Tuesday, November 23, 2010

New iGate Buildout

After seeing no operational iGate in the Victorville,
California area, I decided to build another iGate
for deployment. I had an extra WRT54GL, and I
acquired two Motorola Keynote receiver boards
from a friend nearby. He pretuned them to the
144.390 MHz APRS Frequency for me to use for
this iGate.

After a lot of building and troubleshooting, this was
the end result. An operational iGate without external
peripherals, besides the antenna.

I salvaged a window clip antenna and attatched the RF
Connector onto the case, making this a clean looking
iGate. Whats inside can be a mess, but it has to look
good on the outside, and function.

My previous version, I mounted an audio input jack to
the case, and tied in a cheap scanner. This version will
not have an external reciever, instead it is all inside the
router case.

Here is the rat nest of wire and parts. The Keynote
reciever board was double stick taped to the RF case
for the WiFi. The TinyTrak4 was left in its case,
because of the proximity to the motherboard, and the
power supply for the pager board sandwhiched in

First I configured the TT4 with the Callsign, RXAMP,

Callsign: KJ6HVB
ABAUD: 9600

Here is the power supply I built for the pager board.

LM317T Regulator and Schematic

Keynote Pager Reciever Board.

Pin 1 - 1.3 VDC
Pin 2 - GND
Pin 4 - Audio Out
Pin 8 - Battery Saver (Jumper to power with 10k resister
to enable receiver)

This is a view of the bottom of the pager board, to show where to solder on the connector for the external antenna.

This is the RS232 to TTL 3.3v converter. I had to modify it,
so it wouldn't mess up the TT4. I cut the tracer between
pins 7 & 8 of the Serial connector, and also cut the
tracer going to pin 6.

Pinouts (Components on top)
Pin 1: Transmit TTL
Pin 2: Receive TTL
Pin 3: GND
Pin 4: 3.3-5v

Serial to 3.3v TTL converter (A232DBH3v):


Pin  1: 3.3V          Pin  2: 3.3V
Pin  3: Tx (ttyS1)  Pin  4: Tx (ttyS0)
Pin  5: Rx (ttyS1)  Pin  6: Rx (ttyS0)
Pin  7: NC            Pin  8: NC
Pin  9: GND         Pin 10: GND

The end result, an operational RX Only iGate for an area that needs it, that isn't messy.


  1. With the fine tuning you did, this seems to be working great as a back up unit for the high desert travelers going through Victorville valley area.

    I like that it's a small compact unit with low energy usage demands.

  2. Nice article!

    There seems to be a slight problem though, possibly with the real-time clock of the Linksys box you're using, or the aprx igate software that's relying on it. It's sending out telemetry packets at a high rate of 1 packet per second: http://aprs.fi/?c=raw&limit=&call=KI6PSP-10

    Could you please investigate this a bit, maybe together with Matti OH2MQK via the aprx users group (http://groups.google.com/group/aprx-software)? Thanks!

  3. I only have this problem with my home router. This new one I documented here doesn't do it. I will work on upgrading my system, and I will document all of my commands for another blog post.