Re: Sband and Eagle: an appeal for a higher level discussion
This thread so reminds me of the past pleas for more mode B birds to replace AO-10 and AO-13. The AMSAT board response was that the VHF and UHF bands were getting noisy, illegal VHF and legal UHF interlopers were showing up and for the membership to embrace microwaves and build S band and L band stations.
Well I am one who has such a station and while I would love certainly to see mode B, come back, I am also fully equipped to excercise some S and L band experiments.
I can understand that many households are polluted with 2.4 GHz toys, mine is. My solution will be to pull the plug on that stuff during operation and to utilize a medium size dish for the downlink (Note: those grid panels can't discriminate as well as a bigger dish, and secondly the IC-970 noise blanker works on some types of S band ISM interference).
Please someone tell me that we can work L and S band modes with HEO and linear transponders, I would become so much more interested in the hobby!
Hi all, Received my Amsat journal to day. I think this argument is crazy. We are talking about a digital transponder, I assume is alot wider than any AO-40 signal. Anything digital I have seen receives digitally, a slight amount of intreference and gone. no dedgrading it is either their or it is not! 2.4 GHz is a garbage band so is 900 MHz and so will be 5.8GHz. Look at the rules No ISM on 10GHz, 500 MHz of bandwidth. Protected by Military as Primary. I know one of the players on the Band Noise floor measurments, and I know it was done professionally. I am certain that the calculations of Bandwidth and noise floor requirements for the digital mode makes the dispensing with 2.4 GHz a vary reasonable approach..
Analog transponders can tollerate more interference and using a 2.1 KHz band pass has a big advantage for interference rejection. But Eagle is not AO-40! The real question is do we go digital in the spirit of 200 Meters and down or do we take the ARRL route and promote 10 Meters and up as a "step up in Amateur Radio"? We got to love those No Tech Coded Extras!
Art KC6UQH
----- Original Message ----- From: "Joe Leikhim" rhyolite@nettally.com To: amsat-bb@amsat.org Sent: Friday, September 08, 2006 5:47 PM Subject: [amsat-bb] Re: Sband and Eagle: an appeal for a higher leveldiscussion
This thread so reminds me of the past pleas for more mode B birds to replace AO-10 and AO-13. The AMSAT board response was that the VHF and UHF bands were getting noisy, illegal VHF and legal UHF interlopers were showing up and for the membership to embrace microwaves and build S band and L band stations.
Well I am one who has such a station and while I would love certainly to see mode B, come back, I am also fully equipped to excercise some S and L band experiments.
I can understand that many households are polluted with 2.4 GHz toys, mine is. My solution will be to pull the plug on that stuff during operation and to utilize a medium size dish for the downlink (Note: those grid panels can't discriminate as well as a bigger dish, and secondly the IC-970 noise blanker works on some types of S band ISM interference).
Please someone tell me that we can work L and S band modes with HEO and linear transponders, I would become so much more interested in the hobby!
All,
You have received carefully considered responses from three of the people who were in the fateful San Diego meeting where the revised band plan for Eagle was chosen. You also now have access to the meeting minutes and spread sheets on EaglePedia and three articles on the subject in the latest Journal. I too was at the meeting so let me say a few words.
For those of you who still disagree with the decisions we made I am sorry. Your elected volunteer Board members and the volunteer executives and volunteer Eagle team members have done their very best to design Eagle to satisfy the needs of the existing members while providing services that we hope will attract many thousands of Hams to the Amateur Satellite Service who today find us impossible or irrelevant. I congratulate all of AMSAT's dedicated volunteers on a job well done.
The band plan is simple.
a) We will provide an enhanced linear transponder for mode U/V (B) that will support traditional linear transponder modes with a performance and signal quality never before seen on a satellite. In addition, other modes may be supported, especially a new high performance SMS service for text messaging using hand held or transportable equipment even when Eagle is at apogee.
b) We will provide a modified version of C-C Rider, with the uplink on S-band, so I guess you would call it S-C Rider. It will support a full suite of services from voice and video to CW and data using a wide bandwidth digital carrier on the downlink and digitized uplink channels to maximize the link performance using the latest in coding techniques. As a side benefit, we will be transmitting on S-band so you can continue to use much of your existing S-band equipment if you like. We will be developing an open design reference ground station that will be available to buy or copy.
c) There are at least two TSFR (This-Space-For-Rent) packages that could possibly contain other RF or other payloads, conditioned on the availability of power, antenna space and compatibility with the primary payloads.
