February 2014 - AMSAT-BB - mailman.amsat.org

Re: 150 cubesats to provide global WIFI multicasting
by Gregg Wonderly 10 Feb '14

10 Feb '14

As the birds dropped out of the sky above the ground station, there might be some objections. What has to happen for long range, gigabit bandwidth, is a wide frequency range with little time on any particular frequency so that there is no concentrated effects on a single frequency where heating would start to occur. Frequency hopping over large spectrum is not a new thing, but it's something that could alleviate a number of issues with safety. Gregg Wonderly W5GGW On 2/10/2014 11:46 AM, Howie DeFelice wrote: > Just in case anyone was curious about the practicality of actually transmitting WiFi from a cubesat, I did a quick link budget. Based on typical 802.11 specs, the MDS of a receiver is about -90 dBm. The path loss at 2.4GHz between a ground station and a satellite overhead in a 600Km orbit is a little over 155 dB. Assuming a zero gain antenna on the typical WiFi client radio, the required EIRP from the cubesat is in the neighborhood of 4KW. I don't think we are quite there yet with current solar cell technology.... not to mention the difficulty keeping the PA cool :) > > - Howie AB2S > _______________________________________________ > Sent via AMSAT-BB(a)amsat.org. Opinions expressed are those of the author. > Not an AMSAT-NA member? Join now to support the amateur satellite program! > Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb >

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Colorado W1AW/0 Centennial QSO party Satellite operations.
by David W0DHB 09 Feb '14

09 Feb '14

I looking for CO folks who would like to operate a satellite pass or passes as W1AW/0 for the ARRL Centennial QSO party. Colorado operations will be during the weeks starting 21 May 2014 and 16 July 2014 . More info on the QSO party at http://www.arrl.org/centennial-qso-party I'd sure like to get as a many operators in as many different CO grids as possible. Please contact me off of BB if you are interested. Thanks Dave W0DHB

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Re: 150 cubesats to provide global WIFI multicasting
by Robert Bruninga 09 Feb '14

09 Feb '14

> for the life of me, I can't think where we could find 70 Mbytes > of ham radio content. Not useful content, anyway. A good example is the way some people stream live tracking data for all satellites in view plus an update to the DX list of passes over the next 3 hours that is captured and displayed on all APRS radios in the local area. The APRS radios capture this and display on the front panel the range and bearing to the satellite, the uplink and downlink freqs and the Doppler. Everything you needed to know to work the satellite while mobile in real time. In addition, if you have the voice module in the radio, the radio will SPEAK the announcement of the satellite in view and will SPEAK the elevation angle as "LOW or HIGH" every minute during the pass. In addition, at any time during the day (or when you arrive in a parking lot and just before you turn off the radio) one can hit the LIST button on the radio and bring up the DX list and it will contain the next three hours of pass times. (useful if there is one only 2 minutes away and worth waiting for). This way one never has to refer to a PC for tracking data, but simply watch (or listen) for satellite alerts on your APRS radio. In fact it is ideal to get alerts while you are in the mobile because that is also where you can work em! There are many satellites that you can work from a mobile with an FM rig, why not? We have had this capability in all Kenwood and now Yaesu APRS radios going back to 1998. You can see examples of the front panel displays on the APRS HT on this web page http://aprs.org/localinfo.html about 90% down the page under the paragraph heading LOCAL SATELLITE ALERTS. And this is only a small part of the continuous streaming data on the APRS channel (useful for the traveler). You also get the following data in real time: * FREQ, and TONE of locally recommended traveler Voice repeaters (accessible with just a press of the TUNE or QSY button) * FREQ, and TONE of nearby IRLP, Echolink or Allstar links * TIMES and days of any local nets on these repeaters * Times and dates of any local club meetings *Announcements about upcoming HAMfests or events * FREQ, location and distance to any other APRS mobile op in voice range * Actual PING alerts if any other APRS mobile operator is in simplex range. Too many people simply ignore APRS as a "tracking system" when it never was intended that way. It was intended as a mobile data resource, pushing relevant local content to the front panel about everything going on in HAM radio in the local area for instant access. (And that includes satellites in view) The APRS radios have over 900 pages of data memory that are being refreshed constantly and are avaialble at any time. (Plus 10 pages of DX list) Plus the data can be sorted for display by age, callsign, or frquency, or distance. See the above web page for all the content already available. But like anything else in Ham radio, if no one is transmitting content in a local area, then no one is even aware of this powerful Ham radio technique. While traveling and just watching the data coming in from APRS, I have stumbled into Hamfests, Pig roasts, club meetings and nets of all kinds to just drop-in on along the road. Bob, WB4APR On Sat, Feb 8, 2014 at 6:15 PM, Gus <gus(a)8p6sm.net> wrote: > On 02/08/2014 09:24 AM, Robert Bruninga wrote: > > Any ham... to collect this content simply puts his 9600 bd radio > > listing to that repeaer INPUT to join the net! An AP runs together > > building a buffer of that 70 Mbytes of ham radio content per day, which > > is then instantly accessible at any time with is browser. > > Again, we have the sites, the atnennas, the freqs and the radios. > > But for the life of me, I can't think where we could find 70 megabytes > of ham radio content. Not useful content, anyway. >

