RE: Re: [MT63] Listening on 40 meters
Thanks for that info. After I sent the reply, I realized who I was
replying to and felt a little foolish.... Sorry :)
I use MixW most of the time, and have to work with others that are limited
to the 500Hz start frequemcy and haven't learned to reverse sideband and
tune for a signal with a different start frequency.
I use a Kenwood TS-2000, and haven't had the opportunity to monitor more
than one MT-63 signal at a time, but see how the 5 KHz visible on the
waterfall could show multiple 1 KHz wide MT-63 signals. However, I haven't
found any group of folks using it with the disipline and ability necessary
to send multiple usable signals within the visible portion of the waterfall.
I look forward to working some of the folks here on the Ham Bands using MixW
and MT-63. I would also like to try the Contestia mode. I have used Olivia
as much as the MT-63 mode, and both have done well. I think that Contestia
could provide the best of both modes; offering thruput apporaching MT-63 in
conditions that Olivia would normally be the best mode to use.
From: Nick [mailto:ut2uz@...]
Sent: Sunday, December 23, 2007 11:55 PM
Subject: Re: [MT63] Listening on 40 meters
MixW is not limited to 500 hz start and single MT63 channel, so one can
receive several MT63 channels simultaneusly, using one (for most
TRCVRs) or two inputs (like ORION, FT1000, FT2000, IC7800).
I can watch 9 MT63 channels of 1000 hz each on 20m and 9 more on 40m (9 khz
RX bandwidth) with ORION 1. With simple direct conversion DSP RX we can
watch much more. Some people used to tell about dial frequency, usually
forgotting to mention LSB/USB and/or sound shift. That's why I asked to
clarify the frequency for MT63 sked.
Sorry, no MT63 transmission was heard this night on 40m here in Kiev.
Monday, December 24, 2007, 3:41:39 AM, you wrote:
dbn> The MT-63 mode does not affect the receive frequency as far as the
dbn> actual dial frequency. It only impacts where in the 3 KHz
dbn> bandwidth allowed that the center of the transmit falls. That is
dbn> determined from the start frequency and bandwidth set in the
dbn> parameters for MixW.
dbn> If you have your rig connected for rig control from MixW, the
dbn> center "flag" will be the dial frequency plus or minus the offset
dbn> extrapolated from the start frequency and bandwidth.
dbn> As an Example:
dbn> Dial Frequency 7.090.000 MHz = 7,090,000 HZ
dbn> with 500 Hz start frequency and 1000 Hz bandwidth, the difference
dbn> would place the flag (center frequency) at either
dbn> 7.089 (LSB) OR 7.091 MHz (USB).
dbn> Neither affect the dial frequency, or the frequency that the rig is
dbn> tuned to. All the parameters affect is where the software will
dbn> start generating RF Power, and how far it will travel (Bandwidth).
dbn> From those 2 parameters, you are confined to accept the placement
dbn> of the center "Flag" in MixW.
dbn> The questions to ask are:
dbn> What is your starting Frequency? (500 HZ is hard coded in both
dbn> MultiPSK and the MT-63 Terminal program, and allows use of up to
dbn> the 2KHz bandwidth parameter without the resulting data going
dbn> outside of the 3 KHz operating frequency )
dbn> What is your Bandwidth? (1000Hz gives up to 100 WPM throughput in
dbn> good to ideal conditions).
dbn> What Is the Interleave (Long, Short, Very Short or None). The
dbn> Interleave determines how quickly the software will look for the
dbn> next bit of information.
dbn> What mode? USB or LSB. Most software treats USB as the default
dbn> mode. When transmitting on LSB, the inverted mode is selected. It
dbn> doesn't have to be that way; actually you can tune 3 KHz higher or
dbn> lower and reverse the Sideband and achieve the same results. This
dbn> is the only way that MultiPSK and the MT-63 Terminal program allow
dbn> the user to copy a signal with a 100KHz Starting Frequency (or
dbn> anything other than the hardcode 500Hz Starting Frequency.
dbn> Knowing the parameters, Sideband and dial frequency will help in
dbn> getting together on the air.
dbn> Apologies is this is already known. I hear very little MT-63 on
dbn> the Ham bands, and see it used extensively on the NTIA by various
dbn> federal support services.