Ham Radio 2000/Ham Radio 2000.iso/ham2000/misc/sherlock/sherlock.txt

Text File | 1996-06-30 | 25KB | 566 lines

                        SHERLOCK INSTRUCTIONS


                             GENERAL


     Sherlock is a public domain software and hardware system designed
to capture and display analog data as  graphs. The resolution depends on
the speed of the computer. The schematics for the simple hardware
were published ( or are to be published ) in September 1996 CQ/VHF magazine.

     One type of data it can graph is the the turn-on and turn-off
characteristics of VHF and UHF transmitters.

     The program is a compiled QuickBasic program and works well
on a 486 DX 33 clone computer, or a faster IBM clone, 486 or Pentium.
The program must be run under DOS, not in a DOS Window under 3.1.
It is not known if the program will run under Windows 95.

     The computer should have a hard drive and at least 640K of
ram.  There must be a parallel port, LPT1, often referred to as
the printer port.  A manual switch can be used to switch between
the hardware and a printer. The computer must also have a VGA
screen card and a monitor that can handle VGA.



                 HARDWARE  FOR TRANSMITTER ID


     The hardware consists of an A/D converter with a buffer
between the A/D chip and LPT1. The schematics were published in
an article in September 1996 CQ-VHF. The hardware includes an audio
amplifier that amplifies the audio from the discriminator, ratio
detector or quad detector of the FM receiver before it goes to
the A/D converter.  The input to the hardware must be from the
detector of the FM receiver through a shielded cable.  The audio
that goes to the speaker and to the earphone jack of a modern FM
receiver has the low frequencies removed or altered, which would
distort or remove the turn-on and turn-off characteristics.

     See the schematic (in September 1996 CQ-VHF) of the A/D converter
and audio amplifier for further info.

     The output of the A/D converter must be connected to LPT1 on
the computer by a cable that has all 25 pins connected.

     When you have the hardware finished and connected, follow the
software installation instructions below. Ground the audio input to the
A/D converter.  Run Holmes(x).exe , where x is the version number.
Select I, Input Data with Manual Stop and Display from the main menu.
You see a white line across the screen. Midway from the top to the bottom
of the screen there is a short violet line toward the left side. Adjust
VR2 so that the line across the screen is centered, that is, it is over
the short violet line.

     Connect the input of the audio amp. to the shielded cable from
the detector of your fm receiver. Observe a nearby FM transmitter turning on
and off. Adjust  VR1 by experimentation with the program in operation for
the best display of turn-on and turn-off.  The correct setting is when
most detail can be seen on most signals.  It is impossible to design a
circuit that will not "rail" with strong deviation on turn-on and still show
the characteristics of transmitters that have slight deviation on turn-on.
To arrive at the final setting of VR1, you will have to experiment with
the program, by storing and viewing files as is explained below. The hardware
can also be used to capture other data. You may want to modify the feedback
resistor and capacitor connected from the input to the output of the 741
op-amp, depending on what kind of other data you are capturing. You can use
the main menu command Z to slow down the sampling rate if that is necessary
because of the data you are sampling.


                      SOFTWARE INSTALLATION


     The program Holmes{x}.EXE, where {x} is the version number,
must be in a directory on the C: drive named TI. The sample data file
SAMPLE must be in a subdirectory C:\TI\DTA .

     Use the DOS command MD from the root directory of the C:
drive to create the directory TI.  Use the DOS command CD to
change the default directory to TI.  Then use MD to create the
subdirectory DTA ( C:\TI\DTA ).

     Copy the file Holmes{x}.EXE into the C:\TI directory.
Copy the file SAMPLE into the C:\TI\DTA subdirectory.

     All data files will be saved in the DTA subdirectory.

