July 2009 - AMSAT-BB - mailman.amsat.org

Lunar link budget
by Howie DeFelice 03 Jul '09

03 Jul '09

Hi Domenico, I could be wrong but I think your budget is correct for a regenerative transponder but for a bent pipe transponder we need to add the uplink noise to the downlink noise where C/N (total) = 1/((1/C-Nup)+(1/C-Ndn)) which in this case would be about 6.7 dB. Still pretty good, but would probably be better even at the lower microwave freqs. If we used PSK31 exlusively, even 2.5 KHz many simultaneous QSO's. Howie AB2S _________________________________________________________________ Insert movie times and more without leaving Hotmail®. http://windowslive.com/Tutorial/Hotmail/QuickAdd?ocid=TXT_TAGLM_WL_HM_Tutor…

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FW: Re: G-5500 and LVB tracker question.
by Pierre van Deventer 03 Jul '09

03 Jul '09

I found that the regulator output voltage inside the G-5500 drifted slightly. The problem was resolved by changing the value of C9, 0.01 MFD, at output of the regulator to a 0.1 MFD capacitor. Before the mod the azimuth values varied by 15 degrees from switch on to final operating temperature, after the mod the Azimuth and Elevation values are steady. Hope that helps. 73, Pierre ZS6BB -----Original Message----- From: amsat-bb-bounces(a)amsat.org [mailto:[email protected]] On Behalf Of Allan Saul Sent: 03 July 2009 11:13 To: 'racer5039'; amsat-bb(a)amsat.org Subject: [amsat-bb] Re: G-5500 and LVB tracker question. Hi Howard and Marv, I had exactly the same problem. The issue revolved around the 7806 regulator the is used in the G-5500 control box that supplied the 6V DC to the position feedback potentiometers on the rotators. If you monitor the output voltage of the regulator, you will find they drift down considerably as the box warms up. Maybe they had a bad batch. I replaced the 7806 with a LM317T set for 6V and that solved the problem. 73's Allan Saul ZS1LS -----Original Message----- From: Howard Long [mailto:[email protected]] Sent: 30 June 2009 10:09 AM To: 'racer5039'; amsat-bb(a)amsat.org Subject: [amsat-bb] Re: G-5500 and LVB tracker question. Hi Marv. If you have the LCD fitted, do both the left and right Az/El readings move too? I am assuming you don't have the problem if the LVB Tracker is unplugged. 73, Howard G6LVB -----Original Message----- From: amsat-bb-bounces(a)amsat.org [mailto:[email protected]] On Behalf Of racer5039 Sent: 30 June 2009 00:13 To: amsat-bb(a)amsat.org Subject: [amsat-bb] G-5500 and LVB tracker question. I have the G-5500 and a LVB Tracker on my antenna set. I have noticed that when the pair are just setting there the LVB tracker will loose its place. By that I mean if the G-5500 box is at 180* the LVB will start out at 180 but as it sets there it will soon be at 178, 174, 172 and so on. I also noted the meter on the g-5500 is going down too. Where do I start looking ? Marv N0FJP _______________________________________________ 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 _______________________________________________ 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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Moon can cost less than HEO/GEO, Thanks for the Data
by MM 03 Jul '09

