AMPKT – Amateur radio packet explorer

[mzerod]

I have a QPSK & BPSK packet radio link to several other stations via the QO-100 satellite narrowband transponder, using a couple of Pluto SDRs and in some cases a mix/match of RTL SDR dongles and 70cm radios with transverters.

Only a small group (4 so far) doing it, but we can be heard on the WEBSDR hosted at Goonhilly Earth station[1]

Due to small dish sizes on RX (10GHz) we are keeping it simple and open at 1200 BPSK and QPSK 2400 with IL2P[2][3] for FEC+RS robustness, and not even close to the 2.7Khz max permitted bandwidth.

[1] https://eshail.batc.org.uk/nb/ - 10489630 USB

[2] https://tarpn.net/t/il2p/il2p.html

[3] https://eindhoven.space/il2p

[sidewndr46]

This is very cool. I wish those of us in North America had access to a satellite like this

[hexagonal-sun]

This is a project to connect two Linux machine's network stacks via the amateur radio bands. It uses Linux's TAP interface to read & write packets at layer 2 to/from the kernel. QPSK modulation is used at the RF layer.

For now experimentation has mainly been done in a Ramsey box. The next step is to add a callsign field to the QPSK frames so the data can be legally TX'd.

[drmpeg]

You'll like my IP over DVB-T2 test bed using GNU Radio. It uses the ULE protocol dvbnet driver that's built into Linux.

Not shown on the diagram is that it also supports IPv6.

https://www.w6rz.net/ofdm3.png

[kunwon1]

I recently got back into amateur radio with an SDR (listening only, my license has lapsed and I need to renew it)

I found that using the FT8 protocol, I can pick up transmissions from up to ~6000 miles away, using a very cheap magnetic loop antenna mounted indoors in my apartment. My building is made of concrete slabs and I was pretty shocked that I was able to receive such distant transmissions.

I think I've invested maybe $70 into radio equipment for this capability. I've listened to a lot of other signal sources, but so far FT8 is the most interesting. I can run a companion app that maps out all the contacts, it is pleasing to watch on a nice slow evening

[bmitch2112]

FT8 is lots of fun. Even more fun when you go to a park or up a summit and see how far you can get out and how far you can hear.

You don't need very expensive radio equipment to transmit FT8 so if you do get your licence back it is worth looking into.

http://qrp-labs.com/qdx.html

[nvy]

Wow. Can you link to the antenna you use?

Could you achieve those distances transmitting with the same antenna, assuming you renewed your license?

[JKCalhoun]

Interesting. Also interested in getting into this. I have played with SDR, not FT8 though. Maybe you can point to a site that helped get you started with FT8.

[lobsterslive]

If anyone is looking for a really good place to get started with SDR, I'd highly recommend the RTL-SDR Blog V3:

https://www.amazon.com/gp/product/B0BMKB3L47

[cogman10]

Dumb question (and maybe this isn't legal?) but are there SDR transceivers/libraries?

It'd be neat to have a zigbee/zwave hub with my SDR so I could mix and match some stuff.

[jonah]

Note that you're not allowed to use encryption or engage in commercial activities on the amateur bands. (In the USA but probably in other countries as well.)

[kwk1]

An important distinction is that what's not allowed is "messages encoded for the purpose of obscuring their meaning", not encryption altogether, which means things like digital signatures can be permissible, if the public key is available through well-known means or included as a separate part of the transmission.

https://www.ecfr.gov/current/title-47/part-97#p-97.113(a)(4)