Hello Tony,
>The sound card was already calibrated, but the offsets were not locked.
>Locking them seems to have made a difference. I repeated the
Yes the locking of the sampling frequency, at least, must be done to compare.
Note: I did this complex automatic shift sampling determination because MT63
has a problem which is inherent to the exagerated number of carriers (64). The
more you have carriers the more the calibration must be precise. MT63 was done
for almost perfect sound cards (Sound Blaster or equivalent). For the on-board
sound cards, there is a problem due to the poor sampling accuracy of these
cards, so you can't be sure that the other Ham has a well-calibrated sound
card. It's the reason why I propose an automatic sampling autodetermination, by
default, working only with good signals (as you saw in the previous tests). I
think, aside to the poor average power/peak power ratio (about 0.1), this
problem of calibration is an issue which limits the use of MT63 (Hams, in
general, use their on-board sound card installed in their PC).
>have. Minimum SNR (errorr-free throughput) is -8db for IZ8BLY and -6db for
>Mutlipsk.
-6dB for Multipsk seems correct for 10 bauds (I measure -5dB for 10 bauds). I
agree that Nino's program has a better decoding program.
TKS for all your interesting tests!
73
Patrick
----- Original Message -----
From: Tony
To: digitalradio@yahoogroups.com
Sent: Saturday, September 27, 2008 10:32 PM
Subject: Re: [digitalradio] MT63 -- Mutlipsk, IZ8BLY, MixW
Patrick,
The sound card was already calibrated, but the offsets were not locked.
Locking them seems to have made a difference. I repeated the same tests and
decoding did improve with Multipsk (see below).
As for one program having an advantage over another, I guess it could be due
to the slight sensitivity advantage Nino's program seems to have. Minimum SNR
(errorr-free throughput) is -8db for IZ8BLY and -6db for Mutlipsk.
This seems to show-up in test #1 where the selective fading may be causing
the signal to dip below the -6db decode threshold for Multipsk. Nino's software
has a 2db "buffer" with this test.
In test #3 where there's selective fading and lightning static, things
improve with Multipsk when the SNR is inceased to +3db from -3db:
Multipsk Test #3
SNR +3db
THE QUIK BROW FOX JUMPS OVER THE LAZY DOG
THE QUICK BROWN FOX JUMPS OVER THE LAZY DOG
THE QUICK BRWN FOX JUMPS OVER THE LAZY DOG
THE QUICK BROWN FOX JUMPS OVER THE LAZY DOG
SNR -3db
HE QUIK3,ROWS F'XexMn OVER THE L/ZY DOG
THE QUICK BROWN FOX JUMPS OVER THE LAZY D+G
THE QUICK BRWg FOX JMPS OVER THE LAZY DOG
THE QUICK BROWN FOX JUMPS OVER THE LAZY DOG
Thanks for all Patrick.
Tony, K2MO
++++++++++++++++++++++++++++++++++++++++++++++++++
Test #1: SNR -6db selective fading
IZ8BLY
TH; QUICK BAOWN FOX JUOPS OVrR THE LAZY [OG
THE QUICK BROWN FOX JUMPS OVER THE LAZY DOG
THE QUICK BROWN FOX JUMPS OVER THE LAZY DOG
THE QUICK BROWNFOX JUMPS OVER THE LAZY DOG
MixW
2Hx QU/8qvB,4YNn}mGbSI*+OenJX|Y aO|
TH3N$aaK RptNWFOX JUMPS OVER THE LAZY DOG
THE QUICK BROWN FOX JUMPS OVER THE LAZY DOG
THE QUIcK BROWN FOXFJUmPS "VER THE LAZY DOG
Multipsk
THN QUICKFB;OW ZX JP OVXR THErL,ZY RG
THE [UICK BROW FOX JUMPS OVER THE LAZY DOG
THE QUICK BROWN FOX JUMPS OVER THE LAZY DOG
THE QUICK BROWN FOX JUMPS OVER THE LAZY DOG
________________________________________________
Test #2: SNR -3db selective fading
IZ8BLY
THE QUICK BROWN FOX JUOPS OVER THE LAZY DOG
THE QUICK BROWN FOX JUMPS OVER THE LAZY DOG
THE QUICK BROWN FOX JUMPS OVER THE LAZY DOG
THE QUICK BROWN FOX JUMPS OVER THE LAZY DOG
MixW
THE AUICKROWN F:X JUMPS ,VER THE L/ZY [OG
THE QUICK BROWN FOX JUMPS OVER THE LAZY DOG
THE QUICK BROWN FOX JUMPS OVER THE LAZY DOG
THE QUICK BROWN FOX JUMPS OVER THE LAZY DOG
Multipsk
THE QUICK BROWN FOX JUMPS OVER THE LAZY DOG
THE QUICK BROWN FOX JUMPS OVER THE LAZY DOG
THE QUICK BROWN FOX JUMPS OVER THE LAZY DOG
THE QUICK BROWN FOX JUMPS OVER THE LAZY DOG
_______________________________________________
Test #3: SNR -3db selective fading / lightning static
IZ8BLY
THE QUCIK BROWq FOX JUMPS OVrR THE LAZY DOG
THE QUICK BROWN FOX JUMPS OVER THE LAZY DOG
THE QUICK BROWN FOX JUMPS OVER THE LAZY DOG
THE QUICK BROWN FOX JUMPS OVER THE LAZY DOG
MixW
THH mUICK0I\OWm iZM JUMPS ,VER THE 2AZYzDOG
THE QUICK BROWN FOX xUMPS OVER THE LAZY DOG
THE QUICK BRO9N FOX JUMPS OVER THE LAZY DOG
THE QUICK BROWN FOX JUMPS OVER THE LAZY DOG
Multipsk
HE QUIK3,ROWS F'XexMn OVER THE L/ZY DOG
THE QUICK BROWN FOX JUMPS OVER THE LAZY D+G
THE QUICK BRWg FOX JMPS OVER THE LAZY DOG
THE QUICK BROWN FOX JUMPS OVER THE LAZY DOG
___________________________________________________
Test #4 SNR -9db
IZ8BLY
TH QUICK BROWN FOX_UMPS OVER THE LAZY DOG
THE QUICK BROWN FOX JUMPS OVER THE LAZY DOG
THE QUICK BROWN FOX JUMPS OVER THE LAZY DOG
THE QUICK BROWN FOX JUMPS OVER THE LAZY DOG
MixW
UHE qU4C? BROWN 9GX'JUMPS OVE THE LAZY DOG
THE QUI^d BnCWNlFOX JUMPS OVERDTHE LAZY OGj
HEs%#IC BRWN FOX JUMS OV5R THE LAZYBDOG
THE QrCK BROWN FBX UXPS OVER {HE"LAZpHDOG
Multipsk
TH\ QUIF,RO\[ F(U'xM
S OV:R THE LAZY DOG
THE QUICKBRON FOX JUMPS OVER THE LAZY DOG
THE QUICK BRKWN FO { MPS OVER THE LAZY DOG
THE QUICK BROWN FOX JUMPS OVER THE LAZY DOG
----- Original Message -----
From: "Patrick Lindecker" <[EMAIL PROTECTED]>
To: <digitalradio@yahoogroups.com>
Sent: Friday, September 26, 2008 7:04 PM
Subject: Re: [digitalradio] MT63 -- Mutlipsk, IZ8BLY, MixW
Hello Tony,
About Multipsk, could you first (if not done) the MT63 sampling calibration
by clicking on "Sampling freq." and start the automatic calibration.
Note: in Multipsk there is a double correction:
* determination of the sampling frequency offset between the TX and the RX
sound cards. This function does not belong to the original soft nor Mixw,
* determination of the frequency offset.
If you do a comparizon, click on the first "lock" to 0 (to avoid the
determination of the sampling frequency offset, function which needs a good
MT63 signal).
However, the original soft could be much better (I wrote an independant MT63
decoding code and I don't know the way the original soft decodes).
73
Patrick
----- Original Message -----
From: Tony
To: digitalradio@yahoogroups.com
Sent: Saturday, September 27, 2008 12:35 AM
Subject: [digitalradio] MT63 -- Mutlipsk, IZ8BLY, MixW
All,
There seems to be some difference between Mutlipsk, MixW and IZ8BLY's
software when it comes to decoding MT63. I ran all three programs
simultaneously with a path simulator in line and the SNR set above the decode
threshold.
The results were the same whether I ran the programs one at a time or
simultaneously. Not sure why this is; would appreciate it if someone can shed
some light on this. I plan to run each program on-the-air to see if the results
change.
Tony, K2MO
Test #1: SNR -6db selective fading
Test #2: SNR -3db selective fading
Test #3: SNR -3db selective fading / lightning static
Test #1
IZ8BLY MT63 Terminal
TH QUICK BRAOWN FOX JUOPS OVER THE LAZY [OG
THE QUICK BROWN FOX JUMPSOVER THE LAZY DOG
THE QUICK BROWN FOX JUMPS OVER THE LAZY DOG
THE QUICK BROWNFOX JUMPS OVER THE LAZY DOG
MixW
TH QUI4 M)9"Nd3/ANjV (UT$ExLZY UG
THE QUICK BRmWN 1OX JUMPS OVER THE LAZY DOG
THE QUICK BROWN FOX JUMPS OVER THE LAZY DOG
THE QUI>K BROWN F9XFJUmPS "VER THE LAZY DOG
Multipsk
YhlU+ O~^ FlX JUiPSkOVER THE LAZY DOG
THE QUICK{BOovFV!D.M]y5xVr| +v75UX7ØOpL{
z]p?Bx~i6GzV$cSNVDcTH: LØZY DOG]mOT*
_________________________________________________
Test #2
MT63 Terminal
THE QUICK BROWN FOX JUMPS OVER THE LAZY DOG
THE QUICK BROWN FOX JUMPS OVER THE LAZY DOG
THE QUICK BROWN FOX JUMPS OVER THE LAZY DOG
THE QUICK BROWN FOX JUMPS OVER THE LAZY DOG
MixW
THF QUIaK BRORNdFOX J$MPS ?[7@ TWE LAZY DOG
THE QUICK BROWN FOX JUMPS OVER THE LAZY DOG
THE QUICK BROWN FOX JUMPS OVER THE LAZY DOG
THE QUICK BROWN FOX JUMPS OVER THE LAZY DOG
Multipsk
THE QUICK BROWN FOX JM8; O5Es HE LAZY DG
THe*QICK BROWN F+X JUMPS OVER THE LAZY DOG
THE QUICK BROWN FOX JUMPS OVER THE LAZY DOG
THE QUICK BROWN FOX JUMPS OVER THE LAZY DOG
______________________________________________________
Test #3
IZ8BLY MT63 TERMINAL
RON FOX JUMPS OVER THE LAZY DOG
THE QUICK BROWN FOX JUMPS OVER THE LAZY DOG
THE QUICK BROWN FOX JUMPS OVER THE LAZY DOG
THE QUICK BROWN FOX JUMPS OVER THE LAZY DOG
MIXW
HE QUIAn BROWtF?X:J+MPS v)rR TE L/ZY DOG
THE QUICK BRKWN FOX JUMPS OVER THE LAZY DOG
THE QUICK BRO9 FOX JUMPS OVER THE LAZY DOG
THE QUICK BROWN FOX JUMPS OVER THE LAZY DOG
MULTIPSK
$Xiu(L Kka?SO?m)#-ap^jtOu{+^d4,-`Ø$P{&&8YAZY O)
,njl'KuBRja "_J(/S VØRU!H5N(1=YDOG
THE QUIkK B}O9g OY4JUMPS OVER THE LAZY DOG
THE QUICK BROWN FOX JUMPS OVER THE LAZYØDOG