03 Jul '09

He Everyone. thank you for your good input. Lets slow down this thread for a few days, while i recompile all of the Great information you have sent me. Then I will post a memo to the marex web page for your review later next week. I do need 2 more key items. Link budget: Assume SSB Moon to Earth on 2.4 Gig Earth to Moon on 1.2 gig (note, under curret ITU rules we can not use 1.2 gig for Moon to Earth, is this still valid?) Thanks Miles WF1F --- On Thu, 7/2/09, Ransom, Kenneth G. (JSC-OC)[BARRIOS TECHNOLOGY] <kenneth.g.ransom(a)nasa.gov> wrote: > From: Ransom, Kenneth G. (JSC-OC)[BARRIOS TECHNOLOGY] <kenneth.g.ransom(a)nasa.gov> > Subject: RE: [amsat-bb] Moon can cost less than HEO/GEO > To: "MM" <ka1rrw(a)yahoo.com>, "amsat-bb(a)amsat.org" <amsat-bb(a)amsat.org> > Date: Thursday, July 2, 2009, 10:29 PM > I realize this is still very early in > the dreaming stage but it would be nice to start seeing some > realistic proposals soon. How about starting with a blank > worksheet that outlines the desirements and requirements. > This would give folks some specifics to address. > > *LUNAR System* > Modulation type: > Mode: > Power source: > Lunar transmitter (type, output power and band): > Lunar TX antenna (type and gain): > Lunar receiver (type and band): > Lunar RX antenna (type and gain): > Lunar controller (type and capability): > > Delivery deadline for flight certified hardware to be > launched: > Length of time the system is expected to operate: > Periods that the system is expected to be available for > use: > > Once you have some general ideas as to what the items are > then you will have a good idea of the total weight, size and > what it will cost to buy, build and certify for spaceflight. > It would also be nice to know what sort of station equipment > would be needed to use this lunar system. > > *EARTH Station* > Description of minimal Earth station capable of operation > through above mentioned lunar system: > Transmitter (type, output power and band): > TX antenna (type and gain): > Receiver (type and band): > RX antenna (type and gain): > Antenna tracking system: > > The above should allow for a realistic guess at the number > of users willing to and capable of operating through the > system. > > Kenneth > ________________________________________ > From: amsat-bb-bounces(a)amsat.org > [amsat-bb-bounces(a)amsat.org] > On Behalf Of MM [ka1rrw(a)yahoo.com] > Sent: Thursday, July 02, 2009 8:14 PM > To: amsat-bb(a)amsat.org > Subject: [amsat-bb] Moon can cost less than HEO/GEO > > High orbit launch prices > > It is hard to find exact values for the price per kilo to a > geo-stationery orbit. I did find a few old numbers on > the web suggesting that around the year 2000 prices were > approximately 25,000 to 35,000 USD per kilo. I can > only assume it will cost more today’s 2009 dollars. > If we were to build our own Geo-stationary satellite and > were able to keep the weight down to the same weight of > AO-40 (244 kilos), that would only cost us $8.5 USD million > in launching fees (plus inflation). That is not > including the cost of the satellite. A ballpark > Geo-stationary amateur radio satellite and launching fees > would be in the 20-40 million-dollar range per satellite > (SWAG). > > If you have an extra 40 million kicking around then go > ahead and build us a Geo satellite. Or if you work at Huges > and can talk them into attaching a Micro Satellite to the > next geo satellite for Free great, go for it. > > I can’t afford that and I do not know anyone at Huges, so > I am looking into the piggyback options. Let some > other company pay the big bucks for the flight and > navigation and just tag along for the ride. > > In this case NASA wants to send Un-manned Landers to the > Moon. All we need to do is convince them to let us > attached a 1-2 kilo micro-satellite to the moon lander and > use some of their power and antennas, etc. > > Just look at the Huge Savings $$$ > No navigation system (we have never had much luck at > building our own rocket motors (AO-10- damaged satellite, > AO-13 Miss fired and caused a premature reentry and AO-40 > Kaboom) > > No command and control RF links (just command between the > Microsat and existing command and control system) > > NASA will pay for the rocket (we hope) > > Assuming a good landing, there will not be any need for > periodic orbital changes. > > It’s true that our resources for building new satellites > are very limited. > I believe that Putting the effort into building a Moon > qualified micro satellite seems to be the most economical > path to take. And will provide the greatest return on > our investment. > > Sincerely > > Miles WF1F MarexMG.org > > > > > > > > _______________________________________________ > 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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Re: Software Commodore 64
by Rich Dailey (iPhone 3GS OS 3.0.3) 03 Jul '09

03 Jul '09

>Hey, I'm not crazy... Hi !! I'm looking for satellite prediction software or similar for Commodore 64. Anybody know where I can find this !?!? You might want to contact John Magliacane, kd2bd - as I recall he wrote some early basic code for the c-64 that later was incorporated into PREDICT. Rich, N8UX

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How you do DOPPLER correction in Linear Transponders?
by Fabiano Moser 03 Jul '09

03 Jul '09

Dear friends, We know that some Satellite Operators use diferent system to doppler control. For Linear Transponder 1) Adjust uplink and downlink automatic by CAT? (Not always woks, some times I´m up or down from the computer adjust) 2) Adjust uplink and downlink manual 3) Keep Uplink fixed and adjust only the Downlink frequency. What is the more indicate method to use? FT-847 have knob to adjust Uplink without change downlink VFO, and I´m using it to keep my voice in downlink at same downlink much I can. But I know some operators use fixed uplink. How you do? -- 73 Fabiano Moser CR7/PY5RX ARISS-PORTUGAL (Amateur Radio on the International Space Station) Representative at Teleconference and Portugal Telebridge Coordinator. AMRAD/AMSAT-CT http://www.amrad.pt/ariss.php "There is no great talent without great will. (Honoré de Balzac)"

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Moon can cost less than HEO/GEO
by MM 03 Jul '09