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How to get a cheap handheld broadband RF preamp
by andy thomas 09 Feb '14

09 Feb '14

This is primarily for the team getting ready for the Kicksat Sprite project but I am posting it on the amsat -bb as well as there may be a science teacher out there who may be interested.I'm not claiming it's revolutionary, but timely. The requirement is for an inexpensive antenna-head preamp, lightweight, running on a battery. I wouldn't claim it is a low noise preamp, but CATV ampifiers are available for under £5 including delivery from China. I bought one in a car boot sale for a £1. It was supposed to work on mains electricty (220 volts!) and is therefore obviously unsuitable to use outside. So I have taken out the mains transformer and the diode rectifier matrix and now run it off a 9 volt battery. I've also shown that the input and output sockets can be changed. This is simple soldering as even I can do it. Obviously the same principle applies to any TV amplifier, broadband, and needing filtering at the antenna head. Just look to see if 435 MHz is included in the bandwidth. At some point I'll design and construct an input filter. For those who may be interested, here's a direct link to my page: https://sites.google.com/site/andythomasorg/funcube/cheap-rf-amplifier or you can get there by going to http://www.andythomas.eu , choosing "Funcube" from the drop down menu and then get the page from the bottom of the Funcube page. 73 de andy G0SFJ

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Next SpaceX Dragon Launch Scheduled
by B J 09 Feb '14

09 Feb '14

http://www.newspacejournal.com/2014/02/08/spacex-sets-date-for-next-crs-mis… http://www.nasaspaceflight.com/2014/02/spacex-dragons-crs-3-launch-march-16/ 73s Bernhard VA6BMJ @ DO33FL

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Re: 150 cubesats to provide global WIFI multicasting
by Gus 08 Feb '14

08 Feb '14

On 02/08/2014 09:24 AM, Robert Bruninga wrote: > Any ham wanting to collect this content simply puts his 96000 baud radio > listing to that repeaer INPUT to join the net! An AP runs together > building a buffer of that 70 megabytes of ham radio content per day, which > is then instantly accessible at any time with is browser. > > Again, we have the sites, the atnennas, the freqs and the radios. But for the life of me, I can't think where we could find 70 megabytes of ham radio content. Not useful content, anyway. -- Gus 8P6SM The Easternmost Isle

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AO-7 Mode B Beacon
by Paul Stoetzer 08 Feb '14

08 Feb '14

I had a 75 degree pass of AO-7 this afternoon and thought I'd try to hear the beacon. I've tried a couple of times now and not heard anything. Maybe my high local noise level prevents me from hearing it, but I don't have much noise with the antenna pointing almost straight up. Does the Mode B beacon on 145.975 MHz still function or has it failed? 73, Paul, N8HM

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SatPC32 CAT with IC-9100
by Gabriel - EA6VQ 08 Feb '14

08 Feb '14

I am testing SatPC32 V.12.8c together with my new IC-9100 for Doppler correction. The only problem I notice is that when I activate the CAT (C+) it doesn't set the rig in satellite mode and I have to do it manually in the transceiver. Not a very big trouble, but I wonder if I am doing something wrong as I can't believe something so simple is not done by the program. I will appreciate your comments. 73. Gabriel - EA6VQ _________________________________________________________ Web-Site: HTTP://www.dxmaps.com VQLog 3.1 (build 78): HTTP://www.vqlog.com _________________________________________________________

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Re: Listening on USB when operating CW
by Kevin M 08 Feb '14

08 Feb '14

> Computer-control stations and manual-control stations are adjusting for > Doppler differently. I have done - and will continue to do - both. In my > opinion, neither is incorrect; they simply differ from each other. This was posted during the assemblage of my long winded reply. I think it gets at the same thing I was beating around the bush at. I'm glad to know when I am eventually able to get back on the linear birds (yagis, preamps, cables and rotor in the closet... conduit for burying piled up outside) I will be able to find someone to work without getting my rig hooked up to a PC. (It will be enough to get the rotor hooked up to one!) I just hope I can remember which dial to turn when... anyone hearing me screw the pooch, please send instructions promptly! X^D 73 all, Kevin, N4UFO proud to be a full fledged Gridiot!

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IiNUSAT nanosatellite
by M5AKA 08 Feb '14

08 Feb '14

The Indonesian IiNUSAT nanosatellite is slated for an April/May launch on the Indian PSLV C23. A paper describes it as having a 9600 bps downlink on 436.915 MHz with an uplink at 145.950 MHz. http://tinyurl.com/pmzu3ph 73 Trevor M5AKA

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