


                       IMPROVEMENTS FOR THE
                    KANSAS CITY TRACKER/TUNER
                                                 
                                BY
                                 
                         JOE BARGER  N6KK
                        2009 Harkness St.
                    Manhattan Beach, CA 90266
               internet: barger@aerospace.aero.org
                  satellite: AO-16, LU-19, FO-20
                        bbs: N6KK @ WB6YMH
                      compuserve: 71560,2514


INTRODUCTION

	The Microsats have created an entirely new and
fascinating aspect of amateur radio.  Digital communications,
satellite tracking, communications protocols and BBS operations
are just a few of the diverse disciplines that are instrumental
to the operation of the Microsats.  Assembling the hardware and
software elements for a successful Microsat station is an
educational, challenging and absorbing experience.  The
technology is so new that there are many aspects of Microsat
operation where experimentation and advancement in the state of
the art is possible and needed.

	Operating the low earth orbit Microsats can be a hectic
experience.  Two hands are not enough to handle the "routine"
jobs of pointing azimuth and elevation antennas, tuning the
uplink and downlink radios to correct for doppler shift,
switching antenna polarization to correct for polarity shifts,
etc.  Add the "mothering" of computer programs necessary to
upload or download files and the number of simultaneous tasks
becomes tedious and error prone.  Automation of some of these
routine functions makes life on the Microsats much easier and
more productive.  Automation of the tracking and tuning functions
also makes unattended data collection over a period of several
days possible and is a necessary step toward automatic gateway
operations.

	The Kansas City Tracker (KCT) and Tuner by L. L. Grace is
a commercially available product that automates antenna tracking
and downlink/uplink tuning.  It consists of a plug-in hardware
board and complementary software that interfaces with the antenna
rotors and the uplink/downlink radios.  It works in concert with
satellite tracking programs such as Quiktrak and GRAFTRAK.

	The Tracker function works beautifully.  It keeps the
antennas pointed within a few degrees and eliminates a major
source of work during the passes.  Relatively large errors in the
keplerian elements (keps) and time can result in pointing errors
of a few degrees, but the 3 db antenna beam widths used by
amateurs are typically 30 degrees or more, so pointing errors of
a few degrees are not critical.

	The Tuner, however, is not so forgiving.  To tune the
downlink (and uplink, although the uplink isn't nearly as
critical), the Tuner requires very accurate time of day and
keps.  An error of just 1 second in the time of day can result in
a maximum downlink tuning error of around 100 Hz for high
elevation passes of the Microsats.  Accurate time of day can be
obtained via WWV, but getting keps that are accurate enough seems
very difficult.  Even using the "freshest" keps I can find,
tuning errors occasionally exceed 500 Hz during the middle of the
pass (when the doppler shift rate is highest).  My TAPR PSK modem
loses lock when the tuning error approaches 200-300 Hz.  And even
the best set of keps seems to be good for a week or so before the
tuning errors build up and the modem loses lock sometime during
the pass. 

SOLUTIONS TO THE TUNING PROBLEM

	There are (at least) two solutions to this problem. The
accuracy of the keps can be increased by periodically correcting
them to reflect the current orbital parameters, perhaps by
massaging several element sets to produce a "smoothed" element
set that may be good for long periods of time.  Since I'm not a
math wiz, and I didn't have much information on how such
corrections should be made, I decided to take another approach
that does not require extremely accurate keps.

	The original Tuner uses an "open loop" method of
determining the downlink frequency.  It simply predicts the
downlink frequency based on the time and keps for the satellite
of interest.  With accurate keps and time, this calculation is
good enough to keep the modem locked.  But if the time or keps
are just a little off (particularly in the middle of the pass
when the change in doppler shift is highest), the calculated
frequency is in error.  The Tuner does reliably calculate the
downlink frequency at AOS even with moderately inaccurate time
and keps, since the change in doppler shift is minimal at AOS.  

	In a "closed loop" system, the actual tuning error is
included in the downlink frequency calculation, which results in
a self-correcting system to keep the modem locked to the downlink
frequency.  The TAPR PSK modem (and others) provide an error
signal in the form of "mic-step" tuning pulses that can
automatically step the downlink receiver up or down to track the
doppler shift once the modem is locked.  The key to the problem
was to find a way to incorporate the modem step tuning pulses in
the downlink frequency calculations to correct the computed
downlink receiver tuning commands.  Unfortunately there isn't a
convenient method of incorporating these error signals directly
into the Tuner downlink frequency calculations.  

