RTL SDR Reciveve and Rebroadcast Remotely (Tv / Radio etc) - Page 1
Forum section: electronics / rf-microwave

author: Mikek400
author_rank: Regular Contributor
timestamp: April 21, 2025, 06:29:00 am
content: A bit of a beginner so please forgive,Had an idea to use an RTL SDR or some other SDR to capture a TV signal far away from me and rebroadcast it locally over coax to my tv. Probably not feasible but sounds like could be interesting to setup if possible.I don't currently own a SDR, but trying to find a reason to buy one.Any thoughts on how to do this?

author: Lord of nothing
author_rank: Super Contributor
timestamp: April 21, 2025, 02:43:54 pm
content: https://www.digital-devices.eu/Business-TV/QAM-SDR-Modulator/https://www.tbsdtv.com/products/modulator-card.html

author: Mikek400
author_rank: Regular Contributor
timestamp: April 22, 2025, 04:37:33 am
content: Thanks for the reply!Was thinking something with the HackRF ONE might be possible. Will keep digging.

author: rteodor
author_rank: Frequent Contributor
timestamp: April 22, 2025, 04:55:25 am
content: What type of signal do you have at the input ? Analog/DVB-C/T/T2 ? I guess DVB-S does not apply.And what kind of signal does the TV take ? Analog or DVB-C ?I know ofthis gr-dvb projectthat is a GnuRadio module for DVB but I have yet to check in what state the project is."Crazy Danish Hacker" YT channel has somevideos featuring it.

author: A.Z.
author_rank: Super Contributor
timestamp: April 22, 2025, 07:48:58 am
content: Quote from: Mikek400 on April 21, 2025, 06:29:00 aman SDR has a software portion which controls the HW unit snd decodes the received signsls now, nothing forbids you from piping the decoded stream to another piece of software which, in turn, may act as a "media server" snd stream the A/V over a network at that point a "smart tv" or a computer may receive the stream and disPlay it

author: Mikek400
author_rank: Regular Contributor
timestamp: April 22, 2025, 08:51:01 am
content: Quote from: A.Z. on April 22, 2025, 07:48:58 amI may end up just doing this and "stream" the tv here using some sort of media center. Would definitely be the simple and easiest solution.Although I thought it might be fun to be bring a TV from Japan (my former home) to here in the US and rebroadcast the signal to it.

author: Mikek400
author_rank: Regular Contributor
timestamp: April 22, 2025, 08:58:37 am
content: Quote from: rteodor on April 22, 2025, 04:55:25 amThe signal is ISDB-T (JAPAN) and the TV would be as well. Would bring tv with me.Not sure if there is any way to just replicate input to output like an amplifier would. Then figuring out how to do it with network / internet pipe in the middle... One thing at a time.Hmm. Will check his youtube channel out.I found this project to broadcast tv over raspberry pi's GPIO pins. Seems... funF5OEO /rpidatv Digital Television Transmitter on Raspberry Pihttps://github.com/F5OEO/rpidatv?tab=readme-ov-fileAs well as a RF transmitter for Raspberry Pi F5OEO /rpitxhttps://github.com/F5OEO/rpitx?tab=readme-ov-file

author: rteodor
author_rank: Frequent Contributor
timestamp: April 22, 2025, 09:26:25 am
content: Quote from: Mikek400 on April 22, 2025, 08:58:37 amMy bad. The world is bigger than I think:From Wikipedia:QuoteQuote

author: radiolistener
author_rank: Super Contributor
timestamp: April 22, 2025, 04:22:31 pm
content: Quote from: Mikek400 on April 21, 2025, 06:29:00 amRTLSDR cannot receive full TV signals in SDR mode because its maximum usable bandwidth is 3.2-3.4 MHz, while analog TV signals require at least 6-8 MHz, and digital standards like DVB-T need even more.However, RTLSDR was originally designed as a DVB-T receiver, so it can be used in its native (non-SDR) mode with appropriate drivers and TV software to receive digital TV broadcasts - though this is not SDR-related.

author: rteodor
author_rank: Frequent Contributor
timestamp: April 22, 2025, 05:33:32 pm
content: Quote from: Mikek400 on April 22, 2025, 08:58:37 amThere are potentially many ways to do this. The simplest one I see does not involve an SDR but only RF equipment: oscillator, mixer, filter and maybe an amplifier: receive the ISDB-T channel, translate it to another free channel and re-transmit it. Maybe do the re-transmission over coax as not to transmit in the air.If you want to involve SDR(s) to decode and recode from and into ISDB then ... hmm, its quite a lot of "fun". And you need 2 SDR's.A bit more simple would be to just decode ISDB and broadcast it into network/internet in some form that the TV would accept.Quote from: Mikek400 on April 22, 2025, 08:58:37 amI knew about 'rpitx' for transmitting relatively low data rate info. But 'rpidatv' is another level. DVB needs more bandwidth (like 8MHz) and more complex modulation and its all transmitted by jiggling a GPIO ... I must say I am impressed.I am not sure that this GPIO Tx transmitter is practical: it can not have too much range, needs an antenna. Oh, and yeah ... it needs a filter otherwise its also a short range jammer.Sure, it makes a nice one time learning project but I have some doubts.Also 'rpidatv' project is for DVB and not for ISDB.

author: Lord of nothing
author_rank: Super Contributor
timestamp: April 22, 2025, 07:20:16 pm
content: Normally there are Server who run 24/7 do that stuff.First you need a Demodulator Card = a "normal" TV Card and some kind of special Software also a Modulator Card (see my Links) to make a TV Signal out of it.That normally is done in big Installation where you need a one Cable System.Depend of the Facility it got replaced by IP TV where the Server make an normal IP Stream. That work in an Closed Environment like an Hotel or Hospital.There are also (for Europe at least) Company who produce Systems who can distribute DVB-S(2) over Fiber where a 1:1 Signal as you would get from a Dish come out.I do at Home IP TV where my Box at the Attic receive DVB-S(2) and on my Virtual Server a TV Card Software connect to them to record the Program.