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VA5BNC15 aprs signal


Bill Brown
 

Hi Bruce,

  I believe I have your signal spotted OK in the waterfall display along with all the other APRS signals on 144.390. Yours appears to have a large 300 to 500 msec TxD keydown before sending the APRS data...pretty distinctive and looks like a flagpole on top of the APRS data. Is that correct?

- Bill WB8ELK


Bruce Coates
 

Hi Bill

For some reason my spam filter is discarding a lot of the messages from the GPSL list.  I'll get that figured out.

Your absolutely right.  I'm running DRA818V and it takes about 1300 ms from key up for the transmitter to energize and the Tx audio to reach full deviation.  The only solution I've found is to key it up then wait 1300 ms for before sending any data.  The result is a period of dead air, followed by what feels like a very long Tx delay with the audio level ramping up then the the two packets.  My code can also use the SR-FRS module which doesn't have this bug.  I don't remember why I'm using the DRA818 as opposed to the SR-FRS.  Probably just what I had on hand at the time.

The module is rated at 500mW when powered at 4.0.  It's powered directly from the LiPo so it will fluctuate a bit based on the battery voltage.

The GPS is a ublox NEO6MV2.  I've broken out the enable pin on the regulator to allow me to completely shut it down for deep sleep.  The micro-controller is an 8Mhz Arduino Pro mini powered directly from the LiPo and it's running a heavily modified version of Trackuino.

73, Bruce 


Bill Brown
 

I used the Pro-mini for my first prototype of my Skytracker....What Lipo are you using and how heavy is it?

- Bill WB8ELK


-----Original Message-----
From: Bruce Coates <bruce.coates@...>
To: GPSL@groups.io
Sent: Mon, Jul 13, 2020 11:09 am
Subject: Re: [GPSL] VA5BNC15 aprs signal

Hi Bill

For some reason my spam filter is discarding a lot of the messages from the GPSL list.  I'll get that figured out.

Your absolutely right.  I'm running DRA818V and it takes about 1300 ms from key up for the transmitter to energize and the Tx audio to reach full deviation.  The only solution I've found is to key it up then wait 1300 ms for before sending any data.  The result is a period of dead air, followed by what feels like a very long Tx delay with the audio level ramping up then the the two packets.  My code can also use the SR-FRS module which doesn't have this bug.  I don't remember why I'm using the DRA818 as opposed to the SR-FRS.  Probably just what I had on hand at the time.

The module is rated at 500mW when powered at 4.0.  It's powered directly from the LiPo so it will fluctuate a bit based on the battery voltage.

The GPS is a ublox NEO6MV2.  I've broken out the enable pin on the regulator to allow me to completely shut it down for deep sleep.  The micro-controller is an 8Mhz Arduino Pro mini powered directly from the LiPo and it's running a heavily modified version of Trackuino.

73, Bruce 


Bruce Coates
 

Hi Bill

It's a 601235 (6mm x 12mm x 35mm) rated at 220mAh and weighs in at 4 grams.  For my design, that was the sweet spot of weight, size and capacity.  I might have been able to use a slightly smaller one but would have had to sacrifice reserve capacity and would have only gained a gram or so.

73, Bruce - VE5BNC