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Re: [Advisors] [Fwd: Re: S band and Eagle: an appeal for a higher level discu...
by RaySoifer＠cs.com 19 Sep '06

19 Sep '06

Hi all, As discussed with Bob McGwier at this weekend's TAPR conference in Tucson, I believe that the current frequency recommendations for the Eagle digital payload somewhat underestimate the inefficiency and time lags of the international regulatory process, as well as the inconsistency of application from one country to another. While amateurs in some countries may well find themselves unable to use 1.2 GHz uplinks for the reasons stated, that situation may not apply to others. Some countries, such as many in Region II, may continue to permit 1.2 GHz uplinks because their navigation systems will continue to be GPS-based. In some other countries, in and out of Region 2, there is effectively little or no telecommunications regulation at all, or such regulation is ineffective in practice. Similarly, as Robin has pointed out, some countries may well prohibit uplinking on 2.4 GHz for whatever reasons, such as interference with Wi-Fi etc., irrespective of whatever the ITU Radio Regulations might say. So, depending on where he is located and the RF environment in his area, an individual user may find that: 1. He may not use 1.2 GHz but may use 2.4 GHz. 2. He may not use 2.4 GHz but may use 1.2 GHz. 3. He may use both. 4. He may use neither. Since the actual regulatory environment on the ground is unpredictable, Eagle's uplink configuration needs to take all four possibilities into account. The first three may be accommodated by flying BOTH 1.2 and 2.4 GHz uplinks, which I am recommending. Planning for the fourth, however, is a little more complicated. As has been discussed previously, the link budget argues strongly against the use of 10 GHz or higher frequencies, and we cannot realistically fly a 5 GHz uplink since it would be too close in frequency to our 5 GHz downlink. The use of 3.4 GHz is prohibited in Region 1. My suggestion, therefore, is to fly a digital uplink at 70 cm in addition to those at 1.2 and 2.4 GHz, and also in addition to the 70 cm analog SDX uplink already planned. Since the amateur-satellite service allocation there is only 3 MHz wide, the uplink bandwidth would be limited accordingly. My "straw man" suggestion for that would be 435.5-437.5 MHz, with 435.0-435.5 used primarily for SDX and other such systems (e.g., P3E if it is still up and working by then), and 437.5-438.0 used, as now, primarily for human spaceflight applications, i.e., whatever succeeds ISS. A 2 MHz bandwidth would not be as good as the 10 MHz envisioned for L-band and S-band, and the uplink EIRP requirement (and thus ground antenna size) would be higher than I would like, but remember that the 70 cm uplink would be primarily for those who cannot use 1.2 and 2.4 GHz. For them, such an uplink would make the difference between being able to use the Eagle digital payload or not. My 2 cents worth, anyway. 73, Ray P.S. I am speaking here only for myself and not for the IARU Panel, which has not considered this matter.

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Region-1 Countries with S2 Access - REVISED
by Rick Hambly (W2GPS) 18 Sep '06

18 Sep '06

All, The following is a revised list of countries that already have terrestrial Amateur Radio access to S2 in Region 1. This data was collected from Graham Shirville and the official www.efis.dk <http://www.efis.dk/> site. There may be other countries as the sources are focused on Europe. Cyprus 3400-3500 Czech Republic 20 W (info of OK2ZI, 5/2003). Perhaps not. Denmark 3400-3410 Finland 3400-4200? Perhaps upper limit 3408, cw=150,ssb=600W Germany 3400-3475 Great Britain 3400 to 3475, Terrestrial only, 400W at antenna (no EIRP limit). Israel 10 Watt Netherlands 3400-3410 Norway 3400-3500, usage 3400-3410 MHz Poland 3400-3500, Perhaps upper limit 3470? Slovenia 3400-3600. Upper frequency is an assumption. Rick W2GPS AMSAT LM2232

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Region-1 Countries with S2 Access
by Rick Hambly (W2GPS) 18 Sep '06

18 Sep '06

All, The following countries already have terrestrial Amateur Radio access to S2 in Region 1. This data was collected by Graham Shirville and the official www.efis.dk <http://www.efis.dk/> site. There may be other countries as the sources are focused on Europe. Cyprus 3400-3500 Czech Republic 20 W (info of OK2ZI, 5/2003). Perhaps not. Denmark 3400-3410 Finland 3400-4200? Perhaps upper limit 3408, cw=150,ssb=600W Germany 3400-3475 Great Britain Israel 10 Watt Netherlands 3400-3410 Norway 3400-3500, usage 3400-3410 MHz Poland 3400-3500, Perhaps upper limit 3470? Slovenia 3400-3600. Upper frequency is an assumption. Rick W2GPS AMSAT LM2232

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Re: [Advisors] Re: Re: [Fwd: Re: S band and Eagle: an appeal for ahig...
by RaySoifer＠cs.com 17 Sep '06