	I talked to the KCT developer, Brooks Van Pelt, about my
project.  He was very supportive but, since he was very busy with
the DSP-12 project, he didn't have the time to make and test the
necessary changes to the software.  He was willing, however, to
provide me with the source code (which is in assembly) and a
hardware schematic so I could make the changes myself.  Making
changes to your own software and hardware is scary enough, but
making mods to a product as complex as the Tracker/Tuner is
crazy.  I decided to give it a try.  

	The first order of business was to find a way to make the
state of the "step-up, step-down" pulses from the modem available
to the software that does the downlink frequency calculation.  An
inspection of the schematic showed that there are two tristate
buffers connected to the KCT internal bus that are used to
determine the configuration of the KCT hardware.  The hardware
configuration is read by the software once during initialization
and merely modifies the driver "RIO" state.  Since there is a
driver command line switch (RIO) that can be used to set the RIO
state, there is no need to dedicate these buffers to determine
hardware configuration.  Therefore, once the code that reads the
hardware configuration is removed, these two tristate inputs can
be used to sample the state of the modem step signals.  The
easiest way to run the step signals to the tristate buffer inputs
is to isolate the buffer inputs by cutting the copper traces that
go to the inputs and attaching small wires from the isolated pins
to appropriate spare pins on the DB25 connector.  Unfortunately
the inputs of interest are tied to copper traces that run under
the tristate buffer chip (which is soldered directly to the
card), and are therefore inaccessible.   Only two other (rather
drastic) options came to mind.

	First, the two pins of interest can be cut as close to
the board as possible and then bent up so wires can then be
attached directly to the pins and run to the DB25 connector. 
Locate the two large socketed 2651 chips near the upper center of
the board (U10 and U11).  Directly below the lower socketed chip
is a 74LS126 (the only 74LS126 on the card, U7).  The two pins we
are interested in are pins 9 and 12.  Cut them as near to the
board as possible and carefully bend them up from the board so
they point straight out from the chip.  Because the LS126 is very
close to another chip, very fine pointed cutters are required. 
Make sure the tools you have will do the job, or you may mangle
the chip and possibly the card.  Once the pins are cut and bent,
use a fine tip, low wattage soldering iron and connect a small
wire from pin 9 to pin 2 on the DB25 connector.  Connect another
small wire between pin 12 and pin 4 on the DB25.  Space is tight
around the 74LS126, so be sure you don't short anything
together.  Connect the modem "up" step signal to pin 2 on the
mating DB25 connector and the modem "down" step signal to pin 14
on the mating DB25 connector.  Make sure the step signal levels
provided by the modem are TTL compatible (see "USING THE MODIFIED
TUNER" below).

	An alternative approach involves removing the chip
entirely and replacing it with a socket.  I prefer this approach
since the original functionality of the board can be completely
restored by simply putting a new 74LS126 in the socket (and it's
easier to make more modifications for future projects). Locate
the 74LS126 as described above and carefully snip each of the
pins with fine pointed cutters.  Use a low wattage soldering iron
with a fine point to remove the remaining part of the pins that
extend through the board.  Remove the remaining solder with the
same iron and some solder wick.  I tried using the solder wick to
suck up the solder and remove the chip without cutting the pins,
but I had no luck getting enough solder out to completely free
the chip.  Proceed very carefully, being sure not to use too much
heat to remove the solder or damage the copper traces on the card
can result.  After the chip has been removed and the holes
through the board freed of solder, solder in a PC mount socket. 
Then take a new 74LS126 and carefully bend pins 9 and 12 away
from the body of the chip until they make a 90 degree angle with
the other pins.  Insert the chip in the socket (make sure pin 1
is properly oriented) and check the clearance between pins 9 and
12 and the adjacent chip.  It may be necessary to cut the lower
half of the pins off to avoid shorting against anything.  Then
follow the instructions in the preceding paragraph on wiring pins
9 and 12 to the DB25 and wiring the modem step signals to the
mating DB25.   

	Once the hardware was modified, the software needed to be
changed to read the state of the modem step signals and adjust
the downlink frequency calculation accordingly.  Fortunately,
Brooks took the time to comment the source code in enough detail
that I found the spots in the code that needed to be modified
without too much problem.

