New station.. does this look ok ?

[Jumpy07]

Have setup a new basic ground station, RPI, with 820T dongle and home made BI quad antenna located in my loft.

Based just on edge of Glasgow CTR at southern end of Loch Lomond.

I think I have it setup correctly..  but not seeing anything.. that said most of the GA traffic, ML, HG etc.. come out to play over the Loch at the weekends.

I am a 360 radar MLAT and ADS-B feeder.. couple of RPI's setup running for a few months now..

This is the stats from the webpage off the RPI:


RTLSDR OGN demodulator and decoder 0.2.6.RPI-GPU/Mar 31 2017

System   
Host name   ogn-receiver
Configuration file path+name   /home/pi/rtlsdr-ogn.conf
Local time   15:14:21
Software   RTLSDR-OGN 0.2.6.RPI-GPU
CPU load   1.3/1.2/1.1
RAM [free/total]   42.1/188.7 MB
CPU temperature   +51.9 ℃
NTP UTC time   15:14:21
NTP est. error   0.1 ms
NTP freq. corr.   -10.06 ppm
Position   
Position.Latitude   +55.99000 deg
Position.Longitude   -004.57200 deg
Position.Altitude   5 m
Position.GeoidSepar   +55 m
RF   
RF.FreqPlan   1: Europe/Africa
RF input noise   -1.1 dB
Demodulator   
Demodulator.DetectSNR   10.0 dB
Demodulator.PipeName   ogn-rf.fifo
Demodulator.ScanMargin   20.0 kHz
Traffic rates [visible/all]   
Aircrafts received over last 12 hours   0/ 0
Aircrafts received over last hour   0/ 0
Aircrafts received over last minute   0/ 0
Positions received over last minute   0/ 0
APRS   
APRS.Server[0]   -> aprs.glidernet.org:14580
  connected to   37.187.40.234:14580
  connected for   10h11
  KiloBytes sent/received   21/138
APRS.Call   LOCHLMND
APRS.Icon   I&
APRS.FilterRange   0.0 km
APRS.Beacon.Interval   300 sec
APRS.Status.Interval   300 sec
APRS.MaxBitError   16 bit
APRS.HighResolution   1
APRS.SAR   1
APRS.PositionInterval   20 sec
APRS.MaxDistError   20 m
APRS.ReportDelay   5 sec
DDB   
DDB.RefreshInterval   0
DDB.UseAsWhitelist   0

APRS beacon:
LOCHLMND>APRS:/151014h5559.40NI00434.32W&/A=000016

APRS status:
LOCHLMND>APRS:>151014h v0.2.6.RPI-GPU CPU:1.1 RAM:41.3/188.7MB NTP:0.1ms/-10.1ppm +52.5C 0/0Acfts[1h] RF:+20+149.5ppm/-1.09dB

RF spectrograms: OGN

List of aircrafts being tracked: long or short

RTLSDR OGN RF processor 0.2.6.RPI-GPU/Mar 31 2017

System   
Host name   ogn-receiver
Configuration file path+name   /home/pi/rtlsdr-ogn.conf
Local time   15:20:30
Software   0.2.6.RPI-GPU
CPU load   1.2/1.1/1.1
RAM [free/total]   41.7/188.7 MB
CPU temperature   +51.4 ℃
NTP UTC time   15:20:30
NTP est. error   0.1 ms
NTP freq. corr.   -10.06 ppm
RTL-SDR device #0   
Name   Generic RTL2832U OEM
Tuner type   R820T
Manufacturer   Realtek
Product   RTL2838UHIDIR
Serial   00000001
Center frequency   868.303 MHz
Sample rate   1.000 MHz
Frequency correction   +169.5 ppm
Life Time   97.1% ppm
RTL Xtal   28.800575 MHz
Tuner Xtal   28.800575 MHz
RF   
RF.FreqPlan   1: Europe/Africa
RF.Device   0
RF.SampleRate   1.0 MHz
RF.FreqCorr   +20 ppm
RF.FreqRaster   28125 Hz
RF.OffsetTuning   0
Fine calib. FreqCorr   +149.5 ppm
RF.PulseFilter.Threshold   0
RF.PulseFilter duty   0.0 ppm
RF.OGN.GainMode   1
RF.OGN.Gain   60.0 dB
RF.OGN.StartTime   0.375 sec
RF.OGN.SensTime   0.850 sec
RF.OGN.SaveRawData   0 sec
RF.GSM.CenterFreq   950.0 MHz
RF.GSM.Gain   49.6 dB
RF.GSM.SensTime   0.250 sec

RF spectrograms: OGN
GSM frequency calibration


RF raw data of a time-slot (8-bit unsigned I/Q) - a 2 MB binary file !

I ran the GSM cal and tweaked the gain and freq for best results..

Does this look okay ?

[Ben Smith]

Your frequency correction is wrong, what type of dongle are you using? If it is one with a TCXO then the correction should be close to zero, the cheap Chinese ones have corrections as high as 50-60 but never as high as 169.5 the problem often arises when running the default GSM scan as it expects a stick with an offset around 50, with a TCXO stick the scan fails to go down low enough so it locks on to the next highest GSM signal and gives an incorrect offset, try stopping the OGN service and re-run the GSM scan with an initial offset of zero, (you cannot run the scan if the OGN service is still running)
Also unless you are in an area with very poor GSM coverage then you should probably reduce the GSM gain, somewhere around 20-25 is usually sufficient once the offset is correct.
Other than that it all looks pretty good.
Ben. (Aldersht2 / PWAldersh)

[Admin]

Is this an OGN or OGNR ?
I dont see a pilotaware feed to the APRS
Also there is a section on the forum for OGN
Thx lee

[Jumpy07]

Your frequency correction is wrong, what type of dongle are you using? If it is one with a TCXO then the correction should be close to zero, the cheap Chinese ones have corrections as high as 50-60 but never as high as 169.5 the problem often arises when running the default GSM scan as it expects a stick with an offset around 50, with a TCXO stick the scan fails to go down low enough so it locks on to the next highest GSM signal and gives an incorrect offset, try stopping the OGN service and re-run the GSM scan with an initial offset of zero, (you cannot run the scan if the OGN service is still running)
Also unless you are in an area with very poor GSM coverage then you should probably reduce the GSM gain, somewhere around 20-25 is usually sufficient once the offset is correct.
Other than that it all looks pretty good.
Ben. (Aldersht2 / PWAldersh)

Alloy 820T.. ie: the better one..     have set the offset to zero and gain to 20, will see what tomorrow brings.

Many thanks for the reply and pointer
Craig

[Jumpy07]

Is this an OGN or OGNR ?
I dont see a pilotaware feed to the APRS
Also there is a section on the forum for OGN
Thx lee

OGN, should be on the list can see the station on the map and have added it to the station list  (LOCHLMND)

Cheers
Craig

[Admin]

Hi Craig

If it is a vanilla OGN station you may be better joining the google group
Open Glider Network

This is specifically for OGN support, whereas here we are only really concerned with the additional support of the PilotAware Rebroadcast - OGB-R

if you want to add PilotAware Rebroadcast capability, then please email
ogn@pilotaware.com

Thx
Lee