Please, give a frequency alternative to 14.101
________________________________
De: KH6TY <kh...@comcast.net>
Para: digitalradio@yahoogroups.com
Enviado: lun,22 febrero, 2010 22:39
Asunto: Re: [digitalradio] ROS Advantage?
That is good, Dave, except for receivers that distort heavily when the AGC is
disabled. If you just use manual gain control, and reduce the gain for strong
signals, the effect is the same, only manual. You will lose the weak station
because you have reduced the gain and the sensitivity. The only way to still
copy your weak station and get rid of the strong one is to filter at IF
frequencies, which is what fixed filters or passband tuning does. IF DSP will
do it also these days, but it needs to be at IF frequencies and not audio
frequencies if you are going to prevent AGC capture by an unwanted stronger
signal.
14.101 is adjacent to Pactor activity and if you monitor it long enough, you
will see the Pactor station stop decoding of ROS. However, most of the
automatic Pactor activity we hear is in the US, so the problem may not be as
big on the other side of the big pond.
73 - Skip KH6TY
Dave Ackrill wrote:
>KH6TY wrote:
>
>> 2. Pactor signals of 500 Hz width, outside the ROS signal, that capture
>> the AGC, do desensitize the receiver and cause loss of decoding, as
>> expected. Passband tuning takes care of that problem however.
>>
>
>As with many other digital modes, I've been using it with AGC switched off.
>
>Dave (G0DJA)
>
