-=- Schematix -=-
by sv3ora
User's Guide
Schematix is intended to be used by the radio amateurs, to draw simple schematics, PCBs and diagrams in a quick and easy way and to efficiently send these to other HAMs through morse code, phonetic alphabet or any other text mode. Apart from drawing, there are a variety of ways in which these schematics can be exported or imported. Schematix has been designed with simplicity in mind, so anyone with basic electronics knowledge can immediately use it, without much effort or documentation reading.
Schematix is written in HTML and Javascript, which implies several advantages. It can run live from a webpage, without any need to download, or as an offline standalone application when downloaded to your computer. It is multi-platform, meaning that it can run on any OS (Windows, Linux etc.) as long at there is a javascript enabled browser installed. It is widely opensource, since the code is immediately available to anyone. Any distribution of the application automatically distributes the source code, since it is the actual source that is distributed, no binaries, no executables. The application can be modified easily using a simple text editor, without the need for special installed tools or compilers on your computer. Radio amateurs are encouraged to take the code, modify it, and create something even more useful to the ham community. The way Schematix operates, is not limited to schematics, so PCB drawings and diagrams are added.
Schematix has been developed from sv3ora, based on a primitive program written by Jim Osburn, WD9EYB.
2. Basic Operation
Schematix is designed to be simple to use, by anyone with basic electronics experience, without the need to extensively read the user's guide. However, right next to most functions, there is a little help symbol "[?]". If you click that, you are redirected to the relevant section of this guide, that explains the current function. This is done as a quick help for the impatient.
As the program loads, you will see the symbols in the top frame clunk in. Once it has fully loaded, you should see a table of symbols at the top of the page, with the current chosen symbol displayed above the table and a blank area at the bottom of the page. If your browser pops-up any messages related to blocked content, you must allow this blocked content, for Schematix to run correctly.
Note that if you refresh the web page your schematic will disappear. Don't go to a different web page or your schematic will also disappear. Temporarily save your schematic first by clicking "Save". Click "Recall" to load a previously saved schematic. More information below.
The first thing to do, is to select the symbol that you want from the table. This is also where you will find out if your browser is going to work with the program or not. Put the mouse pointer over any of the symbols in the table and click it. The symbol that's isolated above the table (current chosen symbol) should change to the symbol in the table that you have clicked.
If it doesn't work, try a few more times. If you can't make it work you might need to enable Javascript. If it just absolutely refuses to obey you might need to upgrade your browser.
Now that you have selected the symbol you want, you can place it anywhere in the drawing area below the table of symbols. Put the mouse pointer where you want the symbol to be placed and click. The symbol should clunk into that place. You can place as many symbols as you want in the drawing area but the drawing area is of limited size. You can't place symbols outside the drawing area.
The drawing area is also a table like the table of symbols above it, but there's no border around each individual symbol. You can place only one symbol in each cell of the the table. For convenience, the drawing area is marked into lines and columns (A-Z), so that you know in what cell a component is placed. The alignment and the size of the table cells is fixed. You can't place a symbol halfway between one cell and another. This is why when you place a symbol it seems to magically line up with the other symbols in the drawing. On Schematix you can only put symbols in the places that have been defined for them.
To experiment, proceed to place some resistors or capacitors or whatever you want in your circuit. Now comes the process of hooking them up. In other programs you just start drawing in wires. In Schematix, you have to place the wires as though they were symbols. In the table of symbols you should find straight wires, elbows, tees, and one kind of cross.
To draw a straight wire that crosses more than one cell you have to place a straight symbol in each cell. When you want to turn a corner you select the appropriate elbow and place it. If you need a tee just select it and place it.
These wires connect the middle of the sides of the cells. The component symbols are also designed so the components connect to the middle of the sides of the cells, so the wires and the components line up.
When you place a symbol that you don't want by mistake, you can erase it by selecting the blank symbol in the upper left corner of the symbol table and clicking on the symbol you don't want. If you want to change a symbol to a different one, just select the desired symbol in the symbol table and click on the place it goes. What ever symbol was previously there, will disappear and the correct one will clunk into place.
3. General Operation
Two frames will appear, one on top and one on the bottom. The top frame has the drawing symbols and the bottom frame has the drawing area. Schematix uses a grid of 26x26 positions, where you can draw your schematics into, by simple pick-and-place. Each line and each column of the grid, has assigned a letter (A-Z). You can click on symbols in the symbol table and place them in the drawing grid. Frames were used because they are independently scrollable. So, you can scroll the symbol frame to the symbols of interest and you can scroll the drawing frame to the spot in the drawing you working on.
Note that if your screen resolution is not very high, not all lines or columns (A-Z) may appear in the drawing area. If you draw small schematics, this may not be a problem, but if you draw larger schematics this might be. If not all columns appear in the drawing area, you can make them show by horizontally resizing your browser window. If not all lines appear in the drawing area, you can make them show by resizing the bottom drawing area frame, whereas reducing the top symbols frame. If you still can't make all lines and columns appear, you can zoom out your browser's window view. In many browsers, a quick way to zoom in/out, is to hold down the left CTRL key on the keyboard, whereas at the same time scroll the middle wheel of the mouse. If this can't change the zoom level, you can zoom in/out from the browser preferences. See your web browser's documentation on how to change the zoom level.