     To run the program, change the default directory to C:\TI
with the CD command and type Holmes{x}<ENTER>, where {x} is the
version number. Example:  HOLMES5<ENTER>




                       MAIN MENU COMMANDS


        I -- INPUT DATA WITH MANUAL STOP AND DISPLAY


     Command I from the main menu starts the input of data from
the A/D converter into Buffer 1 and displays it.  There are two Buffers,
however, Buffer 1 is the only Buffer that data can be placed into from the
A/D.  This command is only for use to set-up the hardware.  The
display of the incoming data on the screen slows down the data
input and the data is interrupted when a new screen is begun.

       When command I is entered from the Main Menu, all data in
Buffer 1 is erased. Therefore, if you do not want to loose the
data in Buffer 1, you must use the S command to save it to a file
before using the I command to start the data input.

     Each Buffer can hold 20 screens of data. The screens are
filled, one after the other.  When 20 screens of data have been
taken in, the new data goes into screen one, overwriting the data
there.  Then screen 2 is overwritten.  The data input continues
in that circular fashion, rewriting Buffer 1, until any key is
pressed to stop the data intake.

     When the data input is stopped, the point at which the data
input was stopped is marked and you are prompted for the
Callsign, Frequency and comments.  The date and time are
automatically added to Buffer 1.  You may then use the command V
to view the data or the command S to save the data to a file.
Of course, the data in Buffer 1 will be erased when you press I
again.  Therefore, save the data to a file if you want to keep
it.

     You must be alert to press any key when there has been a
turn-on or turn-off.   Do not try to tell that from the screen,
instead, listen to the receiver speaker.

     Being able to confirm that there is data input is sometimes
helpful in setting up the hardware and in adjusting VR1 on the
circuit board for a good display of a turn-on.

     However, normally you should not use that mode of taking in
data. You should use command D, which will be discussed next.



          D -- INPUT DATA WITH MANUAL STOP & NO DISPLAY


     Command D from the main menu starts the input of data from
the A/D converter into Buffer 1.  There are two Buffers, however,
Buffer 1 is the only Buffer that data can be placed into from the
A/D. There is no screen display.  This command is for normal use.
The command I displays the data while it comes in, but it arrives
too fast to see and the use of the screen slows down the data
input and distorts the data by breaking it up at the end of each
screen. Therefore, use command D from the main menu for normal data
input.

       When command D is entered from the Main Menu, all data in
Buffer 1 is erased. Therefore, if you do not want to loose the
data in Buffer 1, you must use the S command to save it to a file
before using the D command to start the data input.

     Each Buffer can hold 20 screens of data. The screens are
filled, one after the other.  When 20 screens of data have been
taken in, the new data goes into screen one, overwriting the data
there.  Then screen 2 is overwritten.  The data input continues
in that circular fashion, rewriting Buffer 1, until any key is
pressed to stop the data intake.

     The scan rate, or data input rate, is slightly over 3500
readings of the A/D converter per second, when using a 486 DX 33
computer.  The program has a data input mode with delay for very
fast computers. Only those with Pentium 100 MHZ machines will
need that mode.

     When the data input is stopped, the point at which the data
input was stopped is marked and you are prompted for the
Callsign, Frequency and comments.  The date and time are
automatically added to Buffer 1.  Make sure that the computer date and
time are correct when you start the program..You may then use the
command V to view the data or the command S to save the data to a file.

     Of course, the data in Buffer 1 will be erased when you
press D again.  Therefore, save the data to a file if you want to
keep it.

     You must be alert to press any key when there has been a
turn-on or turn-off. Listen to the receiver.  If you find you are
not interested in the station whose turn-on or turn-off you have
saved, use <return> to cycle back to the menu and press D again
to erase the data you do not want and start taking in data.

     You will use command D to input data more than any other
data input mode.



           Z -- INPUT DATA WITH DELAY AND MANUAL STOP


     A very fast computer, such as a Pentium 100 MHZ computer,
may take in data so fast that the turn-on is spread over several
screens.  The operator may not react fast enough to press any key
to stop the input after a turn-on or turn-off has occurred.

     Command Z works just like command D, except that the data
input is slowed down.  A number you are asked to enter
( generally 1 through 5 ) slows the scan rate down.

