Re: [Freetel-codec2] FYI: mode 2400B handheld

Fine business Jeroen, Great set up and experiment! I've been experimenting with direct FM modulation of my FT817 using the "data port" connector on the back. This works well, and I can pick up the 2400A signal on a SDR OK. I'm using an external DAC (actually a stm32f4 discovery) with

Re: [Freetel-codec2] FYI: mode 2400B handheld

On Wed, 2 May 2018, Jeroen Vreeken wrote: A small update: the dra818 module is a bit dissapointing. The worst problem: it takes almost a second before it modulates after switching to TX. So I went for a different approach: You might reconsider as I've been playing with one module that works

Re: [Freetel-codec2] FYI: mode 2400B handheld

probably not HARD amplitude limited. sign bit would still rule though... but band limited of course. and if in linear mode, AGCed so there would be a reasonably consistent level there, FM or SSB probably 10-16dB max dynamic range. (guess) still worthwhile doign your numbers to see where all

Re: [Freetel-codec2] FYI: mode 2400B handheld

I like it. good use of undersampling. Although the SFDR of the microcontroller at 4x undersampling is probably in the toilet, since it is band limited, that does not matter of course. very good. Glen - would the FM be limited by that stage? That would mean a simple ADC would suffice, we're

Re: [Freetel-codec2] FYI: mode 2400B handheld

Great work Jereon ! I like it. good use of undersampling. Although the SFDR of the microcontroller at 4x undersampling is probably in the toilet, since it is band limited, that does not matter of course. very good. glen VK1XX On 2/05/2018 8:00 AM, Jeroen Vreeken wrote: Hi all, A small

Re: [Freetel-codec2] FYI: mode 2400B handheld

I would rather add bluetooth support for it. You could then couple it to a smartphone and have all apps. You could even use a headset. On 10 Jan 2018 14:04, "Adrian Musceac" wrote: > Hi Jeroen, > > This is a very interesting project. If there's anything I would > change, I

Re: [Freetel-codec2] FYI: mode 2400B handheld

On 1/10/18, Sebastien F4GRX wrote: > > -during your own developments, avoid reinventing the wheel. Focus on > existing > open standards when one exists. For example, use IP, TCP, and things like > that. > We have a full class-A 44/8 IP network reserved for our own ham use. That's

Re: [Freetel-codec2] FYI: mode 2400B handheld

On 1/10/18, Sebastien F4GRX wrote: > Hello, > > Yes we need to get more people interested in open DV systems. > Lack of interest is a BIG problem. I have my own project which I mentioned here before. It's basically a PoC, a toy, without much use outside of making "cool" demos or

Re: [Freetel-codec2] FYI: mode 2400B handheld

Hello, Yes we need to get more people interested in open DV systems. My part of the job at the moment is building an UHF modem that also talks ethernet, so we can connect it to hamnet. It will be a kind of accesspoint for mobile units, OR, a gateway to build long range hamnet UHF links. One of

Re: [Freetel-codec2] FYI: mode 2400B handheld

On 1/10/18, Jeroen Vreeken wrote: > http://dmlinking.net > That's a very well architected project, and I'm not saying it lightly. Unfortunately the user docs are quite sparse, and it does not have enough visibility. Basically I would have liked to know if I could use that to

Re: [Freetel-codec2] FYI: mode 2400B handheld

There was a project based on a CML Micro chip (the same one used in Tetra handsets), I think Bruce Perens was its godfather. It sounded very interesting considering those chips were not very expensive, but I have no idea what the status of that is currently. My main concern is coming up with a

Re: [Freetel-codec2] FYI: mode 2400B handheld

Let's build a module with these: http://www.analog.com/en/products/rf-microwave/iq-modulators-demodulators/iq-modulators/adrf6755.html http://www.analog.com/en/products/rf-microwave/iq-modulators-demodulators/iq-demodulators/adrf6850.html some manufacturers may even have IQ transceivers on a

Re: [Freetel-codec2] FYI: mode 2400B handheld

On 01/10/2018 02:11 PM, Sebastien F4GRX wrote: have a look at the hermes lite 2 ( http://www.hermeslite.com ) It is in the process of being finalized, and can work with a raspi host. I am also working on this: https://github.com/f4grx/hn70ap Not SDR, more SDFSK (with a si4463) some boards

Re: [Freetel-codec2] FYI: mode 2400B handheld

very interesting! I did not know that! Thanks for sharing! Sebastien Le 10/01/2018 à 14:48, Jeroen Vreeken a écrit : > On 01/10/2018 02:14 PM, Sebastien F4GRX wrote: >> Reading again these boards are more the basestation part of the system. >> >> But a freedv handheld is also something that can

Re: [Freetel-codec2] FYI: mode 2400B handheld

On 01/10/2018 02:14 PM, Sebastien F4GRX wrote: Reading again these boards are more the basestation part of the system. But a freedv handheld is also something that can be VERY interesting. As well as inventing a real solid open digital voice architecture made by hams for hams. Something that

Re: [Freetel-codec2] FYI: mode 2400B handheld

Reading again these boards are more the basestation part of the system. But a freedv handheld is also something that can be VERY interesting. As well as inventing a real solid open digital voice architecture made by hams for hams. Something that could work with open standards, like hamnet, SIP,

Re: [Freetel-codec2] FYI: mode 2400B handheld

have a look at the hermes lite 2 ( http://www.hermeslite.com ) It is in the process of being finalized, and can work with a raspi host. I am also working on this: https://github.com/f4grx/hn70ap Not SDR, more SDFSK (with a si4463) some boards are being made right now. freedv software can

Re: [Freetel-codec2] FYI: mode 2400B handheld

Hi Jeroen, This is a very interesting project. If there's anything I would change, I would add a more powerful CPU, capable of running some other applications, like chat, maps, email, pictures. Otherwise you could end up for example receiving a position report but no being able to plot it without

Re: [Freetel-codec2] FYI: mode 2400B handheld

That's a neat CPU. By the way SV1AFN has some nice designs for the 818 chip (output filter, etc). https://www.sv1afn.com/dra818.html I was thinking that the only thing missing was: 1) a Doppler correction input for satellites. 2) PPS output from GPS for syncing to time slice generator.

[Freetel-codec2] FYI: mode 2400B handheld

Hi, For a while now our local repeater PI2EHV has been capable of receiving both analog FM and FreeDV mode 2400B. However the amount of digital users is low (not a big surprise). Inspired by the SM1000 I have been thinking about a project to make using it easier: A small handheld capable of