Dear All,
I have been experimenting with AO-92 as from its launch. Some observations:
1) The fading on this bird seems to be high and quite unpredictable, requires a lot of changes of polarization to keep the Rx signal to an adequate level.
2) Seems that the fading is both on the U/V and L-mode, more seems to me that the uplink is more affected.
3) Telemetry seems to be quite reliable with FoxTelem in all modes.
Today, it was even worse losing the bird many times during the pass, it seems that it is degrading quite quickly, hope that this is not the case.
Just to share my observation.
73
Jean Marc (3B8du)
All of the Fox-1 satellites seem to spin faster or slower depending on orbit illumination or other factors.
For example, this is the +Z panel rotation on AO-92 since launch.
Someone more well-versed in these matters can comment further on what causes this, but it is definitely not an indication of the health status of the satellite.
73,
Paul, N8HM
On Tue, Mar 27, 2018 at 1:59 PM, Jean Marc Momple [email protected] wrote:
Dear All,
I have been experimenting with AO-92 as from its launch. Some observations:
The fading on this bird seems to be high and quite unpredictable, requires a lot of changes of polarization to keep the Rx signal to an adequate level.
Seems that the fading is both on the U/V and L-mode, more seems to me that the uplink is more affected.
Telemetry seems to be quite reliable with FoxTelem in all modes.
Today, it was even worse losing the bird many times during the pass, it seems that it is degrading quite quickly, hope that this is not the case.
Just to share my observation.
73
Jean Marc (3B8du)
Sent via [email protected]. AMSAT-NA makes this open forum available to all interested persons worldwide without requiring membership. Opinions expressed are solely those of the author, and do not reflect the official views of AMSAT-NA. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb
If you have seen a model or picture of the Fox satellites, you may have noticed that some of the solar panels seem to be mounted off-center. This is intentional so that photons that reflect off the shiny side give it a tiny off-center push that spins the bird to distribute the heat more evenly. Thus it spins faster the more time it spends in the sun. In addition, when it crosses the equator, it should flip over (-Z and +Z reverse sides). This is because of the passive magnetic stabilization. But I'm guessing that since it is spinning, that causes it to wobble.
Why 92 seems worse I don't know--I can only assume it has something to do with the orbit. That graph that Paul posted looks very different from AO-85, for example.
Some RF person can correct me, but I believe that the 70cm antenna only uses the antenna that sticks out one side, while the 2m antenna actually uses the antennas on both sides. Could that explain why the uplink has more fading than the downlink? I don't know. Something to think about.
73,
Burns WB1FJ Fox-1 Flight Software
On Tue, Mar 27, 2018 at 2:12 PM, Paul Stoetzer [email protected] wrote:
All of the Fox-1 satellites seem to spin faster or slower depending on orbit illumination or other factors.
For example, this is the +Z panel rotation on AO-92 since launch.
Someone more well-versed in these matters can comment further on what causes this, but it is definitely not an indication of the health status of the satellite.
73,
Paul, N8HM
On Tue, Mar 27, 2018 at 1:59 PM, Jean Marc Momple [email protected] wrote:
Dear All,
I have been experimenting with AO-92 as from its launch. Some
observations:
- The fading on this bird seems to be high and quite unpredictable,
requires a lot of changes of polarization to keep the Rx signal to an adequate level.
- Seems that the fading is both on the U/V and L-mode, more seems to me
that the uplink is more affected.
- Telemetry seems to be quite reliable with FoxTelem in all modes.
Today, it was even worse losing the bird many times during the pass, it
seems that it is degrading quite quickly, hope that this is not the case.
Just to share my observation.
73
Jean Marc (3B8du)
Sent via [email protected]. AMSAT-NA makes this open forum available to all interested persons worldwide without requiring membership.
Opinions expressed
are solely those of the author, and do not reflect the official views of
AMSAT-NA.
Not an AMSAT-NA member? Join now to support the amateur satellite
program!
Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb
Sent via [email protected]. AMSAT-NA makes this open forum available to all interested persons worldwide without requiring membership. Opinions expressed are solely those of the author, and do not reflect the official views of AMSAT-NA. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb
One of the questions I have is why one would think that the uplink (polarization) is a problem since you only have the downlink to assess and how would you differentiate between uplink "weakness" from downlink since that is the only thing you hear. In addition, at least for uplink, you could "in principle" very quickly adjust with higher power... and no, I am NOT promoting crocodile behavior (big mouth little ears)
Stefan, VE4NSA
On Tue, Mar 27, 2018 at 2:26 PM, Burns Fisher [email protected] wrote:
If you have seen a model or picture of the Fox satellites, you may have noticed that some of the solar panels seem to be mounted off-center. This is intentional so that photons that reflect off the shiny side give it a tiny off-center push that spins the bird to distribute the heat more evenly. Thus it spins faster the more time it spends in the sun. In addition, when it crosses the equator, it should flip over (-Z and +Z reverse sides). This is because of the passive magnetic stabilization. But I'm guessing that since it is spinning, that causes it to wobble.
Why 92 seems worse I don't know--I can only assume it has something to do with the orbit. That graph that Paul posted looks very different from AO-85, for example.
Some RF person can correct me, but I believe that the 70cm antenna only uses the antenna that sticks out one side, while the 2m antenna actually uses the antennas on both sides. Could that explain why the uplink has more fading than the downlink? I don't know. Something to think about.
