Posts mit dem Label APRS werden angezeigt. Alle Posts anzeigen
Posts mit dem Label APRS werden angezeigt. Alle Posts anzeigen

Donnerstag, 18. September 2014

AP510 / AVRT5 APRS tracker - HF signal


AVRT5 APRS tracker
With the help of one of my colleagues @ QRL we measured the HF signal (144.800MHz - European APRS QRG) of the AVRT5 APRS tracker with a R&S Spectrum analyzer (3kHz-7GHz).
All measurements were made with a 6dB attenuator and 1m RG58CU between the Tracker and the Analyzer.













HF Signal - 144.800MHz



Power Measuring: 30.46dBm / 1.1Watt

At -5khz from center freq we measured a delta of 41.18dB


Harmonic frequ: The 1st harmonic at 289.7MHz has a delta of -9.13dB. That is too high for using it for a permanent digi. A filter is needed to further lower the harmonic signal.


AFSK data signal burst (my beacon of DK7XE-8) ~1sec duration

AFSK data signal - last 320ms

Montag, 8. September 2014

AP510 / AVRT5 APRS tracker

The AP510 / AVRT5 APRS tracker is a tiny APRS tracker with built in GPS and bluetooth.
Transmitting power is around 1W (detailed measurement result available on ap510-avrt5-aprs-tracker-hf-signal).

The official website is http://www.y027.com/dvbbs8/dispbbs.asp?boardid=5&Id=829 (chinese) / webshop at  http://avrtt.taobao.com/ but there is an english group on Yahoo https://groups.yahoo.com/neo/groups/AP510/info
You will find the latest firmware / configuration software there as well.

For the German's: Klaus, DJ7OO hat einen Erfahrungsbericht auf seiner Homepage.

I got mine from a Taiwanese Hamradio friend while being there on a business trip in June 2014.

Some details

  • Transmission can be set to a fixed timing, smart beaconing or triggered manually via button.
  • Built in GPS.
  • Acts as a WIDE1-1 or WIDEn-n digipeater if needed.
  • Fixed position can be programmed (e.g if used as a fixed station).
  • Tracks can be stored on MicroSD card.
  • Built in Battery
  • Configuration / Charging to be done via serial connection (miniUSB connector).
  • KISS / Waipoint / UI frame output on serial (4800Bd) and Bluetooth.
  • Works perfectly with APRSdroid as BluetoothTNC (Output to be set to KISS).
  • Operating frequency can be set via configuration program.
  • Some parameters can be set via AT commends
I'm really happy with this device since it works perfectly with APRSdroid and fit's in every pocket.


Remarks

  • Bluetooth connection only works after GPS lock therefore you have to wait some seconds before connecting to the device. Bluetooth pairing code is 1234.
  • miniUSB connector is a Serial Port therefore the included USB cable needs to be used for programming (charging works with every standard USB cable).
  • Help is provided via the AP510 / AVRT5 Yahoo Group.
  • Be aware that the TX power is low compared to other stations therefore not every transmission might reach a Digi/Gate when being in a busy APRS area.
  • If you have problems on connection via serial take a look at the Video on AP510 APRS tracker configure software and firmware

Serial / BT commands


According the info on http://avrtt.taobao.com/ some settings can be changed by sending AT commands.
Either you connect via the serial (USB) port with following settings 4800Bd 8N1. Or you use a bluetooth, e.g. BluetoothTerminal on Android.
Import: serial/bluetooth communication seems to work ONLY after GPS lock.

To make it work you have to follow the steps below
1) connect
2) send ^M
3) send the AT command. E.g. AT+BEEP=0
4) the device will send OK back.
5) reboot the device to have the NEW settings active.

The following commands are currently known

setting the callsign
AT+CALL=BG6QBV7

setting frequency
AT+FREQ=144.6400

switch tone on
AT+BEEP=1

switch tone off
AT+BEEP=1
 


Pictures