ahhh....when I use LSB and a sound card I use a 200hz filter on my
756pro...quess the issue is if you use the rtty mode and some other hardware
John W1NET
----- Original Message -----
From: "Bill Turner" <wrt@dslextreme.com>
To: "Marijan Miletic" <s56a@bit.si>
Cc: "ON4MA Marc" <marc.wullaert3@pandora.be>; "John Devoldere (ON4UN)"
<john.devoldere@pandora.be>; <cq-contest@contesting.com>
Sent: Saturday, October 18, 2003 14:02
Subject: Re: [CQ-Contest] Re: ON4UN and the Ten-Tec Orion
On Sat, 18 Oct 2003 10:24:45 -0000, "Marijan Miletic" <s56a@bit.si>
wrote:
>I am sure that reputable antenna experts know that the minimal RTTY RX
>bandwidth should be 170 + (2 x 45) Hz!
>
>The only Orion data provided by ON4UN were filter passbands. We can see
>clearly that even 250 Hz filter actually measures 240 Hz.
>
>Deplorable Icom and good old Collins offer 330/350 Hz filters for RTTY
mode.
>
>"Write" or wrong?
>
>73 de Mario, S56A, N1YU
_________________________________________________________
Right. My ICOM IC-746PRO using a 250 Hz filter copies ok if the
sending station uses 170 Hz shift, but if he is using 200 Hz, the copy
gets a bit erratic. Widening out the filter to 300 Hz makes good copy
again.
I would STRONGLY recommend everyone use 170 Hz shift only. The
various AEA products default to 200 Hz for some reason. PLEASE change
them to 170 Hz. I have a spectrum scope I use when receiving RTTY and
I can easily tell which stations are at 200 Hz. Fortunately the
number is decreasing with time.
I don't believe AEA is in business any more, but their legacy lingers
on. :-(
--
Bill, W7TI
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