PA6H GPS with SMA for APRS Trackers

Name: PA6H GPS with SMA for APRS Trackers
SKU: 4406
Price: 99.00 USD
Availability: OutOfStock

GPS with SMA for APRS, compatible with Byonics TinyTrak (and probably ArgentData OpenTracker)

Designed by ptudor in United States of America

2015-02-22T10:35:54.026Z-IMG_2907 (1).jpg

$99.00

Out of Stock

Sold out since Jan 31, 2017

GPS with SMA for APRS, compatible with Byonics TinyTrak (and probably ArgentData OpenTracker)

A replacement for the puck-style GPS commonly used with APRS transmitters. Built for APRS transmitters If you don't have an amateur radio license, you may as well stop reading now and go check out th…

Built for APRS transmitters

If you don't have an amateur radio license, you may as well stop reading now and go check out the ARRL website for information about taking the (cheap and easy) test. If you are a licensed operator, you probably know APRS from Bob Bruninga is packet data for position reporting. Byonics designs great transceivers like the TinyTrak and distributes my favorite transmitter, the Micro-Trak RTG. But the only supported branded GPS is a magmount puck and I wanted to bring my own antenna so I made this.

Compatible with Byonics

The Byonics GPS puck is unique in its 5V power on pin 4 of a DB9 connector and RS232 levels. It's not necessarily a complex challenge, but just barely unique enough there's not a large market for off-the-shelf solutions. But I really wanted something with an SMA jack so I could plug a roof mount antenna in to the Micro-Trak in the trunk of my car.

Possibly compatible with ArgentData's OpenTracker.

I don't own one. I don't know if it will work. Reading the manual, section 3.1 suggests the pinout is identical and section 4 lists the jumpers to provide 5V power. I bet it works if you set the baud rate to 9600 in the GUI config tool as shown in section 11.6 or with the ABAUD or BBAUD commands in section 12. The pinout is the same. Let's try it out; if doesn't work I'll refund and pay your return shipping.

How's it designed?

The right side of the board has a female DB-9 that interfaces with the tracker.

DB9/DE9 has four connections: 2 is Out, 3 is In, 4 is 5V, and 5 is Ground.
5V goes to an RT9193-3.3 to drop the voltage to 3.3V for all the ICs.
Out and In go to an SP3232 that boost the GPS data to RS232 levels.
The GPS is a PA6H built on the MTK3339, same as the Adafruit Ultimate GPS v3.
The far left edge of the board has an SMA jack that goes into the GPS.
There is a 5mm LED that blinks red without a fix and green with PPS when it does.
On the bottom of the board is room for a 1220 or 2032 coin cell for the GPS.
Later I added an optional ATTiny85 that listens to the GPS Tx and blinks the number of satellites in view.

How well does it work?

Go track my car on your favorite APRS site, I'm KB6GE-12. Change the "tail" length to seven days or so. Basically, it's phenomenal. I have no complaints with the old GPS, but I now experience the performance you'd expect from a roof-mounted antenna and aesthetically I'm so happy to have an antenna mounted on my roof that blends in.

Limitations

While I initially used the ATTiny85 to drop the bit rate from 9600 to 4800, I later decided to just check the box in the tracker configuration to make it expect NMEA coming in at 9600; be aware that is a non-default option.

There is no case for this board. I like seeing my electronics. If you operate in a dusty environment, you might want to make a case for it, or wrap it in heat-shrink tubing.

There is a typo on the silkscreen, I know, I know. It should read MTK instead of MKT. Somehow the board still works great despite that.

Antenna Options

Because I designed this specifically to add support for roof-mounted antennas, here's some options I considered: A.01.C.301111 from Taoglas, JCA601 from Jin Chang, and 2J669B from 2J Antenna among others. This board does not come with an antenna, you must bring your own. Some have 12mm posts, some have 18mm, and you won't have to search hard to find one that attaches to an NMO mount. The PA6H does not support GLONASS so 1575.42MHz without 1602.0MHz is ideal.

Can one order just a blank PCB?

The parts are easily sourced and with all the components on one side of the board it's easy for you to do your own reflow thing or however you like to solder. So, sure. Use the discount code "9167BD8" for 90% off when ordering and I'll send two PCBs instead of one assembled board. It's just not an option here because I can't (yet) decrease the price on options, I can only increase.

Cool.

This product really only exists because the TinyTrak and MicroTrak are such awesome devices and after a few years of dealing with the puck GPS I finally decided to fix the only thing that annoyed me. So, if you're not already using APRS, go buy an MTT4B soon. I am just a happy customer and the product in this listing has nothing to do with them, if you buy it and need help, ask me not various APRS groups on Yahoo.

Since this is ham radio related, I'll finish with:

73 KB6GE