Web browsers have a full screen mode of operation. It might good to put the web browser in that mode while you're working on the schematic. On some web browsers it's as easy as hitting the F11 key on the keyboard. See your web browser's documentation on how to use full screen mode.
The only thing in the drawing frame, is the schematic. So when you open the webpage it will appear blank. Nothing will in it until you place a symbol. Be careful about going to other web pages, either by entering new URL's, the history list, refresh, or the back button. Your schematic will disappear and your work will be lost! To prevent this, click "Save" to temporarily save your schematic and "Recall" to load a previously saved schematic.
The save function, uses cookies to save your schematics, so cookies have to be enabled on your web browser. Cookies are those nasty things that web browsers keep so commercial sites can store information on your machine. But in this case cookies are used to save your schematic. The schematic cookies aren't transmitted back to the server, they are only kept locally in your computer.
Near the symbol table, there are keywords for various functions. One keyword is "Save" and another is "Recall". When you click the keyword "Save" you schematic will be saved to a cookie associated with the online server called f1save. When you click the keyword "Recall" the f1save cookie will be recalled and the schematic redrawn. If you remember to click save while you're drawing your schematic, intermediate copies of it will be saved and you can recall them and recover if your schematic accidentally disappears. Cookies are associated with sites. So if you access the online site with one URL and use a different URL later, you can't get at the cookies you saved with the first URL.
Later a way of saving cookies with more than the name f1save will be discussed. The f1save cookie is retained on your machine for 30 days. If you need to keep it longer, recall it and save it again. Another way to save your schematic indefinitely, is by using the "List" function. When you have drawn your schematic, click "List" and in the next page click "Export shown schematic to list". The schematic shown in the bottom drawing area, will be exported to a list of symbols in the top text area. Copy that text and paste it inside a text file, that you can create anywhere you like in your computer. When you want to load a schematic from a list, copy the list text from the previously saved file and then paste it inside the top text area provided by the "List" function. Then click "Import new schematic from list" to load the schematic into the drawing area. In that case, you might want to make changes to the freshly loaded schematic. This is done by clicking "Back", so that the symbols table appear in the top area. Now you can edit your loaded schematic.
In Schematix, there are also keywords for "Left", "Right", "Up", and "Down". If you run out of room on the right side of a schematic, you can slide the whole thing to the left by clicking on the left keyword. You can also slide the whole schematic right, up or down by clicking on the appropriate keyword. Symbols falling off one side of the schematic will show up on the other side. But symbols falling off the top or bottom of the schematic are lost! There is also a "Clear" function, which erases the whole schematic (after a confirmation dialogue), so that you can start all over again from the beginning.
There might be cases where you need to copy or move part of the schematic, to another area in it, so that you don't have to erase and redraw everything. For that reason, Schematix includes the "Copy", "Cut" and "Paste" functions. These functions work together with the "MARKER" icon in the components table. To copy or cut a schematic area containing some components and labels, you have to place two markers near this area. Place the first marker, at the most top-left position of the area and the second marker at the most bottom-right position of the area. This way, you create a virtual selection box, for this area. Then click "Copy" to copy this area, or "Cut" to cut this area. Note that if you select "Cut", the components under this area will be cut. Also, note that you must not place more than two markers each time you need to copy or cut an area. If for example you place four markers, the last two will be used. If you place three, you might mess up the schematic.
If instead of an area, you need to copy or cut components in a single line, place the two markers at the beginning and at the end of the line, just before and after the components you need to copy/cut. The same applies for columns. If you need to copy or cut components in a single column, place the two markers at the top and at the bottom of the column, just before and after the components you need to copy/cut.
To paste the schematic area you have just copied or cut, place a "MARKER" icon at the most top-left position of the place you want the area to be pasted and then click "Paste". Note that if you have previously copied an area, you can place more than one markers at once, before clicking "Paste". If you do so, each time you click "Paste", the copied area will be pasted where the next marker is. Just make sure there is enough space in your drawing area to paste, so that you do not overwrite your existing schematic. In case where components in a single line or column have been previously copied/cut, place the marker at the beginning of the line or at the top of the column, where you want your components to be pasted.
It is important to note, that markers are not symbols that must be exported or saved. They exist just to be used by the copy/cut/paste functions and they disappear after these functions have been correctly used. Please ensure there are no markers left in your schematic, prior to clicking "Utilities", or any save function. You may erase a marker, just like any other component.
Additional symbols, appear in row 4 of the symbol table. To get the extra symbols to appear in row 4, click on the appropriate component type in the "More components" table. For example, if you want to draw with vacuum tubes, click on the "Tube" keyword. Symbols for a diode, triode, tetrode, and pentode will appear in row 4. You can now select these symbols and place them just as you would with any other symbol.
