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Stefan,
2013-12-28 22:43:49 DK7FC 175km
137573.000Hz 4mHz -19.9dBOp 47% 17.6dB
;-)
239 bits will suffice, you won't need trailing
zeroes with SpecLab. They were only added as a workaround to match the
length of audio chunks processed by SndOutpt.
Opera sequences are Manchester encoded, ie
each of the 120 original bits generates either a "10" or "012 symbol.
That's why you'll never find three ones in a row.
Re WSPR: Yes you can load an arbitrary
waveform from a text file and modulate the generator tone. But I just
haven't found a way to restart the arbitrary waveform from
the first sample at a defined point in time.
Best 73,
Markus
PS Any progress on bypassing the divider in your
VLF transmit chain?
Sent: Saturday, December 28, 2013 10:54 PM
Subject: Re: LF: Sending Opera with SpecLab und
WSPR?
Hello Markus,
I just configured SL to
transmit OP32. Works well it seems.
However, if i try to use a
macro:
di.tx"1101100110010110010110010110010101100110101001100101010110010101100110101001101001011010010110011001101001101010100110010101100110100101011010011001101010100101101001101001101010100101011010101010010101100101100110101001010110010101101001000000000000000000"
the
last signs, 00000000", are ignored by SL. Probably a limitation of characters in
one row of the scheduled actions?
When i take a look to the binary code, does
0 mean a break, 1 a short dash and 11 a long dash? (I can find no 111). If so,
there are 18 0s at the end. Can i remove these 0s without changing the code as
long as i leave a break of 18 0s for the decoder?
I'm just trying that. If i
remove the last 0 and replace it by ", SpecLab accepts the row and transmits the
sequence from the scheduled actions...
73, Stefan/DK7FC
PS:
Finally my frequency is accurate:
old: 2013-12-26 00:08:27
DK7FC 0km 137572.917Hz 140mHz -21.1dBOp 100% 22.0dB
new:
2013-12-28 22:03:32 DK7FC 0km 137573.000Hz 4mHz -29.9dBOp 24% 17.9dB
This was a local test. I'm going to test your RX accuracy now
:-)
PPS: If you can find out how to transmit WSPR in SL, one could run an
automatised beacon WSPR/OP32/DFCW! Maybe the signal generator with arbitrary
waveform can be used, if the WSPR frequencies are converted into an image that
can be read by this wave form generator?
Am 27.12.2013 01:45,
schrieb Markus Vester:
Today I finally found a simple solution
to send Opera sequences from SpecLab's digimode terminal. The nice thing about this is that you can use all of
SpecLab's powerful functions, like samplerate correction, adjustable pulse
shaping, or high audio frequencies. This seems very
useful, especially in the context of possible future VLF Opera
transmissions.
First you will need to create a text file
consisting of the 239 bit 1101... sequence for your callsign. This can be
generated from the PIC menu in the original Opera software. Or you can
use my little code generator tool at http://df6nm.bplaced.net/opera/opera_generator.zip - simply
copy opgen.exe from the zip and
type
opgen mycallsign >opera.txt
into a command window.
In SpecLab, open the digimode terminal and
configure it for ASK with no encoding, as shown in the attached "_settings"
screenshot. The symbol rate has to be set to the inverse dotlength for
the desired Opera speed:
mode dotlength
rate
(seconds)
(sym/s)
Op-8 2.048s
0.4883
Op-32 8.192s
0.12207
Op-4H 65.536s 0.01526
Shaping time can be selected from hard
(0%) to soft (50%) keying. Then enter your desired audio frequency
and use "Load TX text" from the file menue to load your opera.txt file.
The sequence will appear in the TX window, and the transmission can
be started by hitting the RX / TX button.
Best 73,
Markus (DF6NM)
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