[aprssig] Interesting Findings - 300 Baud AX.25 on VHF-FM APRS

[Stephen H. Smith]

On 4/4/2016 11:27 AM, Fred Hillhouse Jr wrote:
>
>
> What I could really use is a tiny single board computer ala Raspberry Pi
> that
> can run normal Intel x86 OSes and software.
>
> Not quite a single board PC but closer.
>
> Kangaroo Mobile Desktop Computer KJ2B#001-NA Intel Atom X5-Z8500 (1.44 GHz)
> 2 GB LPDDR3 32 GB eMMC Windows 10
>
> http://www.newegg.com/Product/Product.aspx?Item=N82E16883722001
>

Interesting...   I love small form-factor PCs and have played with them for 
over a decade as APRS appliances like digipeaters, igates and APRS webservers.

The Kangaroo device appears to be basically an Intel-Atom-powered Windows 
tablet minus the screen.  I have used devices similar to this -- see my review 
of the Microcenter TW-700 Winbook tablet here:
.
.    <http://WA8LMF.net/WinbookTablet>
.
It is a very useful building block for ham applications like digipeaters, 
igates, mapping APRS clients, etc since it will run standard Windows software 
in an ultra-compact form factor.
.
In fact, my 300 vs 1200 baud testing used a Winbook running the UZ7HO 
Soundmodem at the receiving end, connected to a Yaesu FT-1500 transceiver.
._______________________________________________________

Comparing the Kangaroo to the Winbook tablet:
.
.
Kangaroo is $100     Winbook TW-700 lists at $80 on it's website, but is often 
available in Microcenter stores for $60-70 new on promotional blowouts, and as 
open box / returns  for $50-60.
.
The Kangaroo has more RAM and flash memory "hard drive" than the Winbook.
.     2GB RAM vs 1GB        32GB flash vs 16 GB

Two FULL-SIZE USB ports (one USB 3.0) on provided docking adapter of Kangaroo 
vs one FULL-SIZE directly on body of Winbook. (Winbook has second, micro-USB 
port, normally used for charging.)

Kangaroo dock also provides standard full-size HDMI port, while Winbook has 
micro-HDMI directly on body.

The Kangaroo chassis runs directly off 12 VDC making it nice for mobile ham 
applications.   Winbook requires 5 VDC external power from wall-wart or 
external 5VDC USB car charger.

According to specs, Kangaroo external 110/220VAC power supply provides 3A at 12 
VDC, implying power consumption is probably around 25-30 watts. User reviews 
are commenting on how hot it gets.   I have measured Winbook power consumption 
via 12VDC-->5VDC USB car adapter at around 10 watts (less than 1 amp) from 12 
VDC system.  No detectable warming - it could be stuffed into closed spaces 
like my ammo-can tracker without problems.   The Winbook can run autonomously 
on it's internal battery for almost 6 hours.

And of course, the Winbook has a built-in "half-HD" 1388x720 display - handy in 
field settings where you don't want to bother with an external monitor.     The 
Winbook can output a  1920x1080 full-HD image to an external HDMI display.  (I 
now routinely use the Winbook plugged into my Acer full-HD projector for ham 
club presentations and swap meet demos, instead of lugging a larger laptop.)

My conclusion is that for stationary applications, the greater number of ports 
on the Kangaroo combined with it dock would be a better choice.   For 
in-the-field applications, the Winbook, with all it's ports directly on the 
body of the device, a built-in display, and lower power consumption would be 
the winner.

______________________________________________________________________
Stephen H. Smith    wa8lmf (at) aol.com
Skype:        WA8LMF
EchoLink:  Node #  14400  [Think bottom of the 2-meter band]
Home Page:          http://wa8lmf.net

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