Thursday, July 31, 2008

Voice Alert Summary

A good summarization of Voice Alert as posted by Joseph/NE3R on APRSSIG...


I've come across a lot of hams who don't have a good understanding of APRS Voice Alert. While Bob Bruninga, WB4APR explains it well on his voice alert page, I'll try to explain it in just a few lines.

Voice alert is essentially adding a 100hz CTCSS tone to the transmitted APRS packets on 144.39 (US), just set the tone as if you needed it to access the repeater and setting the radio to tone squelch (CT on the D700) and leaving the volume on the data channel up. When a packet is received with the 100hz tone, you'll hear it on the radio, and you should also see the call on whatever APRS display you are using. The radio will still decode packets that don't have the 100hz tone, you just won't hear them. This works with most rigs/tncs that don't rely on the speaker output to feed audio to the TNC.

The full details can be found:

Even hams that don't use APRS can take advantage of voice alert, just listen to 144.39 with your tone squelch set to 100hz. When an APRS mobile is in the area, you'll hear them, and you can give a general call for APRS voice alert stations.

Once contact is made on the voice alert channel, the conversation should be moved to another frequency to keep the channel clear for packets, and to keep the packets from crashing your QSO.

One thing that makes voice alert less useful is when the tone is transmitted with the packet, but nobody is listening (unattended, volume down, etc). That is one disadvantage to the D710, it isn't as easy to turn off voice alert once you have it on, which leads to folks just turning down the volume.

I hope this helps spread the word regarding APRS voice alert.

Thanks & 73 de Joseph Durnal NE3R

Friday, July 25, 2008

BigRedBee announces integrated APRS and GPS

BigRedBee, LLC is pleased to announce the world's smallest, completely integrated 5 watt 2 meter APRS/GPS transmitter.

Features include a frequency agile 2 meter RF transmitter (144 - 148Mhz), integrated SiRF star III GPS with patch antenna and 5 watts of RF power output. All on a single board measuring less than 1 1/4 x 3 3/4inches.

The high sensitivity 20 channel WAAS capable SiRFstar III GPS allows operation in areas where GPS reception is troublesome, including"urban canyons", wooded areas, even inside buildings.

Nonvolatile on-board memory stores more than 1000 waypoints at a user selectable rate which can be downloaded as a .kml file viewable via Google Earth.

An integrated voltage regulator allows direct connection to anautomobile (or any unregulated 12V) power source For truly portable operation, you may also provide power (4-9 volts) via (2)lithium-poly (7.4v) or (6) alkaline batteries (9.6v).

The transmitter supports fixed beacon rates, time slotting and SmartBeaconing (TM) for dynamic transmission rates based on speed and heading. For periodic operation, the GPS power may be powered downresulting in longer battery life.

For "high flying" projects, Trimble's Lassen IQ GPS module is also available for an additional cost, allowing battery powered operation above 18,000 meters.

Just plug in your SMA antenna and 12V power supply and you are on the air!



A BeeLine GPS 2MHP package deal is available for just $275, which includes a water resistant plastic case, automotive (cigarette lighter) power adapter and an RS-232 serial programming interface.

RF transmit antenna and batteries are not included.



The BeeLine 2MHPGPS is available now, but built to order. Please visit for more information including detailed pricing and ordering information.

Thursday, July 17, 2008

Publish Hamfests with APRS (updated)

Come on APRS!

Surely we can put HAMFEST objects on the map to help alert and remind our fellow hams of such important upcoming events! I just checked, and not a single HFEST is showing. There is one HAMFEST object, but it is in New Zealand!

Please use this format for the name of your HAMFEST object:


Use the "\h" symbol which is a bright red object...

This not only makes them stand out on the map, but also includes the DATE (dd) in the object name to make it clear this is a future object. The "x" on the end makes it unique so that FINDU
can find them all:*

For details of this format, see the LOCAL INFO page about 30% down the slider:

It's the season, lets show what APRS can do...



APRS EVENTS application for generating this info... Thanks to Stephen H. Smith wa8lmf


The application, APRS Events, is available from M0CYP's UI-View add-on pages

It actually doesn't depend on UI-View or it's settings at all. It is a standalone application that uses the AGW Packet Engine as an interface to access one or more TNCs. You specify a callsign and path completely independently of UI-View.

Currently at my station, AGWpe is arbitrating access to both the HF and VHF ports of a classic original KAM, and access to a second KPC3+. It allows 4 copies of UI-View, UI-Traffic Monitor, UI-Network Analysis and APRS Events to access/share both TNCs.

APRS Events is controlled by a text file "APRSevents.csv" that contains lines like these (these are single lines that may wrap in email):

#2008-07-11 15:05:00#,#2008-07-12 10:00:00#,"Inland Empire ARC Swapmeeet 8AM Sat - Cable Airport in Upland",28

#2008-07-21 15:05:00#,#2008-07-22 21:00:00#,"Pasadena ARC Meeting 7:00 PM Tuesday at Kaiser in Pasadena",28

#2008-07-25 15:05:00#,#2008-07-26 10:00:00#,"TRW Swapmeet Saturday 8:00 AM Manhattan Beach",28

The final set of digits is the repetition rate in minutes. I purposely set the rep rate slightly faster than 30 minutes so that if my "half-hourly" beacons happened to coincide with someone else's, the beacons would gradually drift out of phase over time.
The application has a fill-in template to add events, but the user interface is so clumsy and erratic when it comes to editing existing events that I find it easier to edit the .CSV file directly outside of UI Events. (On most Windows systems with MS Office installed, double-clicking the APRSevents.csv file makes it open in an Excel spreadsheet where it is neatly columnated and easy to edit. )

The application is hardwired to transmit in bulletin format. (I wish it could transmit objects as well -- perhaps in a future revision it will). It stores it's own path and originating callsign independent of any other application using AGWpe.

I have set a single-hop path using the actual callsign of a single digipeater (N6EX-1) that covers the area of interest (the San Gabriel Valley -- the area between 5 and 20 miles east of downtown Los Angeles that includes Pasadena, Alhambra, Monterey Park, Arcadia, Monrovia, El Monte, etc). This avoids setting off 4 or 5 digipeaters all over the greater Los Angeles basin simultaneously with the generic WIDE2-2 path normally used around here.

Friday, July 11, 2008

APRS Symbols - current list

The complete symbol set (and the codes that create them) is here:


Other APRS resources by WA8LMF: