| |
VE2HAR > MT63 15.03.05 21:46l 260 Lines 7051 Bytes #-7001 (0) @ WW
BID : 9429SENTTO
Read: GUEST
Subj: Re: [MT63]
Path: DB0FHN<DB0FOR<DB0SIF<DB0FHK<DB0FBB<DB0IUZ<DB0GOS<DB0EEO<DB0RES<ON0BEL<
VE2PAK<W1NGL<VA2HAR<VE2HAR
Sent: 050315/1911z @:VE2HAR.#MTL.QC.CAN.NOAM Laval #:42839 $:9429sentto
Hi Steve,
> Point 1. Checking the byte size will not tell you anything other than i=
f=20
> a byte is added or missed. Checksum is the correct way to do that. It=20
> adds all of the data together to creat a binary number. Filecheck also=20
> works by doing a direct comparison byte by byte of the data and giving=20
> an indication of where the error or discrepancy is.
Yes...didn't I say an MD5 check (isn't that a checksum?)? I think that w=
ould be
a better check.
Filecheck??? Is that a MS command or Unix command? In Unix its "diff" of=
the
difference between two files. I've been away from REAL Unix for such a l=
ong
time that I have forgotten the commands. Hi Hi.
>=20
> Point 2. 3,000 words is not less than 3,000 bytes. That would be closer=
=20
> to (8 bits/byte X 5 Bytes/word + spaces and puncuation) 144,000 which a=
t=20
> 200WPM would take 12 minutes to send.
Hummm, my math was probably wrong also...400 words=3D2400 characters and =
with 8
bit and start and stop bits that's 10 bits per character so 2400 * 10 =3D=
24KBPS.
Is that right? Well that might be a little large.
>=20
> The file needs to be a bit smaller. I recommend a small gif or bmp file=
=20
> of a test pattern. 1) so that it is able to be sent within 3 - 4=20
> minutes, not over 10 minutes for ID purposes. 2) A quick visual=20
> inspection of the file would show gross errors.
The problem here is that if you want to apply the same file to MFSK16 or =
AMTOR
or RTTY or AX.25 for comparison, the binary file wouldn't work...so we ne=
ed text.
Walt/K5YFW
>=20
> Steve/WM5Z
>=20
> karl larsen wrote:
>=20
> > Hi Walt, I agree we need to define our text that we send, the amount=
=20
> >of bytes that are sent and then have a method to check the number of=20
> >errors. The size can be more than 3 Kbytes but no larger is better. Th=
e=20
> >text can be anything but it must conform with the ASCII text format. T=
he=20
> >test text must be sent to this list so everyone that is interested can=
=20
> >get the accurate file. In linux you can check both files by knowing=20
> >there total byte size. If they are the same, it's perfect. You get the=
=20
> >byte size with ls -al.
> >
> >Using the Linux gMFSK I can send the test file directly with clicking=20
> >File and then Send file. When I receive the test file I can simply cut=
=20
> >it out of my lof file. I have my system set to log everything. Fun to=20
> >look at later.
> >
> >I have a file we can use. It is the ARRL bandplan. It is way too long=20
> >but I will cut it down to about 3,000 words.
> >
> >karl
> >
> >
> >dubose@texas.net wrote:
> >
> > =20
> >
> >>Thanks to Patrick, F6IN, for bringing PathSim to our attention. This=
is truly a
> >>nice application.
> >>
> >>Building on what I believe Tomi or others have said, as well as my ow=
n thoughts
> >>about having a "test" file. Also, looking at G4HPE's papers found at
> >>http://www.rsgb.org/emergency/datamodesinfo.htm . And not to be left=
out, my
> >>several E-Mails with Charles, G4GUO.
> >>
> >>Back in Jan/Feb of 1990, the US TRANSCON began "testing", on-the-air,=
HF
> >>transmissions of a file which became their standard. It was a 40KB =
file. The
> >>modes being used were the MIL-STD-188-110 type. These were interesti=
ng test.=20
> >>The MD5 sum was used on each received file to verify that its was the=
same as
> >>the original file. Throughput and accuracy were important.
> >>
> >>G4HPE in his paper "A PRACTICAL EVALUATION AND COMPARISON OF SOME MOD=
ERN DATA
> >>MODES" (http://www.rsgb.org/emergency/articles/datmodes2.pdf) Richard=
speak of
> >>the test he did on MT63 and MFSK16.
