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PA2AGA > HDDIG 11.12.99 17:59l 226 Lines 7819 Bytes #-9654 (0) @ EU
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Subject: HamDigitalDigest 99/311G
X-BBS-Msg-Type: B
>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: Thu, 2 Dec 1999 10:08:31 -0500
From: "Rob" <NoEmail@NoWay.com>
Subject: RS-232 HELP for internal RTTY modem in DSP-599zx
Hi Randy,
Thanks for the EMAIL. Yes I will keep experimenting (like most hams hi)
But I do have one more question, you mention that the internal modem is
optimized for 45 baud RTTY using 170 Hz? Will the internal modem work as
well at 200 hz shift which has become very popular for RTTY these days??
Will the AFSK generator also generate the 200 hz shift signal (at line
output jack)?
It is too bad that the internal modem and remodulator cannot be used at
higher baud rates and for pulse modes like AMTOR or PACTOR. There are a
number of programs which can implement the PACTOR, RTTY and AMTOR protocols
in the PC. (Some will even do Hardware memory ARQ if you feed the data from
the A/D converter).
For example, there is the freeware program TERMAN93 by HB9JNX (Tom Sailor)
which you can find at Tom Sailors Home page at
http://www.ife.ee.ethz.ch/~sailer/ham/ham.html TERMAN93 will send and
receive AMTOR, PACTOR and RTTY using a modem that provides MARK/SPACE
signals (like old HAL ST-6 or maybe even DSP-599zx)
There is also the shareware program PCTOR by KC7WW which you can find at a
number of the FTP sites. PCTOR implements RTTY and AMTOR. To my knowledge
the latest version is 3.08. If you can't find it, I can send you a copy.
It will be interesting to see if these programs work with DSP-500zx. I
agree that there may be more bit errors than usual since the DSP-599zx
internal modem is not designed for baud rates above 75 baud. But my biggest
fear is timing. The DSP delay (i.e. the time it takes for the DSP599zx to
process the signal and generate MARK/SPACE signals) may throw off the ARQ
timing preventing a stable link.
By the way what is the latest firmware version of DSP-599zx? (I don't even
know what version of firmware is in my DSP-599zx)
73'
Rob
"Randall R. Gawtry." <rgawtry@timewave.com> wrote in message
news:8250vg$qt7$1@newsfeed.minn.net...
> In article <Aom14.195393$5r2.458711@tor-nn1.netcom.ca>, "Rob"
<NoEmail@NoWay.com> wrote:
> >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.
>
> Actually, the manual states the RTTY Remodulator and RTTY Modem are not
> designed to work above 75 baud -- see pages 1-12 and 1-13.
>
> >
> >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??
>
> You can try operating some of the faster modes if you can get one of the
> programs working. Some may work, but not necessarily as well as you might
> like. We were not trying to built a multimode data controller when we
> designed the DSP-599zx so we did not make any attempt to specify or design
it
> as anything more than a very flexible and accurate filter product for all
> popular HF data modes, voice and CW as well as a great low speed 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?
> 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: Thu, 2 Dec 1999 17:54:28 -0500
From: "Rob" <NoEmail@NoWay.com>
Subject: RS-232 HELP for internal RTTY modem in DSP-599zx
Hi John,
Thanks for the info. I have the most current version of the firmware!
If it is not too much trouble, please send me the address (and EMAIL address
if there is one) on COMP-RTTY.
It would appear that your DSP-RTTY program is the only WINDOWS based RTTY
program for modems that only provide MARK/SPACE signals. (e.g. DSP-599zx,
HAL ST-6 etc)
Even though I appreciate that the market today for such a program is small,
I do hope that one day you can offer DSP-RTTY at a lower price.
73's
To be continued in digest: hd_99_311H
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