No subject

be
of interest to K3 users.    With this enhanced FSK filtering, the K3 has =
a
significantly narrower FSK bandwidth than any other FSK radio that I'm =
aware
of.  Hopefully, other manufacturers will follow suit.

The Beta DSP 281 firmware will be released to production soon.  =
Meanwhile,
if anyone is interested in trying it, let me know and I'll email it to =
you.

Ed W0YK

=20

> -----Original Message-----
> From: RTTY [mailto:rtty-bounces at contesting.com] On Behalf Of=20
> aflowers at frontiernet.net
> Sent: Thursday, March 21, 2013 6:16 PM
> To: RTTY Mailing List
> Subject: [RTTY] K3 reduced-bandwidth RTTY analysis
>=20
> Hello again,
> =A0
> I have finally gotten around to finishing up a short=A0analysis of the =

> reduced-bandwidth FSK keying in the K3.=A0 As many of you are aware,=20
> Elecraft made some beta firmware available several weeks ago=A0that=20
> attempts to reduce the clicks that result for unshaped =
keying.=A0=A0They=20
> analysis=A0involves a before and after pictures comparing the FSK=20
> spectra from the=A0general release firmware (representative of most=20
> radios, to the best of my limited=A0knowledge) and the =
bandwidth-reduced=20
> firmware.
> I've also included some analysis using a=A0300 Hz=A0"roofing filter" =
to=20
> measure the noise floor at different dial offsets from the transmitter =

> to give and idea of what it "feels" like when it is QRM.=A0=A0There =
are a=20
> few people who operated WPX and and other contests with this firmware, =

> and I am sure they could tell of their experiences on the transmitter=20
> side.
> =A0
> http://www.frontiernet.net/~aflowers/k3beta/
> =A0
> While on the subject of clicks, spurs, and other nasty things, I also=20
> would encourage people to have a look at N2QT's question on p. 55 in=20
> the April QST and WB1GCM's (at ARRL Lab) response,=A0which also =
address=20
> this and some other issues around RTTY keying.=A0 He distinguishes=A0
> "clicks" that result from the waveform from=A0the other bad things =
that=20
> can happen with broken audio signal chains.=A0=A0This=A0is an =
important=20
> distinction to keep in mind.
> =A0
> Enjoy!
> =A0
> Andy K0SM/2
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