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What is the minimum set of GPS NMEA messages for QCX? #qcx #gps

Torbjorn Skauli
 

Hans, what is the bare minimum set of NMEA messages that need to be enabled for WSPR locator and time to be set on the QCX? My QCX appears to hang after the first WSPR transmission with the GPS connected, but not when running without GPS. When it hangs, it displays the frequency and "WSPR" in the upper line, but no timer on the lower line. I wonder if the QCX is somehow overloaded by GPS serial data. I currently have the GGA, GSA, GSV and RMC messages enabled on my chinese V.KEL VK2828U7G5LF GPS module. I wonder if I should try to strip down the GPS data set, even if it means that diagnostic data in menu item 8.13 become incomplete.

Torbjorn, LA4ZCA

terry murphy <marter1229@...>
 

My Qcx40 does the same thing.  And I have no answer.

Terry W6leo 

Hans Summers
 

Hi Torbjorn

The QCX parses the following GPS sentences: 

$GPRMC
$GPGSA
$GPGSV
$GPGGA

The only sentence actually *REQUIRED* for WSPR operation and all calibration functions is $GPRMC. The other three are only used for the GPS info screen and they could be switched off, everything else would work fine but you just wouldn't see the number of satellites and SNR etc on the GPS Info menu item. 

Note also that QCX implements checksum validation on all GPS strings, it cannot be disabled as it can on the Ultimate3S. 

73 Hans G0UPL

On Wed, May 29, 2019 at 10:53 PM Torbjorn Skauli <tskauli@...> wrote:
Hans, what is the bare minimum set of NMEA messages that need to be enabled for WSPR locator and time to be set on the QCX? My QCX appears to hang after the first WSPR transmission with the GPS connected, but not when running without GPS. When it hangs, it displays the frequency and "WSPR" in the upper line, but no timer on the lower line. I wonder if the QCX is somehow overloaded by GPS serial data. I currently have the GGA, GSA, GSV and RMC messages enabled on my chinese V.KEL VK2828U7G5LF GPS module. I wonder if I should try to strip down the GPS data set, even if it means that diagnostic data in menu item 8.13 become incomplete.

Torbjorn, LA4ZCA

Alan G4ZFQ
 

Torbjorn,

I do not have a QCX but my two V-KEL both work like that with a U3S. Are you sure the messages are not corrupted?

73 Alan G4ZFQ

have the GGA, GSA, GSV and RMC messages enabled on my chinese V.KEL VK2828U7G5LF GPS module.

Torbjorn Skauli
 

Thanks a lot Hans. I will explore a bit more and report back.

Torbjorn

Torbjorn Skauli
 

Problem solved, by checking the GPS signals with an oscilloscope. I had not wired the PPS correctly, so the QCX was not receiving PPS at all. This led to the problem with hanging WSPR beacon. Now everything runs smoothly. Thanks, Hans.

Torbjorn, LA4ZCA