-DC Area

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Re: Join a FUNcube Eval
by Kilroy, Patrick L. (GSFC-5680) 06 May '11

06 May '11

An update: I received my FUNcube Dongle! Initial bench test results receiving a strong PICetSat signal (see http://simsat.net/carrollsat/) look good so far to me. One reluctant evaluator, however, questioned whether the tiny unit was little more than a toy. So, I would like to run some formal tests on it and other receivers at the same time under the same conditions, and then compare results. More testing and evaluation will follow. In the mean time, one fine group in Texas may have stolen my thunder. See below for an insightful message from Ken N8KH, who uncovered the recent NTMS test results and offered additional helpful comments to us. But, as an aside about Ken's pre-amplifier recommendation, I found several amplification stages in the FUNcube Dongle itself that are variable and can be easily changed. I will experiment with them before purchasing another satellite-grade low-noise pre-amp. I also have a nice big DCI filter for 145 MHz and another for 435 MHz to insert between the dongle and antenna if and when needed. Immediately below Ken's message, please see the related links of interest for your convenience. Did YOU order a FUNcube Dongle yet? Keep trying. The next sale should be announced on the FUNcubeDongle Web site soon. Cheers, Pat N8PK -----Original Message----- From: Ken Hendrickson [mailto:khendr01@harris.com] Sent: Thursday, May 5, 2011 11:19 PM To: pat(a)patkilroy.com Subject: MDS & NF Tests (Including FUNcube Dongle) The North Texas Microwave Society (NTMS) just did some testing of minimum detectable signal (MDS) and noise figure (NF) measurements for common IF receivers, including the FUNcube Dongle Pro [and the IC-910H]. (It was published tonight.) The FUNcube performed very well. On both 435 MHz and also 1296 MHz it was within 3 dB of the best out there. As you know, 3 dB is just barely measurable in the laboratory with expensive test equipment, and only barely noticeable on the air. Their report/slides: http://www.NTMS.org/files/MDS_NF_Measurements_IF_Rigs_RevC.pdf If you want to make up that 3 dB, just add a very good pre-amp to the front end. But be careful, and do not overload the FUNcube with too much signal. You don't want much gain -- only the lower noise figure and enough gain to overcome feedline losses. Make sure to measure dynamic range after adding the preamp, to ensure you haven't degraded dynamic range. But to be honest, 3 dB probably isn't worth it. Here are some quick and easy rules of thumb: If you want to double range, you need +6 dB. If you cut the bandwidth in half, you will add +3 dB of performance (at the expense of time). So if you need 6 dB, you can cut the bandwidth in half twice. Use slower signaling, and longer integration times at your receiver, and you will have your 6 dB and doubling of range. The first step to deciding if your FUNcube will really work in your application is to do a link budget. Do you have antenna gain pattern figures? Bandwidths? Power output? Perhaps I can help you out with the link budget. My gut level feel is that your system will work well, but math is better than a gut feeling. 73, Ken N8KH PS Please send the address of the Carroll County amateur radio club meeting on Monday night. -------------------------- LINKS FUNcube Dongle Pro http://www.funcubedongle.com/ SoftRock SDR http://www.wb5rvz.com/sdr/ http://homepages.wightcable.net/~g4zfq/Si570.htm Power SDR http://www.flexradio.com/Products.aspx?topic=PowerSDRv2 http://flexradiowiki.com/frsradoiowiki/index.php?title=Main_Page http://support.flex-radio.com/Downloads.aspx HP 83712A http://www.home.agilent.com/agilent/product.jspx?cc=US&lc=eng&nid=-53690019… MDC High-Altitude Balloon Experiments http://simsat.net/carrollsat/ -------------------------- Sent: Wednesday, April 27, 2011 11:08 AM Subject: Join a FUNcube Eval Cross-posted from amsat-dc(a)amsat.org ... Yesterday I ordered a FUNcube Dongle Pro from Howard Long, G6LVB, and AMSAT-UK at http://www.funcubedongle.com/ for under $200 USD to evaluate. [] I am evaluating this SDR receiver for dual use on the Amateur Satellites and my STEM project of SimSat, specifically, currently, on quality of reception of my high-altitude balloon experiment PICetSat flight modules. We will fly again this summer. Part of the FUNcube Dongle Pro technical FAQ is reproduced below, FYI. I am looking for others who wish to also evaluate the same receiver for whatever one's purpose. Please let me know if you got one or when you get one, and what software you are trying. Thoughts? THANKS and 73, Pat Kilroy, N8PK AMSAT Area Coordinator MDC Area >From http://www.funcubedongle.com/ . . . Technical FAQ Q. What is the FUNcube Dongle Pro frequency range? A. 64-1,700MHz, although straw poll tests on pre-production units indicate that units can be stretched down to 51.5MHz or so. Upper frequency limit is beyond 2,000MHz. In testing, we have determined that there is a gap between about 1,100MHz and 1,270MHz where the design of the local oscillator VCO, PLL and divider chain in the tuner chip don't provide seemless coverage. Q. What can the FUNcube Dongle receive? A. The FUNcube Dongle has no restriction on modulation schemes: it is limited only by the application program running on the host computer. As long as the signal fits within about an 80kHz bandwidth, the FUNcube Dongle is capable of receiving the radio signal. So, for analogue reception, as well as narrow band FM and SSB, it is also possible to receive, for example, sound subcarriers for TV broadcast. Similarly for data reception, as long as a data demodulator has been written that will accept standard soundcard quadrature I/Q reception, that will work too. Q. What is the bandwidth? A. 96kHz is the quadrature sampling rate. Once the ADC's decimation filter skirts have been taken into account, you have about 80kHz. Q. What applications work with the FUNcube Dongle? A. As well as the forthcoming FUNcube front end application, any application that understands a standard stereo soundcard configured for quadrature, or I/Q, reception should work. Examples include Linrad, Spectravue, Rocky and M0KGK. Q. What is the sensitivity? A. Each unit is tested for 0.15uV for 12dB SINAD NBFM at 145MHz and 435MHz. Q. What operating systems are compatible? A. Currently Windows 2000 SP4, XP 32 bit, and Vista and Windows 7 32 and 64 bit have been tested. The sound card element works with Mac OSX and Ubuntu 10.10 32- and 64-bit, but the frequency setting application has not been ported yet. [snip]

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