	The modifications described above are not radio specific,
so they should work with any radio supported by the KCT.  The
only radio I have checked thoroughly, however, is the Yaesu
736R.  As it turned out, the Tuner didn't send 736R frequency
update commands fast enough during periods of maximum doppler
shift.  The maximum change in the doppler shift for the Microsats
downlink is approximately 100 Hz/sec.  The period between
frequency updates (either uplink or downlink) using the 736R is
around 2.4 seconds.  The step size can then approach 240 Hz,
which can result in momentary loss of lock.  The cause of the
slow update rate turned out to be due to the way the frequency
updates for the 736R are done in the Tuner.  To initialize the
Yaesu Computer Aided Transceiver (or CAT, which allows computer
control of the 736R), four separate CAT commands are required. 
The Tuner simply sends the entire initialization sequence of four
commands for each and every frequency update.  After
initialization, however, only one command is required to update
the frequency.  The update rate was increased by changing the
software to send only the frequency command after initialization
is completed.  The Tuner is designed to recalculate the uplink
and downlink frequencies every second, so improving the radio
update rate beyond one second is not necessary.  This change
results in around 100 Hz steps maximum and much better
performance.

POLARITY TRACKING

	Another manual task that can be automated is polarity
switching of the downlink (and uplink) antenna.  Cross
polarization between the satellite antenna and the ground station
antenna due to satellite rotation and Faraday rotation can result
in deep fades during a pass.  The KCT can (via the Yaesu CAT)
access the 736R S meter to obtain relative signal strengths.  The
KCT can also control an external antenna switch, which can be
used to switch antenna polarity.  I developed a simple algorithm
based on the relative downlink signal strength to select the
appropriate downlink polarity.  The downlink is sampled every 3
seconds.  If the signal strength is above about S-2, no change is
made.  If the signal strength is below S-2, the polarity is
switched and the resultant signal strength compared to the
original.  If it is higher, the polarity stays at the new
position.  If the signal strength is less, the polarity is
switched back to the original polarity.

	How the uplink polarity switching should be handled is
another matter, however, and I don't know how to do it at the
moment.  One potential problem is that the Tuner may attempt to
switch the uplink polarity while the transmitter is transmitting,
resulting in hot switching the polarity relay.  More importantly,
changes in uplink signal strength at the satellite are difficult,
if not impossible, for individual users to accurately evaluate.

	The polarity tracking function requires an S meter
reading to be returned from the 736R over the serial CAT bus. 
The KCT hardware is configured for interrupt driven CAT input,
but (since reading data over the serial CAT bus isn't required in
the stock Tuner) there is no software to support interrupt driven
input.  Writing the required interrupt drivers is not a trivial
task and, if not implemented properly, prone to erratic
operation.  I decided to avoid interrupt driven input if
possible.

	As it turns out, the 736 returns 5 bytes of data for each
"read S meter" command; 4 copies of the S meter reading and the
"read S meter" command.  The only data that is needed is one copy
of the S meter reading, so capturing just the first byte returned
after the read S meter command is issued is adequate.  The 736
spits out the 5 bytes of data very fast, so a method of reliably
capturing the first byte returned must be used.  The 2651 USART
used for the CAT serial communication link between the KCT and
736 has an output signal that indicates when a byte has been
received and is ready to be read (RXRDY) as well as an input
signal that disables further data input (DCD).  Simply connecting
these two signals will disable the USART receiver after the first
byte is received.  This minor hardware change and some software
to enable the USART receiver and poll for data ready is a simple
and effective method of reading the S meter without developing
complicated interrupt driver software.  The hardware changes do
not affect stock Tuner operation.

	Fortunately the USARTs are mounted in sockets.  Assuming
your 736R is on Port A, pull U11 (a 2651 chip) from its socket. 
Carefully bend pin 16 90 degrees so that it points straight out. 
Bend pin 15 just enough so that it will slip just outside the
socket when the chip is reinserted.  Put the chip back in the
socket and verify that pin 16 doesn't touch or interfere with the
adjacent parts.  Also make sure pin 15 is not seated in the
socket but rather outside of the socket.  Solder a small wire
directly to pin 16 on U11.  Connect the other end of the wire to
pin 8 of U13 (a 7406 chip).  Now remove U10 and bend pin 15 just
enough so that it will just slip outside the socket and reinsert
U10.

	If you are using Port B instead of Port A, simply reverse
U10 and U11 in the procedure above.

