[Elecraft] Center Frequency when setting RTTY Filters

[Bill Coleman]

On Oct 9, 2005, at 2:30 PM, Jeff Stai wrote:

> You want to set it to the center of the two tones you are using for  
> AFSK. If 1000Hz is your Mark frequency, and 170Hz is your shift,  
> then you should center at 1000-(170/2) or 915Hz.

If you do this, don't use OP1 as your FL1 filter. The second harmonic  
of your tones will be in the passband when you are transmitting,  
otherwise.

I recommend higher frequencies. I ended up using 1500 Hz as the  
center of my RTTY filter passband.


Bill Coleman, AA4LR, PP-ASEL        Mail: aa4lr at arrl.net
Quote: "Not within a thousand years will man ever fly!"
             -- Wilbur Wright, 1901