Langstone build thread - join in the fun!

[G4FKK]

Crikey, that was quick! I didn't notice your post until just after I shut the Langstone down for the night. I'll update tomorrow

I think they should move GB3BUX off 70MHz exactly. There's all sorts of sproggies there these days

Cheers,

Martin - G4FKK

[radiogareth]

Interesting, It certainly did transmit on 50MHz but I couldn't make sense of what was happening on rx. It was certainly receiving something but it didn't seem to match the input signal.....AFAIK it CAN be done (SATSAGEN uses it) but I'm not the one writing the SW so I should be quiet!
Whatever, it's not as if we are short on other solutions for 50Mhz
Loosely related, and as a beginner in Linux, how do I edit the python file if I want to experiment with a different sound-dongle/card?
I have no idea how to get into the relevant file(s) but have managed to get reports of what my system is seeing.
If its complex no problem please ignore but if one sentence would 'open the box' I'd be grateful.
Gareth G4XAT

[g4eml]

Hi Gareth,

The transmitter seems to work down to about 47MHz. The receiver might have appeared to be working but it was actually still receiving at 70 MHz. Any attempt to move below that seems to be ignored by the Pluto. As it seems to stop at exactly 70MHz I suspect it is a limit encoded in the driver. Other programs might be able to receive lower by using a high sample rate but the pi can’t handle that.

Editing the files is relatively simple but requires a little knowledge of Linux and comes with the usual risks of messing things up.
First you need to SSH into the Pi as you did when you built the card.

cd Langstone
./stop
nano Lang_RX.py

Nano is a simple text editor in Linux. You make the changes by moving around with the cursor keys. When finished you use <control>O to save the file and <control>X to exit.

./run



As an alternative, if you really don’t want to get involved with Linux you could install something like FileZilla on you PC. That will allow you to connect to the Pi and copy files back and forth to you PC. You can the edit them using notepad or Pspad.

73
Colin G4EML

[G8GKQ]

Hi Gareth

It's all down to personal preference. I use WinSCP for all the Portsdown coding. It means that I can use my Win 10 desktop PC to explore, view and edit all the files on any of the RPis in the shack.

The website is here. https://winscp.net/eng/index.php; make sure that you click on the correct download link, not the adverts!

Dave, G8GKQ

[radiogareth]

Meanwhile, over on the satsagen group on groups.io there are some great pics of how a metal box and some work has added excellent stability to a 0.5 txco equipped Pluto. It would certainly help the one thats in the stock Pluto too, although maybe not enough for the highest bands.
But keeping Pluto screened from the RPi hash (if mounting close together) might be seen as an additional benefit.
HTH
Gareth

[radiogareth]

Not strictly Langstone but the Portsdown (longmynd) bit of it anyway, using MT plugged in to check myself across the shack. Very quick to lock and show a picture. Finally worked out how to make the Amsat-DL "DVB-S2 Demod GUI" to work with both a RTL Dongle and my RSP1, so now I can RX DVBS2 on 70 MHz. LimeSDR and a C920 webcam On a Pi3/Portsdown Buster giving great pictures with sound at 333ks.
Hoping to use some of this for the ATV contest weekend.....
Gareth

[oe6rke]

hi all,

just want to share my langstone which was pretty handy during the iaru microwave contest last weekend. ODX about 100km have been done with just 20mW of the amplified langstone. To get some impression of my setup i put some videos online as well.

Demo FM: https://www.youtube.com/watch?v=AF27mc3WW_k
Demo 9cm via OpenWebRX: https://www.youtube.com/watch?v=SDQ1G_KzqdA

Great project, congrats and very thankful to the creators of this project,

br Robert, 73 de oe6rke

[G4FKK]

Nice job Robert - a quart in a pint pot

73, Martin - G4FKK

[radiogareth]

A few years ago you could hardly have dreamed up this sort of capability. 10 Watts DATV or NB multimode on 5.7GHz via my pair of 22.3dBi flat-plates originally bought for FM-TV on the band. Pluto has had a TXCO change.
There are now TWO 'best things to do with a RPI' - the Portsdown and the Langstone. Thanks Dave and Colin

Gareth

2020-06-12 15.23.27.jpg (96.91 KiB) Viewed 7453 times

[G7JTT]

Morning all
I'm in the process of building my setup , so far I have a 7" screen, RPi4, RPi camera, minitiouner, limeSDR, RTL dongle, sound dongle and 4 port powered hub. I'm now starting to think towards the power requirements, I have a buck converter (xl4015} which is rated to 5A but I'm starting to think this may not be adequate on it's own. So has anyone done any current tests to see what their systems use? And secondly what buck converters are you using ?

Cheers John