🚀 go-pugleaf

I have followed with great interest, the various problems that Demon
Customers have had with their connections, especially with regard to line
drops, connections freezing and logon/negotiation problems. I have a
Motorola 28.8/3400 modem that I bought as part of an "Internet Solution"
package a few months ago. As a complete novice with Modem witchcraft, I
fell into all the traps and had all these problems, but by following the
advice in this ng, as well as others, I have obtained a relatively stable
setup, but... I can't change my Tx level!  
I have tried various ways to enter the magic string 'ATS39.0=1*TD9&F'. I
set up HyperTerminal to talk to the modem on COM1 and can change all the
settings in the handbook, but this string just produces an ERROR message.
If I introduce it in my initialisation string, I get a message from Win95
telling me that the modem is not communicating. Any help would be very
welcome.
I include the following details from Hyper Terminal as assistance - 

Motorola 28.8 External 68356 RAM  SW REV 1
S209415900 -07 5/02/95    9:30 AM

ACTIVE PROFILE:                                      DTE = 115200 BPS 
8/NONE/1
E1 H2 L2 M1 Q0 V1 X4 Y1 &C1 &D2 &G0 &L0 &M0 &P0 &R1 &S0 &T4 &X0 %A0   %B16 
%C1
%D0   %L1  %R0 \A3 \B35  \C0 \G0 \J0 \K5 \M1 \N7 \Q3 \R1 \T0   \V0 \X0 *AS1
*DG0 *DN0 *DR0 *FT0 *ID0 *MM0  *OR0 *RA0 *TD18 *TH2 *TL21
S00:000 S02:043 S03:013 S04:010 S05:008 S06:004 S07:030 S08:004 S11:080
S12:050
S18:000 S25:005 S26:000 S41:061 S42:050 S73:000 S74:015 S75:000 S76:015
S77:000

ATS39.0=1*TD9&F
ERROR

I must be missing something...it seems so straightforward?
Thanks in anticipation
-- 
Larry Richardson