73,
Burns WB1FJ Fox-1 Flight Software
On Tue, Mar 27, 2018 at 2:12 PM, Paul Stoetzer [email protected] wrote:
All of the Fox-1 satellites seem to spin faster or slower depending on orbit illumination or other factors.
For example, this is the +Z panel rotation on AO-92 since launch.
Someone more well-versed in these matters can comment further on what causes this, but it is definitely not an indication of the health status of the satellite.
73,
Paul, N8HM
On Tue, Mar 27, 2018 at 1:59 PM, Jean Marc Momple [email protected] wrote:
Dear All,
I have been experimenting with AO-92 as from its launch. Some
observations:
- The fading on this bird seems to be high and quite unpredictable,
requires a lot of changes of polarization to keep the Rx signal to an adequate level.
- Seems that the fading is both on the U/V and L-mode, more seems to
me
that the uplink is more affected.
- Telemetry seems to be quite reliable with FoxTelem in all modes.
Today, it was even worse losing the bird many times during the pass, it
seems that it is degrading quite quickly, hope that this is not the case.
Just to share my observation.
73
Jean Marc (3B8du)
Sent via [email protected]. AMSAT-NA makes this open forum available to all interested persons worldwide without requiring membership.
Opinions expressed
are solely those of the author, and do not reflect the official views
of
AMSAT-NA.
Not an AMSAT-NA member? Join now to support the amateur satellite
program!
Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb
Sent via [email protected]. AMSAT-NA makes this open forum available to all interested persons worldwide without requiring membership.
Opinions
expressed are solely those of the author, and do not reflect the official views of AMSAT-NA. Not an AMSAT-NA member? Join now to support the amateur satellite
program!
Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb
Sent via [email protected]. AMSAT-NA makes this open forum available to all interested persons worldwide without requiring membership. Opinions expressed are solely those of the author, and do not reflect the official views of AMSAT-NA. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb
You can hear your own signal if you have a full duplex (two radio) setup. However, it's still pretty hard to tell if you use a single antenna (arrow, elk, etc) since you're changing the RX polarity while you're changing the TX polarity too.
On Tue, Mar 27, 2018 at 7:22 PM, Stefan Wagener [email protected] wrote:
One of the questions I have is why one would think that the uplink (polarization) is a problem since you only have the downlink to assess and how would you differentiate between uplink "weakness" from downlink since that is the only thing you hear. In addition, at least for uplink, you could "in principle" very quickly adjust with higher power... and no, I am NOT promoting crocodile behavior (big mouth little ears)
Stefan, VE4NSA
On Tue, Mar 27, 2018 at 2:26 PM, Burns Fisher [email protected] wrote:
If you have seen a model or picture of the Fox satellites, you may have noticed that some of the solar panels seem to be mounted off-center.
This
is intentional so that photons that reflect off the shiny side give it a tiny off-center push that spins the bird to distribute the heat more evenly. Thus it spins faster the more time it spends in the sun. In addition, when it crosses the equator, it should flip over (-Z and +Z reverse sides). This is because of the passive magnetic stabilization. But I'm guessing that since it is spinning, that causes it to wobble.
Why 92 seems worse I don't know--I can only assume it has something to do with the orbit. That graph that Paul posted looks very different from AO-85, for example.
Some RF person can correct me, but I believe that the 70cm antenna only uses the antenna that sticks out one side, while the 2m antenna actually uses the antennas on both sides. Could that explain why the uplink has more fading than the downlink? I don't know. Something to think about.
73,
Burns WB1FJ Fox-1 Flight Software
On Tue, Mar 27, 2018 at 2:12 PM, Paul Stoetzer [email protected] wrote:
All of the Fox-1 satellites seem to spin faster or slower depending on orbit illumination or other factors.
For example, this is the +Z panel rotation on AO-92 since launch.
Someone more well-versed in these matters can comment further on what causes this, but it is definitely not an indication of the health status of the satellite.
73,
Paul, N8HM
On Tue, Mar 27, 2018 at 1:59 PM, Jean Marc Momple [email protected] wrote:
Dear All,
I have been experimenting with AO-92 as from its launch. Some
observations:
- The fading on this bird seems to be high and quite unpredictable,
requires a lot of changes of polarization to keep the Rx signal to an adequate level.
- Seems that the fading is both on the U/V and L-mode, more seems to
me
that the uplink is more affected.
- Telemetry seems to be quite reliable with FoxTelem in all modes.
Today, it was even worse losing the bird many times during the pass,
it
seems that it is degrading quite quickly, hope that this is not the
case.
Just to share my observation.
73
Jean Marc (3B8du)
Sent via [email protected]. AMSAT-NA makes this open forum
available
to all interested persons worldwide without requiring membership.
Opinions expressed
are solely those of the author, and do not reflect the official views
of
AMSAT-NA.
Not an AMSAT-NA member? Join now to support the amateur satellite
program!
Subscription settings: http://www.amsat.org/mailman/
listinfo/amsat-bb
Sent via [email protected]. AMSAT-NA makes this open forum available to all interested persons worldwide without requiring membership.
Opinions
expressed are solely those of the author, and do not reflect the official views
of
AMSAT-NA. Not an AMSAT-NA member? Join now to support the amateur satellite
program!
Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb
Sent via [email protected]. AMSAT-NA makes this open forum available to all interested persons worldwide without requiring membership.
Opinions
expressed are solely those of the author, and do not reflect the official views of AMSAT-NA. Not an AMSAT-NA member? Join now to support the amateur satellite
program!
Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb
Sent via [email protected]. AMSAT-NA makes this open forum available to all interested persons worldwide without requiring membership. Opinions expressed are solely those of the author, and do not reflect the official views of AMSAT-NA. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb
Thanks,
Again, even in full duplex how do you distinguish between a non-matching uplink vs non-matching downlink? You only "hear" the downlink!
73, Stefan VE4NSA
On Tue, Mar 27, 2018 at 8:38 PM, Sterling Coffey [email protected] wrote:
You can hear your own signal if you have a full duplex (two radio) setup. However, it's still pretty hard to tell if you use a single antenna (arrow, elk, etc) since you're changing the RX polarity while you're changing the TX polarity too.
On Tue, Mar 27, 2018 at 7:22 PM, Stefan Wagener [email protected] wrote:
One of the questions I have is why one would think that the uplink (polarization) is a problem since you only have the downlink to assess and how would you differentiate between uplink "weakness" from downlink since that is the only thing you hear. In addition, at least for uplink, you could "in principle" very quickly adjust with higher power... and no, I am NOT promoting crocodile behavior (big mouth little ears)
Stefan, VE4NSA
On Tue, Mar 27, 2018 at 2:26 PM, Burns Fisher [email protected] wrote:
If you have seen a model or picture of the Fox satellites, you may have noticed that some of the solar panels seem to be mounted off-center.
This
is intentional so that photons that reflect off the shiny side give it a tiny off-center push that spins the bird to distribute the heat more evenly. Thus it spins faster the more time it spends in the sun. In addition, when it crosses the equator, it should flip over (-Z and +Z reverse sides). This is because of the passive magnetic stabilization. But I'm guessing that since it is spinning, that causes it to wobble.
Why 92 seems worse I don't know--I can only assume it has something to
do
with the orbit. That graph that Paul posted looks very different from AO-85, for example.
Some RF person can correct me, but I believe that the 70cm antenna only uses the antenna that sticks out one side, while the 2m antenna actually uses the antennas on both sides. Could that explain why the uplink has more fading than the downlink? I don't know. Something to think about.
73,
Burns WB1FJ Fox-1 Flight Software
On Tue, Mar 27, 2018 at 2:12 PM, Paul Stoetzer [email protected] wrote:
All of the Fox-1 satellites seem to spin faster or slower depending on orbit illumination or other factors.
For example, this is the +Z panel rotation on AO-92 since launch.
Someone more well-versed in these matters can comment further on what causes this, but it is definitely not an indication of the health status of the satellite.
73,
Paul, N8HM
On Tue, Mar 27, 2018 at 1:59 PM, Jean Marc Momple [email protected] wrote:
Dear All,
I have been experimenting with AO-92 as from its launch. Some
observations:
- The fading on this bird seems to be high and quite unpredictable,
requires a lot of changes of polarization to keep the Rx signal to an adequate level.
- Seems that the fading is both on the U/V and L-mode, more seems
to
me
that the uplink is more affected.
- Telemetry seems to be quite reliable with FoxTelem in all modes.
Today, it was even worse losing the bird many times during the
pass, it
seems that it is degrading quite quickly, hope that this is not the
case.
Just to share my observation.
73
Jean Marc (3B8du)
Sent via [email protected]. AMSAT-NA makes this open forum
available
to all interested persons worldwide without requiring membership.
Opinions expressed
are solely those of the author, and do not reflect the official
views
of
AMSAT-NA.
Not an AMSAT-NA member? Join now to support the amateur satellite
program!
Subscription settings: http://www.amsat.org/mailman/l
istinfo/amsat-bb
Sent via [email protected]. AMSAT-NA makes this open forum available to all interested persons worldwide without requiring membership.
Opinions
expressed are solely those of the author, and do not reflect the official views
of
AMSAT-NA. Not an AMSAT-NA member? Join now to support the amateur satellite
program!
Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb
Sent via [email protected]. AMSAT-NA makes this open forum available to all interested persons worldwide without requiring membership.
Opinions
expressed are solely those of the author, and do not reflect the official views of AMSAT-NA. Not an AMSAT-NA member? Join now to support the amateur satellite
program!
Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb
Sent via [email protected]. AMSAT-NA makes this open forum available to all interested persons worldwide without requiring membership. Opinions expressed are solely those of the author, and do not reflect the official views of AMSAT-NA. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb
If linear polarized, if you can keep your RX/downlink antenna still and you can at least hear the satellite, and rotating your TX/uplink antenna results in correlated signal level changes on the RX/downlink, then you've isolated it to the uplink polarization variable.
On Tue, Mar 27, 2018 at 8:44 PM, Stefan Wagener [email protected] wrote:
Thanks,
Again, even in full duplex how do you distinguish between a non-matching uplink vs non-matching downlink? You only "hear" the downlink!
73, Stefan VE4NSA
On Tue, Mar 27, 2018 at 8:38 PM, Sterling Coffey [email protected] wrote:
You can hear your own signal if you have a full duplex (two radio) setup. However, it's still pretty hard to tell if you use a single antenna (arrow, elk, etc) since you're changing the RX polarity while you're changing the TX polarity too.
