With the K3 it doesn't matter - the K3 DSP passes both AFSK and FSK
through a narrow filter *after* the modulation stage. The one limit
is that you cant go clicking around on the waterfall in AFSK because
you will quickly get outside the transmit bandpass filter.
With the FT-dx5000 AFSK is probably cleaner *if* you can be sure there
is no hum on your audio, that the audio does not cause clipping before
the modulator and the transmit *IF* stages don't have so much gain that
they generate clicks/sharpen the keying edges unnecessarily and cause
ALC overshoot on the leading edge of each pulse.
The problem is that most rigs come from the factory with excess IF gain
specifically so the manufacturers don't get complaints about low power
output.
73,
... Joe, W4TV
On 2/5/2014 8:31 PM, RLVZ@aol.com wrote:
Hi Guys,
I really appreciate _rtty@contesting.com_ (mailto:rtty@contesting.com) as
I've still got a lot to learn about RTTY.
Am I understanding recent comments correctly that say "FSK stations
typically have worse RTTY sidebands and clicks than properly adjusted AFSK
stations"?
I wondering whether to use FSK or AFSK on my K3 and FTdx5000. Or perhaps
AFSK on the K3 and FSK on the FTdx5000? (which method would create the
cleanest sidebands?)
Hope to work you in the WPX RTTY Test this weekend!
73,
Dick- K9OM
From: Kok Chen <chen@mac.com>
To: RTTY Reflector <rtty@contesting.com>
Cc: Bill Turner <dezrat1242@wildblue.net>
Subject: Re: [RTTY] Change in pileup procedure?
Message-ID: <2F228A20-E260-46CE-A5AB-595256D3FA91@mac.com>
Content-Type: text/plain; charset=us-ascii
On Feb 5, 2014, at 12:38 PM, Bill Turner wrote:
What am I missing?
Let me explain.
The keying sidebands of a continuous phase FSK signal is down only about
50 dB, even when 1 KHz away from the signal. A waveshaped AFSK signal or a
K3 FSK signal will not be as poor, and a phase coherent FSK signal will be
much worse, but lets assume that a lot of people in the pile are using
continuous phase FSK (what most DDS superhet rigs today use).
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