RF (Radio Frequency)

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I have always enjoyed older technology and love vintage radios and TV's. This brings me to my project at first I thought lets make another radio but you know what that has been done so many times and then I thought doing something with SDR but once again that has been done many times and its been since the pi2 release that I last dug deep into SDR.

 

That only leaves me with one option......

 

As you can tell by the title of this blog post that is correct a Raspberry Pi TV Broadcaster.

 

First thing I have to look at is what my options are for raspberry pi's. The first pi with its RCA output would certainly be the quickest route but then would suffer later on with hardware limitations when it came to rendering or even broadcasting live video.  But this will make a great testing board then I can move it on to another board with a bit more power and ram for those higher bit rate videos.

 

So I decided if I was going to use the pi1 for testing I would have to grab some cartoons to start my testing because you certainly want to make sure if you are broadcasting anything its pretty PG in description until you figure out ranges.

 

Parts and parts.... lets see what we will start with on this project.

  1. Raspberry Pi 1 (for testing)
  2. Raspberry Pi 3b+ (for final build)
  3. RCA Cable
  4. 3.5mm headphone jack to RCA adaptor
  5. Random RF Modulator
  6. Game Elements GPSICC2 integrated command centre
  7. A few TV Antenna's  (1 powered and 1 non powered for testing)
  8. coaxial cable
  9. VCR
  10. OLD TV with actual tuner knob (analogue) (so we don't have to auto-scan on newer TV's over and over)

 

The first thing I will do is take the pi1 and install noobs on it and get it up to date....as I am doing this I am thinking to my self right away this will not work at all for website streaming services which will be done on the 3b+ once we get there for now it will be VLC Player windowed mode so we can get some sound and video playing.  even as a smaller player I noticed the pi1 was running at 100% the whole time the video was playing.  I am sure if I overclocked it we might see some improvement but once again this is just for testing to make sure we can output so its not a huge worry at this current time. After removing the pi from the internet I was able to run VLC in a larger window that at least filled up the screen when the video was playing but full screen was having issues.

 

So what better way to test then use good old classic cartoons nothing beats a good session of watching some bugs bunny.

 

Lets start with what failed....

First off I thought I would try the old fashioned VCR with a powered antenna.  This didn't work but it probably could have but due to not finding the issue in my powered antenna this was passed over for now possibly revisit this again after.

Secondly I decided I would try a RF Modulator with the powered antenna on it.  Even after finding the fault in my antenna this didn't work  I had plugged RCA out from the pi to RCA in on the modulator then on the coaxial the powered antenna.

Seems I got a lot to learn when it comes to RF but sure if fun to play with.  Slowly finding more and more connectors and items while working on this project seems I had more thing then I thought that would be useful but will visit that down the road when experimenting a bit more.

 

So onto what did work...

The tv I used is silver but the same as this one here.

 

So with the raspberry pi connected to the icc2 (integrated command centre)  to the input we then plug in the antenna to the tv out on the coaxial rf.  I thought at first I would run it through the RF Modulator then into the ICC2 but after testing it wasn't going to work I thought I might get a bit of a power boost that way.

 

 

I had issues with the antenna and I really wouldn't suggest anyone buy it here is a link to it just for reference of what not to buy.  https://www.amazon.ca/gp/product/B07CLGB8WY

So after testing and pulling it apart the only simple solution to get it working was this.

 

 

I mounted the antenna on the wall in my office as high up as I could cause that just made sense to me and its just a odd antenna in my books.

 

OK so when I was first testing I did run a coaxial cable from the tv out and then was able to touch the antenna so that I could tune in the channel before seeing if I was able to broadcast to it without any cables this worked but i noticed the tv might have seen better days as well.  I thought I had another around but I must have put it in the recycling pile at some point since I had 3 of these tv's just laying around forever.  You just never know when a project comes up and you want to use them right?

Now it was on to the moment of truth with how well it ended up looking.  Now I know there is lots yet to explore and play around with which I will get to as I am  having lots of fun with it and love being able to broadcast on older equipment you never know what will end up on the bench that might require some old school flavor.

 

Well that's not that bad I wasn't sure I was even going to get to this part as I have just been playing with this in my spare time. I had planned to make my own antennas and try to make something a bit more portable but that will come in time as I learn more and more cause really there is just so much I had forgotten and so much I didn't know that I have to learn now.

 

So possible options going forward would be to attempt to try on the VCR again I did have a VHS playing (flash dance) which was pretty clear when I first attempted to run coaxial to the antenna so will have to see on that.  I would love to just build my own board and powered antenna's that is on my list of things to do for sure.  Now I might not know as much as most on the subject I have to say its still fun to play with and with parts that I had laying around plus a junker antenna from amazon I was able to get it working.

 

I would certainly like to test on a few other TV's as well as I really do think there is something up with my TV.  There we go a pi1 still working away broadcasting some good ol WB Cartoons. There is lots to learn and lots of fun to be had with playing with old equipment but for now until later......