Cubesat HF experiment:
We have revised our HF satellite experiment proposal to be a CW telemetry beacon on 40, 20, 15 and 10 meter bands. The experiment will last only a few days, since the deployed 1000m tether will have so much drag, we will de-orbit in only a few days.
The idea is a keyed CW oscillator on 7.010 MHz with harmonics on 14.020, 21.030 and 28.040 MHz. These bands are all in the IARU Satelilte allocation. We will filter all harmonics above 28 MHz.
The challenge will be how to feed a 1000m long wire from only a 4"x4"x7" counterpoise (on all bands). transformer coupling?
The tether will be vertical and can act as a long wire antenna with a very narrow cone angle pointed straight down. Antenna gain will be more than 10 dB on all bands. This moving donut gain pattern sweeping across the earth should pose some interesting reception reports (If any of it gets through the ionosphere).
Launch Opportunity no earlier than March 2012. Putting us closer and closer to the Solar Max which would be the worst time for this experiment.
Other than a nice AMSAT experiment, if anyone can use this for valid ionosphereic science, come join us.
Bob, WB4APR
Hi Bob,
Congratulations, sounds like an interesting experiment. I will be listening for the transmissions. Do you have estimated output power yet? Will the cubesat TX in eclipse, less active ionoshere. Will the beacon be on all the time, or intermittent.
73 John G7HIA
________________________________ From: Bob Bruninga bruninga@usna.edu To: amsat-bb@amsat.org Sent: Tuesday, 19 April, 2011 14:22:52 Subject: [amsat-bb] HF Satellite Experiment?
Cubesat HF experiment:
We have revised our HF satellite experiment proposal to be a CW telemetry beacon on 40, 20, 15 and 10 meter bands. The experiment will last only a few days, since the deployed 1000m tether will have so much drag, we will de-orbit in only a few days.
The idea is a keyed CW oscillator on 7.010 MHz with harmonics on 14.020, 21.030 and 28.040 MHz. These bands are all in the IARU Satelilte allocation. We will filter all harmonics above 28 MHz.
The challenge will be how to feed a 1000m long wire from only a 4"x4"x7" counterpoise (on all bands). transformer coupling?
The tether will be vertical and can act as a long wire antenna with a very narrow cone angle pointed straight down. Antenna gain will be more than 10 dB on all bands. This moving donut gain pattern sweeping across the earth should pose some interesting reception reports (If any of it gets through the ionosphere).
Launch Opportunity no earlier than March 2012. Putting us closer and closer to the Solar Max which would be the worst time for this experiment.
Other than a nice AMSAT experiment, if anyone can use this for valid ionosphereic science, come join us.
Bob, WB4APR
_______________________________________________ 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 hoping for 1 Watt and on all the time.
Bob, wbapr
From: John Heath [mailto:g7hia@btinternet.com] Sent: Tuesday, April 19, 2011 1:14 PM To: Bob Bruninga Cc: Amsat Subject: Re: [amsat-bb] HF Satellite Experiment?
Hi Bob,
Congratulations, sounds like an interesting experiment.
I will be listening for the transmissions.
Do you have estimated output power yet?
Will the cubesat TX in eclipse, less active ionoshere.
Will the beacon be on all the time, or intermittent.
73 John G7HIA
_____
From: Bob Bruninga bruninga@usna.edu To: amsat-bb@amsat.org Sent: Tuesday, 19 April, 2011 14:22:52 Subject: [amsat-bb] HF Satellite Experiment?
Cubesat HF experiment:
We have revised our HF satellite experiment proposal to be a CW telemetry beacon on 40, 20, 15 and 10 meter bands. The experiment will last only a few days, since the deployed 1000m tether will have so much drag, we will de-orbit in only a few days.
The idea is a keyed CW oscillator on 7.010 MHz with harmonics on 14.020, 21.030 and 28.040 MHz. These bands are all in the IARU Satelilte allocation. We will filter all harmonics above 28 MHz.