     Use this mode of data input if you have a Pentium 100 MHz
computer and the data input is too fast for you to react.


               A -- INPUT DATA WITH AUTOMATIC STOP


     Command A from the main menu starts the input of data from
the A/D converter into Buffer 1.  There are two Buffers, however,
Buffer 1 is the only Buffer that data can be placed into from the
A/D.  This command is for unattended use.  There is no screen
display.

     When command A is entered from the Main Menu, all data in
Buffer 1 is erased. Therefore, if you do not want to loose the
data in Buffer 1, you must use the S command to save it to a file
before using the A command to start the data input.

     Each Buffer can hold 20 screens of data. The screens are
filled, one after the other.  When 20 screens of data have been
taken in, the new data goes into screen one, overwriting the data
there.  Then screen 2 is overwritten.  The data input continues
in that circular fashion, rewriting Buffer 1, until the program
detects a carrier.

     The program detects a carrier by checking each screen, after
it has taken in 20 screens of data, for a screen in which there
are minimal deviations from the center frequency. If it finds a
screen that looks like a carrier is on the frequency, all 20
screens, together with the date and time are written into a file
called AUTO.A .  The next time the program detects a carrier the
file the data will be written into will be called AUTO.B and so
forth until the last file Auto.Y is written. Only 26 files may be
saved in automatic mode.  The AUTO files will be overwritten from
A to Y the next time you press A from the main menu, so you must
use the DOS commands to rename an AUTO file you want to keep. All
AUTO files appear in the subdirectory C:\TID\DTA , therefore you
can protect AUTO files from being overwritten by moving them to
another directory as well as renaming them.

     Clearly, automatic mode is useful only when the only
expected operation is the station you want to observe.  On a busy
channel, all 26 files would soon be written.

     The receiver in use, VR1 setting on the circuit board and noise
present will vary from user to user.  Therefore, the check-number to
which the program compares the sum of the deviations from center
frequency may have to be changed.  Increasing the number will increase
the ease with which the system is "tripped" and decreasing the
number will decrease the ease with which the system is "tripped".
The default number is 1500.


               P -- CHANGE AUTO-SAVE CHECK-NUMBER


     The command P permits you to change the number used to
determine when the input should be stopped in the automatic input
mode. See the last paragraph of the preceding section of these
instructions.




                  V -- VIEW DATA FROM BUFFER 1
                  2 -- VIEW DATA FROM BUFFER 2


     The Main Menu command V lets you view data from Buffer 1
while the 2 command lets you view data from Buffer 2.  Remember,
data can be loaded from the A/D converter only into Buffer 1 and
data can be saved to a file only from Buffer 1.  However, data
can be copied from Buffer 1 to Buffer 2, data from a file can be
loaded into either Buffer and you can compare data in the two
buffers.

     Since the view commands, V and 2 , work the same, they will
be discussed together.

     After pressing V or 2, you will be asked to enter the sample
rate for viewing.  This takes a little explanation.

     The data is entered into the computer by the program. How
many times per second that the computer samples the output of the
A/D converter depends on the computer's speed.  A 486 DX 33 will
take in about 3,500 readings per second, which is about 5 screens
of data at 640 readings displayed across the screen.  If the
computer is faster there will be more readings per second and the
data will spread out over more screens when it is displayed.

     Some transmitters have turn-on periods so long that they
extend over more than one screen, when the data is taken in by a
486 DX 33.  You may want to see the entire turn-on pattern on one
screen. You can do that by simulating the reduction of the sample
rate while you are viewing the data.  By responding with 2
through 5 to the "Enter Sample Rate" prompt, you can "compress"
the data into less horizontal space (screens). Of course you will
loose detail.

     The effect is the same as using a slower computer when
originally taking in the data. When you use the Sample Rate entry
to compress the data while in the view mode, you can later view
the data with full detail by going back to V or 2 on the Main
Menu and entering 0 or 1 in response to the "Sample Rate" prompt.

