tinyGS brain dump

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 Super rough brain dump of some of the process of re-using some of my old satnogs antenna / LNA hardware on a tinyGS.

Satnogs has lost their way for a while now. Just flakey software and an overall bloated experience.
I wanted to press the UHF and VHF antennas into use, so figured I'd move my single tinyGS from its V-Dipole to the UHF antenna and spin up a new receiver for the VHF antenna setup. 
(This has the nice side effect of freeing up two raspberry pi's, two RTLSDR V3s and some assorted cables for ACARS work).

The UHF antenna has a built in LNA, so the current Bias-T that is powering it remains.
Just a matter of moving the ESP receiver from the V-Dipole coax to the end of the Bias-T.
I'm not too interested in tweaking it any more than its current setup.
Easy to see when the move took place in the packet count graph. The coverage heat map looks healthy enough, so we are done here.

thebaldgeek_433 tinyGS

The 137Mhz setup took a tiny bit longer because of my interest level in what the beep Starlink are doing on that mode on that frequency.... (I don't have an answer to that one - please comment if you do know for sure).

The other reason I wanted to do this is because weirdly, I am only the third 137Mhz tinyGS in all of USA. That seemed a bit odd and so I was interested in adding some more data to the pool and to see what all is involved in this odd mode.

The VHF antenna does not have a built in LNA, so I need to raid the spares draw and see what we had.
LNA4ALL and a NooElec SAWbird+NOAA (And an FM trap filter - which I removed in the end).

So, lets hook some stuff up and see what we get.
First up, needed a baseline.


My visualization method for all my ham / satcom / ACARS monitoring is Node-RED feeding RESTful data to a HTML5 responsive zero code dashboard that the company I work for has.

Getting the required data took two MQTT topics, one API call and a http GET.


Honestly, I found it a bit odd that it took that many hoops to jump through to get a reasonable dashboard payload together.

The top pink MQTT node fires off a JSON payload when the first (beginning) packet is detected. (AOS? Acquisition Of Signal) and the second pink node below it fires off a JSON payload for every frame decoded (Bad CRC or not).

Below that, the yellow HTTP API call node gets the health of the station.
Lastly, the odd tricky one is getting the station NF.



The tinyGS ESP has a little dashboard that requires you to log in to see (and another page to setup the station and lastly another to update its firmware).
The odd thing is that the NF (noise figure) is only here on this little dashboard page. 
I faffed about trying to screen scrape the HTML to get it, but then stumbled on the 'hidden' URL of the IPaddress/wm 
No idea what 'wm' stands for but hit that URL and you get a CSV of pretty much everything you see in the three boxes on the screenshot.

So, now you can build a bit of a dashboard...



It was interesting to see the NF improve just by moving from a good quality USB-A phone plug pack to a linear power supply. I should move the 433Mhz setup over to the same supply since the ESP LoRA boards are super low power compared to a Raspberry Pi and RTLSDR.

Not surprised to see the NF take a dive with the wide open megaphone LNA yelling into the front end of the ESP.
It is also odd to me that everyone is using a 433Mhz board on 137Mhz, but moving on....
The big jump came when we put the SAWbird on. This makes some sense. Its got quite a bit of filtered gain. NooElect tend to over-gain their stuff to the point of instability, but in this brute force use case, I suspect its a good thing.

So, enough in the roof space work. Let's let it run for a few weeks and see how we go.
I'm currently waaaaay outperforming the other two tinyGS stations in USA, but not doing anywhere near as good as the guy in Australia, VK2PSK near Canberra.

Do you 'have' to make your own dashboard? No, just throw the thing together and have fun watching whatever you get on the daily totals, but RF is an interesting topic for some, me included. Measuring and quantifying the changes is useful. The interesting thing about the tinyGS ESP is that unlike an SDR where you can run a waterfall and see what's going on, here you are blind. You can't see if you are overloading, have interference nor can you change the gain value (that I know of). 

Honestly, it did not take me a lot of time, about an hour all up and I needed a mental health break from ACARS / Iridium / airframe database stuff.

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