[RTTY] Distortion

[Phil Duff NA4M]

I use my 1000MP's RTTY (FSK) DIN connector "shift" input (pin 1) driven by 
a COM port TxD line via a simple homebrew keying interface that uses a 
transistor and resistor.   The COM port is driven by MMTTY or other RTTY 
s/w that uses the MMTTY engine.

So - with this scheme there's no levels to adjust that I know about.  I 
assume that the MP's RTTY shift input only needs to be toggled via the COM 
port TxD line and interface to drive the internal 1000MP generator.

73 Phil NA4M

At 02:02 8/25/2004, Don and Diana Cunningham wrote:
>Phil,
>You have to turn down the audio from your AFSK generator, which I assume is
>the soundcard output.  Does your "interface" have a means to adjust audio to
>the mic input on the rig?? If not, you will need to build up a "padder" of
>some sort to do that.  There is an awful lot of output from my soundcard, so
>would HAVE to have some way to cut it back here to use it.  Hope that helps!
>73,
>Don, WB5HAK
>----- Original Message -----
>From: "Phil Duff NA4M" <na4m at arrl.net>
>To: <rtty at contesting.com>
>Sent: Tuesday, August 24, 2004 7:44 PM
>Subject: Re: [RTTY] Distortion
>
>
> > At 18:53 8/24/2004, Kok Chen wrote:
> >
> > >So, if you operate without a single of the ALC bars lit, then IMO you are
> > >just as clean as operating "FSK" from that rig.
> > >
> > >I used to have my 1000MP's meter set to show Power/SWR.  Now that I have
> > >transitioned from FSK to AFSK, I seem to have my meter sitting most of
>the
> > >time at Power/ALC :-) :-).
> >
> > I have an 1000MP
> >
> > I see no adjustment for FSK/AFSK drive level in RTTY mode to have no ALC
> > indication.
> >
> > All adjustments I make to RF power, MIC, or PROC levels on front panel
>have
> > little effect on indicated ALC in RTTY mode.
> >
> > The 1000MP manual indicates that the MIC control should be set to
>mid-scale
> > for RTTY operation and then adjust output power.  This results in an ALC
> > indication of about mid scale with small variation depending on output
> > power adjustment.
> >
> > 73 Phil NA4M
> >
> >
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> >
> >
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