March 2007 - AMSAT-BB - mailman.amsat.org

Re: Help with MixW2 getting AO-51 TLM
by Edward Cole 25 Mar '07

25 Mar '07

Pass #14375 per NOVA. PIcked up tlm about elev=5 with 11-elem yagi with no preamp and Doppler about +8 KHz. Not full copy but enough to demonstrate the sw is working. I printed raw data on both MixW2 and tlmEcho, so I would guess things are OK for looking for CAPE-1 tomorrow night (3/27 0801 utc). Here's the MixW2 output: Open ABCD: PLCTL-8>PLCTL-8>UI,?,F0: PLCTL Mode:2 TXA:0 TXB:0 BatTrip:0 PACB-1>TIME-1>UI,?,F0: PHT: uptime is 037/13:39:30. Time is Mon Mar 26 02:21:57 2007 PACBLS-8>PACBLS-8>UI,?,F0: PACBLS S Meter = 0 73, Ed - KL7UW ====================================== BP40IQ 50-MHz - 10-GHz www.kl7uw.com 144-EME: FT-847, mgf-1801, 4x-xpol-20, 185w DUBUS Magazine USA Rep dubususa(a)hotmail.com ======================================

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Help with MixW2 getting AO-51 TLM
by Edward Cole 25 Mar '07

25 Mar '07

Hi, I have upgraded my MixW2 (demo) to vers 2.18 and going over settings to receive 9600 bps FM AX.25 telemetry from AO-51. I doing this in hopes to get a good test before trying to receive CAPE-1 after launch March 27. Long time ago I had it working with virtual connection with tlmEcho program, but I am just wanting to recover raw telemetry for CAPE-1 since no decoding sw is available for CAPE-1 to my knowledge. I tried capturing some on the last pass which was north of me, but I had the wrong frequency for most of the pass. Still tuning near 435.150 toward the end of the pass I could not detect any signal (quieting) from the 9600 packet signal. I know that 9600 does not provide sound that is heard but I recall that it should provide some quieting in the passband. I wonder if anyone is using MixW2 with tlmEcho to recover AO-51 tlm? I sure would appreciate having someone check my sw settings for MixW2. There is no local source of 9600 packet to use for checkout. I am stumped why MixW2 comes up with a window stating my demo period has expired as I just downloaded it yesterday (supposed to get 15-day free demo period). Will this kill any chance of retrieving data? Thanks! 73, Ed - KL7UW ====================================== BP40IQ 50-MHz - 10-GHz www.kl7uw.com 144-EME: FT-847, mgf-1801, 4x-xpol-20, 185w DUBUS Magazine USA Rep dubususa(a)hotmail.com ======================================

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Upcoming Cubesat Launch
by bklofas＠calpoly.edu 25 Mar '07

25 Mar '07

Hey Everybody-- Just a quick update from Cal Poly about the upcoming launch. Everything is going very well and we are very excited here. The launch is happening Monday night at 23:46 Pacific time / Tuesday morning at 02:46 Eastern time. There is a lot of information about frequencies, modes, keps, etc, on the main Cubesat webpage at www.cubesat.org Due to the $8k cost of the private webcast last time, we are not doing it again. So, instead, we will be providing live updates on the Cubesat IRC channel. Point your favorite IRC client to #cubesat on irc.freenode.net We will also be providing a MP3 download of launch countdown audio stream a few hours after launch. All of this will be accessible on the CubeSat webpage. We also have a data packet entry form where you can enter data packets you received (from any satellite) at your earth station. The form is at: http://cubesat.atl.calpoly.edu/pages/missions/dnepr-launch-2/data-packet-fo… Preliminary keps: P-POD A (CP2.1, AeroCube2, CSTB1) 1 xxxxxU xxxxxxxx 07086.29310451 .00000000 00000-0 00000-0 0 0000x 2 xxxxx 098.0870 161.6633 0071000 198.4663 339.8290 14.5270000000001x P-POD B (CP3, CAPE1, Libertad-1) 1 xxxxxU xxxxxxxx 07086.29312766 .00000000 00000-0 00000-0 0 0000x 2 xxxxx 098.0870 161.6633 0090000 199.4051 339.9000 14.5050000000001x P-POD C (MAST triple-cube) 1 xxxxxU xxxxxxxx 07086.29311609 .00000000 00000-0 00000-0 0 0000x 2 xxxxx 098.0870 161.6633 0084000 198.3918 339.9240 14.5160000000001x Any other questions, feel free to email me. Thanks! -- Bryan Klofas, KF6ZEO Cal Poly State University

