Someone wrote:
as I recall there were 50 some odd pounds of ballast launched with the
bird...to
bad it wasnt an amateur repeater.
to bad we didnt have something to use that excess performance...they flew ballast on the flight
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Why would they fly ballast on their rocket when they could have flown a ham satellite?
1. Ballast does not need to be tested for Electromagnetic Compatibility or contamination of the primary payload. The Interface Control Document for a block of concrete can be exceedingly simple, with no need to pay a room full of engineers to review it for completeness and accuracy.
2. Ballast does not need to have a separation interface tested and qualified, there is no chance of it coming loose inside the payload shroud during liftoff.
3. Ballast is certain to be ready in time for the launch date, without bringing another organization into the mix. There is no need to conduct a crash engineering program to design a satellite structure that will fit on the Atlas and then test and certify the satellite for compliance with the Atlas vibration and acoustic specifications.
4. Ballast does not have an e-mail group full of whining little people who think they could have designed it better or that it operates on the wrong band or mode, and complaining loudly when the mission falls months or years behind its original launch date.
If you were the Colonel in charge of the mission, you could not make a safer choice than launching a block of concrete ballast. A ham satellite is just a lot of additional risk and headache with no possible gain for you or your future career.
Somewhere in the world there may be an officer who is willing to take that risk. That is how Oscar-1 was launched in 1961. The challenge is to find that person and nurture a relationship with him or her. If they are reading the comments on Amsat-BB they are probably thinking "there is no way I would ever want to have a relationship with that wacky organization"
Dan Schultz N8FGV
Dan
Why would they fly ballast on their rocket when they could have flown a ham satellite?...
I didnt ask why.
Your list sounds a lot like my 10 year olds explaining why something didnt get done when they know that they should have done it. Their first inclination (and that is a hallmark of childhood) is to try and blame someone or something elses. .
Nothing in life is easy except inertia.
Robert WB5MZO
_________________________________________________________________ Your E-mail and More On-the-Go. Get Windows Live Hotmail Free. http://clk.atdmt.com/GBL/go/171222985/direct/01/
On both 70cm and 2 meter antennas, I have DCI filters tuned to sat passbands as well as ARR preamps. My question is: what's the preferred order? Presently, I have the filters closer to the antennas, with the assumption I'd be better off supressing spurs first, thus preventing them from hitting preamps and desensing.
Any thoughts?
what's the preferred order?
As ever "that depends". In the specific case I was involved in at Worcester Polytech, we found that we could get the best trade off by putting the preamp at the antenna then knocking down the out of band stuff with the filter between the preamp and the receiver. The losses in the filter hurt your system noise figure much more if you go ant -> filter -> preamp -> receiver
If the out of band stuff is desensing your preamp, well, that is another story. At +12 dBm for the ARR GaAs FET we were using there was no problem, even in an urban environment.
-Joe KM1P
And I've been on the other side of things where the "noise" we had to filter out was so close to the signal we wanted, we had no choice but to put a tight bandpass filter at the antenna, ahead of the amp, to keep the amp from overloading. 6 of one...half a dozen of the other.... 73, jim KQ6EA
--- On Mon, 10/19/09, Joe Fitzgerald jfitzgerald@alum.wpi.edu wrote:
From: Joe Fitzgerald jfitzgerald@alum.wpi.edu Subject: [amsat-bb] Re: Filters and Preamps Question To: Cc: amsat-bb@amsat.org Date: Monday, October 19, 2009, 4:33 PM
what's the preferred order?
As ever "that depends". In the specific case I was involved in at Worcester Polytech, we found that we could get the best trade off by putting the preamp at the antenna then knocking down the out of band stuff with the filter between the preamp and the receiver. The losses in the filter hurt your system noise figure much more if you go ant -> filter -> preamp -> receiver
If the out of band stuff is desensing your preamp, well, that is another story. At +12 dBm for the ARR GaAs FET we were using there was no problem, even in an urban environment.
-Joe KM1P
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 Fitzgerald" jfitzgerald@alum.wpi.edu Cc: amsat-bb@amsat.org Sent: Tuesday, October 20, 2009 1:33 AM Subject: [amsat-bb] Re: Filters and Preamps Question
what's the preferred order?
