Smallest EMWIN antenna

[kt4wo]

Ohhhh ..one other thing. I am seeing a odd looking signal at 1694.5 ....Ideas?

Trip - KT4WO

 

[usa-satcom]

That is DCS relay from GOES to ground from UHF to L-Band.

And a screenshot from my LRIT decoder showing DCS reception (left side). Right side is EMWIN over LRIT service.

https://www.dropbox.com/s/aye0pxmtz1o6y2h/goes15_update.PNG

All of this is also processed and available in one of the virtual channels for LRIT service.

https://www.dropbox.com/s/3mizasd2g2f5vbn/goes_dcs.PNG

Joe

 

[usa-satcom]

This forum would not allow me to post the URL to the NOAA website for the UHF to LBand info on DSC. So see attached picture of the link, type it in or search on google if you are interested.

 

[Titanium]

Spam prevention...
A few more posts and you will be able to post links!

Message me with the URL and I'll post it for you.


Sent from my iPhone using SatelliteGuys mobile app

 

[usa-satcom]

Spam prevention...
A few more posts and you will be able to post links!

Message me with the URL and I'll post it for you.


Sent from my iPhone using SatelliteGuys mobile app

I tried to send it via "conversation" (is that same as message?) but it also triggered the spam prevention and would not allow me to post link.

Joe

 

[Titanium]

Sorry, Joe! I thought the link would be allowed in a conversation. I'll type in the URL when I get on my office PC.


Sent from my iPhone using SatelliteGuys mobile app

 

[outatyme]

How would I go about submitting a sample recording to Joe for him to test with?

 

[usa-satcom]

How would I go about submitting a sample recording to Joe for him to test with?

What SDR do you have ?

 

[outatyme]

SDRPlay, R820T and E4000 based RTL-SDR's

 

[usa-satcom]

I don't have direct support for any of those SDRs, but i can suggest to try this:

1) use sdr-console with whichever SDR is best at l-band
2) set sample rate for 500K
3) tune center frequency at 1692.7 (unless your SDR has a spike at 0, then offset by 50KHz (exactly).
4) record IQ file that is a say 4-5 minutes long (must be IQ not audio).
5) give me a link to that file and i will test it for you.

If that works, then the UDP server part of sdr-console can be used to stream IQ data to my decoder.

If you have an LNA, please use it as it will improve things considerably.

Joe

 

[outatyme]

Allrighty - Thanks Joe! I will go outside and re-peak my grid parabolic.

 

[Titanium]

URL to the NOAA website for the UHF to LBand info on DSC
http://www.osd.noaa.gov/Spacecraft Systems/Ground_Systems/GOES DCS/goesdcs.html

 

[outatyme]

Hopefully this recording is allright.
https://www.dropbox.com/s/dc5bgw9649w2p1j/09-Mar-2016 061007.009 1692.640MHz 000.rar?dl=0

 

[usa-satcom]

Hopefully this recording is allright.
https://www.dropbox.com/s/dc5bgw9649w2p1j/09-Mar-2016 061007.009 1692.640MHz 000.rar?dl=0

Thanks, will try it out tonight/tomorrow is internet cooperates (i'm traveling).

Joe

 

[outatyme]

Gracias. - I just hope I got it right.

 

[kt4wo]

Well,,,,,As my signal was too low I now have a "LNA4ALL" inroute. It's coming across the pond so it may
be a few weeks before I get it and get inline. Will update ya'll when.........

Trip - KT4WO

 

[usa-satcom]

Hopefully this recording is allright.
https://www.dropbox.com/s/dc5bgw9649w2p1j/09-Mar-2016 061007.009 1692.640MHz 000.rar?dl=0

The recording is OK. The signal is stronger than the one I tested from kt4wo. The decoder will lock periodically, however, it's jut on the edge of being a reliable signal. Here is screenshot from decoder. See the yellow highlighted box? That is a good decode, the SYNC is 1ACFFC1D is correct, Viterbi is 392 (which is OK, not great, great is 0) and Reed Solomon corrections is 8 (again, OK, not great). Things would be fine if every frame was like the one in yellow, but it's not. It also looks like you have some broadband noise with l-band, you might try increasing gain a bit to overcome that noise (that won't likely increase SNR however).

https://www.dropbox.com/s/jxdwo69lwvas68v/outatyme.PNG?dl=0

So, you have a couple of options. 1) bigger dish 2) LNA if you don't have one 3) cut trees if you have them in the way 4) if you feed is linear, be sure to rotate for max signal, if your feed is circular, consider linear to add 3dB

HTH

Joe

 

[outatyme]

Thanks for the excellent analysis Joe! I am using an LNA in addition to the LNA built into the sdrplay, there are no trees in the way (will post rig porn shortly) Perhaps the noise is coming from a streetlight in the vicinity or some power lines or the LNA just is not cutting the mustard. Gain was pretty much near maxed out when I did that recording.

 

[usa-satcom]

Thanks for the excellent analysis Joe! I am using an LNA in addition to the LNA built into the sdrplay, there are no trees in the way (will post rig porn shortly) Perhaps the noise is coming from a streetlight in the vicinity or some power lines or the LNA just is not cutting the mustard. Gain was pretty much near maxed out when I did that recording.

If you can get rid of the interference or slightly improve the signal such that each frame decode is like the one in yellow then it will work. Feel free to post another recording if you feel you have improved things.

A good signal will look like this: https://www.dropbox.com/s/aafsaz5etd0ln0u/emwin_sdrsharp.PNG?dl=0

A marginal but OK signal will look like this:

https://www.dropbox.com/s/717mt3yt58pufgo/emwin_min_snr.PNG?dl=0

Joe

 

[doubleohwhatever]

Is that demodulator plugin available somewhere? It looks very similar to the meteor demodulator but I can't find the one in your screenshot on his site.