If, after considering all the information that is now available, you still feel strongly that we are doing a bad job then ask yourself not what AMSAT can do for you, but what you can do for AMSAT. If you want to have more direct influence on decisions then volunteer your time and money; run for office, join the Eagle team, join Field Operations, or one of the executive teams. At the very least have the courtesy of sending your comments directly to those who are involved so you can get informed responses. The Board meeting in San Diego is open to all members so you could express your feeling there.
Rick W2GPS AMSAT President
If this is true ... that there is space for other linear transponders on Eagle then how about S/U (or S/V) and/or L/U ? Did he mean S/X instead of S/C (Band) Rider?
Les W4SCO
c) There are at least two TSFR (This-Space-For-Rent) packages that could possibly contain other RF or other payloads, conditioned on the availability of power, antenna space and compatibility with the primary payloads.
Rick W2GPS AMSAT President
On 9 Sep 2006 at 6:21, Rick Hambly (W2GPS) wrote:
.
If, after considering all the information that is now available, you still feel strongly that we are doing a bad job then ask yourself not what AMSAT can do for you, but what you can do for AMSAT. > Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
Your clients eg:your actual and former members nearly unanimously voices their opinion about maintaining an S band downlink on Eagle as previously planned by you by the way. Do you feel strongly that you are doing your job ignoring them?
Answer your own question first don't blackmail your membership. You are a grown up and you are able to take you own decision... when you already feel the pressure from your membership it takes only an open mind to adjust the plan not bad faith.
Yours truly
Luc Leblanc VE2DWE Former AMSAT-NA coordinator and member. Skype VE2DWE www.qsl.net/ve2dwe
Quoting Luc Leblanc VE2DWE lucleblanc6@videotron.ca:
On 9 Sep 2006 at 6:21, Rick Hambly (W2GPS) wrote:
.
If, after considering all the information that is now available, you
still
feel strongly that we are doing a bad job then ask yourself not what
AMSAT
can do for you, but what you can do for AMSAT. > Subscription
settings: http://amsat.org/mailman/listinfo/amsat-bb
Your clients eg:your actual and former members nearly unanimously voices their opinion about maintaining an S band downlink on Eagle as previously planned by you by the way. Do you feel strongly that you are doing your job ignoring them?
This is a long letter, and though it replies to Luc, it is not specifically directed at him. I respect Luc as a long-standing contributer to this list and an experienced satellite radio operator who has dug my lousey signal out of the mud many times. However, in my opinion, the statement above is not an accurate description of the situation. Many of us are willing to be convinced by the science, and I, for one, have heard nothing convincing from the pro S-band group and some pretty discouraging numbers from Bob B.
What the board faces in this discussion is some members who, according to the research of their engineers, want two mutually exclusive things: a satellite design that will support the defined uses; and an s band downlink. To my mind, if the research is right, the Board is making the only sensible choice: to plan to build a working bird without the s band downlink. It seems silly to build a bird that has a S band downlink and doesn't work, that's why there are people who think they'd rather do other things with their lives. (Of course, The horns of this dilemma may be avoided if the research is wrong.)
Answer your own question first don't blackmail your membership. You are a grown up and you are able to take you own decision... when you already feel the pressure from your membership it takes only an open mind to adjust the plan not bad faith.
Thus as I see them, the statements of other Board members do not constitute extorsion (which I assume Luc means when he writes 'blackmail'). In fact, I'd say there is good evidence that this board has put together an excellent Design Team: they've focussed well on the purpose of the bird in its future use and, in the process, questioned all assumptions. I worry, though, that the reaction on this list will inspire them to delay announcements of partial results. We want an open process, under peer review; let's act like peers.
One idea came to me this morning as a means of exploring the situation on S band right now. Setting aside Eagle for a moment, this will help some of us get an idea if our set-ups will work for P3E and ESEO, which, if they both work, will give us plenty of S band linear action.