The challenge will be how to feed a 1000m long wire from only a 4"x4"x7" counterpoise (on all bands). transformer coupling?
The tether will be vertical and can act as a long wire antenna with a very narrow cone angle pointed straight down. Antenna gain will be more than 10 dB on all bands. This moving donut gain pattern sweeping across the earth should pose some interesting reception reports (If any of it gets through the ionosphere).
Launch Opportunity no earlier than March 2012. Putting us closer and closer to the Solar Max which would be the worst time for this experiment.
Other than a nice AMSAT experiment, if anyone can use this for valid ionosphereic science, come join us.
Bob, WB4APR
_______________________________________________ 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
What is your launch date and good luck?
nick
-----Original Message----- From: amsat-bb-bounces@amsat.org [mailto:amsat-bb-bounces@amsat.org] On Behalf Of Bob Bruninga Sent: Tuesday, April 19, 2011 12:16 PM To: 'John Heath' Cc: 'Amsat' Subject: [amsat-bb] Re: HF Satellite Experiment?
I'm hoping for 1 Watt and on all the time.
Bob, wbapr
From: John Heath [mailto:g7hia@btinternet.com] Sent: Tuesday, April 19, 2011 1:14 PM To: Bob Bruninga Cc: Amsat Subject: Re: [amsat-bb] HF Satellite Experiment?
Hi Bob,
Congratulations, sounds like an interesting experiment.
I will be listening for the transmissions.
Do you have estimated output power yet?
Will the cubesat TX in eclipse, less active ionoshere.
Will the beacon be on all the time, or intermittent.
73 John G7HIA
_____
From: Bob Bruninga bruninga@usna.edu To: amsat-bb@amsat.org Sent: Tuesday, 19 April, 2011 14:22:52 Subject: [amsat-bb] HF Satellite Experiment?
Cubesat HF experiment:
We have revised our HF satellite experiment proposal to be a CW telemetry beacon on 40, 20, 15 and 10 meter bands. The experiment will last only a few days, since the deployed 1000m tether will have so much drag, we will de-orbit in only a few days.
The idea is a keyed CW oscillator on 7.010 MHz with harmonics on 14.020, 21.030 and 28.040 MHz. These bands are all in the IARU Satelilte allocation. We will filter all harmonics above 28 MHz.
The challenge will be how to feed a 1000m long wire from only a 4"x4"x7" counterpoise (on all bands). transformer coupling?
The tether will be vertical and can act as a long wire antenna with a very narrow cone angle pointed straight down. Antenna gain will be more than 10 dB on all bands. This moving donut gain pattern sweeping across the earth should pose some interesting reception reports (If any of it gets through the ionosphere).
Launch Opportunity no earlier than March 2012. Putting us closer and closer to the Solar Max which would be the worst time for this experiment.
Other than a nice AMSAT experiment, if anyone can use this for valid ionosphereic science, come join us.
Bob, WB4APR
_______________________________________________ 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
What is your launch date and good luck?
Launch Opportunity no earlier than March 2012. Putting us closer and closer to the Solar Max which would be the worst time for this experiment.
Bob, Wb4APR
-----Original Message----- From: amsat-bb-bounces@amsat.org [mailto:amsat-bb-bounces@amsat.org] On Behalf Of Bob Bruninga Sent: Tuesday, April 19, 2011 12:16 PM To: 'John Heath' Cc: 'Amsat' Subject: [amsat-bb] Re: HF Satellite Experiment?
I'm hoping for 1 Watt and on all the time.
Bob, wbapr
From: John Heath [mailto:g7hia@btinternet.com] Sent: Tuesday, April 19, 2011 1:14 PM To: Bob Bruninga Cc: Amsat Subject: Re: [amsat-bb] HF Satellite Experiment?
Hi Bob,
Congratulations, sounds like an interesting experiment.
