Fix bugs in the rds_tx example

[argilo]

This commit fixes the following bugs in the RDS transmit example:

1. The filter window constants need to be updated for GNU Radio 3.9
2. The maximum FM deviation should be 75 kHz, not 80 kHz
3. The RDS gain should be set to produce a deviation of 2 kHz, not 24 kHz
4. The pulse shaping filter should be RRC, not low-pass
5. The stereo pilot magnitude should be 10%, not 30%
6. The input gain needs to be reduced to avoid excess deviation

I also made the following changes:

• Removed unnecesary Multiply Const blocks
• Replaced Map & Char to Float blocks with a Chunks to Symbols block

Before:

After:

Signed-off-by: Clayton Smith argilo@gmail.com

[bastibl]

Awesome :-) Thank you!