[RTTY] RTTY & Digital Interference problems

[Joe Subich, W4TV]

It is a bit difficult for JT65/JT9 to generate "noise" on demand.
Those protocols will only start transmitting at one second after
the top of a minute.  A RTTY contester who tunes on a frequency at
xx:yy:50 is not going to hear anything for 10 seconds and by then
he has pushed F1.

It is *still* important to know what activity is generally found
in a given range and adjust one's behavior accordingly.  In the
case of Joe Taylor's modes that means listening "on the minute of
*both* odd and even minutes" before one can assume a frequency is
free.

73,

    ... Joe, W4TV


On 2015-01-05 9:16 PM, Jeff Stai wrote:
> On Mon, Jan 5, 2015 at 5:41 PM, Joe Subich, W4TV <lists at subich.com> wrote:
>
>> Neither JT65, JT9, PSK31, PSK63, nor PSK125 sound like "random noise".
>> All have a distinctive "sound" and are clearly identifiable on a
>> waterfall or spectrum display.  It should even be possible to make an
>> informed guess as to the mode just based on the frequency - the
>> "center of activity" for each digital mode is published just about
>> everywhere except in the contest rules.
>>
>
> My point exactly.
>
> 1. If it sounds like something, it probably is something.
>
> 2. If you send QRL? and you hear something, assume it means "in use".
>
> 3. If you are using a frequency, and you hear something, assume it is a
> QRL? and make a sound.
>
> That should handle most cases and doesn't require knowing a bandplan or
> center of activity. Just good manners.
>
> jeff wk6i
>
>
>