----- Original Message -----
From: "Denis O' Flynn" <ei6hb@eircom.net>
To: <writelog@contesting.com>
Sent: Monday, March 20, 2006 7:44 PM
Subject: [WriteLog] QRM
> Ho Folks,
> I hope somebody can help me with my problem
>
> I am using my Kenwood 850S with MMTTY and WL 10.55D. When
> doing the last few RTTY contests I find I cant get rid of
> adjacent signals. I use the 2.7kfilter on the 8.33 and the
> 500 on the 455. I have to turn the Low Cut Slope Tune
> nearly fully clockwise and the High Cut slightly
> anticlockwise in order to be able to copy anything. This
> is real annoying !! especially on 40M.
>
> I am assuming that I am doing something really wrong here
> and would like the groups advise.
Let me guess at what you are doing. I will guess that you
are using AFSK tones 2125/2295 with the TS-850 in the LSB
mode. The 850's bandpass is centered around 1500 Hz in LSB,
and your 500 Hz filter is limiting the audio response to
something like 1250 - 1750 Hz, so the 2125/2295 tones are
out of the bandpass. Your transmitted signal may be messed
up also, because I think the same filters are used in
transmit. I may be wrong about that.
There are two solutions at this point.
Solution #1 - Preferred - Build an interface circuit so that
MMTTY can key the TS-850's FSK input, with the TS-850 in FSK
mode.
Solution #2 - Workable - In the MMTTY control panel, choose
a Mark frequency of 1275 instead of 2125, and continue to
use the TS-850 in AFSK LSB. Your tones will then be
1275/1445, within the bandpass of the 500 Hz filter.
Dave Hachadorian, K6LL
Yuma, AZ
.
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