just-(E-Mail Removed) wrote:
> Several weeks ago I posted some messages on here trying to determine
> why my dialup connection suddenly dropped from around 44K to always
> connecting at 24K. I tried most of the tests you all recommended,
> spent days trying all sorts of diagnostics, calling my ISP, the phone
> company, etc. I finally ordered another external modem (because I got
> tired of fighting with the internal ones that dont have drivers for
> Win98).
>
> I just got the new modem. Installed it, and I am once again getting
> 44 to 45K.
>
> Why would the old modem suddenly just quit connecting at any speed
> higher than 24K? It always used to connect at 40K or higher, and I
> used it for years. It just suddenly started to connect at 24K and I
> have lived with that for almost a month.
>
> There could have been a lightning surge, but having had a few other
> modems die from lightning, they normally just die completely. I just
> can not understand why this old one just dropped to 24K and will not
> connect higher. The old modem is a US Robotics 56K Voice Pro PNP.
> (which was a top of the line modem).
>
> This makes no sense to me....
>
> Thanks
>
If the damage to the analog front end, affected the frequency
response, then that could account for a lower connect rate.
(It is unfortunate, that all the pictures in this article,
did not get archived.) It isn't something I would have
thought of, or considered, because the analog front
end should be pretty simple (maybe a transformer with
capacitive coupling - not really sure - some front ends
are "silicon" and don't use the older methods). The front
end is there, to protect the user's computing equipment,
from the voltages and transients found on telephony
equipment. For example, ringing voltage from the
ringing generator, are enough to give you a shock, and
the front end on your modem is there, to isolate those
voltages, so they don't get to any 5V or 3.3V logic chips.
http://web.archive.org/web/200212130...ty11/aty11.htm
The rest of the graphs can be found here.
http://members.cruzio.com/~jeffl/aty11/?N=D
The above graphs are constructed from the data collected
with the ATY11 command. If you compared the ATY11 data
from the old modem to the new modem, it would allow
comparisons like Jeff was making.
Congratulations on getting your speed back :-)
Paul