some questions

Everything technical about radio can be discussed here, whether it's transmitting or receiving. Guides, charts, diagrams, etc. are all welcome.
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yentzee
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some questions

Post by yentzee » Thu Jul 21, 2022 7:10 pm

Hi,
I was wondering what would be the better option. Setting up a computer at home that grabs the stream multiplexes sends online again which is taken up by a raspberry pi which then sends the audio output to the gunnmodulator which sends to the transmitter.
Has anyone tried using ESP 32 with LORA? I heard they can connect up to 6 kilometers.
Also I was wondering if it is possible to have the raspberry pi grab the stream and multiplex.
Considering that people will play from their studios that might be a better option but I don't know if this is working.
From what I read the raspberry pi needs 192 khz output for rds and mpx to work. Does the microwave link allow to transmit that or is the signal once processed fine to go and not in need of a super highfi connection?

Sorry for maybe asking dumb questions I just havent figured out what the best concept is.
Oh and stereo tool is sold for 300 Euro but there seem to be downloadable versions on their website as well. What is the difference?

Cheers,
Jens

jvok
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Re: some questions

Post by jvok » Fri Jul 22, 2022 1:54 am

LORA is very low bandwidth (kbps) and only allows very infrequent transmissions of small packets (a few kb minutes to hours apart). Not useful for sending continuous high quality audio streams.

Albert H
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Re: some questions

Post by Albert H » Mon Jul 25, 2022 1:56 am

The "free" Stereotool plays an ident every half hour, making it useless for actual broadcasting.

The way I've done it is to use a Raspberry Pi with a 192kHz sound card (there are several on the market that connect straight to the Pi I/O pins), and run stereo coding, RDS and stream receiving software on the Pi. There are lots of Open Source tools to do what you need, but you're going to have to learn some coding.

The studio end is much simpler - another Raspberry Pi with an audio input card running "DarkIce", and sending the programme stream to the 'net.

I use a streaming hosting company to forward the stream from my studio end, since you (usually) cannot guarantee the I/P address of the receiving end (particularly if it's using a public wi-fi service). I keep the address of the stream private. The nosting server is configured to allow other studios to contribute remotely, too, allowing other DJs and presenters to send their programmes from their home studios. This was particularly useful during the Covid "lockdown" idiocy!
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yentzee
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Re: some questions

Post by yentzee » Tue Jul 26, 2022 7:21 am

Awesome, thanks a lot for helping :)

yentzee
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Re: some questions

Post by yentzee » Mon Aug 08, 2022 1:53 pm

Sorry for asking again. Will a raspberry pi zero 2 w be strong enough to do the work or do I need a regular model and if so from which model on this will work without problems? The prices went up like mad unfortunately

Albert H
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Re: some questions

Post by Albert H » Tue Aug 09, 2022 4:25 am

The Pi Zero works well. Don't try to do too much with it! You can used the minimal version of Rasbian, or any of the other small Pi distributions. You don't even need it to run a desktop!
"Why is my rig humming?"
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yentzee
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Re: some questions

Post by yentzee » Tue Aug 09, 2022 1:05 pm

Awesome, thanks a lot for your help. I suppose I can just ssh into it. So I could get a used pi zero as the zero 2 w got ridicolously expensive.
So I then could use PCM5201A DAC to output the multiplexed signal to the transmitter.
Just out of curiosity - considering we are talking about a non licensed broadcast, where do you pull the wifi? Using some linux tools to get into a wifi or a directional antenna to grab a free wifi of somewhere or is the pi in a link site and you send the signal using microwave? I still got a ck horn and some satcans somewhere at my parents house but I suppose it would be way more elegant to have a wifi connection on site. Not sure how much the pi can handle but maybe it could even do a small webserver allowing to switch some relais. gonna check ebay for a zero now. Thanks a lot for helping :)

jvok
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Re: some questions

Post by jvok » Tue Aug 09, 2022 1:50 pm

MFJ do a wifi yagi with 15db gain: https://www.radioworld.co.uk/wifi_24ghz ... 02_11g_wir

Some back of the envelope maths makes me think you could probably link over a mile or so using one of these at each end. One day I'll get round to buying one and try it.

yentzee
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Re: some questions

Post by yentzee » Wed Aug 10, 2022 1:13 pm

there are some china wifi adapters that can up their watts so this might be an option worth trying.

jvok
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Re: some questions

Post by jvok » Wed Aug 10, 2022 3:21 pm

Got a link for the high power wifi cards?

yentzee
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Re: some questions

Post by yentzee » Wed Aug 10, 2022 5:04 pm


yentzee
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Re: some questions

Post by yentzee » Wed Aug 10, 2022 5:05 pm

Didn't measure or anything but I remember to get it working using linux.
I might check the next days. It is somewhere inside a box. Just need to find it

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reverend
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Re: some questions

Post by reverend » Thu Aug 11, 2022 8:14 am

Albert H wrote: Mon Jul 25, 2022 1:56 am The "free" Stereotool plays an ident every half hour, making it useless for actual broadcasting.
That's not strictly true. Some of the features are available without a licence, however the ones which make the biggest difference to sound quality (such as the MPX clipper) do require a licence. There are lots of 'free' pre-sets available on the Stereotool forum, but these will never be as loud or clear as ones which require the licence.
if it ain't broke, keep tweaking

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