August 2008 - AMSAT-BB - mailman.amsat.org

Nasa - NanoSail-D/PRESat Update
by Trevor 10 Aug '08

10 Aug '08

NanoSail-D/PRESat Update from http://www.nasa.gov/mission_pages/smallsats/nanosaild.html NASA's NanoSail-D and PRESat missions ended on Aug. 2, 2008, about two minutes after launch, when the SpaceX Falcon 1 launch vehicle experienced a problem during stage separation and was unable to achieve an Earth orbit. Although we were not able to test our payloads in space, NASA mission managers and payload engineers achieved success in these two low-cost missions by rapidly pulling together expertise from across the agency to develop, build and ground-test an innovative solar sail nanosatellite and a fundamental space biology micro-laboratory. The communications team also successfully established a fully operational South Pacific Ground Communication System using two ground stations, which were transported and installed at Kwajalein Atoll in the Marshall Islands and at the Universidad Centroamericana in El Salvador. This mission provided an excellent opportunity for collaboration between two NASA centers, other government agencies, academia and the burgeoning space industry. Through the development of NanoSail-D and PRESat, NASA gained experience and knowledge it can apply to future small and nanosatellite missions. ---- __________________________________________________________ Not happy with your email address?. Get the one you really want - millions of new email addresses available now at Yahoo! http://uk.docs.yahoo.com/ymail/new.html

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WD9EWK's first non-FM satellite QSOs today!
by Patrick STODDARD (WD9EWK/VA7EWK) 10 Aug '08

10 Aug '08

Hi! After months of trying to make a portable station that would allow me to work the SSB/CW satellites (first with an FT-817ND and AOR AR8200Mk2B wide-band receiver, then later with two FT-817NDs, all using my Arrow Antennas handheld Yagi), I finally made everything work. At 1756 and 1758 UTC today, I logged my first two satellite QSOs not using FM on either the uplink or downlink. As I expected, it was not an easy thing; FO-29's 2m uplink seemed to make it a bit easier than a 70cm uplink like I had tried before on VO-52 or AO-7. Now, after over 4100 satellite QSOs in the last 2 1/2 years or so, I can say I've got at least a couple SSB satellite QSOs to go with the others I've done on FM. I know that computer control for either - or both - of the radios is the preferred way to go. Less work for the operator, reducing how much my signal moves through the passband due to Doppler, and simply more time to work other stations. I will most likely end up with a portable setup using a small laptop that can control these two FT-817NDs or some other radio(s), eventually. I will also rig up a tripod or something for the Yagi, or try another antenna, so I don't have to hold it while trying to work the radio(s). I decided that the 1745-1759 UTC FO-29 pass this morning to my east would probably be a good pass to try. Good elevation, and a footprint covering most of North America. I set up my radios in the back of my truck just over the line into grid DM44ha northeast of Phoenix AZ, and tried my luck. It took a couple of minutes to get used to finding my signal in the downlink. My 5W signal with the Yagi was more than enough. I heard some CW early in the pass, then I could hear a couple of voices - Joe K3SZH and Jeff K7WIN. When those two finished their QSO, I quickly called K7WIN. K3SZH came back instead, and I made a quick QSO with Joe. I followed that up with another quick QSO with Jeff K7WIN. Both Joe and Jeff commented I had a good signal through the satellite. Thanks for the QSOs, and especially for dealing with my non-automated station near the end of the pass! Now I can go back to working on VO-52 and AO-7, plus the new Delfi satellite, and see if I can do the same with a non-FM satellite using a 70cm uplink. And keep on working FO-29, a very nice bird. I'm not turning my back on the FM birds, but adding more options when I want to play radio via satellite. :-) 73! Patrick WD9EWK/VA7EWK http://www.wd9ewk.net/

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Re: GO-32 query on AMSAT-BB Digest, Vol 3, Issue 400
by joe cassano aka jmario 09 Aug '08

