david, at 22:25 on Feb 27 1996, you wrote to Bill Grimsley...

BG> I strongly suspect so, given the less-than-perfect lines somewhere
BG> between here and Wollstonecraft.

db> No matter what I change, I never get more than 21.6Kbps with Dave Hatch; 

Is that to his Courier or his Viper ?

db> also get lower-than-expected connections with 3M. 

Agreed.  3M from here is a very poor connect as well.

db> Maybe those guys are all in an area that to each other is fine, but to them 
db> from somewhere else is pot luck (with DD being lucky, you and me varying in 
db> luck)?

Quite likely.  Only the USR's ATY11 line-probe stats will tell, I guess...

BG> The higher the frequency, the worse the line becomes (see the line probe
BG> stats I've posted lately?).

db> Yes .. the "%L" command has a coded minimum of -11dBm, but
apparently an 
db> undocumented command ("#T") will let you go higher, so
maybe Paul can 
db> change it in his M34F to see if it makes any difference.  I think I tried 
db> -9dBm to Dave Hatch, and it didn't work - but it might help Paul.

According to Joe at USR, too high a transmit level can be just as
deleterious as one which is too low, which is why USR have adopted floating
transmit levels, which vary according to several constantly monitored
parameters.  Indeed, mine vary from -11dBm to -18dBm (on very good lines). 


BG> The USR manual is a little obscure, and only lists the various carrier
BG> freqs for a given protocol...

db> Gimme!  :-)

Done.  If you want V.32ter, V.32bis, and HST as well, let me know.

BG> I was half-serious, as the problem does appear to be peculiar to his end
BG> of the link (other STD V.34 calls work perfectly from here, even to
BG> NetComms). :)

db> Entirely possible - wasn't Paul complaining about poor TV reception at one 
db> stage? 

Yeah, but phone signals come in via a landline, not a TV aerial.  :)

db> The 'phone lines may be questionable too, and as you say the USR 
db> may be better able to handle that. 

I'd say that's a foregone conclusion (quite aside from the fact that USR
have actually announced as much publicly).  :)

db> NetComm *may* still be able to do *something* with their ROMs, but of 
db> course Rockwell Semiconductor have control of the situation here.

True, if it's in the hard-coded data pump, it's unfixable.

BG> It's starting to look like Rockwells just can't handle poor lines as well

db> No idea if that's just with the default settings, or if USR is able to 
db> ignore the defaults when appropriate, or if the Rockwells are just plain 
db> unable to do it at all.  Anything's possible, of course.

Dunno about the Rockwells, but the USRs do continually monitor conditions,
and adjust their Tx levels accordingly.  USRs also add shaping, precoding,
and pre-emphasis (etc.) to the signal if necessary, but once again, that
may not be USR-specific.

db> If nothing else, this proves that the M34F isn't as stuffed as first 
db> thought.

BG> Of course, Rod would simply call that zealotry...  :)

db> Who?

:)

Regards, Bill

--- Msgedsq/2 3.20