How do I modify my SAT100 receiver from PAL B/G to PAL I?
One aspect that you need to consider is:
- The output of the RF modulator for the I standard requires a spacing between the video - audio carriers of 6 MHz, instead of the 5.5 MHz of PAL B/G.
- Therefore an additional modification in the hardware for PAL I is necessary:
- There are three components between pins 17 & 18 of the IC TDA5666-5:
- l1 variable coil.
- There is a 100k resistence at pin 16 followed by a "T" that consists of two resistors:
- R202. (table)
- l3 has to be adjusted to obtain the 6 MHz spacing between the video and audio.
- This can be carried out by using the field strength meter to measure the 6 MHz video & audio carrier frequency spacing .
- Never use the spectrum analyzer for this.
- The frequency accuracy of the FSM is much better.
- For SAT100 receivers, the video/audio ratio is fixed.