Hi Selva,
it depends on what filter you use normally. My standard filters for
RTTY are the two cascaded 500Hz ones. If the bands get really crowded
I switch to the 250Hz cascaded filters. These eliminate most of the
QRM. My FT1000MP is the original one, so I have no problems using
any filter combination for any mode.
So my recommendation is to go for narrow(er) filters first. The QRM
that you notice may also come from badly overdriven SSB transmitters.
Unfortunately in each and every contest we experience lots of such
signals with spurii many kilohertz up and down of the main signal,
often almost the same strength. There is nothing you can do if such a
spurious signal is right in your receivers passband. You might try
to find the offending station and tell him to reduce audio drive
(from soundcard into TX).
73 de Goetz
dj3iw@t-online.de
----- Original Message -----
From: "K C Selvadurai" <kcselva@starhub.net.sg>
To: <rtty@contesting.com>
Sent: Wednesday, March 30, 2005 2:35 AM
Subject: [RTTY] Disturbance from station on adjoining freq
> During a RTTY contest last month, I had spells of difficulty copying the
> number given to me in response to my cq call. This was because another
> station was transmitting on a frequency close by.
>
> That station was an overseas station, there is only one other active RTTY
> contestor in my home country.
>
>
>
> I use a FT 1000MP transceiver. What should I be doing to address that
> disturbance:
>
> - Use a narrower filter?
>
> - Acquire the 'roofing filter' from Inrad?
>
> - Some other solution?
>
>
>
> Many thanks for advice
>
>
>
> Selva 9V1UV
_______________________________________________
RTTY mailing list
RTTY@contesting.com
http://lists.contesting.com/mailman/listinfo/rtty
|