Can a mpx'ed signal be transferred through microwave or does the mpx has to be done at the transmittersite?

MPX can be sent over a microwave (and VHF, UHF) link without problem, as long as the channel has a flat bandwidth of at least 100khz.

Yep thats usually how stereo is done, otherwise if you were sending raw audio then you'd need 2 links

Thanks

I used to send a complete composite across my link system - stereo, RDS and control data to select power supplies and so on.

Perfect. I am just visiting my parents where I have a couple of microwave antennas, modulators and satcans. I started that project 15 or so years ago when I was living in the UK but never transmitted as the local scene seemed pretty rough and the officials very well trained which didn't seem like a good framework for a complete beginner to practice. I am now living in another large city with a comparable electronic music scene and I thought I might give it another try.
Ohh and by the way.. thanks for helping and answering all those questions

Yes, Microwave is cheap but has lots of difficulties..

A Dell Optiplex 790 / 7010 / 9020 with a dongle and prepaid card is a bit more expensive but way easier

Microwave is a good solution for secure short links, if you're prepared to do some work to get them right. I've frequently used them out from a studio to a mid-point, and then UHF from the mid-point to the main rig. In a few set-ups, I used multiple microwave "hops" for added security (and range) and then UHF (usually) for the last stage.

Properly done, a microwave link is a pretty reliable and difficult to track system. If you have reasonably concealed transmit and receive ends, and use UHF (with ordinary TV Yagi aerials), you're reasonably safe. It's just too much hassle for the "authorities" to try to locate those links. They usually just rely on the stupidity of the average DJ to reveal the location of their studio......!

ronald001 wrote: ↑Thu Sep 01, 2022 1:55 pm Yes, Microwave is cheap but has lots of difficulties..

A Dell Optiplex 790 / 7010 / 9020 with a dongle and prepaid card is a bit more expensive but way easier

Why those pcs specifically? Theres mini pcs much smaller than a full size desktop that would be better. Hell even a raspberry pi would do the job and be cheaper than almost anything

jvok wrote: ↑Thu Sep 01, 2022 2:14 pm

ronald001 wrote: ↑Thu Sep 01, 2022 1:55 pm Yes, Microwave is cheap but has lots of difficulties..

A Dell Optiplex 790 / 7010 / 9020 with a dongle and prepaid card is a bit more expensive but way easier

Why those pcs specifically? Theres mini pcs much smaller than a full size desktop that would be better. Hell even a raspberry pi would do the job and be cheaper than almost anything

- These machines are also available in small SFF or USFF housings
- Costs virtually nothing (somewhere between 35 - 55 euro)
- Direct 192Khz (MPX ST/RDS) out, no need for an external soundcard
- Runs on windows, less difficult than Linux
- Can run Stereotool or Breakaway One (Rasp can also run ST but with limitations, BAO is not available for Linux )

Intelligent people find Linux MUCH easier than Windoze. There are just too many problems with M$-ware. It's unstable, virus-prone, expensive and has huge amounts of bloat. It's also proprietary and "phones home" all the time (even though M$ claim that it doesn't). I know of two stations in Eastern Europe who were located by the "authorities" because of their use of Windoze computers.....

Incidentally, ST and BAO are horrible compared to a properly professional system!

If you want a minimal Linux install, you can get the whole thing - including the streaming software and any required drivers - well within 1 Gb. That will fit on a cheap SD card. You can get a minimal Raspberry Pi with wi-fi built in (Pi Zero W) for ~£10 and a suitable 192 kHz soundcard for just over £5. The hardware will fit inside a tiny aluminium box, and requires just 250 mA @ 5V. As usual with Linux, software is free. You might have to learn a little, and type a simple configuration script, but it will run forever without intervention, and a simple one-line Bash script will make sure that it's connected to the 'net, and re-try if it isn't. You can even include silence detection, and have it trigger a cheap mp3 player with an "emergency" programme if the "link" is lost.....

Albert H wrote: ↑Tue Sep 06, 2022 9:28 pm Intelligent people find Linux MUCH easier than Windoze.

Yes i know... i'm dumb - just like 95% of the people on the planet who are using Windows.
Also which pirate radio stations invests 4 ~ 8K in an Orban or Omnia? (Except for a few dutch pirates who are also running 15Kw on a 100meter crane )
For the rest i can say that almost everyone over here are running the same setup without any problems, no one gets caught and with proper tweaking they are louder than most commercial station...

BTW the only way to send MPX over the internet is with MicroMPX (ST product) of with Livewire - and a Pi Zero does not have enough resources for that to run...

Errr.... no. You're using Linux already, but you don't realise it. Did you know that when you type any web URL you're issuing a Unix command? Every web server, web switch and every part of the Interweb Infrastructure is exclusively Linux-based. Your home router, your mobile phone, your printer, your TV and even your car will already be running Linux. In Europe, ~50% of desktop and laptop computers run Linux, and if you go to China, India or South America, it gets close to 90%!

Windoze (and Mac) are now just poor proprietary clients for a Unix / Linux world. M$ will alienate even more of their userbase when they start charging a monthly fee for a "licence" to use Windoze. You'll have to rent applications by the hour....

Did you know that Unix / Linux / BSD is virtually exclusively used in modern computing courses in Universities? There's a good reason for that.....

Get with the programme! The days of proprietary crapware are almost over, and our productivity, security and safety will all be improved by the demise of the dreadful rubbish that is Windoze. Did you realise that Dave Cutler's original, unfinished and incomplete 1988 kernel is still used in Windoze 10 / 11? M$ still fondly believe that security is something that can be maintained by not revealing the innards of their "Operating System"..... Do you know just how many pieces of Windoze malware there are? Do you not understand that there cannot be Unix / Linux / BSD malware - simply because of the proper "permissions structure" built in at the most fundamental level?

Using a pi sounds pretty awesome. Unfortunately at the moment the prices are ridicolously high. I still have a 3b+ but that sits in a gameboylike case with a teensy and midi interface attached on a small board running m8 tracker software and I don't want to give that up for now.
Does anyone know, if for the receiving site an esp32 with the same dac (i2c connection I believe) could be used and either stereo and rds done by hardware or if possible encoded at the linkstation and send within a stream? Stereotool says it does send the mpx in a stream I think. Esp32 is quite powerful, there are icecastprojects on github and they are very cheap.
Unfortunately I haven't even started putting things together to be able to test so it will take quite a while until I am at this stage. By the way there are esp32 boards with a connector to connect a wifi antenna, one smd has to be removed and two contacts bridged for the antenna to work. Even if small it isn't too difficult.

I2c is too slow for audio, you want a dac with i2s

yentzee wrote: ↑Wed Sep 07, 2022 6:49 pm Using a pi sounds pretty awesome. Unfortunately at the moment the prices are ridicolously high.

Prices not too bad at RS Components.

It's also worth checking out some of the other single-board computers. I've used the "Orange Pi" in a couple of projects.

Albert H wrote: ↑Wed Sep 07, 2022 11:29 pm It's also worth checking out some of the other single-board computers. I've used the "Orange Pi" in a couple of projects.

I saw those. Are those 1:1 clones or more or less comparable? They go for way less money than the original rapsberry stuff. Which one did you use?

Albert H wrote: ↑Wed Sep 07, 2022 11:29 pm It's also worth checking out some of the other single-board computers. I've used the "Orange Pi" in a couple of projects.

I saw those. Are those 1:1 clones or more or less comparable? They go for way less money than the original rapsberry stuff. Which one did you use? For wifi you just added a usb wifidongle (with antenna port?)

No they're "sort of" clones. Close enough in most cases, but they have their own OS which can be a bit tricky to use.