As ever "that depends". In the specific case I was involved in at Worcester Polytech, we found that we could get the best trade off by putting the preamp at the antenna then knocking down the out of band stuff with the filter between the preamp and the receiver. The losses in the filter hurt your system noise figure much more if you go ant -> filter -> preamp -> receiver
If the out of band stuff is desensing your preamp, well, that is another story. At +12 dBm for the ARR GaAs FET we were using there was no problem, even in an urban environment.
-Joe KM1P
Hi Joe, KM1P
You are right and in fact:
It is a common EME procedure to put a passband cavity filter or an interdigital passband filter at the output of the antenna mounted low noise preamplifier because the insertion loss of it in dB decreases only the gain of the preamplifier by the same amount in dB so that the Noise Figure of the preamplifier is not degraded by the insertion loss of the filter.
In this configuration we have --> antenna --->a T/R coax relay----> preamplifier ---->cavity filter all antenna mounted and a coax cable connected to the output of the preamplifier devoted only to receive and directly going down the shack ------>to the receiver.
In more details the antenna is connected to the common port of the T/R coax relay while the preamplifier is connected to the normally closed NC contact of the T/R relay
In order to transmit the TX power amplifier is connected directly to another coax cable dedicated only to transmit and it is connected at the antenna via the normally open NO contact of the T/R relay.
The above configuration using a filter at the output of a preamplifier is the best one because it do not degrade the preamplifier Noise Figure but reduces the bandwidth providing a bonus in selectivity.
It is possible to improve the above configuration introducing between the antenna and input of the preamplifier a filter plus a preamplifier protection device designed by K3PGP showing a very low insertion loss less than 0.1 dB at 432 MHz that without to deteriorate the preamplifier Noise Figure provides in addition another bonus of selectivity at the preamplifier input as you can realize reading the following page:
http://www.k3pgp.org/432filter.htm
From 1977 I was a 432 MHz EME operator so that I actually use for
satellite the above discussed setup both for 2 meters and 70 cm because I live in the center of the gulf on Naples with a terrific RF pollution in every amateur and out of amateur band so that a filter at the preamplifier input and output is also mandatory to reduce the preamplifiers gain compression due of out of band strong nearby signals.
It is evident that using a filter at the output of a preamplifier it becames a complicated matter using a commercial preamplifier with two coax relays into it and by using only one transmission line to receive and to transmit because the preamplifier output filter must be a big one to pass all the transmitter power and particularly it must be tuned in such a way as not to introduce a high VSWR into the TX transmission line.
Best 73" de
i8CVS Domenico
Thanks for all the great responses. I'll try switching them around and see how it affects performance. Although I'm in Kansas City, RF pollution is not too bad at my particular location. One benefit of the filters is reduction of desensing the receiver when xmitting, especially with preamps on.
73, Elan WB2IOL
Dan
4. Ballast does not have an e-mail group full of whining little people who think they could have designed it better or that it operates on the wrong band or mode, and complaining loudly when the mission falls months or years behind its original launch date.
....
this is the one I always find amusing. Almost comical and certainly childish.
Are the people who are suppose to be the experts in building state of the art satellites so thin skinned that a bulletin board slows their progress? LOL
If so then I suggest that they channel The Former First lady Nancy Reagan and "Just say no" either stop building satellites and move on to something that wont be at all critical...or just tune out and stop reading.
It is the childhood equivalent of "he called me a name"
LOL
things are hard
Robert WB5MZO
_________________________________________________________________ Hotmail: Powerful Free email with security by Microsoft. http://clk.atdmt.com/GBL/go/171222986/direct/01/
Robert WB5MZO
Are the people who are suppose to be the experts in building state of the art satellites so thin skinned that a bulletin board slows their progress? LOL
I want to remind you each and every time you write a message: AMSAT is a volunteer run group of space-craft experimenters sharing a hobby and a purpose: Ham Radio & Education. As you should know there is only one paid employee of AMSAT at the headquarters and everyone else is just a member.
With regard to the skill and qualification of the "experts" you refer to in your e-mail, perhaps you have seem to have the expertise of being a cynic and a critic - in addition to being right on everything you say, according to yourself - meanwhile, others are lending their varied expertise in the areas they feel most comfortable electrical, mechanical, thermodynamics, Solar PV etc. etc. and in certain cases, actual donations to fund further R&D at their own cost. I am not sure where you have found any documentation from AMSAT-NA that we have any portion of capability or indeed requirement to build "state of the art satellites". All the bits of stuff that have been incorporated into satellites so far are probably best described as hobby kits or more exactly waste material from other projects.
