Mobilinkd - Bluetooth APRS / TNC (Yaesu FT-991A, Baofeng UV-5RTP and BTech UV-50x3)

G'Day Guys,

I originally purchased the Baofeng to 3.5mm 4 Pole TRRS cable from BTech (APRS-K2 TRRS CABLE) to use with APRSDroid. Unfortunately I quickly learnt that when using the Baofeng in VOX mode the time to change back from TX to RX on average was 4-5 seconds....   Not good for APRS as it would interfere with others and you will not get any traffic for up to 5 seconds hence miss immediate responses from digipeaters etc.  This is not fault of the BTech cable, just seems to be a feature of VOX.

So I then ordered myself a Mobilinkd and the following TNC cables:

• TNC Cable for Kenwood, Wouxun, Baofeng
• MiniDIN-6 TNC Cable and MiniDIN-6 1200 Baud Adapter for the Yaesu FT-991A
• Yaesu FTM-350 8 Pin Mini Din Data Port to 3.5mm TRRS Mobilinkd TNC - 1200 baud - This is for the BTech UV-50x3 

Baofeng UV-5RTP

The Mobilinkd arrived quickly 1.5 wks and out of the box was able to hook it up to the Baofeng within 5min and using the Mobilinkd android app was able to connect and adjust the input setting fairly quickly and the default for out left as they were.  For the Baofeng I have the "attenuation" enabled and adjust volume to the first red led starts to flicker and bingo I was up and running.

 Yaesu FT-991A

I'd read from others that I need to ensure I was using the 1200 baud data pin of the FT991A data port as the 9600 had low voltage / volume. Hence when I ordered from Mobilinkd the MiniDIN-6 1200 Baud Adapter.

Since I use the FT-991A for data comms via the USB I have to switch the following values back and forth when using Mobilinkd:

• #075 - FM Out - 98
• #076 - FM PKT PTT Select - DAKY
• #077 - FM PKT Port Select - DATA
• #078 - FM PKT TX Gain - default value 50 (just FYI)

Mobilinkd settings - I turned "attenuation" off.

After changing the FM PKT settings to rear and the volume out from radio I was up and running.

BTech UV-50x3

The Yaesu FTM-350 8 Pin Mini Din Data Port to 3.5mm TRRS Mobilinkd TNC arrived today and apart from having to grind the "rectangular" part of the mini din plug to allow it to plug into the  back of the BTech it was well constructed and worth the money.  Plugged in and connected up the Mobilinkd Bluetooth TNC.  Via the rigs PKT settings I set it to the "Right side VFO" and opened the SQL.  Using the Mobilinkd mobile app I had to turn of "attenuation" and got three green bars with flicker of yellow.  The advice on the app says to turn the audio until the first red bar starts to flicker but had to leave at first yellow.  When tracking started APRS signals heard were decoded and just worked perfectly.MY own APRX beaconing worked perfectly.

However!!!!!!  I quickly discovered that while monitoring VHF traffic on the left side VFO and the APRS was beaconing on the right side VFO (using the smart beaconing mode) the left side was desensitised / block / overloaded frequently.... This was even the Right Side VFO power level set to "low"....

DOH!!! What else would one expect with 2 VFO on same band....   So my options are that I monitor UHF voice on the left side or not use "Smart Beaconing" but rather periodic beaconing say every 10-15min.  This would cut down on the interference to a degree of a burst every 10-15min which is not bad....   ORRRR!! continue to use APRSDroid on APRS-IS mode while in range of mobile internet and have the Mobilinkd for all other times......

I'll continue to play around and see how the setup goes using the "Periodic beaconing", just means from a tracking resolution it may be lower to that compared to "Smart Beaconing". 


That's all Folks!
73
de VK4TMZ (Mark)