[aprssig] New Twist on APRN! - Field Test

Stephen H. Smith wa8lmf2 at aol.com
Fri Apr 2 21:32:02 EDT 2010

Stephen H. Smith wrote:
> I now am running a totally software-based APRN  setup.  I have a radio 
> connected to the sound system LINE input and LINE output of a Dell 
> L866r mini-tower PC. [This is a 866 MHz Pentium III PC running WinXP 
> SP3 in 512K RAM; i.e. not a bleeding-edge super-screamer maxed-out 
> machine.]       The same RX audio from the same sound card input is 
> being used simultaneously by mmSSTY, the AGW Packet Engine soft TNC 
> for packet, -AND- Echolink !
> It really works!    The transmitted SSTV pics show up in mmSSTV.  The 
> packet bursts decoded by AGWpe show up on the UIview map.  The Windows 
> Task Manager shows only about 10-15% CPU utilization and only about 
> 320K RAM in use.  And NO serial ports or pain-in-the-neck 
> USB<-->serial dongles required!

I went out for a one-mile walk around the neighborhood to test the setup 
over-the-air "foot-mobile".    Hand-portable setup was Kenwood TH-D7 
with Garmin Foretrex 201 GPS velcroed to it.      A Kenwood VC-H1 
hand-held SSTV device was connected to the D7 with it's stock (awful) 
camera head replaced with the NTSC output of a Canon Powershot A520 
digital camera.  Antenna was a Diamond SRH77ca dual-band SMA-based whip 
that is a full 19" quarterwave on 2 meters, counterpoised with a 
flexible 19-inch "rat-tail" dangling from the hand-held at the antenna 
base. (Soldered 19" of very flexible headphone cable from some dead 
earbuds to a 1/4" ring terminal, and slipped the ring over the D7's SMA 
connector before screwing on the whip.).  The radio was on a belt-clip 
on my waist; i.e. not being held up in the air. 

For this test run, I placed a Yahoo! satellite photo of the neighborhood 
underneath the vector mapping data from Precision Mapping 8.1 in UIview.

Here are the results of the pure software-based APRN system:   


Click on link for "Go to live picture list".  Then scroll down list to 
bottom for today's transmissions (2 April 2010).  Note that current 
versions of Internet Explorer and Firefox try to downsize the oversized 
map images to fit.  Just click in the map picture somewhere to restore 
to full size.  



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

NEW!    Universal HF/VHF/UHF Antenna Mounting System

"APRS 101"  Explanation of APRS Path Selection & Digipeating

Updated "Rev H" APRS            http://wa8lmf.net/aprs
Symbols Set for UI-View,
UIpoint and APRSplus:

More information about the aprssig mailing list