09 Aug '08

Jeff: The url http://mangrove.findu.com/cgi-bin/pcsat.cgi shows (a probably very limited view) of who has moved APRS packets through GO-32. Looking at that site it seems that there is only one sat-gate in the U.S. that monitors GO-32 and that is K3PDK who is located in Maryland so don't expect to see a lot of reports of stateside GO-32 APRS activity. I do occasionally hear other folks APRS packets being repeated by GO-32 and sometimes hear folk poking at the GO-32 pbbs. JoeC, K3FMA > > Message: 9 > Date: Sat, 9 Aug 2008 10:16:39 -0400 > From: "Mr Jeffrey L Ross" <radiooperator(a)comcast.net> > Subject: [amsat-bb] anyone want to digi via sat go-32 @9600 . . . > p.s. does anyone know where the go-32 aprs web page satgate is? And is it > working? >

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Re: brain picking time
by w7lrd＠comcast.net 09 Aug '08

09 Aug '08

Hello Domenico & all Thanks for all the information. The measured F/D ratio works out to 0.375, therefore a patch would be appropriate. As mentioned earlier I would be content to just be able to receive EME (for now). For transmitting no doubt a different feed would be needed. Currently I am looking around for a preamp. I built a dual helix feed I am going to use on a four foot primestar off center dish. I used to receive on AO40 (sobsob) with a 3731AA downconverter. This same system will be used for transmitting (L band) on our next HEO. Maybe by planning and working toward the next HEO will generate more intense drive by all concerned. I can mount the 70 watt amp behind the 12 foot TVRO as suggested. Could a short helix be used for receive on the big dish? They are easier to build as opposed to a patch. All this work (fun) will help fill the void untill the next HEO. From what I am reading on the BB I could be at this for a long time. Any additional information would be helpf ull, p erhaps others can get something out of this. I have some pictures of the dish, dual helix I can send upon request. 73 Bob W7LRD Seattle -- "if this were easy, everyone would be doing it" -------------- Original message -------------- From: "i8cvs" <domenico.i8cvs(a)tin.it> Hi Bob, W7LRD Before to start anyting you must to know the F/D ratio of your dish because this parameter will tell you if a patch as a feed is suitable or not for it. If your TVRO dish is a prime focus dish to measure the F/D ratio is very easy Put your dish horizontal on the ground looking up 90 degrees and strain a rope passing just through the center of the mouth and measure the diameter D Measure the depth of the dish just from the center of the mouth between the rope and the bottom of the dish and call the deepth c 2 D D F/D = ----------------- and the focal point F = -------------- from the bottom of the dish 16 x c 16 x c If the F/D ratio is less than 0.5 then a patch can be used but if F/D is greater then 0.5 then a patch is not suitable. By the way a patch as a feed is not used at all for EME because there are type of specialized feed that are much and much better. If the F/D ratio is less of 0.5 then a VE4MA feed can be used and if the F/D ratio is greater of 0,5 then a dual mode dish W2IMU must be used. Both VE4MA and W2IMU are dual port feeds one the LHCP is used to transmit and the other one the RHCP is used to receive. Waiting for P3E and depending of the F/D ratio of a 5 meter dish that I plan to build for 1296 MHz EME I have already built both a VE4MA and a W2IMU feeds in order to be prepared for EME in the future because unfortunately the future seems to be not bright for the HEO satellites. 73" de i8CVS Domenico ----- Original Message ----- From: w7lrd(a)comcast.net To: Edward Cole ; i8cvs ; AMSAT-BB Sent: Wednesday, August 06, 2008 7:39 AM Subject: Re: [amsat-bb] Re: brain picking time Ed and all Many thanks for the information from many of you. I realize I will need a preamp. For now I will be content to see what I can hear. As you can guess once I can copy signals I will want to join in. That will require at very least mounting the amp at the antenna and a sequencer. I have seen W0LMD' web site as well as several others. I want to start out slow, before I "lose it". 