03 Jul '09

High orbit launch prices It is hard to find exact values for the price per kilo to a geo-stationery orbit. I did find a few old numbers on the web suggesting that around the year 2000 prices were approximately 25,000 to 35,000 USD per kilo. I can only assume it will cost more today’s 2009 dollars. If we were to build our own Geo-stationary satellite and were able to keep the weight down to the same weight of AO-40 (244 kilos), that would only cost us $8.5 USD million in launching fees (plus inflation). That is not including the cost of the satellite. A ballpark Geo-stationary amateur radio satellite and launching fees would be in the 20-40 million-dollar range per satellite (SWAG). If you have an extra 40 million kicking around then go ahead and build us a Geo satellite. Or if you work at Huges and can talk them into attaching a Micro Satellite to the next geo satellite for Free great, go for it. I can’t afford that and I do not know anyone at Huges, so I am looking into the piggyback options. Let some other company pay the big bucks for the flight and navigation and just tag along for the ride. In this case NASA wants to send Un-manned Landers to the Moon. All we need to do is convince them to let us attached a 1-2 kilo micro-satellite to the moon lander and use some of their power and antennas, etc. Just look at the Huge Savings $$$ No navigation system (we have never had much luck at building our own rocket motors (AO-10- damaged satellite, AO-13 Miss fired and caused a premature reentry and AO-40 Kaboom) No command and control RF links (just command between the Microsat and existing command and control system) NASA will pay for the rocket (we hope) Assuming a good landing, there will not be any need for periodic orbital changes. It’s true that our resources for building new satellites are very limited. I believe that Putting the effort into building a Moon qualified micro satellite seems to be the most economical path to take. And will provide the greatest return on our investment. Sincerely Miles WF1F MarexMG.org

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Re: DO-64 software support for PSK-1(T) hardware?
by Wouter Jan Ubbels 03 Jul '09

03 Jul '09

Hi Greg, actually, when we developed RASCAL, we had PSK-1 (or another KISS TNC that could do PSK) support in mind. However, PSK TNC's such as the PSK-1 have become a scarce item:) Furthermore, COM port access in JAVA can be tricky sometimes, especially when you want to preserve the cross platform capability. In the meantime, I had started work on a 1200bd BPSK soundcard demod in JAVA (contrary to the PSK-1, PC's with soundcards are abundant in today's ham shacks hi). The Warbler software was my first try at this. In the end we decided to integrate this demod with RASCAL and abandon the KISS TNC support in favour of the soundcard solution. So, unfortunately, KISS TNC support is not included in RASCAL. 73 on behalf of the DO-64 / Delfi-C3 team, Wouter Jan PE4WJ

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G-5500 and LVB tracker question.
by racer5039 03 Jul '09

03 Jul '09

I have the G-5500 and a LVB Tracker on my antenna set. I have noticed that when the pair are just setting there the LVB tracker will loose its place. By that I mean if the G-5500 box is at 180* the LVB will start out at 180 but as it sets there it will soon be at 178, 174, 172 and so on. I also noted the meter on the g-5500 is going down too. Where do I start looking ? Marv N0FJP

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Yaesu LVB Nova issues - Help
by bpn518＠aol.com 02 Jul '09

02 Jul '09

Thanks for those answering my questions on my odd 5400 motors 5600B control box situation. Now I have it working with LVB Tracker and Nova. But the motors stop tracking after a few minutes. First it seems to track fine, with motors turning as Nova instructs. But after a few minutes of activating and turning motors here and there, the motors don't seem to respond to the Nova software to move any more. I have to shut down Nova (getting a cannot write to file error), reboot the computer (otherwise when I go to Nova I get an error msg that the device is already connected? (but no response)), and restart Nova.? Then the motors will seem to track as Nova directs, but only for a few minutes and then motors stop working again.? I cannot tell if it is a computer problem (IBM T41 laptop, Win XP), or LVB (just got), or what? Any clues?? Thanks for the space. Bennett ko2ok

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FW: Re: The Moon is our Future
by Dave 02 Jul '09

02 Jul '09

Could the antenna be a launched in the craft as piece of small, folded reflective plastic that when activated by gas or ??, expands to a dish shape, and becomes a super large plastic large dish? The dish then could be any size we wanted it to be and not be a hindrance to the launch craft size. I've seen these but have trouble no putting my finger on the name. We could make the dish 30ft around and folded it could be 4 inches square. Dave DM78qd // KA0SWT If it weren't for Philo T. Farnsworth, inventor of television, we'd still be eating frozen radio dinners.-- Johnny Carson +++++++++++++++++++++++++++++++++++++ -----Original Message----- From: amsat-bb-bounces(a)amsat.org [mailto:[email protected]] On Behalf Of Tony Langdon Sent: Thursday, July 02, 2009 7:07 PM To: James French; AMSAT-BB Subject: [amsat-bb] Re: The Moon is our Future At 02:30 AM 7/3/2009, James French wrote: >Why not use a L/s, U/L. or a U/s transponder for this? >Why limit ourselves to V/u for everything? >Aren't we supposed to 'experiment' with the higher frequencies we have >allocated? I agree. I believe the Moon is a job for the microwave bands. Antenna gain on both ends is easier to produce (for a fixed dish/array, the Moon end will be gain limited by the need to have the beam cover for the varying position of the Earth due to libration). Comeing up with a method to align the antenna initially will be an interesting challenge. That will have to be automated, even if it's a one off process. 73 de VK3JED / VK3IRL http://vkradio.com _______________________________________________ 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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