September 2006 - Eagle (INACTIVE)

Eagle L-band receiver
by Miroslav Kasal 23 Sep '06

23 Sep '06

Hello Eagle Group, According to our e-mail correspondence with Bob McGwier today, I would like to repeat my offer to design and build L-band receiver for Eagle. I am designer of P3E L-band receiver (including command receiver and 5 MHz backup oscillator). At present I solve AGC for both mode - analog/SDX. You can see http://www.urel.feec.vutbr.cz/esl/files/Projects/P3E.htm. Already two years ago I promised to built L-band receiver also for Eagle. All my friends from AMSAT-NA showed pleasure, but project managing people didn't ask me officially. So my offer is still valid. Best regards. Mirek Kasal, OK2AQK AMSAT-NA LM2326

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Welcome
by Dick Jansson-rr 23 Sep '06

23 Sep '06

Hello Mirek: It is good to see that you are now on the Eagle team. I welcome your insights and capabilities. I hope that all is well with you and your family. Best regards from Florida, Dick Jansson --------------------------- <mailto:[email protected]> rjansson(a)cfl.rr.com ---------------------------

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Mini-Circuits
by Emily Clarke 21 Sep '06

21 Sep '06

I was working with Mini-Circuits (they have dontated $3200 worth of components for Symposium prizes) and in the course of gathering information found out that Gerry Edson who was listed as our contact at Mini-Circuits retired last year. Paul Vinsand is the new applications engineer. His contact information is: email: pv(a)mincircuits.com phone: 417-335-5935 X4519 Just thought this was good information to pass along. 73, Emily --------------------------------- N1DID formerly W0EEC - CM87tm Support Project OSCAR - http://www.projectoscar.net

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Steve Cripps
by Howard Long 21 Sep '06

21 Sep '06

Folks I was most impressed to see in the AMSAT journal that Steve Cripps was judging the microwave PA's. Having read two of his books*, I cannot think of anyone more in touch with the state of the art in PA linearity and efficiency. Any chance he might be interested in joining us?! 73, Howard G6LVB * RF Power Amplifiers for Wireless Communications * Advanced Techniques in RF Power Amplifier Design

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Recent arguments and proposals, I am off to Tuscon
by Robert McGwier 20 Sep '06

20 Sep '06

I spent yesterday in a lawyer's office in Washington D.C. for AMSAT and actually enjoyed myself. I followed that with a mad dash back to Trenton to teach the SDR class Frank and I are teaching. Microchip is assisting us beautifully and we have a class full of eager students wanting to take on Suitsat-II and Eagle pieces for their design projects. I apologize for this week being so busy for me that I am unable to jump on to much of the discussions this week on BB and here in Eagle. Let me dash off some quick comments. I do not believe we can successfully build the X band component to the modified DCP system. I believe we will be killed by all sorts of LO problems including, but not limited, to phase noise issues. I am already a week behind in delivering Stephensen an analysis of the phase noise on the Class 1 users in SDX, I will add to this a system analysis of the required oscillator performance to use X band in the DCP. Remember, this is a weak signal mode and we are attempting to operate with only a few dB of margin at best. We cannot shed 1 or 2 more in implementation loss (if we are lucky). I support John's contention that we should choose a band that is currently available world wide for the uplink on which we can feasibly build a system. Pick L or S1 is my recommendation. We chose S1 for all of these reasons. If you choose L, we can put in two L's or share one with SDX. The antenna is the same required area, but the packing of the antenna on the spacecraft becomes more problematic. I understand Rick's motivation to not get hammered at the annual meeting. Welcome to the presidency. It is not a reason to make a bad choice for the uplink which will kill the utility of the package is my current opinion. My current vote: stay with what was decided in San Diego or risk L as the primary uplink. I believe that a serious analysis of the impact of trying to get the dual band L/C antenna packed together will be a very illuminating exercise and I believe we will inevitably be led back to the SD decision based on system analysis rather than emotional analysis. Bob -- AMSAT VP Engineering. Member: ARRL, AMSAT-DL, TAPR, Packrats, NJQRP/AMQRP, QRP ARCI, QCWA, FRC. ARRL SDR Wrk Grp Chairman "You see, wire telegraph is a kind of a very, very long cat. You pull his tail in New York and his head is meowing in Los Angeles. Do you understand this? And radio operates exactly the same way: you send signals here, they receive them there. The only difference is that there is no cat." - Einstein

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

19 Sep '06

In a message dated 9/19/06 5:46:16 AM Greenwich Standard Time, kd6ozh(a)comcast.net writes: > When we are considering L/S and U/S, we should remember the advantages of > U/V and V/U. The original choice of U/V for phase 3 satellites allowed for an > antenna that would provide 75% orbit coverage. Path loss for L and S is much > higher so AO13 and AO-40 had much narrower beams and covered less of the > orbit in those modes. So, in addition to the fact that S will be unavailable in > many areas due to noise levels that are 20+ dB higher today, the time > available in those areas for this mode is much less than for U/V or V/U. The attached > document provides a graphical comparison of U and L uplink antenna coverage > for the same ground station radiated power level. The V and S downlinks are > very similar. > > Yes, and we should remember also that uplink QRM levels on 2 meters due to illegal high-power cordless phones and the like are much greater than in the past, as OZ1MY has documented. That is why the Surrey Colloquium recommended, a couple of years ago, that U/V be used in preference to V/U. With U/V, the QRM affects only users in immediate proximity to the interference source, not the entire footprint as is the case with uplinks. 73, Ray

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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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