🚀 go-pugleaf

scottcr@wkuvx1.bitnet writes:
>I am designing a custom 9600 baud link using a voice channel
>with the following specs: BW: 100-5Khz  S/N = 35+ dB.
>Are there any "rules of thumb" about choice of carrier
>freq 2K ?  3k ?  What about FSK deviation?  With this
>type of system how does modulation index affect performance?

        I'd suggest getting the current Rockwell modem data products
book.  There's probably an off-the-shelf single-chip solution to your problem.
Try Rockwell Semiconductor Products at 1-714-833-4655.  Other
manufacturers offer similar solutions.  Using a 9600 baud FAX modem
part is probably the simplest way to go.  The channel you have is
good enough.  FAX modems are half-duplex (one way at a time), so
assuming you want a simplex channel (one way), this is the way to go.
You avoid the complex bidirectional cancelling schemes used to push
data in both directions simultaneously over two wires that are used to
make 9600 baud data modems work.  Those modems won't work over a one-way
link.

					John Nagle