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PA2AGA > HDDIG 06.12.99 11:28l 220 Lines 7004 Bytes #-9659 (0) @ EU
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From: pa2aga
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Subject: HamDigitalDigest 99/309E
X-BBS-Msg-Type: B
>etc?
Page 1-13 "The remodulator is optimized for non-burst data at 75 Baud or
less."
>
>Will the KAM plus DSP-599zx combo work better than the DSP-599zx alone for
>RTTY?
>
The DSP-599zx has a better demodulator than a Kam plus or any other analog
data controller including the AEA PK-232 (non-DSP version). However, by
actual experiment, we have found that most of the RTTY performance gain (lower
error rate for a given s/n) is a result of the optimized filters in the
DSP-599zx. Most any RTTY demodulator works quite well at a high signal/noise
ratio. The DSP-599zx filters can improve the s/n of a signal 3-6 dB over a
typical receiver filter. Depending on where you are on the bit error rate vs.
s/n curve, the result can be an improvement of 100 to 1 in error rate. This
is in line with information presented in communication textbooks and we have
verifed it with the Kam plus and the PK-232 (non-DSP version). Under most
operating conditions, you might not be able to discern the difference between
the DSP-559zx in the RTTY modem mode and the DSP-599zx in front of the KAM
plus or PK-232.
Keep experimenting - you'll never know what you might find. We found that you
can run a 170 Hz shift, 45.5 baud signal through a less than 200 Hz linear
phase filter and still get usable copy (by amateur radio standards!).
Conventional wisdom says you need about 250 Hz bandwidth. The 50 hz can be a
big deal if your're in heavy QRM with a weak signal.
If yu have any other questions, please don't hesitate to ask - I'll probably
learn something. This thread should bring some of amateur radio's lurking
experts out of the woodwork! If it does we may have a rousing and enlightening
discussion among them (the expertise is there - just so they don't decide to
vehmently disagree among themselves :-)
73,
Randy Gawtry, K0CBH
Timewave Technology Inc.
>.
------------------------------
Date: Wed, 1 Dec 1999 23:13:07 -0500
From: "Rob" <NoEmail@NoWay.com>
Subject: RS-232 HELP for internal RTTY modem in DSP-599zx
Hi Randy,
Many thanks for the EMAIL.
I didn't know the internal RTTY modem really only works at 45 baud.
The manual does not state that.
In fact, the manual seems to imply that the RTTY internal modem can be used
at different baud rates. On pg 6-2, it states that you "turn the left knob
to select the appropriate data filter". Then you hit SHIFT+FUNCTION to turn
on tuning display. Press Function for DCD etc.
I tried setting the DSP-599zx's internal RTTY modem for different baud rates
and modes (75 baud RTTY, AMTOR, PACTOR). The DSP-599zx accepts the settings
(but that might NOT mean that it changes the internal modem). Are you sure
the internal modem is designed only for 45 baud and that the different
settings do not affect the internal RTTY modem??
I also have an old KAM. I can use the DSP-599zx as a front end filter using
it it also remodulate the RTTY, AMTOR etc tones for the KAM to ultimately
demodulate-- Will this work not only for RTTY but also for AMTOR, PACTOR
etc?
Will the KAM plus DSP-599zx combo work better than the DSP-599zx alone for
RTTY?
73's
Rob
"Randall R. Gawtry." <rgawtry@timewave.com> wrote in message
news:824ml9$qef$1@newsfeed.minn.net...
> In article <u1k14.195354$5r2.458508@tor-nn1.netcom.ca>, "Rob"
<NoEmail@NoWay.com> wrote:
> >My Timewave DSP-599zx has an internal RTTY modem which provides
mark/space
> >input and output (like the old Hal ST-6).
> >
> >I would like to try Tom Sailor's TERMAN 93 with my DSP-599zx. (I would
also
> >like to try some older programs like PCTOR by KC7WW)
> >
> >MY DSP-599zx filter/modem has a DB9 RS-232 connector with the following
> >pin-outs:
> >
> >MODEM PORT on DSP-599ZX
> >-------------------------------------------
> >
> >PIN 2 RD -- IN MARK/SPACE
> >PIN 3 TD -- OUT Mark/Space
> >Pin 5 ---- Ground
> >Pin 7 --- RX/Tx Activation (ie PTT)
> >
> >According to TERMAN93's documentation, It would appear that I cannot use
a
> >simple straight through modem cable with DB9 connectors at both end -
one
> >connected to my DB9 modem connector and one connected to my DB9 computer
> >serial port.
> >
> >It would appear that I need to connect Pin 2 (RD) of my DB9 modem
connector
> >to Pin 1 (DCD) of the computer's DB9 serial port.
> >
> >But some other RTTY programs like PCTOR use Pin 2 RD (not Pin 1 DCD) on
the
> >computer's DB9 serial port to receive the mark/space signals from the
modem
> >for RTTY.
> >
> >Can I just place a jumper from Pin 2 to Pin 1 at either end of my modem
> >cable??
> >
> >Will shorting out the RD and DCD pins of my computer's serial port damage
> >it??
> >
> >It is too bad that the output of the DSP-599zx's DSP chip is not readily
> >available for HARDWARE memory ARQ. (Does anyone know of anyone who has
> >modified the DSP-599zx for hardware memory ARQ and connected the A/D
outputs
> >to LPT 1 for use with TERMAN93?)
> >
> >73's
> >
> >Rob
> >VA2FB
> >
> >
> >
> Rob,
>
> A number of programs support the DSP-599zx in the RTTY mode. The WF1B
> contest program and Timewave's DSP-RTTY are the most popular, but there
are
> others available.
>
> Keep in mind the DSP-599zx RTTY modem in designed for RTTY only (170 Hz.
> shift, 45 baud), not for the higher rates of AMTOR and Pactor. It may
work
> at slightly higher rates than 45.5 baud RTTY, but the modem filters are
> optimized for 45.5 baud RTTY.
>
> Hardware memory ARQ was not included in the DSP-599zx because it was not
> designed for Pactor or AMTOR demodulation.
>
> With respect to the computer connections, we have not tried either of the
> programs you are interested in, but I would not recommend shorting two
RS-232
> lines together. It will probably not cause damage, because the RS-232
standard
> has some current-limiting protection built into it, but there is no
guarantee!
>
> 73,
> Randy Gawtry, K0CBH
> Timewave Technology Inc.
>
>
>
>
>
>.
------------------------------
Date: Wed, 01 Dec 1999 23:07:42 -0800
From: Kevin <xrivaznyl@ubgznvy.pbz>
Subject: Used HAM Software?
On Wed, 01 Dec 1999 22:44:11 -0600, ka9s
<3845F91B.527F75C@mediaone.net> wrote:
>I can
>certainly buy MicroSoft Office on CD and later sell it legally to a second
party.
No you can not. Please read the EULA.
--
Kevin
http://nworegon.htmlplanet.com/
Email address Rot-13 Encoded:
znvygb:xrivaznyl@ubgznvy.pbz
>.
------------------------------
End of Ham-Digital Digest V99 #309
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