If we degrade our links to AO-51 by an appropriate amount, we could simulate working a S band HEO satellite (ok, in FM mode :-). I'm not sure what the gain of the antenna on AO-51 is, and I believe the power out is 3w, but perhaps that's max and not in use. Based on Bob's formula, the improved path loss will, I think, be on average (40000km /2000km )^2 = 400 or 26 dB.
So, assuming that the HEO has higher gain antennas and better power out, just for fun, let's put some 20 dB resistor pads in the right place (help me here: it would need to be between the antenna and the downconverter, right?). Actually, the right amount of RG58 could probably do the trick. We could even have a sim-HEO night on AO-51. Someone in Ohio could pretend they're in New Zealand :-)
73, Bruce VE9QRP
I have one (immediate) question...why no switches? I thought the AO-40 switches worked well...and if we have "space for rent" why not plan to fly a 2.4 gHz transmitter and use it as an "alternate" downlink?
Alternatively, does the "space for rent" indicate that contributions to another organization or sponsor, who supports 2.4 Gig, could fund a transponder on the spacecraft? A very interesting concept...
Roger WA1KAT
----- Original Message ----- From: "Rick Hambly (W2GPS)" w2gps@cnssys.com To: amsat-bb@amsat.org Sent: Saturday, September 09, 2006 6:21 AM Subject: [amsat-bb] Eagle Satellite Design
All,
You have received carefully considered responses from three of the people who were in the fateful San Diego meeting where the revised band plan for Eagle was chosen. You also now have access to the meeting minutes and
spread
sheets on EaglePedia and three articles on the subject in the latest Journal. I too was at the meeting so let me say a few words.
For those of you who still disagree with the decisions we made I am sorry. Your elected volunteer Board members and the volunteer executives and volunteer Eagle team members have done their very best to design Eagle to satisfy the needs of the existing members while providing services that we hope will attract many thousands of Hams to the Amateur Satellite Service who today find us impossible or irrelevant. I congratulate all of AMSAT's dedicated volunteers on a job well done.
The band plan is simple.
a) We will provide an enhanced linear transponder for mode U/V (B) that
will
support traditional linear transponder modes with a performance and signal quality never before seen on a satellite. In addition, other modes may be supported, especially a new high performance SMS service for text
messaging
using hand held or transportable equipment even when Eagle is at apogee.
b) We will provide a modified version of C-C Rider, with the uplink on S-band, so I guess you would call it S-C Rider. It will support a full
suite
of services from voice and video to CW and data using a wide bandwidth digital carrier on the downlink and digitized uplink channels to maximize the link performance using the latest in coding techniques. As a side benefit, we will be transmitting on S-band so you can continue to use much of your existing S-band equipment if you like. We will be developing an
open
design reference ground station that will be available to buy or copy.
c) There are at least two TSFR (This-Space-For-Rent) packages that could possibly contain other RF or other payloads, conditioned on the
availability
of power, antenna space and compatibility with the primary payloads.
If, after considering all the information that is now available, you still feel strongly that we are doing a bad job then ask yourself not what AMSAT can do for you, but what you can do for AMSAT. If you want to have more direct influence on decisions then volunteer your time and money; run for office, join the Eagle team, join Field Operations, or one of the
executive
teams. At the very least have the courtesy of sending your comments
directly
to those who are involved so you can get informed responses. The Board meeting in San Diego is open to all members so you could express your feeling there.
Rick W2GPS AMSAT President
Sent via AMSAT-BB@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
----- Original Message ----- From: "Joe Leikhim" rhyolite@nettally.com To: amsat-bb@amsat.org Sent: Saturday, September 09, 2006 2:47 AM Subject: [amsat-bb] Re: Sband and Eagle: an appeal for a higher leveldiscussion
Please someone tell me that we can work L and S band modes with HEO and linear transponders, I would become so much more interested in the hobby!
-- Joe Leikhim K4SAT "The RFI-EMI-GUY"©
Hi Joe, K4SAT
The HEO satellite P3E in preparation at AMSAT-DL will use L band for the uplink and S band for downlink.
In a separate email I have attached for you additional information about this satellite.
73" de
i8CVS Domenico
participants (8)
-
Bruce Robertson -
i8cvs -
Joe Leikhim -
kc6uqh -
Luc Leblanc VE2DWE -
Rick Hambly (W2GPS) -
Roger Kolakowski -
sco＠sco-inc.com