	The signal that the KCT provides to switch antenna
polarity is a single TTL output.  Fortunately, there is a spare
relay driver on the KCT card that can be used to drive a 12 volt
relay.  The inputs on the spare relay driver are grounded, so
they must be isolated by cutting the copper trace that goes to
them.  Cut the wide copper trace on either side of pins 6 and 7
on U24 (a 75452 chip).  Verify that pins 6 and 7 are indeed
isolated from ground but still connected to each other.  Connect
a small wire from U13 (a 7406 chip) pin 14 to U24 pin 8.  This
reconnects the path to U24 pin 8 that was severed when pins 6 and
7 were isolated.  Connect a small wire from U17 ( a 74LS273 chip)
pin 12 (the antenna control output signal) to pin 6 on U24.

	Unfortunately, if the tuning improvement modifications
described earlier are implemented, there are no more spare output
pins on the DB25 connector.  As far as I can tell, none of the
radio interfaces require the -12 volt that is supplied to pin 14
on the DB25 connector, so I isolated pin 14 from the -12 volts by
cutting the trace that goes to pin 14.  Then connect a small wire
from pin 5 on U24 to pin 14 on the DB25 connector.  The relay
itself is connected by wiring one side of the 12 volt coil to pin
14 on the mating DB25 connector and the other side of the 12 volt
coil to pin 21 of the mating DB25 connector.  (This is exactly
the same as how the "rotor interface option" external relays are
interfaced.)  Be very careful not to short either of the wires
running to the relay to anything, since both sides are at 12
volts until the relay driver is activated (which grounds one
side).  I simply connected the normally open contacts of a Radio
Shack #275-218B 12 volt relay in parallel with the switch I use
to manually control polarity.  In this case, the manual switch
must be open for the automatic polarity switch to work.


TUNER "POP UP" DISPLAY IMPROVEMENTS

	The Tuner Pop-Up display contains some interesting and
necessary information and some less useful data.  The top half of
the display contains the shifted beacon, uplink, and downlink
frequencies, uplink and downlink enable/disable control, and
uplink and downlink frequency selection.  The bottom half of the
pop-up is devoted to the radio port settings, which are not
configurable from the pop-up.  In fact, the only way the ports
can be configured is via command line switches during bootup and,
therefore, these settings rarely change.

	After operating the satellites for a while, I found
myself wishing I had several bits of information on this display,
such as the time to LOS when a pass is active, the time to the
next tabled pass, and a list of the tabled passes.  It would also
be nice to have some of the features of the "OSC" pop-up, such as
the ability to delete a single pass or the whole table and view
the current az and el rotor positions.  My version of the KCT
Tuner Pop-Up deletes the port setting information and replaces it
with this data and more.

	Figure 2 is an example of the new Tuner Pop-Up during a
typical pass with two more passes in the table.  The new features
perform the following functions.  "F-Trak" shows the status of
the frequency track function (or modem assisted mode) as
described above.  Pressing "F" toggles the F-Trak function on and
off. "P-Trak" shows the status of the polarity track function. 
"P" toggles the P-Trak function on and off.  P-Trak will be
blanked from the display and polarity processing disabled if a
Yaesu 736R is not the radio type assigned to the selected port
since only Yaesu 736R radios support this function.  If a pass is
not active, P-Trak is also blanked from the display because a
port (and therefore radio type) is not selected until a pass
starts. 

	"S-Mtr" is a relative indication of received signal
strength.  It ranges between 1 and 128 or so and is updated every
4 seconds during a pass.  This display is also blanked until a
pass starts and continues to be blanked if the radio selected is
not a Yaesu 736R.  The "AZ" and "EL" values indicate actual rotor
positions during a pass.  The values are blanked between passes. 
"LOS" indicates the time until loss of signal during the current
satellite pass and is blank between passes.  "Doppler" displays
the beacon doppler shift during a pass (it is simply the
difference between the real beacon frequency and the shifted
beacon frequency).  It is also blanked between passes.

	The rest of the Tuner Pop-Up shows the AOS date and time,
duration of the pass and time until AOS for the next two
satellites in the pass table.  If the time to AOS is greater than
60 hours or the AOS time has passed, the display will show
"--:--:--".  As in the OSC pop-up, pressing "S" will delete an
active pass or the next pass in the table and pressing "X" will
delete the entire pass table.  The Tuner "Help" screen has been
updated to include these changes.