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Antenna's?
by Stargate 25 Mar '07

25 Mar '07

Howdy all, Still building up my station but cash is starting to get tight! I was considering the M2 436CP42 U/G and M2 2MCP22 antenna's. I think I'm down to the build-it, instead of buy it stage, so I was wondering if anyone has links to websites with PROVEN designs for a CP beam such as these? I have seen a few sites but I hate to build a CP antenna without prior recommendations from someone else. So, What have you? :-) Station so far... FT-847 (computer controlled) G-5500 rotor (computer controlled) LVB tracking board Orbitron tracking software ARR MSP432VDG-160 preamp ARR MSP144VDG-160 preamp Thanks, RoD KD0XX A good friend will come and bail you out of jail, A TRUE friend will be sitting next to you saying..... "DAMN THAT WAS FUN"

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OZ7IGY beacon over FO-29 for 50 year aniversary this week
by OZ1MY 25 Mar '07

25 Mar '07

Hi all, The old vintage OZ7IGY (International Geographic Year) beacon has been activated on approximately 145.988 MHz. They wanted to use another frequency, but had problems so that they asked me if it was OK to use 145.988 MHz. That is is nice frequency since OZ7IGY is retransmitted by FO-29 in the low end of the downlink band. That end is not used by anyone normally, so it should not be a problem. It will be for this week only. It is not on all the time since it is very old valve (tube)equipment. I think the plan is to use it most af the day during the weekend - and 16 - 22 during working days. The signal from FO-29 is really good when the elevation angle from JO55 (Denmark) is low. I could hear it from FO-29 at a distance of 4100 km from my QTH. The beacon OZ7IGY is probably the oldest VHF beacon in the World ? Try to listen for it - this is a one time event ! Stations in Europe may want to have QSO with OZ7IGY, which is manned this weekend and from 16 to 22 during the comming week. I have heard it on 432.270 MHz. They use the beacon antennas and 25 W only. Have a nice weekend 73 OZ1MY Ib

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Re: CubeSat launch 27Mar07 6:46:35UT
by W.J. Ubbels 25 Mar '07

25 Mar '07

Hi all, with the discussion about the upcoming CubeSat launch in mind, and since we have not been able to update our website regularly just a couple of words from the Delfi-C3 office:) We are currently very busy integrating the spacecraft. Although it's a 3-unit CubeSat, it's still very, very small... so that gives some headaches sometimes:) Delfi-C3 carries two redundant (primary and backup), and almost similar radio transceivers, connected to the antenna system by a hybrid combiner which also takes care of generating the correct phase relationship between the antennas. Both transceivers consist of a UHF frontend, a command receiver, linear IF, telemetry generator and the final stages capable of 400mW RF power. Each transceiver is housed on a single 96 x 90mm board. Our tight power budget allows only one transmitter to be active at all times. Delfi-C3 contains no batteries, one of the reasons being the fact that it's primary mission is to perform a solar cell and sun sensor experiment which depend on the presence of sunlight. Therefore, the spacecraft is only active when in sunlight. Of course, since there's no such thing as a free lunch, this has made the design complicated on an other level, especially software-wise. (proper boot-up sequences etc.) The first three months of the mission are what we call the "science" mission, in which the spacecraft will be transmitting 1200 bit/s AX.25 telemetry on either the primary or backup VHF downlink frequency, frequency information can be found on our website http://www.delfic3.nl Telemetry is contained in UI frames, with roughly one frame every second. All detailed information regarding telemetry will be announced on the website as well. Modulation is Raised Cosine (in time) BPSK, more or less similar to that of the Microsats. Therefore, owners of a PSK TNC such as the NB-96/PSK-1 combo can use them with the software (written in JAVA) that we will supply (will be made available via our website). This software package connects to the TNC in KISS mode, and allows you to display telemetry in real time, and upload it to our central server in Delft. Since PSK TNC's are not that common anymore in today's shacks, and PC's are, we are developing a soundcard application in JAVA that can be used with the telemetry decoding software. An other option is to use the popular mixw program, which can demodulate BPSK and emulate a KISS TNC. After three months, the linear transponder will be activated, with a 40kHz bandwidth. In transponder mode, a CW beacon will be active instead of BPSK telemetry. This CW beacon is actually transmitted as double sideband, with two carriers spaced 1200Hz apart. It will transmit a message saying "hi hi de delfi-c3 delfi-c3". Beacon power is set at 10dB below transponder PEP, users are requested to limit uplink power to the necessary minimum to maintain a proper downlink, while not driving the AGC excessively high. Since Delfi-C3 can indeed be considered a "hardsat", with only 400mW of downlink power, it is wise to pay attention to a good receive system. The transponder IF is very basic, consisting of ceramic filter to set the bandwidth, an amplifier chain on 10.7MHz and a fast-attack / slow-decay AGC. You can listen to an audio clip of the first transponder test QSO (in Dutch...) between PA3WEG (who designed the local oscillators) and PE4WJ at http://www.delfic3.nl/wavs/Delfi-C3_transponder_link_with_QRM.mp3 (Mind you, there is some QRM in the file that might sound a bit like Leila, but this is pure coincidence) With regard to the orbit, TLE's will be anounced on the website (www.delfic3.nl) once they are available, for now I can give the following preliminary parameters: -altitude: 630km circular -inclination: 97.91 degrees -sun-synchronous -LTAN: 10:30 Ok, back to satellite building now:) Best 73, Wouter Jan Ubbels PE4WJ -- W.J. Ubbels MSc. Delfi-C3 project manager electronic systems and communications Faculty of Aerospace Engineering Delft University of Technology www.delfic3.nl PE4WJ