I will be listening for the transmissions.
Do you have estimated output power yet?
Will the cubesat TX in eclipse, less active ionoshere.
Will the beacon be on all the time, or intermittent.
73 John G7HIA
_____
From: Bob Bruninga bruninga@usna.edu To: amsat-bb@amsat.org Sent: Tuesday, 19 April, 2011 14:22:52 Subject: [amsat-bb] HF Satellite Experiment?
Cubesat HF experiment:
We have revised our HF satellite experiment proposal to be a CW telemetry beacon on 40, 20, 15 and 10 meter bands. The experiment will last only a few days, since the deployed 1000m tether will have so much drag, we will de-orbit in only a few days.
The idea is a keyed CW oscillator on 7.010 MHz with harmonics on 14.020, 21.030 and 28.040 MHz. These bands are all in the IARU Satelilte allocation. We will filter all harmonics above 28 MHz.
The challenge will be how to feed a 1000m long wire from only a 4"x4"x7" counterpoise (on all bands). transformer coupling?
The tether will be vertical and can act as a long wire antenna with a very narrow cone angle pointed straight down. Antenna gain will be more than 10 dB on all bands. This moving donut gain pattern sweeping across the earth should pose some interesting reception reports (If any of it gets through the ionosphere).
Launch Opportunity no earlier than March 2012. Putting us closer and closer to the Solar Max which would be the worst time for this experiment.
Other than a nice AMSAT experiment, if anyone can use this for valid ionosphereic science, come join us.
Bob, WB4APR
_______________________________________________ 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
Now, a question,
Is there a difference in which way the signal travels through the ionosphere be it going ground up or space craft down, does it make any difference?
And or how about incendense angles? the angle the signal hit the ionosphere. if it's a grazing blow does it get reflected more vs a straight on assault like straight up and down.
It can't be blocked all that much because I remember playing on that russian bird all the time Mode "K"? 15/10 meters.
How about listening to Jupiter also?
Joe WB9SBD
The Original Rolling Ball Clock Idle Tyme Idle-Tyme.com http://www.idle-tyme.com
On 4/19/2011 3:05 PM, Bob Bruninga wrote:
What is your launch date and good luck?
Launch Opportunity no earlier than March 2012. Putting us closer and closer to the Solar Max which would be the worst time for this experiment.
Bob, Wb4APR
-----Original Message----- From: amsat-bb-bounces@amsat.org [mailto:amsat-bb-bounces@amsat.org] On Behalf Of Bob Bruninga Sent: Tuesday, April 19, 2011 12:16 PM To: 'John Heath' Cc: 'Amsat' Subject: [amsat-bb] Re: HF Satellite Experiment?
I'm hoping for 1 Watt and on all the time.
Bob, wbapr
From: John Heath [mailto:g7hia@btinternet.com] Sent: Tuesday, April 19, 2011 1:14 PM To: Bob Bruninga Cc: Amsat Subject: Re: [amsat-bb] HF Satellite Experiment?
Hi Bob,
Congratulations, sounds like an interesting experiment.
I will be listening for the transmissions.
Do you have estimated output power yet?
Will the cubesat TX in eclipse, less active ionoshere.
Will the beacon be on all the time, or intermittent.
73 John G7HIA
From: Bob Bruningabruninga@usna.edu To: amsat-bb@amsat.org Sent: Tuesday, 19 April, 2011 14:22:52 Subject: [amsat-bb] HF Satellite Experiment?
Cubesat HF experiment:
We have revised our HF satellite experiment proposal to be a CW telemetry beacon on 40, 20, 15 and 10 meter bands. The experiment will last only a few days, since the deployed 1000m tether will have so much drag, we will de-orbit in only a few days.
The idea is a keyed CW oscillator on 7.010 MHz with harmonics on 14.020, 21.030 and 28.040 MHz. These bands are all in the IARU Satelilte allocation. We will filter all harmonics above 28 MHz.