There are also some symbols with the tubes that help you make connections to them. Next to the triode is a symbol that lets you make connections to the filaments and the cathodes of the tubes. Next to the pentode is a symbol that lets you connect to the screen grids. Just place these symbols next to the tubes and then you can make the connections to them. There are also symbols like that for the switches and others.
The keywords in the "More components" table, are an attempt to be descriptive of the kind of symbols that will appear in row 4 when the keyword is clicked. If you click one of those keywords and you're off-line, the symbol might not appear in row 4 because the browser hasn't yet down loaded it. Click on save to save your schematic, Refresh the web page, which will require reconnecting to the server. Then click the keyword of the symbols you want. Then click recall to get your schematic back. ADSL users, will not have this problem since they are always on-line. In any case, you can download the Schematix application on your computer, so that you can always work off-line.
The "Display" function, allows you to display your schematic all by itself. Clicking on "Display" will open a new browser window and after a while, the schematic will be displayed there. After the schematic has appeared, you can do a screen capture (Print Screen key on your keyboard) and paste the result into a paint program for further editing. On some machines a screen capture is done by first holding down the alt key and then hitting the print screen key on the keyboard.
Schematix is very clunky about the way annotation is done, that is, the way components are labeled, such as R1, C3, U4, etc. Since html is frozen once it is displayed, the annotations can't be added as you draw. However space for them can be reserved. If you click the "LABEL" icon in the components table, you should be able to place the "LABEL" word in the drawing area, next to the component you want. The actual labels (components values) will be added later, using the "Utilities" function.
There are 2 other external ways of annotating your schematic if you like. Perhaps the easiest and most straight forward is to just print it out and write the labels on the print out, if you want your schematic as a hard copy. The other way is to do a screen capture as above and use a paint program to edit the schematic and add the annotation.
Print your schematic by using the web browsers print command.
4. Theory of the schematic drawing operation
The symbols are images that are 37 by 37 pixels. An image can be anything that fits in 37 by 37 pixels, even little photographs. The symbols are designed with a paint program and then translated into files for use with the web page. The choice of 37 by 37 pixels was arbitrary but seems to be working very well.
The symbol table is just a table of available symbols. A border is drawn around each symbol to denote that it is in the symbol table.
The drawing area is also just a table of symbols. A border is not drawn around each symbol here. Even in a blank schematic the drawing area is full of symbols, they're all blank symbols.
When you click on a symbol in the symbol table, the Javascript program records the source URL for the symbol. It also sets the source URL of the current symbol image to that. That causes the current image to change to the symbol that was clicked.
When you click on a spot in the drawing area, the URL for that spot is set to the source URL that has been recorded. This causes the current symbol to appear in the drawing area.
By clicking on symbols in the symbol table and then clicking in the drawing area, a schematic is drawn. Since the symbols are images in html, a web browser that supports click events in images is required. If your web browser doesn't, nothing will happen. The newest version of the popular web browsers support click events in images.
The middle points of the top, bottom, left and right sides of most of the symbols, are the connection points to them. So for a symbol to connect to the one next to it, a line must be drawn to the middle of the appropriate side. That means most symbols really only have 4 connection points, one on each side. Symbols that need more than 4 connection points, such as tubes, can be accommodated by having special symbols to bring the non-standard connection points, out to the standard points.
Having the connection points in the middle of the sides also means that some creativity needs to be used when designing symbols for components that look better when connected at other than the center of a side. If it looks really bad a special symbol to bring the connection out to a standard point to be used with the component symbol can be created.
The wires in the Schematix are symbols. A commercial schematic editing program will allow you to enter wires just by clicking on the ends of where they go and where they turn. But Schematic has to use symbols for straight horizontal and vertical sections, and 4 elbows for each direction of a turn, and 4 kinds of junctions, and 1 four-way cross. This is proven useful in the "Export data" and "Import data" functions discussed later.
The keywords that perform the various functions, are links that instead of taking you to another URL, they call a Javascript routine. So you might notice that they behave like links. They're one color before you use them, and another color after.
Since not all symbols fit in the symbol table at once, row 4 is reserved for additional symbols that are selected. Initially row 4 of the symbol table is blank. Clicking a keyword from the "More components" table, makes additional symbols to appear in row 4. This was easy to do. Clicking the keywords calls Javascript functions that copy the source URL's for a group of symbols into the row 4 images source URL's. When the row 4 symbols are then clicked, the source URL's become the current symbol.
5. Utilities
Clicking the "Utilities" function, will cause the symbols table to disappear and the utilities frame to appear in the top frame. The schematic should still be in the bottom frame but click "Save" before clicking utilities, or save your schematic to a list, just to make sure.
The top part of the utilities frame lets you use more cookies. You can name a cookie almost anything, by typing the name in the box next to the cookie function you want to perform. However, there are restrictions on the name. Spaces, commas and semicolons are not allowed. Names like "vfobuffer" are.
