[CQ-Contest] Re: ON4UN and the Ten-Tec Orion

[W1NET]

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 at dslextreme.com>
To: "Marijan Miletic" <s56a at bit.si>
Cc: "ON4MA Marc" <marc.wullaert3 at pandora.be>; "John Devoldere (ON4UN)"
<john.devoldere at pandora.be>; <cq-contest at 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 at 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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