This is the primary difference between compressing the data when
taking it in by use of the Main Menu Z command and "compressing"
the data when viewing.  When you slow down the data input you
forever lose detail. When you view with a simulated slower sample
rate you lose nothing and can go back and view with the fast
sample rate and full detail.

     This sounds a lot more complicated than it is.  By viewing
the sample files with different sample rates you can easily see
what is happening.

     For the first few times, you should respond to the "Enter
Sample Rate" prompt with 1 or <return>  to see the full detail
your computer can provide.

     When you press 1 through 5 in response to the Sample Rate
prompt, you are placed in view mode.  The last screen of data
that was taken is on the screen. The small white dash toward the
bottom of the screen marks the point at which the data entry was
stopped.

     Probably what you want to see, the turn-on or turn-off, is
not on the last screen of data taken. You want to move back and
forth between the 20 screens of data in the buffer and to scroll
around a screenfull.

     To move around in the data, or, rather, to change the data
screen displayed, use the following keys:

     B --- When pressed goes back (in time) a screen to the prior
           screen.

     < --- When pressed scrolls the data about 1/5 of a screen in
           that direction.

     > ___ When pressed scrolls the data about 1/5 of a screen in
           the other direction.

     M --- When pressed takes you back to the Main Menu.

     Any Other Key (Except the above).  Takes you one screen
     forward in time.

     Notice that when you pass the marker that shows when the
data entry was stopped you jump from the end to the beginning of
the data, or the other way depending on which way you are going.
If the scrolling becomes confusing, especially with the slow
sample rates, you are encountering the end of the data.

              If you happen to get confused as to time, do not worry. Use
M to go back to the Main Menu, then go to V or 2 and the data
will be presented so that the point the data input was stopped is
on the screen and marked with the small dash toward the bottom of
the data display area.

     A little experience will make the use of the view command
easy.

     You will notice that the date and time that the data input
stopped are displayed, as are any Call, frequency or comments you
entered when you stopped the input.  If the automatic mode was
used to gather the data you are told that the automatic mode was
in effect.



     C --- COMPARE DATA FROM BUFFER 1 AND BUFFER 2


     You will want to compare the turn-on characteristics of
transmitters that are unknown with data you have filed.  This
mode will let you do that.

     When you press C from the Main Menu, you will be placed in
compare mode. You will be prompted for a sample rate. See the
discussion of sample rate in the previous section of these
instructions.

     After you select a sample rate, the program will place the
data in Buffer 1 at the top of the screen, reduced in size. When
you press C again, the data from Buffer 2 will be placed at the
lower portion of the screen.  The displays are not labeled, and
no date, time or call appears, because the entire screen is used
to display data.  However, you can keep from being confused by
remembering that the data from Buffer 1 is at the top and the
data from Buffer 2 is at the bottom.

     The control keys in the compare mode are the same as the
control keys in the view mode, except that pressing C causes the
effect of pressing the control keys to be transferred from one
set of data to the other.  That way, you can scroll the data from
Buffer 1 and then scroll the data from Buffer 2.


     In the compare mode, to move around in the data, or, rather,
to change the data screen displayed, use the following keys:

     B --- When pressed goes back (in time) a screen to the prior
           screen.

     < --- When pressed scrolls the data about 1/5 of a screen in
           that direction.

     > ___ When pressed scrolls the data about 1/5 of a screen in
           the other direction.


     C --- When pressed toggles the control between the Buffer 1
           data at the top of the screen and the Buffer 2 data at
           the bottom.

     M --- When pressed takes you back to the Main Menu.

     Any Other Key (Except the above).  Takes you one screen
     forward in time.

     When making comparisons you should know that the signal
strength may effect how the turn-on characteristics appear, as
the effect on your receiver's detector circuit may change with
signal level.  Experience in using the system is necessary to
make identifications. Whether or not you can tell the difference
between two transmitters of the same make and model will depend
on the speed of your computer, your skill and the receiver you
use.