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Re: P3E transponder and launch
by Patrick McGrane 25 Mar '07

25 Mar '07

Hello robert- thank you for a very well written explanation of the SDX system. I understand it better now. I'm still of the opinion that the satellites should be kept as simple as possible to increase reliability and life but I also believe in democracy and it sounds like it works well here. I dont agree with your "outdated" label of the old technology. Then again, I dont buy a new car every 5 years. Oscar 7 is a good example of the ruggedness of the old technology. You're a very good tech writer, thanks for taking the time to explain, pat n2oeq ------- Original Message ------- >From : Robert McGwier[mailto:rwmcgwier@gmail.com] Sent : 3/24/2007 11:54:26 AM To : vk3jed(a)gmail.com Cc : k8ocl(a)arrl.net; Patrick.McGrane(a)aceweb.com; amsat-bb(a)amsat.org Subject : RE: [amsat-bb] Re: P3E transponder and launch Thanks to everyone for the comments, concerns, and thoughtful remarks. SDX is no magic bullet. It cannot perform any better than the analog hardware around it and our careful work on doing the mixed signal work and even more careful work to make sure it survives the rigors of traveling through Van Allan radiation belts four times a day! That said, it provides us with several things. The DESIGN of the SDX will allow us to use a high dynamic range receiver in comparison to those we have flown before and to actually realize the potential presented to us by this receiver. If we have this high dynamic range receiver, we can use a much lower noise floor and wider dynamic range transmitter to provide cleaner signals. This will be evidenced, if we do it right, by us no longer hearing the noise floor of the transponder. Next, if we have sufficient DSP horse power, we will be able to mitigate PAVE PAWS pulses by doing pulse detection and subtraction. THIS IS A LINEAR OPERATION. It will be much nicer than clipping. If the pulses get so large that we are clipping then all bets are off but with an 80 dB dynamic range receiver, this will be much less likely to happen. Stephensen has done a detailed analysis of this and this is available on Eaglepedia. Next we are designing in the ability to provide the most capable HELAPS we have ever done. HELAPS is high efficiency linear amplification by parametric synthesis. Technical papers by Karl are on both the AMSAT and AMSAT-DL web sites. It is envelope elimination and restoration amplification. It allows us to use very high efficiency nonlinear amplifiers in the transmit chain and then have the "envelope" of the hard limited signals from the transponder imposed on the signal just before it hits the antenna by modulating the voltage on the last or last few stages. If we do the final transistors and the driver, we can get VERY high efficiency compared to what we have achieved in the past WITHOUT all of the poor IMD we lived with to get the efficiency. SDX is THE enabler in this. SDX provides us with the ability to easily find all alligators and impose our will on them. There will simply be no benefit to running an EIRP that is larger than we decide to allow because YOUR INDIVIDUAL signal will be suppressed! Juan Rivera, WA6HTP, and his team are building the fancy receiver which has been designed by KD6OZH and peer reviewed to death by others. Parts are being purchased NOW and the goal is to have four soon. We are building at least one to fit the P3E box shape. Marc Franco, N2UO, has designed, using modern parts that are very difficult to get without connections, a serious 2 meter final stage. It will provide the highest efficiency 2 meter transmitter we have ever flown for HELAPS. Steve Hendricksen, a TCNJ engineering student, design a S band amplifier in a senior engineering project directed study for Marc, Al Katz (K2UYH), and I. He submitted this for competition in an amplifier efficiency contest. He received an honorable mention and came in very high in the rankings. However, his amplifier was the only one well in excess of the minimum power, at 2.4 GHz rather than 1.0 GHz (the contest minimum). As always there is the balance between "new with great promise but untried" and "the old, standard but somewhat outdated". We can have this argument all year and it will never be easily resolved. AMSAT-UK has agreed to provide SDX software working with P3E and Eagle teams. They have agreed to copy the AO-13 RF if none of these fancier elements shows up and works. AMSAT-DL is planning for these contingencies. So we have arranged for a small trial: Suisat-2 will carry a low power SDX with a few of these capabilities. We are planning a very large AMSAT engineering activity for this coming summer which you will hear more about in the coming weeks. I could go on but what I want to promise is this: I have been extremely busy both professionally, personally, and with AMSAT things and I have not done an Engineering Notebook in a while. I will do a detailed paper on this for the next journal and it will be in my engineering notebook. Following publication I will put the document with more backing material on Eaglepeda as well and give it to AMSAT-DL for both our sites. Bob N4H Tony Langdon wrote: > At 10:46 AM 3/24/2007, John Champa wrote: >> Guys, >> >> The reports I have seen is that the SDX sounded BETTER than the >> traditional analog transponder. Bob, N4HY, can confirm that fact? > > I wouldn't be surprised at this one at all. > >> Anything other than SDX would be a step-backward for AMSAT. > > That's my viewpoint as well. > > 73 de VK3JED > http://vkradio.com > > -- AMSAT Director and VP Engineering. Member: ARRL, AMSAT-DL, TAPR, Packrats, NJQRP, QRP ARCI, QCWA, FRC. ARRL SDR WG Chair "Taking fun as simply fun and earnestness in earnest shows how thoroughly thou none of the two discernest." - Piet Hine _______________________________________________ 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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Help! MGF1402
by W7TYN 24 Mar '07