73 Bob W7LRD -- "if this were easy, everyone would be doing it" -------------- Original message -------------- From: Edward Cole <kl7uw(a)acsalaska.net> > Domenico, > > You said it well. I forgot to mention that polarity sense will > reverse upon reflection at the dish surface, so the feed sense should > be Rx=RHCP; Tx=LHCP. In other discussions about using a patch for > eme, concern has been about sidelobe performance and high power > rating of the patch if full QRO eme is considered. Up to 200w it > probably is OK. > > I assumed that Bob was savy enough about microwave weak-signals to > know that on eme a preamp is not a luxury but an absolute > necessity. LMR-400 would be fine for connection from the preamp to > the receiver in the shack, if at least 15-dB net gain is left after > the cable loss is subtracted. More gain is desirable if the receive r > NF is high. A preamp of 0.3 dBNF is standard at 1296 for eme. > > I have a WD5AGO two-stage preamp with 0.30dBNF and 31-dBgain bought > from Radio Astronomy Supply. > > 73 Ed - KL7UW > > At 05:54 PM 8/5/2008, i8cvs wrote: > >----- Original Message ----- > >From: "Edward Cole" > >To: ; "AMSAT-BB" > >Sent: Tuesday, August 05, 2008 8:24 AM > >Subject: [amsat-bb] Re: brain picking time > > > >At 04:35 PM 8/4/2008, w7lrd(a)comcast.net wrote: > > > > >Next question- which probably would be more aimed at a EME bb. I > > >have a 12 foot TVRO I am building a patch feed for 1296, and feed it > > >through 50 feet of LMR400 to my IC-1271A. I want to see if I am > > >able to "hear" EME signals. Of course if I am able to, you can > > >g u ess what my next effort will be. This will be a cheapie effort as > > >I am only using stuff I already have. I do have a KJ6KO L band 70 watt > >amp. > > >73 Bob W7LRD > > >Seattle > > > > > Bob, > > > > > > Is your patch feed circular polar? EME on 1296 is RHCP in transmit > > > and LHCP in receive. > > > >Hi Ed, KL7UW > > > >It is best to specify to Bob that on 1296 MHz the dish in transmit must > >radiate RHCP in direction of the moon so that the patch or any other > >feed must radiate LCHP in direction of the surface of the dish. > > > > > The switch of polarity sense is due to the fact > > > that reflection at the moon reverses the sense of polarization. > > > >OK > >So that on receiving the wave coming from the moon is received LHCP > ; ; ; ; & gt;over the surface of the dish but the dish reverse by reflection the signal > >in direction of the feed that must be made RHCP polarized on receiving. > > > >In addition a TVRO dish works well with a patch feed if the F/D ratio of > >the dish is ranging from 0.35 to 0.45 > > > > > might be difficult to achieve with a patch feed. > > > >W0LMD make a patch feed for RHCP and LHCP but never I tested it > > > >Since the target of Bob is to see if he is able to only "hear" EME signals > >at 1296 MHz without to complicate his life I suggest at the very beginning > >to build only a patch feed RHCP polarized. > > > >To receive a 1296 EME signal with a 12 foot TVRO and a IC-1271A > >it is strictly necessary to connect directly to the patch connector a low > >noise preamplifier with a NF in the order of 0.5 dB &g t; & gt; ; &g t; >Since the gain of a low noise EME preamplifier for 1296 MHz is > >in the order of 30 dB or more then 50 feet of LMR400 connected from > >the output of the preamplifier up to the input of the IC-1271A will not > >deteriorate the overall NF of the system that will be only a little bit > >higher than 0.5 dB > > > > > 73 Ed - KL7UW > > > >73" de > > > >i8CVS Domenico >

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Re: Boy Scout Contact in AMSAT-BB Digest, Vol 3, Issue 400
by joe cassano aka jmario 09 Aug '08

