* You sharing a room with a analog CRT Television set in Europe (NL) (empty analog tv bands)
* <del> You have a HAM radio license and call sign (legally usable section of the band (6meter, 50MHz)) > TV signal's bandwidth is too high to be legally transmitted (4.5MHz). Only sstv is allowed on carrier: 50.510 MHz, with Bandwidth of: 1.2000Mhz (Our signal is 4.5Mhz....)</del>
## DISCLAIMER
This is illegal. Don't make it. What can you transmit with license:
## Disclamer
This is probably illegal in your counrty. Don't build this. What can you transmit with license:
* <del> You have a HAM radio license and call sign (legally usable section of the band (6meter, 50MHz)) > TV signal's bandwidth is too high to be legally transmitted (4.5MHz). Only sstv is allowed on carrier: 50.510 MHz, with Bandwidth of: 1.2000Mhz (Our signal is 4.5Mhz....)</del>
@ -33,21 +31,29 @@ This is illegal. Don't make it. What can you transmit with license:
Instead of saying 144.500 MHz, these amateur bands are often refered to in meters rather than frequencies. These are the literal wavelenghts of the signal. The 'meter' bands are calculated by speed of light in a vacuum 300 million meters per second divided by frequency in million Hertz/sec (so 300/50Mhz=6 = 'the 6 meter band' )
Raspberry Pi 1 B (fcc id: 2ABCB-RPI21), the first raspbberry pi board (2011-2012), for fullsizecomposite out (RCA) plug.
OR: RPI 3b v2 has composite out trough the minijack trrs connector. NOTE: the ground and + are inverted on this plug... (so centerpin on yellow plug is ground and sleeve is your signal). This also destroys the sound output on the trrs...great job rpi!
### Winding coils and soldering
Use a 5mm drill bit to wind your coil around. (coil = 7 tight turns of 0.7mm (measured 0.6mm) around a 5mm drill bit, after winding TIGHT, spread the coil out to be around 7mm/7.5mm in lenght, coild-end to coil end...).
## Making
### Tools Needed
* Side Cutters
* 5mm drill
* Soldering Iron
* Solder
* Small set of screwdrivers for tuning (plastic prefered)
* Utility knife
* Super Glue
Handy to have:
* Vernier Calipers
* Tweezers (to place components and not burn your fingers)
* Electrical tape to isolate the variable resistor from the ground plane
### Parts
### Parts Needed
* Transitor - Kogawas japanese transitors are from the 1970's and unobtainable, but you can use practically any general purpose NPN transistor: BC547b, BC548b, 2N3904 just take notice of the pins and orientation.
10 parts, total costs: $1.49 excluding the battery and tools needed.
### Winding coils
Use a 5mm drill bit to wind your coil around. (coil = 7 tight turns of 0.7mm (measured 0.6mm) around a 5mm drill bit, after winding TIGHT, spread the coil out to be around 6.7mm/7mm in lenght, coild-end to coil end...).
## Transmitting
### Possible hardware
* Anything putting out a 4MHz PAL (or NTSC?) signal: game consoles (NES), VCRS, Video Title Generators..or:
* Raspberry Pi 1 B (fcc id: 2ABCB-RPI21), the first raspbberry pi board (2011-2012) has fullsize composite out (RCA) plug, with correct polarity...
* Raspberry Pi 3b v2. It has composite out through the minijack trrs connector. NOTE: the ground and + are inverted on this plug... (so centerpin on yellow plug is ground and sleeve is your signal). This also affects the sound output on the trrs...great job rpi!
### Tools
* Side Cutters
* 5mm drill
* Soldering Iron
* Solder
* Small set of screwdrivers for tuning (plastic prefered)
* Utility knife
* Super Glue
Handy to have:
* Vernier Calipers
* Tweezers (to place components and not burn your fingers)
* Electrical tape to isolate the variable resistor from the ground plane
## Tuning the transmitter
roughly 6 variables:
Roughly 6 variables:
* Input Voltage
* Antenna (Type+ Size)
* Coil (Material, diameter, length, wire gauge)
@ -96,7 +101,9 @@ The exact transmitting frequency will always be a surprise. Usingt a SDR like Ha
## Software
* this pi image: TODO (no gui/x)
In case you are using a Raspberry Pi to generate the analog video signal for your transmitter:
* this pi image: TODO
* enable PAL on rpi 1 (sdtv mode 2) in /boot/config.txt
* `$ sudo apt-get install omxplayer`, a command line media player that is designed for HW acceleration on the RPI. Its capable of playing video RTMP streams as well.
* connect to tty1 from ssh:
@ -112,7 +119,7 @@ NOTE: download / update to the LATEST youtube-dl!!
Analog capable TV with antenna. We used an Amstrad CTV 140 with antenna input.
### Tuning your tv
@ -125,7 +132,7 @@ Notes: this transmitter is designed and tested to work on the VHF1, also called
Cheap rtl-sdr sticks dont have enough (4MHz) bandwidth to receive full color pal. Black and white is supposed to be possible using 'TV Sharp': https://www.rtl-sdr.com/analogue-tv-with-rtl-sdr/ (no sound, atleast not withouth 2 stikcs)!
## IMPROVEMENTS
## Improvements
Find a way to transmit legally on this band: Either look into SSTV (and use computers to receive using a cheap sdr dongle) or look into amateur televisie (ATV) that uses much higher frequencies (thus allowing for more bandwidth...but good luck hand soldering such a transmitter/receiver): https://vhf-uhf.veron.nl/atv/hoe-start-ik-met-amateur-televisie-atv/
* 3cm (10GHz)
* 6cm (5,7GHz)
@ -139,10 +146,6 @@ Find a way to transmit legally on this band: Either look into SSTV (and use comp
* Sound: there is no sound. Again Kogawa might have an answer: https://anarchy.translocal.jp/microtv/how_to_advancedTVTX_p0.html
## IDEAS/APPLICATIONS
* put camera on RPI (there are headers no?) I have cameras, and 'live stream'
* THE BOX
## LINKS
## Link Dump
https://www.youtube.com/watch?v=rmGAd_MVaWw (hacking variable inductor to add audio to your fm tv transmitter)
https://www.youtube.com/watch?v=3sVIOg-PlKc (video tutorial of kogawa fm audio transmitter with nice soundtrack by Dan Abrams (if u want this cd, i have it))
https://www.youtube.com/watch?v=3sVIOg-PlKc (video tutorial of kogawa fm audio transmitter)