Are you faulting AMSAT members for wanting to work for $0.00 and pursuing a dream of being creative - and to have chance to tell their children, look I built that and it is in Space ? Are you criticizing the current activity and past activity and anything that they may come up with in the future because, according to you, these AMSAT "experts" don't have the right stuff ? Or are you just trying to get noticed ?
Ok then, assuming you want the spotlight and are correct in your conviction that you know what you are doing, what is your recommendation for steps going forward ? Put your thinking cap on instead of and submit a development plan that will use the annual dues from about 1900 paying members and organize a working group amongst your friends in the amsat community -- and build -- a satellite -- and launch it into space. Or, you could start a campaign to get votes from the members to become the next President of AMSAT-NA... coming up soon.
BTW, you can write off your donation to AMSAT on your taxes, but then you already knew that.
Looking forward to reading about your development plans soon.
Samudra, N3RDX and S21X
Samudra, N3RDX and S21X
interesting post...there are lots of volunteer organizations and all of them managed to do things without the endless whining of "they are all volunteers"...gee if that could lift things into orbit
Robert WB5MZO _________________________________________________________________ Your E-mail and More On-the-Go. Get Windows Live Hotmail Free. http://clk.atdmt.com/GBL/go/171222985/direct/01/
Rocky,
I think you miss the point...
- Ballast does not have an e-mail group
full of whining little people who think they could have designed it better or...
this is the one I always find amusing. Almost comical and certainly childish.
Yes, I think he was referring to you and your incessant fruitless posts...
Are the people who are suppose to be the experts in building state of the art satellites so thin skinned that a bulletin board slows their progress? LOL
Yes, they probably are... On the one hand, small mind kibitzers lambast all the "dooers" in the AMSAT organization for not maintaining a presence here and responding to every little bite and jab and complaint, while you then want to lambast them for trying to respond to your childish and uninformed incessant opinions...
"Just say no" either stop building satellites and move on to something that wont be at all critical...or just tune out and stop reading.
In fact some of them have. And I don't blame them one bit. The damage done by so many trolls and kibitzers such as yourself is real and hurts the organization.
It is the childhood equivalent of "he called me a name"
Yes, he did, and it seems he was talking directly to you. As am I.
LOL things are hard Robert WB5MZO
And you are the one that really makes them that way.
Bob
Maybe AMSAT should make a PIO?
Robert Bruninga wrote:
Rocky,
I think you miss the point...
- Ballast does not have an e-mail group
full of whining little people who think they could have designed it better or...
this is the one I always find amusing. Almost comical and certainly childish.
Yes, I think he was referring to you and your incessant fruitless posts...
Are the people who are suppose to be the experts in building state of the art satellites so thin skinned that a bulletin board slows their progress? LOL
Yes, they probably are... On the one hand, small mind kibitzers lambast all the "dooers" in the AMSAT organization for not maintaining a presence here and responding to every little bite and jab and complaint, while you then want to lambast them for trying to respond to your childish and uninformed incessant opinions...
"Just say no" either stop building satellites and move on to something that wont be at all critical...or just tune out and stop reading.
In fact some of them have. And I don't blame them one bit. The damage done by so many trolls and kibitzers such as yourself is real and hurts the organization.
It is the childhood equivalent of "he called me a name"
Yes, he did, and it seems he was talking directly to you. As am I.
LOL things are hard Robert WB5MZO
And you are the one that really makes them that way.
Bob
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
No virus found in this incoming message. Checked by AVG - www.avg.com Version: 8.5.421 / Virus Database: 270.14.21/2445 - Release Date: 10/19/09 06:40:00
Bob,Right on the money! All I have seen from on the BBS from this guy is "after the fact" and "I can tell you how to do it" and no where does he even attempt to help. He is the greatest Monday Morning quarterback. He is a troll and unfortunately we do fall for his tactics. If, in fact, he is a -- test pilot-- thank God I live in California and not Texas or any where near his flight path! Which makes me want to know what aircraft he tests so that I can stay clear of them. I hope not to fall for the "loud mouth troll that knows everything and wants to tell all that he does". He knows that if he ever tries to do what he tells others to do he will fail. And come to think of it, most of us know that he is talk and no action too.
Don WB5EKU
On Mon, Oct 19, 2009 at 10:34 AM, Robert Bruninga bruninga@usna.edu wrote:
Rocky,
I think you miss the point...