	All the Tuner Pop-Up improvements except the F-Trak and
P-Trak related functions can be used without making any hardware
modifications to the KCT card.  Simply install the software and
turn the F-Trak and P-Trak functions off after bootup.

MISCELLANEOUS

	There are a few other minor changes.  The "alert" morse
code messages at 3, 2 and 1 minute before a pass starts now only
sound once instead of 9 times.  The original version (2.43) of
KCT software also has a bug that can corrupt the uplink
frequencies that are stored for each satellite.  It has been
fixed in this modified version.

	In order to distribute the processing load evenly and
produce periodically spaced updates to the radio, I have reduced
the frequency that the software processes the antenna azimuth and
elevation functions.  The only noticeable effect is an overshoot
of a few degrees during antenna slews that is corrected in a few
seconds.


USING THE MODIFIED TUNER

	There are several hints and kinks that will make using
this modified KCT easier.  I have tested the mods on a Yaesu
736R, PK232 with TAPR PSK modem and a s-l-o-w PC XT clone, but
these comments should apply to other station setups as well.  My
communications software (PB and PG) run on a separate computer,
so I have not been able to check for problems between the
modified tuner software (running as a TSR) and the communications
programs.  I have taken pains to make sure the extra overhead
taken by the mods is minimal and distributed evenly, but some
functions (such as updating the next pass information) take some
time and may interfere with fast data transfer rates on slow
machines.

	KEEP THE TIME AND KEPS AS ACCURATE AS POSSIBLE!  The
errors created by inaccurate keps and time are nonlinear and
build-up very rapidly.  These mods help reduce the sensitivity to
inaccurate keps and time, but they can only compensate so much!

	Make sure the DRV command line switch RIO is set properly
for the version of KCT hardware card that you are using.  It
should be 1 for the LLG02-B board and 0 for all others.  Also
make sure that the dipswitches on the KCT card are set according
to the KCT instructions.

	Set the KCT port tuning step size to 10 Hz (via the Tuner
command line switches).  Anything much higher causes the "F-Trak"
mode to try to correct the shifted frequency in steps that are
too large and the receiver may over-correct when the doppler
shift rate is high.  Also set the time step size to around 6
seconds or less (0.1 in Quiktrak) when loading the pass table. 
This results in large pass tables that take a long time to load,
but the increase in tuning accuracy makes it worth it.

	When a new set of keps are loaded, it is important to
adjust the "fine tuning" for each satellite of interest.  At AOS
with F-Trak off, simply step the ADJUST value in the Tuner pop-up
window so that the modem is in the middle of its lock range. 
This is the ADJUST value that will be stored in the appropriate
parameter table and will be used again at next AOS.  Turn F-Trak
on and the ADJUST value will be changed in real time to keep the
modem locked as the pass progresses.   

	I use the TAPR PSK modem.  The KCT will not respond
properly with the mic-click signals configured for the Yaesu 736R
because in the "low" state the optoisolator in the modem will not
pull the signal down to a low enough voltage.  A simple fix is to
remove the optoisolator chip (U12) in the modem and jumper pins 1
and 8 together and jumper pins 4 and 5 together by inserting
small pieces of wire into the socket.  This connects the TTL
compatible outputs of the 555 timer directly to the modem
mic-click outputs.  Be sure to use a small wire and use care when
jumpering so the socket isn't damage should you ever want to put
the optoisolator chip back in the socket.  I'm sure that the
proper combination of jumpers and pull-up resistors on JP5/JP6
wouldn't require removing the optoisolator, but pulling the chip
and jumpering between socket pins makes returning to the original
configuration easier (simply remove the jumpers and reinsert the
optoisolator chip).

	If you are using a Yaesu 736R, make sure the VFO switch
is set to the downlink VFO (either A or B).  Otherwise you'll be
wondering why the radio doesn't accept frequency update commands.

CONCLUSION

	Once these changes were made, operating the Microsats
became much more enjoyable.  I can now store several passes (for
different satellites, if desired) and the KCT will initialize the
uplink and downlink at AOS.  During the pass, the KCT tunes the
uplink and points the antennas while the modem error signals help
insure accurate downlink tracking.  The Tuner tracks right
through deep fades (which can cause the modem to loose lock).  I
have stored all the passes for WO-18 for four days and captured
all the downlink data.  I can now work several passes of AO-16
and LU-19 and concentrate on getting data to and from the birds
without worrying about antenna pointing or uplink/downlink
frequency tracking or downlink polarity switching.

