Observation 1711434: NOAA 19 (33591) is this bad? any ideas why?

Satellites & Observations Observations
1

Regarding Observation 1711434 …

Hi, trying to get my first observation nailed and struggling to find out where I am going wrong.
Any clues would be much appreciated.
I have had about 12 observations and each is pretty much like this.

Cheers
James

2

Could you provide some more information on your receive setup?

I see your station page mentions use of a V-dipole. These can work, but not always very well. Where is it mounted?

What kind of SDR are you using? Are you using a preamp? How far is the SDR and/or RPi (or whatever computer you are using) from the antenna?

Cheers,
Mark VK5QI

3

That is a “good” observations. I can see the signal in the waterfall, and the decode shows a very basic image. The reception of your station is poor, but it is working.

4

Excellent! Thanks. Step 1 down, now to sort out reception.

5

While writing all of this down I have realised that I have the antenna orientation 180 degrees out. Will fix and update after the next passes tonight.

Thanks, the help is much appreciated.
Setup:

  • Pi3+ with latest (17th feb 2020) image updated from Satnogs.
  • RTL-SDR V3.
  • 10 metres of RG59 coax with F to N type adaptors at each end.
  • An LNA4ALL amplifier at the antenna end.
  • 3D printed housings to ensure accurate angles for antenna and reflector.

Antenna:
V dipole with reflector

  • Two 6.3mm dia Al solid rods, 534mm long, at 120 degrees.
  • PVC pipe housing LNA.
  • Six 534mm AL rods at 60 degrees as a reflector. 272mm below antenna rods.

Currently mounted on side of house 1.8m above metal patio roof. Intend to move to approx 2m above tiled roof once working.

I have ordered a vector network antenna analyser (nanoVNA) to optimise the antenna, however deliver has been affected by problems in China.

Do I need to adjust any software settings to optimise the setup? eg. set gain.

Thanks again for the assistance.
Cheers
James

6

Your gain settings are probably OK. The default gain is ~32 dB or so, with the preamp this should be OK. Is the preamp powered via Bias-Tee? Have you confirmed that the Bias-Tee is active during an observation? (I think others have had to use a pre/post observation script to enable this).

Not sure what you mean by 180 degrees out in orientation - A V-dipole is bi-directional, so being 180-degrees offset should not have any effect.

73
Mark VK5QI

7

Ah! Silly me, forgot to enable the Bias Tee.

After a bit of searching I came across @K3RLD wiki
https://wiki.satnogs.org/Radio#Using_RTL-SDR.com_V3_Dongle.27s_Bias-T_Power_Supply
Have set up to turn on the Bias Tee automatically.
Will update after next pass.

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