09 Aug '08

Ken: http://oscar.dcarr.org is a good place to look for up to date reports on types of ISS activity (when it is active). Another place to look is http://www.ariss.net which indicates that (outside of school contacts) the ISS TM-D700 digipeater has not been active for over a month. The ISS digipeater was more active in the past - wonder why it is rarely active these days. JoeC, K3FMA > > Message: 6 > Date: Fri, 8 Aug 2008 21:29:17 -0700 > From: "Ken Owen" <n6kth(a)n6kth.com> > Subject: [amsat-bb] Help with ISS Boy Scout Contact > To: <amsat-bb(a)amsat.org> > Message-ID: <000801c8f9d8$7d10bc00$2e01a8c0@CIR2> > Content-Type: text/plain; charset="us-ascii" > > Hi folks: > > I will be setting up the station that will contact the ISS in less than two > weeks on behalf of the Santa Barbara Amateur Radio Club and a local Boy > Scout troop. The contact is scheduled, and we have the necessary equipment. > > I would like to make sure in advance that my station is tracking the ISS > correctly. I wonder if anyone is currently making any ISS contacts (of the > not so pre-arranged type) and whether the cross-band repeater is in use. > I've listened on 145.800 for a couple of passes, but I've not heard anything > yet. > > I appreciate any advice from those who have done this before. > > Thanks, > > Ken Owen, N6KTH > AMSAT Area Coordinator > >

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What happens when you loose a satellite
by Keith & Jenny Sloan 09 Aug '08

09 Aug '08

With things like the Falcon launch failure you obviously loose the satellite, but do you get another launch having paid you money or is that it. You loose everything if the launch fails If the later then the launch of P3E and P5A could prove very expensive if the launch fails.

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EA4TX RCI-SE board and Yaesu G-5500 Controller
by Sven Arne Astrup 09 Aug '08

09 Aug '08

Hi! Just switched from using the G-5400B controller to the G-5500 controller and need someone to give me a lesson on how to calibrate the new controller. Would like to get in touch with someone using a simular setup, the ARS RCI-SE board and the G-5500 controller. 73 de Sven LA6KJ No virus found in this outgoing message. Checked by AVG - http://www.avg.com Version: 8.0.138 / Virus Database: 270.6.0/1601 - Release Date: 08.08.2008 09:02

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Re: brain picking time
by G0MRF＠aol.com 09 Aug '08

09 Aug '08

Hi Bob. There is a pre-amp kit available over here for about $70 which gives 0.26dB noise figure and 34dB gain at 1296MHz. Without resorting to cavity designs, this sounds pretty state of the art and is been used for EME. _http://www.g4ddk.com/_ (http://www.g4ddk.com/) Apparently, Sam accepts paypal and has variants of the design for 2.4G and 3.4G Thanks David In a message dated 09/08/2008 14:33:39 GMT Standard Time, w7lrd(a)comcast.net writes: Hello Domenico & all Thanks for all the information. The measured F/D ratio works out to 0.375, therefore a patch would be appropriate. As mentioned earlier I would be content to just be able to receive EME (for now). For transmitting no doubt a different feed would be needed. Currently I am looking around for a preamp.

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Santa Barbara Hamfest Demo Sunday (re-send)
by Ken Owen 09 Aug '08

09 Aug '08

Hi folks: Your assistance is requested to help make my demo at the Santa Barbara Amateur Radio Club's hamfest on Sunday a success. I will be providing demos during the 10 Aug, 15:55 AO-51 pass and the 10 Aug 21:06 AO-27 pass. We'd certainly appreciate some contacts. Thanks! Ken Owen, N6KTH AMSAT Area Coordinator

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anyone want to digi via sat go-32 @9600
by Mr Jeffrey L Ross 09 Aug '08

09 Aug '08

hi folks, anyone want to try and digi to each other via the go-32 sat? Just a short link is all we would have time for but it would be neat to do. We need to find out what freq and call we are to use too. If so contact me off list. 73 all kc8gkf West Michigan USA p.s. does anyone know where the go-32 aprs web page satgate is? And is it working?

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