[aprssig] Ideal Tracker Spec (Cross country on 6 AA's)
Robert Bruninga
bruninga at usna.edu
Thu Dec 6 18:37:16 EST 2012
Don't forget that you can run a micro-kind-of-tracker on 6 AA's for about
a month. It only has to wake up for 1 second every 5 minutes and send a
single shortest status packet. No GPS, no GPS power. Can fit in a
cigarette pack.
Then use FINDU or APRS.FI to "vicinity track" you across country. It
should plot a vicinity circle around the digipeaters you are hitting and
at least show the town you are in.
Lets see. 5W (RF) for one second every 5 minutes at 9 volts is 12 amp
seconds per hour for an average power of under 4 mA. With AA's holding
about 2700 mAH, then that is about 700 hours or about a month. Twice as
long if it only powers up in daylight.
Bob, Wb4APR
-----Original Message-----
From: aprssig-bounces at tapr.org [mailto:aprssig-bounces at tapr.org] On Behalf
Of Matti Aarnio
Sent: Thursday, December 06, 2012 6:14 PM
To: TAPR APRS Mailing List
Subject: Re: [aprssig] Ideal Tracker Spec
On Wed, Dec 05, 2012 at 08:24:33AM -0800, Bryan Hoyer wrote:
>
> We are currently implementing a Tracker Function for our UDR56K
> radio with a USB GPS. (For more info on the radio
www.nwdigitalradio.com)
>
> Most trackers are implemented in small micros with limited
> resources whereas we have an 800MHz Arm (no floating point)
> running Linux 3.x kernel. The project will be open-sourced.
Hi,
That UDR56K is by no means a limited resources thing - it is
both heavy and power hungry if you think about things like
balloons.
A tracker in my opinnion is something you can put into your
pocket or back-pack, and run for days with a set of batteries.
Having it in a car pretty much removes the size, mass and energy
constraints.
A tracker at a balloon is extremely mass and energy budged
optimized thing.
The UDR56K is a much more powerful thing, which is all fine for
running igates, and digis. It is also really promising platform
to do new kinds of transmission protocols.
I would love to see about anything to replace that huge heap
of technical mistakes known as AX.25-over-Bell202-over-NBFM.
Advanced things like:
* more efficient modulations (GMSK et.al.)
* every packet/segment equiped with FEC covering all of
the data (and not only partially like with D-STAR)
* decoding to use soft-decission in FEC resolution
(eats DSPs and FPGAs for breakfast, though)
* CDMA-like multi-carrier operation for igates
* Self-organized TDMA (alike AIS)
* Receivers with legacy modulation support in parallel
to other modes on all channels it receives.
* Multiple central frequencies (channels) receiver
* Multi-antenna receiver ( = diversity receiver)
(Also multi-band if the front-end verter can't fold
6m, 2m, 70cm and so on to single IF.)
What I do like is that the thing is split in two cards with
a connector in between. Doing new radio parts will not need
replacing the host part.
> Bryan Hoyer K7UDR
73 de Matti, OH2MQK
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