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| reply to Bicephale
Re: Tweaks .JPG/thumb.jpg "723268 bytes")
TekSavvy Shipment (2008-Jul-10) |
Here it is, the evaluation can begin!
My only problem: i got disturbed while unpacking so i mixed them up...
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| %20.GIF "40972 bytes")
VelCom - ST516v6-1 (FW v6.2.16.3, 2008-Jul-10) | %20.GIF "41992 bytes")
VelCom - ST516v6-2 (FW v6.2.29.2, 2008-Jul-10) |
1st of all, we've got a sunny day with dark
clouds at the end of the afternoon. 'STMT'
doesn't update the statics numbers while it
is drawing curves, which means that in this
test the MoDems did not have time to settle
before those numbers were recorded (nor did
my spectral response curves adjust neither).
The main purpose of today's 'STMT' captures
was to obtain "noise" curves to compare the
two MoDems, essentially. Consider the rest
as accessorial, other attempts will be made.
The unit identified as "ST516v6-1" had the
plain old transformer type of PSU while i've
used the newer switching-mode unit with the
second ST516 MoDem... | | |
|
 ardo
join:2001-12-20
North York, ON | said by Bicephale:The unit identified as "ST516v6-1" had the plain old transformer type of PSU while i've used the newer switching-mode unit with the second ST516 MoDem... I would expect the switchmode PSU to be somewhat noisy, but the SNR difference looks quite dramatic. Did you have any of your patented  thoroids on the switchmode PSU? I'm not sure if thoroids are good for anything other than 60Hz suppression, but still...
You are testing the 2 modems with slightly different firmware versions, could this make a difference, too? Is there a way to re-test with one modem & different PSUs?
My ST516 came with v6.2.16.3 and I was just thinking of upgrading to v7.4.3. Would you recommend it? You seem to have tested all firmware releases, I wonder if there's a reason why you're running v6.2.16.3. Sorry for the off-top. | |
|  .GIF/thumb.jpg "18705 bytes")
VelCom - ST516v6-1, FW v6.2.16.3 (2008-Jul-11, 16h21) |  .GIF/thumb.jpg "52495 bytes")
VelCom - ST516v6-2 (DMT Part 1, 2008-Jul-12) |  .GIF/thumb.jpg "52113 bytes")
VelCom - ST516v6-2 (DMT Part 2, 2008-Jul-12) | %20.GIF "36230 bytes")
VelCom - ST516v6-2 (STMT, 2008-Jul-12) |  .GIF/thumb.jpg "18827 bytes")
VelCom - ST516v6-2, FW v6.2.29.2 (2008-Jul-11, 0h00) |
Last night, slightly past midnight, i put on-line
what i presume to be Thomson's newer ST516v6 unit
and its alledged corresponding switched-mode PSU.
I brought the linear-mode PSU and its counterpart
with me when i travelled between Louiseville and
my new appartment, there was very little time to
try the set previously labelled as "ST516v6-1"...
Static numbers provide poor information sometimes,
perhaps that's what happened with the 'DMT'/'STMT'
captures made after i returned to Louiseville: it
doesn't plead in favour of the new "ST516v6-2" set
and, yes, i did implement RF choking on the power
leads (i used two toroidal cores with five turns
each, actually)... The WAN side's heavy RF choke
has been replaced with multiple lighter cores to
distribute their effect (i noticed that the line
improved, probably because of the season alone;
hence, there may be little or no need for those).
I scavenge ferrite cores from obsolete PSUs so the
operating frequency of those devices is many times
60 Hz, ideally within the A.M. radio range which
DSL shares... I could swap the MoDems vs the PSUs
but there's not much time left as my departure for
Quebec city is imminent, if all goes well i should
have moved permanently next week. As a consequence,
i prioritize my evaluation of those two device by
collecting long term records, 'STMT' curves, ideally.
FirmWare v7.4.3.2 combined to my ST546v6 suddently
inspired respect, as far as i'm concerned. If it
weren't for the fear that i might never be able to
find the exact FirmWares for later re-installation,
euh... i'd sure give FW v7.4.3.2 a thought or two!
Look at my static numbers and conclude for yourself:
this 8 dB DownStream SNR Margin which i could see
at the end of the day felt inferior, miserable!...
An error of interpretation is possible but i was
under the impression that the initial goal should
be to compare the units as they are shipped, then
to dig up a bit further, eventually... Right now,
it wouldn't be normal for me to flash the devices
without a strong motive: it's not what a regular
customer should do only a couple days after he's
received his brand new MoDem, in my opinion! In
any case, please feel welcomed to comment further.
 | |
| Oups! One word of caution: sometimes you can read
"2008-Jul-12" in the previous post but it was about
the day before (at 0h00 one day got added but my
24 h record is for the day before)... That's an error i
manage to avoid, usually! | |
2 edits | %20.GIF "46865 bytes")
VelCom - ST516v6-1 (STMT, 2008-Jul-12) |  .GIF/thumb.jpg "50532 bytes")
VelCom - ST516v6-1 (DMT Part 1, 2008-Jul-12) |  .GIF/thumb.jpg "50539 bytes")
VelCom - ST516v6-1 (DMT Part 2, 2008-Jul-12) | %20.GIF "42568 bytes")
VelCom - ST516v6-2 (STMT, 2008-Jul-12&13) |  .GIF/thumb.jpg "52583 bytes")
VelCom - ST516v6-2 (DMT Part 1, 2008-Jul-12&13) |  .GIF/thumb.jpg "52404 bytes")
VelCom - ST516v6-2 (DMT Part 2, 2008-Jul-12&13) | %20.GIF "44637 bytes")
VelCom - ST516v6-2 (STMT, 2008-Jul-14) |  .GIF/thumb.jpg "52217 bytes")
VelCom - ST516v6-2 (DMT Part 1, 2008-Jul-14) |  .GIF/thumb.jpg "51865 bytes")
VelCom - ST516v6-2 (DMT Part 2, 2008-Jul-14) |
Thomson SpeedTouch 516v6 (a switching-mode PSU edition)...
Take note that the static numbers shown by 'STMT' have been
read before the real-time record has begun, hence the need to
join 'DMT' captures where those numbers have been read after.
N.B.:
2008-Jul-18 - It seems the versions were mixed up...
ST516v6-1 is FW v6.2.16.3.0 (ZZQ0DV6.2G3)
ST516v6-2 is FW v6.2.29.2.0 (ZZQ0GE6.2T2)
ST516v6-1 has linear power supply
ST516v6-2 has switched-mode power supply | |
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