On Tue, Mar 27, 2018 at 7:22 PM, Stefan Wagener [email protected] wrote:
One of the questions I have is why one would think that the uplink (polarization) is a problem since you only have the downlink to assess and how would you differentiate between uplink "weakness" from downlink since that is the only thing you hear. In addition, at least for uplink, you could "in principle" very quickly adjust with higher power... and no, I am NOT promoting crocodile behavior (big mouth little ears)
Stefan, VE4NSA
On Tue, Mar 27, 2018 at 2:26 PM, Burns Fisher [email protected] wrote:
If you have seen a model or picture of the Fox satellites, you may have noticed that some of the solar panels seem to be mounted off-center.
This
is intentional so that photons that reflect off the shiny side give it
a
tiny off-center push that spins the bird to distribute the heat more evenly. Thus it spins faster the more time it spends in the sun. In addition, when it crosses the equator, it should flip over (-Z and +Z reverse sides). This is because of the passive magnetic stabilization. But I'm guessing that since it is spinning, that causes it to wobble.
Why 92 seems worse I don't know--I can only assume it has something to
do
with the orbit. That graph that Paul posted looks very different from AO-85, for example.
Some RF person can correct me, but I believe that the 70cm antenna only uses the antenna that sticks out one side, while the 2m antenna
actually
uses the antennas on both sides. Could that explain why the uplink has more fading than the downlink? I don't know. Something to think
about.
73,
Burns WB1FJ Fox-1 Flight Software
On Tue, Mar 27, 2018 at 2:12 PM, Paul Stoetzer [email protected] wrote:
All of the Fox-1 satellites seem to spin faster or slower depending
on
orbit illumination or other factors.
For example, this is the +Z panel rotation on AO-92 since launch.
Someone more well-versed in these matters can comment further on what causes this, but it is definitely not an indication of the health status of the satellite.
73,
Paul, N8HM
On Tue, Mar 27, 2018 at 1:59 PM, Jean Marc Momple [email protected] wrote:
Dear All,
I have been experimenting with AO-92 as from its launch. Some
observations:
- The fading on this bird seems to be high and quite
unpredictable,
requires a lot of changes of polarization to keep the Rx signal to
an
adequate level.
- Seems that the fading is both on the U/V and L-mode, more seems
to
me
that the uplink is more affected.
- Telemetry seems to be quite reliable with FoxTelem in all modes.
Today, it was even worse losing the bird many times during the
pass, it
seems that it is degrading quite quickly, hope that this is not the
case.
Just to share my observation.
73
Jean Marc (3B8du)
Sent via [email protected]. AMSAT-NA makes this open forum
available
to all interested persons worldwide without requiring membership.
Opinions expressed
are solely those of the author, and do not reflect the official
views
of
AMSAT-NA.
Not an AMSAT-NA member? Join now to support the amateur satellite
program!
Subscription settings: http://www.amsat.org/mailman/l
istinfo/amsat-bb
Sent via [email protected]. AMSAT-NA makes this open forum
available
to all interested persons worldwide without requiring membership.
Opinions
expressed are solely those of the author, and do not reflect the official
views of
AMSAT-NA. Not an AMSAT-NA member? Join now to support the amateur satellite
program!
Subscription settings: http://www.amsat.org/mailman/l
istinfo/amsat-bb
Sent via [email protected]. AMSAT-NA makes this open forum available to all interested persons worldwide without requiring membership.
Opinions
expressed are solely those of the author, and do not reflect the official views
of
AMSAT-NA. Not an AMSAT-NA member? Join now to support the amateur satellite
program!
Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb
Sent via [email protected]. AMSAT-NA makes this open forum available to all interested persons worldwide without requiring membership. Opinions expressed are solely those of the author, and do not reflect the official views of AMSAT-NA. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb
Hi Sterling,
That would assume you have the ability to switch between linear uplink polarization (vertical and horizontal) and circular polarisation for uplink (right and left) and keep you downlink polarization on the same optimized path all the time, meaning you know in advance which way the downlink signal is the best to compensate for any uplink discrepancies. Good luck :-)
But hanks, good thought!
Stefan, VE4NSA
On Tue, Mar 27, 2018 at 8:47 PM, Sterling Coffey [email protected] wrote:
If linear polarized, if you can keep your RX/downlink antenna still and you can at least hear the satellite, and rotating your TX/uplink antenna results in correlated signal level changes on the RX/downlink, then you've isolated it to the uplink polarization variable.
On Tue, Mar 27, 2018 at 8:44 PM, Stefan Wagener [email protected] wrote:
Thanks,
Again, even in full duplex how do you distinguish between a non-matching uplink vs non-matching downlink? You only "hear" the downlink!
73, Stefan VE4NSA
On Tue, Mar 27, 2018 at 8:38 PM, Sterling Coffey [email protected] wrote:
You can hear your own signal if you have a full duplex (two radio) setup. However, it's still pretty hard to tell if you use a single antenna (arrow, elk, etc) since you're changing the RX polarity while you're changing the TX polarity too.
On Tue, Mar 27, 2018 at 7:22 PM, Stefan Wagener [email protected] wrote:
One of the questions I have is why one would think that the uplink (polarization) is a problem since you only have the downlink to assess and how would you differentiate between uplink "weakness" from downlink since that is the only thing you hear. In addition, at least for uplink, you could "in principle" very quickly adjust with higher power... and no, I am NOT promoting crocodile behavior (big mouth little ears)
Stefan, VE4NSA
On Tue, Mar 27, 2018 at 2:26 PM, Burns Fisher [email protected] wrote:
If you have seen a model or picture of the Fox satellites, you may
have
noticed that some of the solar panels seem to be mounted off-center.