To save the current schematic in a cookie, type the name in the box next to the "Save to cookie" function, and click the "Save to cookie" link. To specify a time other than 30 days to save to the cookie, enter that before saving it. To recall the cookie, type the name in the box next to the "Recall from cookie" function and click the "Recall from cookie" link. You can delete a cookie by entering its name and clicking "Delete cookie". You can see all of the cookies associated with the URL in all of they're encoded glory by clicking the "Show all cookies". That's useful mostly for debugging.
The next function on the utilities page is the "Import from file" function. Enter a URL into the link box and then click "Import from file". A link will appear in the bottom frame, displaying "click here to display the schematic". When that link is clicked, the imported schematic appears in the bottom frame. The URL must be the full path to your htm/html file on your computer, that contains the schematic. If the file is located inside the Schematix directory, no path is needed, just write the filename. Note, the URL can be any web page but it only makes sense to link to htm/html files that have be generated by the program. If you want to edit the freshly imported schematic, click the back command in the top frame to return to the symbol table. You can then edit the schematic.
Components labels
The labels (components values), are entered in the form fields provided in the
top utilities frame.
Labels must be assigned to components, only after successful completion of a
schematic drawing and before the "Generate html", "Display", "Import data" and "Export data" functions. Schematix restricts the
way labels are entered in the form fields. This is done for compatibility with
the "Export data" function. If a label two characters
long, does not contain at least a numeric character, or if a label is less than
two characters long, or if a label is more than six characters long or if label contains special characters
or spaces, this label is not
allowed to be entered. Also, to be compatible with the "Export data" function,
labels with decimal values are automatically converted to non-decimal values.
For example 4.7K is automatically converted to 4k7. So have in mind these things
when assigning labels values.
The number of the label input fields, that are displayed for you to enter data,
is automatically adjusted to match the number of "LABEL" images in your
schematic. Before each label input field, it's line and column letter is
displayed, so that you know which label you edit. For example, a letter pair
"fm" before a label input field, will place the text you type into that input
field, to the cell that exists at the line "F" and the column "M" on the bottom
frame. For your convenience, note that the schematic is scanned for "LABEL"
symbols, starting at the top left of each line and proceeding to the right. When
it gets to the right margin it moves down and does the next line of symbols.
Thus, the order of the label input fields follows this pattern.
Generate html
You can generate html for your schematic by clicking the
"Generate
html" function. The html will appear in a new window.
You can then select all of the text and copy it to a file.
You then have a stand alone web page of your schematic. If an error at a label is made, it's probably easier to edit the html file than
to try to regenerate it.
Display
The "Display" function. It does the same job as the generate html function,
but the actual schematic is opened in a new window and the label values are displayed
on it. An easy way to save the displayed schematic as an image, is to print
screen and then paste it into Paint.
Exporting schematics ("Export data" function)
The "Export data" function is used to export a schematic and it's labels, in a
form that is efficient for sending this schematic over the air, to other HAMs.
With the schematic displayed in the bottom frame and all it's labels filled into
the form fields in the top frame, click "Export data" to export the schematic.
If there is an error in the labels, a pop-up window will be displayed, to tell
you where the error is and how to correct it. If there are no label errors, a
new window will open, that contains the exported data text. Select all text on
that window and copy it. Then paste the copied text inside your favorite sending
program, to send it over the air.
The way "Export data" function works, is as follows. As previously said, Schematix uses a grid of 26x26 positions, where you can draw your schematics into, by simple pick-and-place. Each line and each column of the grid, has assigned a letter (a-z). A pair of letters thus, represents a cell into the grid. For example a letter pair "fm" represents the cell that exists at the line "F" and the column "M" in the grid. When you export a schematic using the "Export data" function, this schematic is exported as a series of words separated together by space. Each word represents either a component and it's location on the grid, or a label and it's location on the grid.
Components:
A component is defined as a
word of 4 letters. The first two letters, represent the line and the column
where the component is placed onto the grid. The next two letters, represent
the component type to be placed. For example, a valid component may be
represented by the word "abne". This means that the component with
filename "ne" will be placed in the cell at line "a" and column "b".
Labels:
A label is defined as a word of 4 or more than 4 letters (up to 8 max). In this word, the
first two letters, represent the line and the column where the label is placed
onto the grid. The next characters, represent label value of the component to be
placed. For example, a valid component label may be represented by the word
"ab2n2222". This means that the label value "2n2222" will be placed in the cell
at line "a" and column "b".
For your convenience, note that the data that is
generated by the "Export data" function is sequential. This means that the
program performs components or labels scanning, starting at the top left of each
line and proceeding to the right. When it gets to the right margin it moves down
and does the next line of symbols. The exported data follows this pattern as
well. Note that to minimize the exported data and increase efficiency, blank
spaces are ignored. Only the "useful" symbols are exported.
Importing schematics ("Import data" function)
The "Import data" function is used to import a schematic and it's labels, that have been previously transmitted to you over the air, by another HAM. By clicking "Import data", a text box is displayed in the top frame. Copy the data text you have received from your favorite receiving program and paste it inside this text box. Then click "Import data" in that page, to import the schematic. The imported schematic will appear in the bottom frame. You can repeat this process as many times as you like, by clearing the text box using the "Clear form" link and pasting again your data text into the box.
