SPOT messenger

Darryl Ramm wrote:

And to Martin's earlier comment, OK etc. does not always take 20
minutes to send, it might take up to that (or may never successfully
send) but you can see that messages often go out quicker than this.
I'm missing the point of the argument used, I use tracking becasue it
is convenient and I don't want to press buttons, not because I think a
track position report is more likely to get out than an OK report.

I also use tracking for these reasons. I do think an OK messages will
get out more reliably a tracking message, because OK messages have a 20
minute window to get out, versus the 10 minute window of the tracking
messages. All my OK messages have been sent, but an ocasional tracking
message isn't, sometimes two in a row.

--
Eric Greenwell - Washington State, USA
* Change "netto" to "net" to email me directly

* Updated! "Transponders in Sailplanes" http://tinyurl.com/y739x4
* New Jan '08 - sections on Mode S, TPAS, ADS-B, Flarm, more

* "A Guide to Self-launching Sailplane Operation" at www.motorglider.org

Matt Herron Jr. wrote:

Good summary Darryl, thanks. I agree with your search area opinions
as well. I assume it makes more sense to have the spot attached to
the chute rather than the plane for pretty much all situations.

I'm thinking of doing this. How has it worked out for other people? Does
it work well sitting semi-vertical in a pouch on the front parachute
straps, or does it work better sitting horizontally on your shoulder?

Since it already misses an occasional message mounted in an ideal
location (horizontal on the canopy rail), I don't want it to miss any
additional messages.

--
Eric Greenwell - Washington State, USA
* Change "netto" to "net" to email me directly

* Updated! "Transponders in Sailplanes" http://tinyurl.com/y739x4
* New Jan '08 - sections on Mode S, TPAS, ADS-B, Flarm, more

* "A Guide to Self-launching Sailplane Operation" at www.motorglider.org

Eric,

For my two Spot flights, both in the 300k range I've kept mine clipped
vertically in the side pouch and yes it does miss a few but it seems
to get the job done just fine so I'll stick with that for now (easy
access).


Unsolicited comments: Changing the OK, Help & 911 comments is so very
simple that one could simply tailor the verbiage for what ever
Situation and Geographical location you may want to use it for, making
it very versatile. For example; Just going for a little XC in
Colorado, Contest Racing in Parowan Utah, Uvalde TX or Backpacking in
Uganda. It only takes about 5 minutes to do each time.

For Soaring I'll only use the OK to confirm I'm safely on the ground
and it's noted this way in my message, this usually goes to my wife’s
cell too. If I need a retrieve then I follow it up with an
informative help message including my cell #s (I carry 2). Of course
in the 911 category I provide a lot more detailed information adjusted
for XC Soaring, Racing or Hiking etc.

I can see this Spot tracking being very handy for crews or even the CD
hanging around the AP with wireless service wondering how pilot # is
doing etc., I plan to use it at two US contests as well as my home AP
this summer and see how well it goes.

21




On May 15, 10:21*am, Eric Greenwell wrote:
Matt Herron Jr. wrote:
Good summary Darryl, thanks. *I agree with your search area opinions
as well. *I assume it makes more sense to have the spot attached to
the chute rather than the plane for pretty much all situations.

I'm thinking of doing this. How has it worked out for other people? Does
it work well sitting semi-vertical in a pouch on the front parachute
straps, or does it work better sitting horizontally on your shoulder?

Since it already misses an occasional message mounted in an ideal
location (horizontal on the canopy rail), I don't want it to miss any
additional messages.

--
Eric Greenwell - Washington State, USA
* Change "netto" to "net" to email me directly

* Updated! "Transponders in Sailplanes"http://tinyurl.com/y739x4
* * * New Jan '08 - sections on Mode S, TPAS, ADS-B, Flarm, more

* "A Guide to Self-launching Sailplane Operation" atwww.motorglider.org

On May 15, 9:21*am, Eric Greenwell wrote:
Matt Herron Jr. wrote:
Good summary Darryl, thanks. *I agree with your search area opinions
as well. *I assume it makes more sense to have the spot attached to
the chute rather than the plane for pretty much all situations.