This
is intentional so that photons that reflect off the shiny side give
it a
tiny off-center push that spins the bird to distribute the heat more evenly. Thus it spins faster the more time it spends in the sun. In addition, when it crosses the equator, it should flip over (-Z and +Z reverse sides). This is because of the passive magnetic
stabilization.
But I'm guessing that since it is spinning, that causes it to wobble.
Why 92 seems worse I don't know--I can only assume it has something
to do
with the orbit. That graph that Paul posted looks very different from AO-85, for example.
Some RF person can correct me, but I believe that the 70cm antenna
only
uses the antenna that sticks out one side, while the 2m antenna
actually
uses the antennas on both sides. Could that explain why the uplink
has
more fading than the downlink? I don't know. Something to think
about.
73,
Burns WB1FJ Fox-1 Flight Software
On Tue, Mar 27, 2018 at 2:12 PM, Paul Stoetzer [email protected] wrote:
All of the Fox-1 satellites seem to spin faster or slower depending
on
orbit illumination or other factors.
For example, this is the +Z panel rotation on AO-92 since launch.
Someone more well-versed in these matters can comment further on
what
causes this, but it is definitely not an indication of the health status of the satellite.
73,
Paul, N8HM
On Tue, Mar 27, 2018 at 1:59 PM, Jean Marc Momple [email protected] wrote: > Dear All, > > I have been experimenting with AO-92 as from its launch. Some observations: > > 1) The fading on this bird seems to be high and quite
unpredictable,
requires a lot of changes of polarization to keep the Rx signal to
an
adequate level. > > 2) Seems that the fading is both on the U/V and L-mode, more
seems to
me
that the uplink is more affected. > > 3) Telemetry seems to be quite reliable with FoxTelem in all
modes.
> > Today, it was even worse losing the bird many times during the
pass, it
seems that it is degrading quite quickly, hope that this is not the
case.
> > Just to share my observation. > > 73 > > > Jean Marc (3B8du) > > > _______________________________________________ > Sent via [email protected]. AMSAT-NA makes this open forum
available
> to all interested persons worldwide without requiring membership. Opinions expressed > are solely those of the author, and do not reflect the official
views
of
AMSAT-NA. > Not an AMSAT-NA member? Join now to support the amateur satellite program! > Subscription settings: http://www.amsat.org/mailman/l
istinfo/amsat-bb
Sent via [email protected]. AMSAT-NA makes this open forum
available
to all interested persons worldwide without requiring membership.
Opinions
expressed are solely those of the author, and do not reflect the official
views of
AMSAT-NA. Not an AMSAT-NA member? Join now to support the amateur satellite
program!
Subscription settings: http://www.amsat.org/mailman/l
istinfo/amsat-bb
Sent via [email protected]. AMSAT-NA makes this open forum available to all interested persons worldwide without requiring membership.
Opinions
expressed are solely those of the author, and do not reflect the official views
of
AMSAT-NA. Not an AMSAT-NA member? Join now to support the amateur satellite
program!
Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb
Sent via [email protected]. AMSAT-NA makes this open forum available to all interested persons worldwide without requiring membership. Opinions expressed are solely those of the author, and do not reflect the official views of AMSAT-NA. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb
I'm specifically thinking of handheld linear antennas; I'm pretty sure you can rotate the RX antenna pol for "maximum smoke" and then the TX antenna faster than the tumbling rate of the satellite just to get an idea of which path is being affected.
This is a moot point though, most of us use Arrow antennas anyway!
On Tue, Mar 27, 2018 at 8:54 PM, Stefan Wagener [email protected] wrote:
Hi Sterling,
That would assume you have the ability to switch between linear uplink polarization (vertical and horizontal) and circular polarisation for uplink (right and left) and keep you downlink polarization on the same optimized path all the time, meaning you know in advance which way the downlink signal is the best to compensate for any uplink discrepancies. Good luck :-)
But hanks, good thought!
Stefan, VE4NSA
On Tue, Mar 27, 2018 at 8:47 PM, Sterling Coffey [email protected] wrote:
If linear polarized, if you can keep your RX/downlink antenna still and you can at least hear the satellite, and rotating your TX/uplink antenna results in correlated signal level changes on the RX/downlink, then you've isolated it to the uplink polarization variable.
On Tue, Mar 27, 2018 at 8:44 PM, Stefan Wagener [email protected] wrote:
Thanks,
Again, even in full duplex how do you distinguish between a non-matching uplink vs non-matching downlink? You only "hear" the downlink!
73, Stefan VE4NSA
On Tue, Mar 27, 2018 at 8:38 PM, Sterling Coffey [email protected] wrote:
You can hear your own signal if you have a full duplex (two radio) setup. However, it's still pretty hard to tell if you use a single antenna (arrow, elk, etc) since you're changing the RX polarity while you're changing the TX polarity too.
On Tue, Mar 27, 2018 at 7:22 PM, Stefan Wagener [email protected] wrote:
One of the questions I have is why one would think that the uplink (polarization) is a problem since you only have the downlink to assess and how would you differentiate between uplink "weakness" from downlink since that is the only thing you hear. In addition, at least for uplink, you could "in principle" very quickly adjust with higher power... and no, I am NOT promoting crocodile behavior (big mouth little ears)
Stefan, VE4NSA
On Tue, Mar 27, 2018 at 2:26 PM, Burns Fisher [email protected] wrote:
If you have seen a model or picture of the Fox satellites, you may
have
noticed that some of the solar panels seem to be mounted
off-center. This
is intentional so that photons that reflect off the shiny side give
it a
tiny off-center push that spins the bird to distribute the heat more evenly. Thus it spins faster the more time it spends in the sun. In addition, when it crosses the equator, it should flip over (-Z and +Z reverse sides). This is because of the passive magnetic
stabilization.