17 Sep '06

In a message dated 9/17/06 4:17:08 PM Greenwich Standard Time, kd6ozh(a)comcast.net writes: > PAVE PAWS is part of the ballistic missle defense system so it will remain > active. > Perhaps, but I bet if Hillary were elected she would de-fund the system (not that I would vote for her, hi). My point is simply that we cannot predict the future, so must prepare for all reasonable possibilities. 73, Ray

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Re: [Advisors] Re: Re: [Fwd: Re: S band and Eagle: an appeal for ahig...
by RaySoifer＠cs.com 17 Sep '06

17 Sep '06

In a message dated 9/17/06 3:08:03 PM Greenwich Standard Time, kd6ozh(a)comcast.net writes: > Path loss is 15 dB less at 435 MHz than 2400 MHz and antenna gain is 13 dB > less. However, the noise figure is 5 dB higher, so almost twice the EIRP wll > be required on a U uplink than an S uplink. The 70 cm receiver has a 200 kHz > bandwidth so some class 2 (4800 bps) uplinks could be accomodated. Since they > will be BPSK and use FEC, I assume that they will occupy at least 15 kHz > each and will have to be spaced at least 25 kHz apart. This could allow 4 > uplinks. It's not good to increase the receiver bandwidth as it will let in more > PAVE PAWS interference. > > John, I was thinking in terms of an additional 70 cm receiver to accommodate several conference-grade channels, for those users who may be prohibited from using BOTH L-band and S-band uplinks (think Europe). Yes, PAVE PAWS is there, sometimes, but it would still be better than no digital access at all. Also, it's not a certainty that PAVE PAWS will even be there in 2020. 73, Ray

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San Diego Meeting report
by Jim Sanford 15 Sep '06

15 Sep '06

All: It has come to my attention that the San Diego meeting report has format problems. I've ZERO idea how the format got gooned. I have taken it offline for correction. I will advise, tomorrow or Saturday, when I've fixed the format and reloaded. Thanks & 73, Jim wb4gcs(a)asmat.org James A. Sanford, PE Amsat Eagle Project Manager

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Team Speak tomorrow night
by Jim Sanford 13 Sep '06

13 Sep '06

Team: I'm not going to be able to put an agenda on EaglePedia until tomorrow. Things I'd like to discuss: 1. Budget submissions -- I have some, what else is ccoming? What estimates are coming? 2. Status reports -- what should I highlight at Symposium in my BRIEF remarks? Who is making what presentations? 3. Did we write off L-band or not in San Diego? I remember, and my notes and one other attendee confirm, that we wrote off L-band for the digital uplink, but briefly discussed it as ananalog uplink. We never made a decision. Lets discuss and decide. 4. Status reports from those we haven't heard from in a while -- power, sensors, etc. 5. Bob and Rick discussed on the phone, (I was next to Rick) the idea of: Rethinking S2 (3GHz) for the Digital uplink This frees up S1 for any use We offer that anyone willing can develop and submit for testing and qualification a stand-alone L/S transponder to fly in one of the TSFR slots, using fixed antennas. It would be usable at/near Apogee, like the microwave packages on AO-13 and A)-40. What do you think? Les's discuss this. Any other topics? Remember 2100 EDT, 1800 PDT. Thanks & 73, Jim wb4gcs(a)amsat.org

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Analog transponder revisited
by Howard Long 13 Sep '06

13 Sep '06

Folks, Under AOB last night I raised a question regarding there apparently being no analog transponder on board as far as I can see in recent documentation. I was of the impression that a parallel analog transponder would be flying as well as the SDX. I am concerned that as this was a hot issue several months ago, I would respectfully request that we clarify the situation at the next meeting prior to the Symposium. 73, Howard G6LVB

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FW: Re: Team Speak tomorrow night
by Howard Long 13 Sep '06

13 Sep '06

Hi Bob > I know from documentation I received from I8CVS that this will > exclude Italy from the digital payload. > I am expecting to hear from several other countries that, excluding > action from a WARC, they will be excluded from the digital > communications package if we use S2. I think it was clear from the meeting last night that there are two options for the wide band DCP that will be proposed for further discussion. Rick will propose a version with both L and S2 uplinks and a C downlink. John will propose a version with C uplink and X downlink (I wasn't sure if an L uplink was also included). In Rick's proposal, as L will still be available so Region 1 with their current allocations, Region 1 will have access to the DCP whether or not S2 is available to us. It seemed clear from last night's discussion that the assessment to drop L band at San Diego wasn't the right decision. There was also some discussion about whether the high bandwidth digital mode would be viable at L band, probably limited by a non-steerable RX antenna on the spacecraft and uplink EIRP, although somehow I doubt Domenico has a problem with with uplink EIRP ;-) As it's being revisited again in the next couple of weeks, we can go over these again in further detail with the benefit of both your's and Tom's input. Cheers, Howard

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N1AL Award
by Tom Clark, K3IO 12 Sep '06

12 Sep '06

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