The challenge will be how to feed a 1000m long wire from only a 4"x4"x7" counterpoise (on all bands). transformer coupling?
The tether will be vertical and can act as a long wire antenna with a very narrow cone angle pointed straight down. Antenna gain will be more than 10 dB on all bands. This moving donut gain pattern sweeping across the earth should pose some interesting reception reports (If any of it gets through the ionosphere).
Launch Opportunity no earlier than March 2012. Putting us closer and closer to the Solar Max which would be the worst time for this experiment.
Other than a nice AMSAT experiment, if anyone can use this for valid ionosphereic science, come join us.
Bob, WB4APR
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
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 - Calculate the resistance of 1000M of whatever wire you are using at the frequencies you are operating on. It will be low. The resistive component of the impedance will dominate the reactive component, so a simple transformer will do. I can do the calculation if you don't have access to the HF resistance data. It would be a good task for a student though. - Duffey On Apr 19, 2011, at 7:22 AM, Bob Bruninga wrote:
Cubesat HF experiment:
We have revised our HF satellite experiment proposal to be a CW telemetry beacon on 40, 20, 15 and 10 meter bands. The experiment will last only a few days, since the deployed 1000m tether will have so much drag, we will de-orbit in only a few days.
The idea is a keyed CW oscillator on 7.010 MHz with harmonics on 14.020, 21.030 and 28.040 MHz. These bands are all in the IARU Satelilte allocation. We will filter all harmonics above 28 MHz.
The challenge will be how to feed a 1000m long wire from only a 4"x4"x7" counterpoise (on all bands). transformer coupling?
The tether will be vertical and can act as a long wire antenna with a very narrow cone angle pointed straight down. Antenna gain will be more than 10 dB on all bands. This moving donut gain pattern sweeping across the earth should pose some interesting reception reports (If any of it gets through the ionosphere).
Launch Opportunity no earlier than March 2012. Putting us closer and closer to the Solar Max which would be the worst time for this experiment.
Other than a nice AMSAT experiment, if anyone can use this for valid ionosphereic science, come join us.
Bob, WB4APR
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
-- KK6MC James Duffey Cedar Crest NM
Subject: Re: [amsat-bb] HF Satellite Experiment?
Bob - Calculate the resistance of 1000M of whatever wire you are using at the frequencies you are operating on. It will be low. The resistive component of the impedance will dominate the reactive component, so a simple transformer will do.
Turns out I just learned today that the tether is going to be about 2k ohms. That's 2 ohms per meter or Huge! For the first half wavelength at 7 MHz, this is 40 ohms or a nice dummy load...
Putting that into EZNEC changes the antenna from the expected long-wire cone with 14 dBi gain straight down to a nearly perfect Dipole pattern (off the sides) with a gain of - 64 dBi and a feed point impedance of 50000 +j36000. In other words, only the first 1/2 wave is really doing anything as far as pattern.
Again, these are only 1st cut assessments(we haven't really modeled the actual cubesat structure yet), but this high resistance of the tether is really going to need some looking at...
Bob, WB4APR
Cubesat HF experiment:
We have revised our HF satellite experiment proposal to be a CW telemetry beacon on 40, 20, 15 and 10 meter bands. The experiment will last only a few days, since the deployed 1000m tether will have so much drag, we will de-orbit in only a few days.
The idea is a keyed CW oscillator on 7.010 MHz with harmonics on 14.020, 21.030 and 28.040 MHz. These bands are all in the IARU Satelilte allocation. We will filter all harmonics above 28 MHz.
The challenge will be how to feed a 1000m long wire from only a 4"x4"x7" counterpoise (on all bands). transformer coupling?
The tether will be vertical and can act as a long wire antenna with a very narrow cone angle pointed straight down. Antenna gain will be more than
10
dB on all bands. This moving donut gain pattern sweeping across the earth should pose some interesting reception reports (If any of it gets through the ionosphere).
