[RTTY] Question

[Hank Garretson]

In addition to Bill's comments, too many RTTY signals are rotten. Too
wide--often caused by hams over driving transmit for AFSK.

73,

Hank, W6SX


On Sat, May 17, 2014 at 1:37 PM, Bill Turner <dezrat at outlook.com> wrote:

> 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
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