- Ballast does not have an e-mail group
full of whining little people who think they could have designed it better or...
this is the one I always find amusing. Almost comical and certainly childish.
Yes, I think he was referring to you and your incessant fruitless posts...
Are the people who are suppose to be the experts in building state of the art satellites so thin skinned that a bulletin board slows their progress? LOL
Yes, they probably are... On the one hand, small mind kibitzers lambast all the "dooers" in the AMSAT organization for not maintaining a presence here and responding to every little bite and jab and complaint, while you then want to lambast them for trying to respond to your childish and uninformed incessant opinions...
"Just say no" either stop building satellites and move on to something that wont be at all critical...or just tune out and stop reading.
In fact some of them have. And I don't blame them one bit. The damage done by so many trolls and kibitzers such as yourself is real and hurts the organization.
It is the childhood equivalent of "he called me a name"
Yes, he did, and it seems he was talking directly to you. As am I.
LOL things are hard Robert WB5MZO
And you are the one that really makes them that way.
Bob
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
I'm surprised this guy has enough time to send emails...finding a cure for cancer, peace in the Middle East and healthcare reform certainly must take up a lot of time!
73 Jeff WB2SYK Sent from my Verizon Wireless BlackBerry
-----Original Message----- From: Donald Jacob wb5eku@gmail.com Date: Mon, 19 Oct 2009 11:01:12 To: bruninga@usna.edu Cc: Amsat BBamsat-bb@amsat.org Subject: [amsat-bb] Re: THE DMSP launch
Bob,Right on the money! All I have seen from on the BBS from this guy is "after the fact" and "I can tell you how to do it" and no where does he even attempt to help. He is the greatest Monday Morning quarterback. He is a troll and unfortunately we do fall for his tactics. If, in fact, he is a -- test pilot-- thank God I live in California and not Texas or any where near his flight path! Which makes me want to know what aircraft he tests so that I can stay clear of them. I hope not to fall for the "loud mouth troll that knows everything and wants to tell all that he does". He knows that if he ever tries to do what he tells others to do he will fail. And come to think of it, most of us know that he is talk and no action too.
Don WB5EKU
On Mon, Oct 19, 2009 at 10:34 AM, Robert Bruninga bruninga@usna.edu wrote:
Rocky,
I think you miss the point...
- Ballast does not have an e-mail group
full of whining little people who think they could have designed it better or...
this is the one I always find amusing. Almost comical and certainly childish.
Yes, I think he was referring to you and your incessant fruitless posts...
Are the people who are suppose to be the experts in building state of the art satellites so thin skinned that a bulletin board slows their progress? LOL
Yes, they probably are... On the one hand, small mind kibitzers lambast all the "dooers" in the AMSAT organization for not maintaining a presence here and responding to every little bite and jab and complaint, while you then want to lambast them for trying to respond to your childish and uninformed incessant opinions...
"Just say no" either stop building satellites and move on to something that wont be at all critical...or just tune out and stop reading.
In fact some of them have. And I don't blame them one bit. The damage done by so many trolls and kibitzers such as yourself is real and hurts the organization.
It is the childhood equivalent of "he called me a name"
Yes, he did, and it seems he was talking directly to you. As am I.
LOL things are hard Robert WB5MZO
And you are the one that really makes them that way.
Bob
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
_______________________________________________ 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
Bob...
LOL really it is funny.
If one person can knock them off their stride then the deserve to bilge...
I guess that any explanation for poor performance works
Robert WB5MZO _________________________________________________________________ Your E-mail and More On-the-Go. Get Windows Live Hotmail Free. http://clk.atdmt.com/GBL/go/171222985/direct/01/
Bob
It is OK, maybe suitsat 2 or whatever it is called with be a success or at least occur..if it flops then all the folks who are always gung ho to make excuses can have something else to do! Work is also needed for those protecting inertia
Robert WB5MZO _________________________________________________________________ Hotmail: Free, trusted and rich email service. http://clk.atdmt.com/GBL/go/171222984/direct/01/
participants (11)
-
Daniel Schultz -
Donald Jacob -
Elan Portnoy -
i8cvs -
jeffk13057＠yahoo.com -
Jim Jerzycke -
Joe -
Joe Fitzgerald -
Robert Bruninga -
Rocky Jones -
Samudra Haque