[RTTY] Question

[Bill Turner]

ORIGINAL MESSAGE:          (may be snipped)

On 5/17/2014 1:22 PM, Fred Souto Maior wrote:
> Can someone pse tell me how many kcs are used by a RTTY signal ??
> This is relative to people operating split and receiving up 1 Khz.
> Usually the TX frequency of the DX station is QRMed by the callers
> just 1 and some times less then 1 up. And if we have a local stn calling
> it's impossible to get a decent signal from the DX. Why not put the RX
> frequency 2 or 3 up ??
>
> Fred - PY7ZZ 

REPLY:

For an amateur RTTY signal with 170 Hz shift, the transmitted bandwidth 
is about 300 Hz, or .3 kHz.  The problem you mention above happens 
because many ops use a receive bandwidth much wider than that and the 
supposed QRM results.  A split of 1 full kHz is more than enough when 
using a narrower receiver bandwidth.

Also, a very strong station 1 kHz away can desense your receiver if it 
does not have an appropriate roofing filter. This is not really "QRM" 
but rather inadequate receiver performance.

73, Bill W6WRT
dezrat at outlook.com