[RTTY] IS0R & 75 baud

[Kok Chen]

On May 10, 2010, at 10:57 AM, WS7I wrote:

> I'll let Chen address the phase-shift and polar problems.  But don't use your 250 Hz filters as they won't work!

Yep, unlike the P5/4L4FN case (50 baud), you will need to use a wider filter for this one.  Perhaps something around 90 Hz wider than the narrowest filter that you could use for "regular" RTTY. 

Jay is also right that multipath is a bigger problem since intersymbol overlap (mark and space overlapping) is more significant due to the shorter bit time.  That is on top of the fact that Eb/No (the normalized "SNR per bit") is reduced since Eb (energy per bit) is reduced due to the shorter bit time.

We'll find out if this is just a poor choice, or is a very poor choice :-) :-).

73
Chen, W7AY