                     S -- SAVE DATA TO FILE


     The command S from the Main Menu saves the data in Buffer 1
to a file.  Only data in Buffer 1 can be saved.  If you want to
save data in Buffer 2, you must first move the data from Buffer 2
to Buffer 1, where it can be saved to a file.

     You will be prompted for a filename.  Use only letters and
numbers, as the characters that cannot be used in DOS filenames
must not be used.  Do not attempt to enter a drive, such as C:,
or a directory, as the file will be automatically placed in the
subdirectory C:\TID\DTA .  Use a filename you can remember, such
as the call of the station creating the data, or some other name
you can remember. Do not use the name of an existing file.

    The data will be saved as a basic sequential file, which is
an ASCII file with 12800 data items expressed in ASCII with each
data item separated by a <CR> . The data items are followed by
ASCII strings for the date, time, callsign and the
frequency/comments. Several empty reserved strings follow. The
string variables in the file are delimited by commas. The empty
reserved strings are for any future program expansion, although
no such expansion is planned.

     The data file can be displayed by any means that an ASCII
file can be displayed, including the DOS command TYPE and the DOS
Editor.



             L --- LOAD DATA FROM FILE INTO BUFFER 1
             E --- LOAD DATA FROM FILE INTO BUFFER 2


     Command L from the Main Menu loads data from a file into
Buffer 1. Command E loads data from a file into Buffer 2.  The
date loaded from a file overwrites any prior data in the buffer.
Both commands work exactly the same, the only difference is which
buffer the data from the file is placed in.

     Be certain to save the data ( if you want to keep it ) that
is in the buffer the file data is to be loaded into.  All data in
the buffer will be overwritten by the new data.

     When you press L or E from the main menu you will be asked
for the filename.  The file must be in subdirectory C:\TID\DTA.
You should only enter the filename followed by <enter> when you
are asked for the filename. Do not enter a drive or directory.
All data files are in the C:\TID\DTA subdirectory.

     When you have loaded data from a file into a buffer you can
see the data by using the command V for Buffer 1 and the command
2 for Buffer 2.


              F ---VIEW SUBDIRECTORY OF DATA FILES


     Command F from the Main Menu lists the filenames of the data
files in subdirectory C:\TID\DTA.  As all data files are in this
subdirectory, the list includes all files that you can load into
the buffers.



                 ] --- COPY BUFFER 1 TO BUFFER 2
                 ] --- COPY BUFFER 2 TO BUFFER 1


     From the Main Menu the command ] copies the data in Buffer 1
into Buffer 2.  Any data already in Buffer 2 is overwritten by
the data copied from Buffer 1.  Be careful before you use this
command that you have saved any data in Buffer 2 that you want to
keep.

     From the Main Menu the command [ copies the data in Buffer 2
into Buffer 1.  Any data already in Buffer 1 is overwritten by
the data copied from Buffer 2.  Be careful when you use this
command that you have saved any data in Buffer 1 that you want to
keep.



                         PRINTING GRAPHS


     If you have a printer that can be set to print graphics by
use of the DOS "GRAPHICS" command, you can print out a turn-on or
turn-off data graph.

     To print the graph of a turn-on or turn-off, you must use
the DOS command "GRAPHICS" from the DOS prompt before you run the
program TID{x}.EXE .  See your DOS manual for the proper usage of
the GRAPHICS command and the printers supported by that command.
In general, the word GRAPHICS must be followed by a specific
designation for your printer. For example, to enable DOS graphics
printing for a HP 4L laser printer, at the DOS prompt you enter
GRAPHICS LASERJETII <enter> .

     If the printer is supported by the DOS GRAPHICS command, and
if that command has been properly used prior to running the
program, pressing <shift><Print Screen> will print out on the
printer whatever is on the screen.  Remember to switch from the
A\D converter to the printer if the printer uses LPT1.



                           Q --- QUIT


     From the main menu the command Q terminates the program and
returns you to a DOS prompt.  Any data in either buffer that has
not been saved to a file is lost.



                                Malcolm C. Mallette, WA9BVS




                                        END