24 Mar '07

I am in need of a supplier of a MGF1402 GaAsfet. The device is for my faithful 70cm Home Brew Preamp. I know that it is 1980 technology but the ARRL handbook PCB I have is spaced just right for a 1402. Tnx & 73 Joe W7TYN AMSAT #03951

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NASA - Solar Storm Warning
by DAVID BIRD 24 Mar '07

24 Mar '07

HI Amsat"s Thought some of you might like reading this. 73 de KC7USS http://science.nasa.gov/headlines/y2006/10mar_stormwarning.htm

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Re: CubeSat launch 27Mar07 6:46:35UT
by Bruce Robertson 23 Mar '07

23 Mar '07

Quoting Graham Shirville <g.shirville(a)btinternet.com>: > Delfi C3 will have a linear Mode B transponder - a triple cubesat > scheduled > for launch in June. See http://www.delfic3.nl/ for details > > To have one in a single cubesat would be a big challenge, especially if > it > needs to share power with other on-board experiments. If we could > fund/develop an amateur only cubesat then it could be a fun project! > > still dreaming! > > 73 > > Graham G3VZV The amateur-only cubesat model is a very exciting one since it reduces the cost of launch considerably and provides the builders with a likely launch scenario early in the process. Delfi C3 is really leading the way in this field, and some of the compromises it makes are instructive. It has a transmitter power of, 400mW, 6 to 10dB below what we are used to in LEO linear birds. It also has no batteries, and will therefore work only when illuminated. I expect that the power trade-off will be acceptable and that a fixed-elevation directional antenna with LNPA will still work well, though CW might be more popular on this bird :-) There seem to be many AMSAT operators who use large Az/El systems for LEOs; perhaps, then, an even weaker transmitter on 2m might be acceptable. My vote would be for an S-band downlink. It would be possible to put a patch antenna on one face, but some of this gain is eaten up in increased 'path loss'. Such a bird could be called a 'HardSat' in contrast to the so-called FM 'EasySats' :-) 73, Bruce VE9QRP

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