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HF APRS Mobile/Portable

Initial Thoughts

My plan is to use either of

  1. TinyTrak3 + serial GPS as a one-way tracker
  2. Netbook with direwolf and a USB GPS
    1. a tracker
    2. xastir for maps etc

Either of these will interface with a Xiegu G90 and some form of mobile whip.

I may use 30m hoping to get packets directly to other iGates in Europe or use 10m and run an iGate on 10m at home. It's all on the drawing board at the moment. It will be interesting to compare local coverage between 30m and 10m as well as seeing how well 30m mobile with a short whip can perform.

Tiny Trak 3

  • Uses serial GPS to provide position data
  • Only transmits, no receive/decode
  • Can transmit VHF (1200bd) or HF (300bd) APRS

HF APRS configuration settings

Date Config.
April 2023 xxxx

Firmware/Docs

Firmware tinytrak3_v1.42.zip
User Guide tinytrak3plus_v1.03.pdf
Configuration Utility tinytrak3_config_v1.4.6.zip

Test and Setup

First Reception

From aprs.fi - packets being received in Germany at DK4XI

https://aprs.fi/?c=raw&call=GM4SLV-11

2023-04-29 07:47:49 BST: GM4SLV-11>APT311,qAR,DK4XI-30:>John on HF
2023-04-29 07:47:52 BST: GM4SLV-11>V0QWRY,qAR,DK4XI-30:`w5Nl  j/"3x}
2023-04-29 07:52:50 BST: GM4SLV-11>V0QWSP,qAR,DK4XI-30:`w5Nl ^j/"4+}

Mobile Journey #1 on 30m

02/05/23:

  • using 10m “stinger” mobile whip and G90's internal ATU / 20W
  • not very encouraging local coverage between mobile and home QTH
  • large gap in coverage - journey actually went to Lerwick and back….
  • next experiment will be to use 10m - hopefully antenna is more efficient on that band

03/05/12

  • found that the antenna used yesterday was tuned to 31MHz… short whip
  • swapped for 2nd whip and this is tuned to 28.2MHz…. longer whip. More efficient?

John Pumford-Green 26/04/23 15:02

Further Information

public/radio/dormant/mobile_hf_aprs.txt · Last modified: 06/03/25 06:49 GMT by 127.0.0.1