FUTURE IMPROVEMENTS

	It would be nice to perform "real time" tuning as well as
tracking without having to load tables in advance of a pass.  In
this mode, tuning as well as tracking info could be passed from
(for example) Quiktrak to KCT to tune the radios and point the
antennas.  I believe Brooks has built the "hooks" into the code
for this function, but I haven't pursued it yet.

	I'm sure there are other enhancements that can be added. 
I'd be glad to hear what other KCT users would like to have
added/changed to make their operations more efficient.


ACKNOWLEDGMENTS

	Many thanks to Brooks Van Pelt of L.L. Grace for doing
the original development of the KCT/T, providing the source to
his code, a schematic of the hardware, and graciously allowing me
to make these modifications available to current users of KCT
with the Tuner option.  Please send a formatted IBM 3 1/2 or 5
1/4 floppy with a return mailer with your name, address, and
enough return postage for the mailer to my home address.  I
should also have the necessary files on Compuserve Hamnet in the
satellite section under KCT500.ZIP.  My mods are based on version
2.43, which has the 9600 baud fix.  Please be sure to read the
README file for the latest information.

	I would also like to thank Paul, KB5MU, for his helpful
comments and encouragement.




		Figure 1.  Parts Placement on LLG02 Board

			Component-Side View
--------------------------------------------------------------
|                                                            |
|         -----------------            -------   -------     |
| ------  |        U10    |            | U19 |   | VR1 |     |
| | U1 |  |               |            -------   |     |     |
| |    |  |               |            -------   -------     |
| ------  -----------------            | UN1 |               |
|         -----------------            -------               |
| ------  |        U11    |                      -------     |
| | U2 |  |               |                      | U28 |     |
| ------  |               |     ---------------  -------     |
|         -----------------     |    U21      |              |
| ------ -------  --------      |             |            ------
| | U3 | |  U7 |  |  U12 |      |             |            |    |
| ------ -------  --------      ---------------            |DB25|
|                                                          |    |
| ------ -------     -----   -----------   -----           |    |
| | U4 | |  U8 |     |U15|   |   U16   |   |U22|           |    |
| ------ -------     -----   -----------   -----           |    |
|                                                          |    |
| ------ ---------  ---------  ----------- -----  ---------|    |
| | U5 | |  SW1  |  |  SW2  |  |  U17    | |U24|  | U13   ||    |
| ------ ---------  ---------  ----------- -----  ---------|    |
|                                                          |    |
| ------ ---------  ---------  ----------- ------------    ------
| | U6 | |  U9   |  |  U14  |  |   U18   | |   U29    |      |
| ------ ---------  ---------  ----------- ------------      |
|                                                            |
|                                                            |
----------------------                                --------
                     |  |  |  |  |  |  |  |  |  |  |  |
                     |  |  |  |  |  |  |  |  |  |  |  |
                     ----------------------------------
			Card-Edge Connector with
			 gold-plated "fingers"






		Figure 2.  Modified Tuner Active Window
				during a pass.

|-------------------- Active Window -------------------------|
| Kansas City Tuner with N6KK Mods  ver 5.00 |  Uplink:  ON  |
|10/21/1991 02:01:16z [+00]            ANT=0 |Downlink:  ON  |
|          Port     F-Trak: ON    P-Trak: ON |---------------|
|  LO-19   /VFO                     Adjust       Shifted     |
|  Beacon :            437.000.000            437.002.038    |
|  UplinkA: AA  USB    145.900.000   -0.900   145.901.000    |
|DownlinkA: AB  LSB    437.125.000   -1.600   437.125.440    |
| S-Mtr: 32  AZ:135 EL: 34 LOS: 00:06:02  Doppler:  2.038    |
|------------------ Next Two Tabled Passes ------------------|
|    Next Sat           AOS         Duration    Time to AOS  |
|    AO-16        10/21 04:16:45z   00:06:06     02:15:29    |
|    WO-18        10/21 04:46:45z   00:11:10     02:45:29    |
|------- Use ESC to exit this window.  Use F1 for help. -----|





L. L. Grace Communications Products, Inc.
41 Acadia Drive, Voorhees, NJ 08043, USA
Telephone: (609) 751-1018
Fax: (609) 751-9705
Compuserve: 72677,1107



