Thanks, Rein, for confirming what I suspected. For a fixed
frequency/mode such as pskmail, I'd have to agree completely, but for
general use, such as me running PSK31 for one QSO, maybe RTTY for
another, and Olivia for yet another, I think the 500 Hz would probably
be my best option.
Tnx es 73
Dave
KB3MOW
Rein Couperus wrote:
We generally use 300 Hz filters for PSK125 and they are too wide.
There is no substitute for good narrow Xtal filters.
I don't understand how you can try to work PSK31 (50 Hz bandwidth) with a 2.7
kHz filter.
That is against all logic (and math).
We recommand using the narrowest filters you can get for pskmail. That is the
only
way to fight Pactor QRM. It helps to use the passband shift and use the sweet
spot of the rig
at 1500 Hz (we use an Icom 756). Our PI4TUE server has good performance with
that, provided you get the filter as narrow as possible (this is for PSK125,
which is 4x the bandwidth of PSK31...).
A 250 Hz Xtal filter is wide enough for PSK125.
73,
Rein EA/PA0R/P
-----Ursprüngliche Nachricht-----
Von: [email protected]
Gesendet: 07.03.07 19:53:26
An: [email protected]
Betreff: [digitalradio] narrow filters/PSK
Has anyone tried using either a 250 Hz or 500 Hz filter for PSK31
reception? My Icom IC-746 (non-Pro) has no filters installed, and is
wide as a barn door on USB for PSK31. I wondered if either of these
filters would help, or would they be too narrow?
The pass-band shift does a fair job of eliminating QRM from one side
or the other of the selected frequency, but when there are two very
strong signals within 2 Khz on each side at the same time, they just
aren't effective on both.
Any input appreciated!
Thanks in advance es 73
Dave
KB3MOW
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