> >>
> >>Also, on page 17 of Rick=92s, KN6KB, presentation to the DCC last Sep=
tember
> >>(2004), he shows throughput using an HF channel simulator from KC7WW=92=
s Oregon
> >>Software Factory.
> >>
> >>G4HPE=92s test concluded that MT63 had a throughput of 200 WPM at a =96=
5 dB SNR on a
> >>poor CCIR Channel. KN6KB=94s results for Pactor II/III indicate a si=
milar (if not
> >>lower) throughput under the same signal conditions.
> >>
> >>While I do not doubt these findings, I believe that as some in this g=
roup are
> >>very technical, we need to develop a standard method of testing vario=
us new
> >>modes under varying conditions using Moe Wheatley=92s, AE4JY, PathSim.
> >>
> >>Here is my suggestion.
> >>
> >>1) Create/develop a standard file of at least 400 words (5 characters=
one space
> >>per word, 6 bytes =852.4KBPs).
> >>
> >>2) Generate this file in the mode to be tested and store it electroni=
cally on a
> >>computer hard drive, CD or other magnetic storage media.
> >>
> >>3) =93Play=94 this file through the AE4JY=92s PathSim application at =
the following HF
> >>Simulation parameters:
> >>
> >>
> >>
> >> CCIR 520-2 Conditions SRN (in dB)
> >> Good Conditions +10 +5 0 -5
> >> Moderate Conditions +10 +5 0 -5
> >> Poor Conditions +10 +5 0 -5
> >> Flutter fading +10 +5 0 -5
> >> Low-latitude quite +10 +5 0 -5
> >> Low-latitude disturbed +10 +5 0 -5
> >> Mid-latitude quite +10 +5 0 -5
> >> Mid-latitude disturbed +10 +5 0 -5
> >> High-latitude quite +10 +5 0 -5
> >> High-latitude disturbed +10 +5 0 -5
> >>
> >>4) Record output or =93play=94 it through the mode detector and captu=
re the output.
> >>
> >>
> >>5) With software techniques to manually determine the throughput at e=
ach signal
> >>condition.
> >>
> >>6) Document the results and provide the results to interested parties.
> >>
> >>I realize that this is just a rough draft of a testing process but t=
hink its is
> >>within the capability of a number of list members and the results mig=
ht be VERT
> >>INTERESTING.
> >>
> >>You comments solicited.
> >>
> >>Thanks & 73,
> >>
> >>Walt/K5YFW
> >>
> >>
> >>
> >>
> >>
> >><< Try MT63 on 80m - great fun!>>
> >>
> >>- The MT63 Reflector -
> >> MT63@egroups.com
> >>
> >>(To unsubscribe. send email to
> >>MT63-unsubscribe@onelist.com)
> >>
> >>Yahoo! Groups Links
> >>
> >>
> >>
> >>
> >>
> >>
> >>
> >>
> >>
> >>=20
> >>
> >> =20
> >>
> >
> >
> >
> ><< Try MT63 on 80m - great fun!>>
> >
> >- The MT63 Reflector -
> > MT63@egroups.com
> >
> >(To unsubscribe. send email to
> >MT63-unsubscribe@onelist.com)
> >=20
> >Yahoo! Groups Links
> >
> >
> >
> >=20
> >
> >
> >
> >
> > =20
> >
>=20
------------------------ Yahoo! Groups Sponsor --------------------~-->=20
Check out Music Videos, Internet Radio, Artist Photos, Music News!
LAUNCH Music on Yahoo!
http://us.click.yahoo.com/wmKGzA/JARHAA/kkyPAA/CPMolB/TM
--------------------------------------------------------------------~->=20
<< Try MT63 on 80m - great fun!>>
- The MT63 Reflector -
MT63@egroups.com
(To unsubscribe. send email to
MT63-unsubscribe@onelist.com)
=20
Yahoo! Groups Links
<*> To visit your group on the web, go to:
http://groups.yahoo.com/group/MT63/
<*> To unsubscribe from this group, send an email to:
MT63-unsubscribe@yahoogroups.com
<*> Your use of Yahoo! Groups is subject to:
http://docs.yahoo.com/info/terms/
=20
Read previous mail | Read next mail
| |