But I'm guessing that since it is spinning, that causes it to wobble.
Why 92 seems worse I don't know--I can only assume it has something
to do
with the orbit. That graph that Paul posted looks very different
from
AO-85, for example.
Some RF person can correct me, but I believe that the 70cm antenna
only
uses the antenna that sticks out one side, while the 2m antenna
actually
uses the antennas on both sides. Could that explain why the uplink
has
more fading than the downlink? I don't know. Something to think
about.
73,
Burns WB1FJ Fox-1 Flight Software
On Tue, Mar 27, 2018 at 2:12 PM, Paul Stoetzer [email protected]
wrote:
> All of the Fox-1 satellites seem to spin faster or slower
depending on
> orbit illumination or other factors. > > For example, this is the +Z panel rotation on AO-92 since launch. > > https://imgur.com/a/uS8TB > > Someone more well-versed in these matters can comment further on
what
> causes this, but it is definitely not an indication of the health > status of the satellite. > > 73, > > Paul, N8HM > > On Tue, Mar 27, 2018 at 1:59 PM, Jean Marc Momple > [email protected] wrote: > > Dear All, > > > > I have been experimenting with AO-92 as from its launch. Some > observations: > > > > 1) The fading on this bird seems to be high and quite
unpredictable,
> requires a lot of changes of polarization to keep the Rx signal
to an
> adequate level. > > > > 2) Seems that the fading is both on the U/V and L-mode, more
seems to
me > that the uplink is more affected. > > > > 3) Telemetry seems to be quite reliable with FoxTelem in all
modes.
> > > > Today, it was even worse losing the bird many times during the
pass, it
> seems that it is degrading quite quickly, hope that this is not
the case.
> > > > Just to share my observation. > > > > 73 > > > > > > Jean Marc (3B8du) > > > > > > _______________________________________________ > > Sent via [email protected]. AMSAT-NA makes this open forum
available
> > to all interested persons worldwide without requiring membership. > Opinions expressed > > are solely those of the author, and do not reflect the official
views
of > AMSAT-NA. > > Not an AMSAT-NA member? Join now to support the amateur satellite > program! > > Subscription settings: http://www.amsat.org/mailman/l
istinfo/amsat-bb
> _______________________________________________ > Sent via [email protected]. AMSAT-NA makes this open forum
available
> to all interested persons worldwide without requiring membership. Opinions > expressed > are solely those of the author, and do not reflect the official
views of
> AMSAT-NA. > Not an AMSAT-NA member? Join now to support the amateur satellite program! > Subscription settings: http://www.amsat.org/mailman/l
istinfo/amsat-bb
> _______________________________________________ Sent via [email protected]. AMSAT-NA makes this open forum
available
to all interested persons worldwide without requiring membership.
Opinions
expressed are solely those of the author, and do not reflect the official
views of
AMSAT-NA. Not an AMSAT-NA member? Join now to support the amateur satellite
program!
Subscription settings: http://www.amsat.org/mailman/l
istinfo/amsat-bb
Sent via [email protected]. AMSAT-NA makes this open forum available to all interested persons worldwide without requiring membership. Opinions expressed are solely those of the author, and do not reflect the official views of AMSAT-NA. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb
On 03/27/18 20:44, Stefan Wagener wrote:
Thanks,
Again, even in full duplex how do you distinguish between a non-matching uplink vs non-matching downlink? You only "hear" the downlink!
I suppose that, if you had really good antennas and preamps, you might be able to hear your reflected uplink signal, no? :-)
--- Zach N0ZGO
The telemetry nuts should have some idea. Independent of any uplink. Good SDR recording exercise and study.
Mark N8MH
On Tue, Mar 27, 2018 at 9:41 PM Sterling Coffey [email protected] wrote:
You can hear your own signal if you have a full duplex (two radio) setup. However, it's still pretty hard to tell if you use a single antenna (arrow, elk, etc) since you're changing the RX polarity while you're changing the TX polarity too.
On Tue, Mar 27, 2018 at 7:22 PM, Stefan Wagener [email protected] wrote:
One of the questions I have is why one would think that the uplink (polarization) is a problem since you only have the downlink to assess
and
how would you differentiate between uplink "weakness" from downlink since that is the only thing you hear. In addition, at least for uplink, you could "in principle" very quickly adjust with higher power... and no, I
am
NOT promoting crocodile behavior (big mouth little ears)
Stefan, VE4NSA
On Tue, Mar 27, 2018 at 2:26 PM, Burns Fisher [email protected] wrote:
If you have seen a model or picture of the Fox satellites, you may have noticed that some of the solar panels seem to be mounted off-center.
This
is intentional so that photons that reflect off the shiny side give it
a
tiny off-center push that spins the bird to distribute the heat more evenly. Thus it spins faster the more time it spends in the sun. In addition, when it crosses the equator, it should flip over (-Z and +Z reverse sides). This is because of the passive magnetic stabilization. But I'm guessing that since it is spinning, that causes it to wobble.
Why 92 seems worse I don't know--I can only assume it has something to
do
with the orbit. That graph that Paul posted looks very different from AO-85, for example.