The way "Import data" function works, is as
follows. The next explanation, assumes you have read the "Exporting schematics"
section above, to understand the way schematics are exported. When importing schematics using the "Import data" function, the data that is
pasted from the user into the text box, is checked for different things, trying
to spot any errors.
If a word is less than 4, or more than 8 characters long (labels not more than 6 characters), or if it contains special characters, an error has been occurred and since
it is not known if the error is at the part of the word that refers to the position of the component or at the
part that refers to the component/label, the symbol is ignored. These errors are shown
as blank spaces into the schematic and in some cases they can be spotted by
looking at the overall schematic for inconsistencies. In some cases, the user
can guess the component behind the error. For example if a continuous straight
wire is broken at some point, the user can easily guess that this point should
be a wire connected to the rest of the wire. Another example may be a label with
a value of "1k" and no nearby component. A resistor can be easily guessed to
exist nearby.
Another check that is done, is if the first two characters of a word contain at
least a number. In that case, an error has occurred and the current
component/label is ignored. This error is shown as a blank space into the
schematic and it is up to the user to spot and correct it, as explained above.
If a word does not contain special characters and it is equal to 4 or not more than 8 characters long and also if it's first two characters
do not contain numbers, the word consistency is correct. In this case, the
reverse process from that of the export function is applied. The first two letters of the
word, represent the line and the column of the component/label into the table
and the remaining characters represent the component or the label value.
However, there is no way to check out if an error has occurred in the actual
components types or labels values. Despite this, there are two things that can be done to spot the
error.
One, is by the user to do a manual error checking/correcting, by looking at the
overall schematic for inconsistencies, as described above. The other, is done
from the Schematix automatically and it refers to the special case where a
component is received, which does not exist in the Schematix library. In this
case, an error has been received for sure and the missing component is shown in
the table as a broken image.
The components are exported sequentially (row by row and column by column) by
the "Export data" function. However, the "Import data" function, does not read
components sequentially. It looks into the whole data and manipulates it without
a special order. This means, that if two components are supposed to be placed
into the same cell due to a data error in their locations, both will be placed in
that cell. In some cases, by looking at the schematic, the user might be able to
decide which of the two components match better the current cell.
Error correction:
In the current version of Schematix, there is no automatic error correction
implemented. This has been done in purpose, to minimize the data that has to be
transferred over the air. However, due to the nature of schematics, which can be
understood by humans by just looking at them, there may be cases where you might
be able to correct an error by just looking at the schematic for
inconsistencies. As described above, in some cases, the user can guess the
component behind an error. For example if a continuous straight wire is broken
at some point, the user can easily guess that this point should be a wire
connected to the rest of the wire. Another example may be a label with a value
of "1k" and no nearby component. A resistor can be easily guessed to exist
nearby.
In case you, or Schematix automatically, spot an error in an imported schematic, you can ask for retransmission of data from your HAM friend. However you do not need to ask for full schematic retransmission. Due to the way Schematix is made, you may ask for retransmission of data, only for the cells that have not been received correctly. This is possible, because schematics are imported exactly in the same locations in the grid, as these were drawn prior to transmission. Thus, instead of requesting for whole schematic retransmission, you can request for single cells retransmission only. Just let your HAM friend know, which cells you have not received correctly (line and column letter of the cell on the grid), in order to retransmit them to you.
6. Sending and receiving data without computer availability
There may be various reasons why one may not have a computer available. For example, some might consider the cost, although not a big issue for computers today, as nearly everyone has already one. Another reason may be the extra weight and size, but more importantly the power requirement, if one has to carry a computer with him, when operating outdoors. Whereas a simple homemade transceiver could draw a few tens or hundreds of milliwatts, a laptop would draw a few watts.
Schematix, allows drawing, sending and receiving schematics, PCBs and diagrams even without the help of a computer, as it has been designed so that it is human oriented. This is a unique feature, that is possible because of the design of the drawing and the exchanging mechanism. Although drawing and exchanging schematics without a computer is more time-consuming, it can be perfectly done with a little patience, if a computer is not available. Note, that you can only use CW or phonetic alphabet modes, if you do not have a computer with you, since these are the only human oriented modes.
Before describing the procedure of drawing and exchanging schematics, a quick reminder of how schematics are encoded in Schematix, is helpful. Schematix sends schematic symbols by encoding them into words and each word is separated from the others by space. Consider the two words below:
egne eh2n2222
The first letter in both words is "e", and it represents the line where the symbols must be placed in the schematic table. The second letter in the first word is "g" and it represents the column where this symbol must be placed in the schematic table. The second letter in the second word is "h", so this symbol must be placed at the next column of the first symbol, at its right hand side.
If we look the rest of the letters in both words, we can deduce which of them is a component, that needs to be placed at the position denoted by the first two letters in each word, and which of them is a label (component value). The rules for this decision, are shown below:
1. A word of four letters (no numbers),
denotes a component.