I'm thinking of doing this. How has it worked out for other people? Does
it work well sitting semi-vertical in a pouch on the front parachute
straps, or does it work better sitting horizontally on your shoulder?

Since it already misses an occasional message mounted in an ideal
location (horizontal on the canopy rail), I don't want it to miss any
additional messages.

--
Eric Greenwell - Washington State, USA
* Change "netto" to "net" to email me directly

* Updated! "Transponders in Sailplanes"http://tinyurl.com/y739x4
* * * New Jan '08 - sections on Mode S, TPAS, ADS-B, Flarm, more

* "A Guide to Self-launching Sailplane Operation" atwww.motorglider.org

I experimented a lot with the location of the spot on my parachute as
I was missing 10-20% of the transmissions, until I heard this is
typical. There was no noticable difference between completly
horizontal on my shoulder (which makes reading the led lights and
accessing the buttons difficult) to 45 degrees when strapped near my
chest.

Ramy

On May 15, 5:39*pm, Ramy wrote:

I experimented a lot with the location of the spot on my parachute as
I was missing 10-20% of the transmissions, until I heard this is
typical. There was no noticable difference between completly
horizontal on my shoulder (which makes reading the led lights and
accessing the buttons difficult) to 45 degrees when strapped near my
chest.

Ramy,

I spoke with Allen Silver today and he noted that wearing it on your
shoulder (where I was thinking of strapping it, for the best view of
the sky) means it's likely to be torn off in a bail out. That comment
also made me wonder if, even worse, it might interfere with chute
deployment. I also called technical support and was told that the unit
works just as well horizontal as vertical. So I'm buying Allen's
Deluxe SMAK Pak, which velcros to the chute near your chest and has
room for a PLB or the SPOT.

Martin

wrote:
I also called technical support and was told that the unit
works just as well horizontal as vertical.

That's good news. Too bad they tell you horizontal is best in the
instructions with the unit.

So I'm buying Allen's
Deluxe SMAK Pak, which velcros to the chute near your chest and has
room for a PLB or the SPOT.

I just got one for that purpose, and it seems to fit well on the chute.
I wish the zipper opened from the top instead of the bottom, so I could
partially open it to check the lights. I suggest you ask Allen if he can
do that for yours, if it's not already shipped.

--
Eric Greenwell - Washington State, USA
* Change "netto" to "net" to email me directly

* Updated! "Transponders in Sailplanes" http://tinyurl.com/y739x4
* New Jan '08 - sections on Mode S, TPAS, ADS-B, Flarm, more

* "A Guide to Self-launching Sailplane Operation" at www.motorglider.org

wrote:
I also called technical support and was told that the unit
works just as well horizontal as vertical.

That's good news. Too bad they tell you horizontal is best in the
instructions with the unit.

So I'm buying Allen's
Deluxe SMAK Pak, which velcros to the chute near your chest and has
room for a PLB or the SPOT.

I just got one for that purpose, and it seems to fit well on the chute.
I wish the zipper opened from the top instead of the bottom, so I could
partially open it to check the lights. I suggest you ask Allen if he can
do that for yours, if it's not already shipped.

--
Eric Greenwell - Washington State, USA
* Change "netto" to "net" to email me directly

* Updated! "Transponders in Sailplanes" http://tinyurl.com/y739x4
* New Jan '08 - sections on Mode S, TPAS, ADS-B, Flarm, more

* "A Guide to Self-launching Sailplane Operation" at www.motorglider.org

Both the GPS and Globalstar antennas are flat planar antennas that
only "see" through a cone shaped pattern (it will have lobes as well)
out of the out top face of the Spot unit. The statement that these
could possibly work as well if the unit is vertical as if horizontal
does not make sense. Now the unit might work *sufficiently* well if
vertical and has a reasonable view of the sky, but it certainly won't
work "just as well". Play with it and see, if it work for you then
great.

