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eHam Forums => Digital => Topic started by: ON6WFO on August 03, 2005, 02:32:37 AM



Title: CW filter of Yaesu FT857D
Post by: ON6WFO on August 03, 2005, 02:32:37 AM
Hi guys,
i'm new beginner of RTTY. I have a small Yaesu FT857D.
it's really funny to play RTTY. very efficient. I can contact North & South Americas very easily on 20 meter bands compare to use SSB.
Now I read my yeasu manual, then I find there is an option 500Hz CW filter available. it says that one can work for digi mode also.

So my question here is wat is the function of those filters. And how it can improve the reception of the RTTY?


thanx, 73

ON6WFO/Feng


Title: CW filter of Yaesu FT857D
Post by: AA4PB on August 03, 2005, 05:53:44 AM
The 500Hz filter will do two things for RTTY. It will reduce the bandwidth of your receiver to just what is needed to pass the RTTY signal thereby reducing the noise and improving the signal to noise ratio. It will also keep strong adjacent channel signals (QRM) from getting into your receiver's AGC circuit and reducing the gain.


Title: CW filter of Yaesu FT857D
Post by: K6IHC on August 07, 2005, 12:25:14 AM
I have had an 857 since 1993, though I haven't (yet) used it for digital.  One thing I did do, that really helped in using this fine radio to it's fullest, was to participate in the Yahoo! Group: FT857.

From the group, I have learned that the Inrad brand of mechanical filters are held in high regard.  I have also learned that the SSB filter really doesn't make much (if any) difference.  The DSP *helps better*.  But the CW filters do work well for narrow bandwidth filtering.