Need help testing a project

Michael Chisena ka2zev at
Mon Oct 26 15:08:12 CDT 2009

Hi all,

Been working with Bob B to make an APRS Voice Alert radio from an inexpensive two way set.

The Kenwoods that can do this run about $1200 each.

If this project works, people can make one of these for about $200 bucks or less.

Right now I'm working on a 'red lined' drawing to get the kinks out and if I build a second unit, there will be photography.

At this time,I have something that seems to meet all the requirements.

It's one of my inexpensive 40 watt, under dash Midland units with a bunch of 'mods' in it.

It supports the data channel of 144.39 and a number of Northern Virginia area repeaters and simplex channels. 
I suppose I can stick in some NWS as well.

If you look up Bob WB4APR's web site you can learn more about the Voice Alert system.

It transmits APRS packets with a 100Hz tone.

The data packet with tone acts like an alert signal to someone with a similar radio.

The call sign and a short message will pop up on the Kenwood's text display saying that a Voice Alert station is near by.

This radio has no display section, but the audio chain and the PL decoder are stock.

The radio receives with a 100Hz pl as well, so if someone transmits a short voice message, you get to hear it, acknowledge and move on to a handy frequency like 146.52 .

As it stands now, the radio has the APRS channel in it.
A modified TT3+ controller.
A fair amount of custom wire work.

When the radio is not on the APRS channel, the data transmission is inhibited.

This is what I expect. 

I expect it to be an APRS tracker first.
A voice alert station second.
General talk around third.

At the moment it has a few local channels in it, I can add more, for a total of about 30 channels.

What I would like is someone who drives a lot in the area to take it for a couple of weeks and see if it works as advertised. 

My path to and from work most likely won't cut it.

What it will need.

A 2M Antenna.
A GPS puck (5 volt only) 

I can program your call sign into the TT3+ and add some of your favorite 2m channels into the program.

Catch me off line at



703 863 4574 after 1630 and before 2100 eastern time.

Thanks in advance.

"You are, what you do, when it counts" 
The Masso

"Gravity, the quickest way down" 
Mayor John Almafi

"You ever drop an egg, and on the floor you see it break? 

You go and get a mop so you can clean up your mistake. 

But did you ever stop to ponder why we know it's true? 

If you drop a broken egg you will not get an egg that's new?" 

MC Hawking

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