Some RF person can correct me, but I believe that the 70cm antenna only uses the antenna that sticks out one side, while the 2m antenna
actually
uses the antennas on both sides. Could that explain why the uplink has more fading than the downlink? I don't know. Something to think
about.
73,
Burns WB1FJ Fox-1 Flight Software
On Tue, Mar 27, 2018 at 2:12 PM, Paul Stoetzer [email protected] wrote:
All of the Fox-1 satellites seem to spin faster or slower depending
on
orbit illumination or other factors.
For example, this is the +Z panel rotation on AO-92 since launch.
Someone more well-versed in these matters can comment further on what causes this, but it is definitely not an indication of the health status of the satellite.
73,
Paul, N8HM
On Tue, Mar 27, 2018 at 1:59 PM, Jean Marc Momple [email protected] wrote:
Dear All,
I have been experimenting with AO-92 as from its launch. Some
observations:
- The fading on this bird seems to be high and quite
unpredictable,
requires a lot of changes of polarization to keep the Rx signal to
an
adequate level.
- Seems that the fading is both on the U/V and L-mode, more seems
to
me
that the uplink is more affected.
- Telemetry seems to be quite reliable with FoxTelem in all modes.
Today, it was even worse losing the bird many times during the
pass,
it
seems that it is degrading quite quickly, hope that this is not the
case.
Just to share my observation.
73
Jean Marc (3B8du)
Sent via [email protected]. AMSAT-NA makes this open forum
available
to all interested persons worldwide without requiring membership.
Opinions expressed
are solely those of the author, and do not reflect the official
views
of
AMSAT-NA.
Not an AMSAT-NA member? Join now to support the amateur satellite
program!
Subscription settings: http://www.amsat.org/mailman/
listinfo/amsat-bb
Sent via [email protected]. AMSAT-NA makes this open forum
available
to all interested persons worldwide without requiring membership.
Opinions
expressed are solely those of the author, and do not reflect the official views
of
AMSAT-NA. Not an AMSAT-NA member? Join now to support the amateur satellite
program!
Subscription settings:
http://www.amsat.org/mailman/listinfo/amsat-bb
Sent via [email protected]. AMSAT-NA makes this open forum available to all interested persons worldwide without requiring membership.
Opinions
expressed are solely those of the author, and do not reflect the official views
of
AMSAT-NA. Not an AMSAT-NA member? Join now to support the amateur satellite
program!
Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb
Sent via [email protected]. AMSAT-NA makes this open forum available to all interested persons worldwide without requiring membership.
Opinions
expressed are solely those of the author, and do not reflect the official views of AMSAT-NA. Not an AMSAT-NA member? Join now to support the amateur satellite
program!
Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb
Sent via [email protected]. AMSAT-NA makes this open forum available to all interested persons worldwide without requiring membership. Opinions expressed are solely those of the author, and do not reflect the official views of AMSAT-NA. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb
Thanks Mark!
Even a good SDR recording exercise only captures the downlink :-)
Stefran
On Tue, Mar 27, 2018 at 8:46 PM, Mark L. Hammond [email protected] wrote:
The telemetry nuts should have some idea. Independent of any uplink. Good SDR recording exercise and study.
Mark N8MH
On Tue, Mar 27, 2018 at 9:41 PM Sterling Coffey [email protected] wrote:
You can hear your own signal if you have a full duplex (two radio) setup. However, it's still pretty hard to tell if you use a single antenna (arrow, elk, etc) since you're changing the RX polarity while you're changing the TX polarity too.
On Tue, Mar 27, 2018 at 7:22 PM, Stefan Wagener [email protected] wrote:
One of the questions I have is why one would think that the uplink (polarization) is a problem since you only have the downlink to assess
and
how would you differentiate between uplink "weakness" from downlink
since
that is the only thing you hear. In addition, at least for uplink, you could "in principle" very quickly adjust with higher power... and no, I
am
NOT promoting crocodile behavior (big mouth little ears)
Stefan, VE4NSA
On Tue, Mar 27, 2018 at 2:26 PM, Burns Fisher [email protected] wrote:
If you have seen a model or picture of the Fox satellites, you may
have
noticed that some of the solar panels seem to be mounted off-center.
This
is intentional so that photons that reflect off the shiny side give
it a
tiny off-center push that spins the bird to distribute the heat more evenly. Thus it spins faster the more time it spends in the sun. In addition, when it crosses the equator, it should flip over (-Z and +Z reverse sides). This is because of the passive magnetic
stabilization.
But I'm guessing that since it is spinning, that causes it to wobble.
Why 92 seems worse I don't know--I can only assume it has something
to do
with the orbit. That graph that Paul posted looks very different from AO-85, for example.
Some RF person can correct me, but I believe that the 70cm antenna
only
uses the antenna that sticks out one side, while the 2m antenna
actually
uses the antennas on both sides. Could that explain why the uplink
has
more fading than the downlink? I don't know. Something to think
about.
73,
Burns WB1FJ Fox-1 Flight Software
On Tue, Mar 27, 2018 at 2:12 PM, Paul Stoetzer [email protected] wrote:
All of the Fox-1 satellites seem to spin faster or slower depending
on
orbit illumination or other factors.
For example, this is the +Z panel rotation on AO-92 since launch.
Someone more well-versed in these matters can comment further on
what
causes this, but it is definitely not an indication of the health status of the satellite.
73,
Paul, N8HM
On Tue, Mar 27, 2018 at 1:59 PM, Jean Marc Momple [email protected] wrote:
Dear All,
I have been experimenting with AO-92 as from its launch. Some
observations:
- The fading on this bird seems to be high and quite
unpredictable,
requires a lot of changes of polarization to keep the Rx signal to
an
adequate level.
- Seems that the fading is both on the U/V and L-mode, more
seems to
me
that the uplink is more affected.
- Telemetry seems to be quite reliable with FoxTelem in all
modes.
Today, it was even worse losing the bird many times during the
pass,
it
seems that it is degrading quite quickly, hope that this is not the
case.
Just to share my observation.
73
Jean Marc (3B8du)
Sent via [email protected]. AMSAT-NA makes this open forum
available
to all interested persons worldwide without requiring membership.
Opinions expressed
are solely those of the author, and do not reflect the official
views
of
AMSAT-NA.
Not an AMSAT-NA member? Join now to support the amateur satellite
program!
Subscription settings: http://www.amsat.org/mailman/
listinfo/amsat-bb
Sent via [email protected]. AMSAT-NA makes this open forum
available
to all interested persons worldwide without requiring membership.
Opinions
expressed are solely those of the author, and do not reflect the official
views
of
AMSAT-NA. Not an AMSAT-NA member? Join now to support the amateur satellite
program!
Subscription settings: http://www.amsat.org/mailman/
listinfo/amsat-bb
Sent via [email protected]. AMSAT-NA makes this open forum available to all interested persons worldwide without requiring membership.
Opinions
expressed are solely those of the author, and do not reflect the official views
of
AMSAT-NA. Not an AMSAT-NA member? Join now to support the amateur satellite
program!
Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb
Sent via [email protected]. AMSAT-NA makes this open forum available to all interested persons worldwide without requiring membership.
Opinions
expressed are solely those of the author, and do not reflect the official views of AMSAT-NA. Not an AMSAT-NA member? Join now to support the amateur satellite
program!
Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb
Sent via [email protected]. AMSAT-NA makes this open forum available to all interested persons worldwide without requiring membership. Opinions expressed are solely those of the author, and do not reflect the official views of AMSAT-NA. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb
-- Mark L. Hammond [N8MH]
Good afternoon, I'm sorry that the question is not for you. Dear members of the group, tell us where you can buy used equipment for work through satellites. Thank you. 73 & GL.
On 3/27/18, Max [email protected] wrote:
Good afternoon, I'm sorry that the question is not for you. Dear members of the group, tell us where you can buy used equipment for work through satellites. Thank you. 73 & GL.
<snip>
I bought my FT-847 and IC-910 through this site:
http://www.kwarc.org/swapshop/
73s
Bernhard VA6BMJ @ DO33FL
Additionally ebay, QRZ, eHam, craigslist, hamfests, reddit.com/r/hamfest..all depends on what you need and what sats you want to work.
On Tue, Mar 27, 2018 at 3:57 PM, B J [email protected] wrote:
On 3/27/18, Max [email protected] wrote:
Good afternoon, I'm sorry that the question is not for you. Dear members of the group, tell us where you can buy used equipment for work through satellites. Thank you. 73 & GL.
<snip>
I bought my FT-847 and IC-910 through this site:
http://www.kwarc.org/swapshop/
73s
Bernhard VA6BMJ @ DO33FL _______________________________________________ Sent via [email protected]. AMSAT-NA makes this open forum available to all interested persons worldwide without requiring membership. Opinions expressed are solely those of the author, and do not reflect the official views of AMSAT-NA. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb
...and, of course, there is EBay...which some here love or hate, but which is the ONLY site that will give you buyer protection from scammers, parts pickers or just outright thieves. The times that I have had to use EBay's 'buyer protection' has been 100% effective ! THAT is a fact..
Now, start the EBay bashing net..
73, Ted K7TRK
-----Original Message----- From: AMSAT-BB [mailto:[email protected]] On Behalf Of Sterling Coffey Sent: Tuesday, March 27, 2018 2:00 PM To: B J Cc: AMSAT Subject: Re: [amsat-bb] Acquisition of equipment
Additionally ebay, QRZ, eHam, craigslist, hamfests, reddit.com/r/hamfest..all depends on what you need and what sats you want to work.
On Tue, Mar 27, 2018 at 3:57 PM, B J [email protected] wrote:
On 3/27/18, Max [email protected] wrote:
Good afternoon, I'm sorry that the question is not for you. Dear members of the group, tell us where you can buy used equipment for work through satellites. Thank you. 73 & GL.
<snip>
I bought my FT-847 and IC-910 through this site:
http://www.kwarc.org/swapshop/
73s
Bernhard VA6BMJ @ DO33FL _______________________________________________ Sent via [email protected]. AMSAT-NA makes this open forum available to all interested persons worldwide without requiring membership. Opinions expressed are solely those of the author, and do not reflect the official views of AMSAT-NA. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb
_______________________________________________ Sent via [email protected]. AMSAT-NA makes this open forum available to all interested persons worldwide without requiring membership. Opinions expressed are solely those of the author, and do not reflect the official views of AMSAT-NA. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb
participants (10)
-
B J -
Burns Fisher -
Jean Marc Momple -
Mark L. Hammond -
Max -
Paul Stoetzer -
Stefan Wagener -
Sterling Coffey -
Ted Krempa -
Zach Metzinger