Darryl

On May 16, 7:28 am, Eric Greenwell wrote:
wrote:

I also called technical support and was told that the unit

works just as well horizontal as vertical.

That's good news. Too bad they tell you horizontal is best in the
instructions with the unit.

So I'm buying Allen's

Deluxe SMAK Pak, which velcros to the chute near your chest and has
room for a PLB or the SPOT.

I just got one for that purpose, and it seems to fit well on the chute.
I wish the zipper opened from the top instead of the bottom, so I could
partially open it to check the lights. I suggest you ask Allen if he can
do that for yours, if it's not already shipped.

--
Eric Greenwell - Washington State, USA
* Change "netto" to "net" to email me directly

* Updated! "Transponders in Sailplanes"http://tinyurl.com/y739x4
* New Jan '08 - sections on Mode S, TPAS, ADS-B, Flarm, more

* "A Guide to Self-launching Sailplane Operation" atwww.motorglider.org

On May 15, 8:19 am, "Robert M. Gary" wrote:
On May 14, 11:34 pm, Darryl Ramm wrote:

On May 14, 4:37 pm, "Matt Herron Jr." wrote:
The SPOT does not "wait for an opening" to talk to Globalstar, it has
no idea where the Globalstar satelites are, it just sends blind, then
retransmits the same message later. It's pure simplex, there is no
"carrier detect", no handshake, no ACK. Nothing. The Globalstar
satellites are just dumb one-way bent pipe repeaters. Sometime being
simple is a beautiful thing.

I always assumed the 20 minute thing was put into the SPOT system
because sat time is expensive.

I've got to be believe the 20 mins is a wild design guess on their
part. The practical transmit reliability with SPOT across their
intended users has got to be dominated by environmental factors,
device antenna direction, obstructions (trees, mountains, etc. for
hikers, car roofs) and finally satellite position. Modeling the number
and durations between retransmit attempts to deal with these factors
would be very difficult. You'd start with a simplified model that just
factored satellite coverage and message collision probabilities and
guess from there. You want to cap retransmits to reduce battery
consumption and just excess further collisions. For 911 it keeps
retransmitting much longer AFAIK. And the only "cost" for the sat time
is the risk of further message collisions.

Darryl

On May 16, 11:00*am, Darryl Ramm wrote:
Both the GPS and Globalstar antennas are flat planar antennas that
only "see" through a cone shaped pattern (it will have lobes as well)
out of the out top face of the Spot unit. The statement that these
could possibly work as well if the unit is vertical as if horizontal
does not make sense. Now the unit might work *sufficiently* well if
vertical and has a reasonable view of the sky, but it certainly won't
work "just as well". Play with it and see, if it work for you then
great.

Darryl

On May 16, 7:28 am, Eric Greenwell wrote:



wrote:

I also called technical support and was told that the unit

works just as well horizontal as vertical.

That's good news. Too bad they tell you horizontal is best in the
instructions with the unit.

* So I'm buying Allen's

Deluxe SMAK Pak, which velcros to the chute near your chest and has
room for a PLB or the SPOT.

I just got one for that purpose, and it seems to fit well on the chute.
I wish the zipper opened from the top instead of the bottom, so I could
partially open it to check the lights. I suggest you ask Allen if he can
do that for yours, if it's not already shipped.

--
Eric Greenwell - Washington State, USA
* Change "netto" to "net" to email me directly

* Updated! "Transponders in Sailplanes"http://tinyurl.com/y739x4
* * * New Jan '08 - sections on Mode S, TPAS, ADS-B, Flarm, more

* "A Guide to Self-launching Sailplane Operation" atwww.motorglider.org- Hide quoted text -

- Show quoted text -

I tried it vertically in my pocket once while hiking and it did not
transmit a single fix. This was shortly after I received it so it is
possible I did not put it correctly in tracking mode, but I was pretty
sure.

Ramy