2. A word of more than four characters (letters or numbers), denotes a
label.
3. A word of four characters, which has at least one number in the last
two characters, denotes a label.
However, in some cases we might also receive an error, so we need to know when
erroneous data has been received. This can be summarized below:
4. A word more than 8 characters, denotes an error.
5. A word less than 4 characters, denotes an error.
6. A word with special characters (non-alphanumeric), denotes an error.
7. A word with at least one number in the first two letters, denotes an
error.
You must always follow these 7 underlined rules when manually encoding or decoding Schematix data, or else your schematics won't be compatible with Schematix. These rules are automatically taken care of in the program, but in the case you manually encode a schematic and you do not follow them, then an operator that receives this schematic with his computer, won't be able to decode it correctly. After this brief summarization of the Schematix rules, let's continue with the process of manually drawing, encoding and decoding schematics.
If you decide that you want to draw and exchange schematics without the help of a computer, you are going to need a few things carried with you, instead of the computer:
a. A pencil.
b. A pencil eraser. Some pencils have an eraser attached at their top. In that
case you won't need an extra eraser.
c. Printouts of the encoding chart, decoding chart and the encoding/decoding
table. You need only one printout of the encoding and one of the decoding chart.
However, I recommend more than one printouts of the encoding/decoding table, if
you want to draw and exchange more than one schematics. All the printouts above,
can be printed by clicking the "Charts" link.
Drawing a schematic
To draw a schematic, you need to have a printout of the encoding chart and the encoding/decoding table. You draw your schematic into the encoding/decoding table, using only the components from the encoding chart, nothing else. For example, do not use a line to connect two components, if this type of line does not exist in the encoding chart. In a cell of the table, a component or a label can be placed, not both. Note that a wire or a corner section, is an actual component in Schematix. Try to draw your schematic components, as accurate in shape as possible and in the correct alignment, having in mind that most components leads, end at the middle of the sides of each cell in the table. For the components labels, make sure you follow the 7 rules of Schematix, underlined in the previous paragraphs.
Labels must be:
a. Greater than 2 and up to 6 characters.
b. Or if they are 2 characters, at least one of them must be a digit.
c. Single character labels or empty labels, are not allowed.
d. Special characters (like +) are not allowed, only letters and numbers without
spaces between them.
e. Label 4.7k is written as 4k7, 5.6pF is written as 5pF6 etc.
Encoding a schematic
After you have successfully drawn your schematic into the encoding/decoding table, it is time to encode it into text, so that you can send it to other radio amateurs through morse code or phonetic alphabet. You have to use the rules specified in previous paragraphs to successfully encode your schematic.
Remember, Schematix sends schematic symbols (components or labels) by encoding them into words and each word is separated from the others by space. The first two letters in a word, represent the line and the column letter respectively, where the component or the label exists in the table. The remaining letters or numbers in the word, represent a component (if they are just two letters) or a label.
In that sense, you would be able to encode your schematic into a series of words, by looking at the encoding chart and finding the combination pair of characters that represent each component placed in a cell. For example, the data "egne eh2n2222" represents a right flipped NPN transistor placed at the cell eg (line e, column g) and a label at the right hand side cell of it, 2n2222. Use the "OPERATOR NOTES" area, provided below the table, to write down the encoded text that represents your schematic.
Decoding a schematic
The Schematix encoded text that has been sent to you by other operators, can be decoded without the use of a computer, following the next procedure.
Like mentioned before, Schematix sends schematic symbols (components or labels) by encoding them into words and each word is separated from the others by space. The first two letters in a word, represent the line and the column letter respectively, where the component or the label exists in the table. The remaining letters or numbers in the word, represent a component (if they are just two letters) or a label.
First, write down the encoded text you have received through morse code or phonetic alphabet, into the "OPERATOR NOTES" area, provided below the table. Then, having a printout of the decoding chart in front of you, decode each word of the encoded text, by locating where the symbol (component or label) represented in this word, must be placed in the table. You do this, by looking at the first two letters of the word, which represent the line (first letter) and the column (second letter) in the table where this symbol must be placed.
Once you have found the location of the component or label in the table, you have to decide if this word is an actual component or a label. You do this, by looking at the remaining characters in the word. For this decision, make sure you strictly follow the 7 rules of Schematix, underlined in the previous paragraphs. This will allow you to see if this word represents a component or a label to be placed in the cell, or if an error has been received.
If the word represents a component, look at the decoding chart, to find out which component refers to the combination pair of letters in the word. Then draw the component in the cell, as accurate in shape as possible and in the correct alignment, having in mind that most components leads, end at the middle of the sides of each cell in the table. If the word represents a label instead, just write down this label in the table cell.
7. Details on the import/export mechanism
Schematix is intended to be used by the radio
amateurs, not only to create simple schematics in a quick and easy way, but also to efficiently
send these to other HAMs through morse code. Despite the import/export mechanism
is designed to achieve efficiency in morse code, it can be used with any other
text mode, or even phonetic alphabet. During exchanging, it achieves efficiency by
minimizing data transfer, as it does not transfer the actual data (images), but
the data information only (which image, goes in which position in the grid).