Launch Opportunity no earlier than March 2012. Putting us closer and
closer
to the Solar Max which would be the worst time for this experiment.
Other than a nice AMSAT experiment, if anyone can use this for valid ionosphereic science, come join us.
Bob, WB4APR
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
-- KK6MC James Duffey Cedar Crest NM
Hi Bob, WB4APR
I suggest you to take a look at the succesful 20 MHz and 40 MHz HF antennas used by SPUTNIK-1
http://www.antenna-theory.com/phpbb2/viewtopic.php?p=451&sid=e909b07b8e9... ac9a04a6adec04932
The 58 cm sphere had four antennas, two were 2.4 meters long and two were 2.9 meters long. They were V shaped turnstile angled at 35 degrees from the longitudinal axis, and two transmitters alternately emitted 20 or 40 MHz.
Following your proposal a deployed 1000m tether have a very poor radiation efficiency and will have so much drag and the Cubesat will de-orbit in only a few days
On the other side the V shaped turnstile are very short and your Cubesat experiment will not be limited by the drag factor and will last a very long time .
Also take a look at the HF antennas of OSCAR-6, OSCAR-7, RS-10/11, RS-12/13, RS-15 and RS-16
73" de
i8CVS Domenico
----- Original Message ----- From: "Bob Bruninga" bruninga@usna.edu To: "'James Duffey'" jamesduffey@comcast.net Cc: "'amsat-bb BB'" amsat-bb@amsat.org Sent: Wednesday, April 20, 2011 8:41 PM Subject: [amsat-bb] Re: HF Satellite Experiment? (hi Z)
Subject: Re: [amsat-bb] HF Satellite Experiment?
Bob - Calculate the resistance of 1000M of whatever wire you are using at the frequencies you are operating on. It will be low. The resistive component of the impedance will dominate the reactive component, so a simple transformer will do.
Turns out I just learned today that the tether is going to be about 2k
ohms.
That's 2 ohms per meter or Huge! For the first half wavelength at 7 MHz, this is 40 ohms or a nice dummy load...
Putting that into EZNEC changes the antenna from the expected long-wire
cone
with 14 dBi gain straight down to a nearly perfect Dipole pattern (off the sides) with a gain of - 64 dBi and a feed point impedance of 50000
+j36000.
In other words, only the first 1/2 wave is really doing anything as far as pattern.
Again, these are only 1st cut assessments(we haven't really modeled the actual cubesat structure yet), but this high resistance of the tether is really going to need some looking at...
Bob, WB4APR
Cubesat HF experiment:
We have revised our HF satellite experiment proposal to be a CW
telemetry
beacon on 40, 20, 15 and 10 meter bands. The experiment will last only
a
few days, since the deployed 1000m tether will have so much drag, we
will
de-orbit in only a few days.
The idea is a keyed CW oscillator on 7.010 MHz with harmonics on 14.020, 21.030 and 28.040 MHz. These bands are all in the IARU Satelilte allocation. We will filter all harmonics above 28 MHz.
The challenge will be how to feed a 1000m long wire from only a 4"x4"x7" counterpoise (on all bands). transformer coupling?
The tether will be vertical and can act as a long wire antenna with a
very
narrow cone angle pointed straight down. Antenna gain will be more than
10
dB on all bands. This moving donut gain pattern sweeping across the
earth
should pose some interesting reception reports (If any of it gets
through
the ionosphere).
Launch Opportunity no earlier than March 2012. Putting us closer and
closer
to the Solar Max which would be the worst time for this experiment.
Other than a nice AMSAT experiment, if anyone can use this for valid ionosphereic science, come join us.
Bob, WB4APR
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
-- KK6MC James Duffey Cedar Crest NM
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
participants (6)
-
Bob Bruninga -
i8cvs -
James Duffey -
Joe -
John Heath -
Nick Pugh K5QXJ