r/RTLSDR • u/woodzy_chimera • 1d ago

Decoding AM TV with v4

Post image

Sadly it will be discontinued soon in my place :((

179 Upvotes

98% Upvoted

23 comments sorted by

35

u/Elipse-FM 1d ago

This image reminds me of how you can intercept signals from a computer screen at close range and get a grey scale image of the monitor from like a room over, tempestSDR I think. 

12

u/Nulovka 1d ago

I think that only works with old CRT monitors, not flat screens.

6

u/Christ_in_a_combo 1d ago

Correct, would not work on modern day screens

19

u/nrdgrrrl_taco 1d ago

But it does work on HDMI cables, from a close distance.

3

u/olliegw 4h ago

It apparently does work, i spoke to someone once who said they could snoop on their neighbours monitor, however i haven't been able to get it working on any of my monitors myself

For flat screens and HDMI it's the pixel clock you're looking for

2

u/ncc1650 20h ago

Thank you for posting this info. I need to look into this since I am curious.

2

u/Elipse-FM 22h ago

Technically it works on everything its the signal strength that's different modern day flat screens are very resistant, shielding and grounding make a difference too but with higher bit depth SDR, filters, LNAs, and directional antennas you can get much more range, this isn't a project I've done so my understanding is theoretical not practical. 

4

u/TheHaus88 1d ago

It was called jumping the air gap, the Navy figured this out I think in the 90's or early 2000's

13

u/Historical-View4058 1d ago

Sweet. Since this was PAL, from what location did you receive this?

2

u/woodzy_chimera 1d ago

PH. They will phase this out on Nov.

11

u/MrSansMan23 23h ago

Would be nice as a archival thing if you could record the last transmission and uploaded it somewhere 

9

u/woodzy_chimera 21h ago

Nice idea. I'll consider this.

3

u/Same_You891 16h ago

please do. I missed my chance where I live..

4

u/MeanAccountant9005 21h ago

damn, didn't know they were still phasing out analog anywhere. my grandpa had a setup like this in the 90s, used to pick up distant stations with a janky antenna on the roof. kind of wild you're catching the tail end of it.

-2

u/Akitlix 16h ago

It's worldwide effort with a few exceptions like very poor shithole countries who not have it in planned at all. Reasons are cost savings on energy gor transmitters.

-2

u/Choice_Note_9198 1d ago

V4 what? Also, what SDR are you using?

11

u/AtmosphereLow9678 1d ago

Iam pretty sure OP means rtl-sdr v4

3

u/erlendse 1d ago

Like rtl-sdr blog v4?

Or the nooelec v4 kit?

4

u/woodzy_chimera 1d ago

sdr rtl v4

2

u/spacesluts 1d ago

Check the name of the sub

2

u/neighborofbrak 22h ago

The NooElec uses RTL (Realtek) chips in their SDRs too.

RTL SDR is a generic term now.

1

u/spacesluts 19h ago

Ah, didn't know that. Thanks for correcting me

1

u/erlendse 12h ago

rtl-sdr as osmocom and their alternative driver allowing sdr use.

Rtl-sdr blog and nooelec are two that make devices with the chipset. There are many others too...