To further increase the efficiency, schematix uses a schema similar to morse
code. In morse code, the code was designed so that the length (timing) of each
character in morse, varies approximately inversely to its frequency of
occurrence in the English language. Thus the most common letter in English, the
letter "e", has the shortest code, a single dot. Schematix uses a similar
scheme. Components that are most likely to be used frequently in a circuit, are
assigned with character combinations with the shortest timing.
Components Characters assignment
The list of letters below, starts from the letters with the shortest timing (in
morse code) and ends to the letters with the longest timing, based on the fact
that each dash equals to 3 dots in timing. The total timing, in terms of dots
number, is shown at the beginning of each line.
1: e .
2: i ..
3: t - s ...
4: a .- h .... n -.
5: d -.. u ..- r .-.
6: b -... f ..-. l .-.. m -- v ...-
7: g --. k -.- w .--
8: c -.-. p .--. x -..- z --..
9: o ---
10: j .--- q --.- y -.--
In the list below, there are all the two-letter combinations. The total timing,
in terms of dots number, is shown at the beginning of each line.
2: ee
3: ei ie
4: et es te se ii
5: it ti is si ea ae eh he en ne
6: ia ai ih hi in ni de ed ue eu re er ss tt ts st
7: di id ui iu ri ir ef fe el le em me ev ve eb be th ht tn nt sa as sh hs ta at
sn ns
8: td dt tu ut tr rt sd ds su us sr rs ah ha an na hn nh nn hh aa ib bi if fi il
li im mi iv vi eg ge ek ke ew we
9: hd dh nd dn ua au hu uh nu un ar ra hr rh nr rn ad da mt tv vt sb bs ls sm ms
sv vs lt sf fs sl tb bt tf ft tl tm ig gi ik ki iw wi ec ce ep pe ex xe ez ze
10: ud dr rd ur ru du rr uu dd hf fh hl hm nb bn nf fn nl kt tw wt sg gs mh hv
vh ab ba af fa al la am ma av va ws ln nm mn nv vn gt tk sk ks sw tg ic ci ip pi
ix xi iz zi eo oe
11: md dv vd ub bu lu um mu uv vu ld dm nw wn uf fu ul ag ga ak ka db bd df fd
dl rb br rf fr rl lr rm mr rv vr nk kn sc cs sp ps sx aw wa hg gh hk kh hw wh ng
xs sz zs gn zt tc ct tp pt tx xt tz io oi ej je eq qe ey ye
12: vv mm ll ff bb bf fb bl lb bm mb bv vb fl lf fm mf fv vf lm ml lv vl mv vm
dg gd dk ug gu uk ku uw kd dw wd np pn nx xn nz wu rg gr rk kr rw wr ac ca ap pa
ax nc zn zh cn xa az za hc ch hp ph hx xh so os hz to ot iy yi ij ji iq qi
13: wb fg gf fk kf gl lk kl lw wl kb bw fw wf lg bg gb vw wv pr rx xr rz zr mg
gm mk km mw wm vg gv vk bk dc cd dp pd dx xd dz kv cr rp ao oa ho zd uc cu up pu
ux xu uz zu rc tj jt tq qt ty oh no on yt sj js sq qs sy ys
14: kg gw wg kw wk ww kk gg gk lx xl lz zl mc bc cb bp pb bx xb bz zb cm mp pm
mx xm mz zm vc lp pl fc cf fp pf fx xf fz zf lc do od uo ou ro cv vp pv vx xv vz
zv cl aj or yh nj ja aq qa ay ya hj jh hq qh hy jn nq qn ny yn
15: xg gz zg kc ck kp pk kx xk kz zk wc cw pg gx gc cg wp pw wx xw wz zw gp ov
bo ob fo of lo ol mo om vo dj jd dq qd dy yd uj ju uq qu uy yu rj jr rq qr ry yr
16: og ko ok wo ow xc cz zc px xp zz xx pp cc cp pc cx pz zp xz zx go bj jb bq
qb by yb fj jf fq qf fy yf lj jl lq ql ly yl mj jm mq qm my ym vj jv vq qv vy yv
17: gj jg gp pg gy yg kj jk kq qk ky yk wj jw wq qw wy yw co oc po op xo ox zo
oz
18: oo cj jc cq qc cy yc pj jp pq qp py yp xj jx xq qx xy yx zj jz zq qz zy yz
19: oj jo oq qo oy yo
20: yy qq jj jq qj jy yj qy yq
The list below, shows the components and the character pairs that have been
assigned to them in Schematix. Components that are most likely to be used in a
circuit, are assigned with character combinations with the shortest timing (in
terms of morse code dots).
ee ground
ei T-connection bottom
ie T-connection right
et T-connection left
es resistor vertical
te capacitor horizontal
se capacitor vertical
ii Corner top right
it Corner top left
ti Corner bottom right
is Corner bottom left
si VCC top
ea straight line horizontal
ae straight line vertical
eh resistor horizontal
he Crossed lines with dot
en T-connection top
ne BJT NPN right
ia JFETN right
ai Diode right
ih Diode left
hi Diode top
in Diode bottom
ni variable capacitor vertical
de variable capacitor horizontal
ed inductor air right
ue inductor air top
eu inductor core right
re inductor core top
er crystal vertical
ss varicap top
tt terminal right
ts terminal left
st capacitor electrolytic vertical, plus up
di capacitor electrolytic horizontal, plus right
id capacitor electrolytic horizontal, plus left
ui LED top
iu LED bottom
ri potentiometer right
ir potentiometer left
ef switch vertical
fe switch horizontal
el BJT NPN left
le BJT PNP right
em BJT PNP left
me JFETN top
ev JFETN left
ve Crossed lines without dot
eb zener top
be switch dual left
th switch dual right
ht switch dual connections left
tn switch dual connections right
nt crystal horizontal
sa antenna
as speaker magnetic
sh speaker crystal
hs switch dual top
ta switch dual bottom
at switch dual connections top
sn switch dual connections bottom
ns dual gate mosfet N right
td mosfet N right
dt mosfet N bottom
tu mosfet N left
ut varicap bottom
tr varicap rignt
rt varicap left
sd zener left
ds zener right
su zener bottom
us capacitor electrolytic plus bottom
sr led left
rs led right
ah pnp top
ha potentiometer bottom
an potentiometer top
na variable resistor vertical
hn variable resistor horizontal
nh ceramic resonator
nn variable inductor right
hh variable inductor top
...the list continues on, with the less commonly occurred components:
aa l124
ib l234
bi l234i
if l124i
fi jfetp
il l14i
li l21i
im l12i
mi l34i
iv l32i
vi l43i
eg l23i
ge l41i
ek l32
ke l34
ew l12
we l41
hd l14
dh l43
nd l21
dn l23
ua pri24a
au pri24c
hu sec24a
uh sec24c
nu l123
un l134
ar l123i
ra l134i
hr t12i
rh t32i
nr t34i
rn t41i
ad t23i
da pri24
mt pri24b
tv pri24i
vt sec24
sb sec24b
bs sec24i
ls sec124
sm sec124i
ms t24bi
sv l42i
vs l42
lt l13i
sf l31
fs sptp1
sl sptp3
tb sptp4
bt sptp2
tf spqp1
ft spqp3
tl spqp4
tm spqp2
ig npn123
gi npn143
ik npn321
ki npn341
iw npn412
wi npn432
ec pnp123
ce pnp234
ep pnp321
pe pnp341
ex pnp412
xe pnp432
ez jfetpl
ze jfetpb
ud jfetnt
dr jfetpt
rd emfetn3pr
ur emfetn3pl
ru emfetn3pt
du emfetn2
rr emfetn3pb
uu dgmfetnb
dd dgmfetnt
hf dgmfetnl
fh dgmfetpr
hl dgmfetpt
hm dgmfetpb
nb dgmfetpl
bn ddiodeff
nf diodeff
fn ftriodeff
nl ftriode
kt ftriodef
tw ftriodefff
wt triode
sg triodef
gs triodeff
mh triodefff
hv ftetrode
vh ftetrodef
ab ftetrodeff
ba ftetrodefff
af tetrode
fa tetrodef
al tetrodeff
la tetrodefff
am fpentode
ma fpentodef
av fpentodeff
va fpentodefff
ws pentode
ln pentodef
nm pentodeff
mn pentodefff
nv tubefff
vn tubeff
gt tubebase
tk pentoder
sk ftubebase
ks fpentoder
sw filament
tg fcathode4
ic fcathode3
ci fcathode1
ip cathode4
pi f4
ix cathode1
xi cathode3
iz lamph
zi lampv
eo right
oe left
md d45a
dv d45b
vd d45c
ub d45d
bu diagonal123
lu diagonal134
um bridge1
mu bridge2
uv bridge3
vu bridge4
ld r45a
dm r45b
nw nand
wn xor
uf not
fu nor
ul and
ag gater24
ga 4
ak opampn
ka opamp
db amp
bd ampn
df optoa
fd optob
dl g2
rb term2
br b24
rf gnd right
fr gnd left
rl gnd top
lr pcb11
rm pcb12
mr pcb13
rv pcb14
vr pcb23
nk pcb24
kn pcb34
sc pcb123
cs pcb124
sp pcb134
ps pcb234
sx pcbich
aw pcbicv
wa pcbpad
hg box1
gh box2
hk box3
kh box4
hw box12
wh box13
ng box14
xs box23
sz box24
zs box34
gn box123
zt box124
tc box134
ct box234
tp box1234
pt bus12
tx bus14
xt bus23
tz bus34
io bus112
oi bus114
ej bus122
je bus123
eq bus124
qe bus134
ey bus144
ye bus223
vv bus233
mm bus234
ll bus334
ff bus344
bb bus1124
bf bus1223
fb bus1344
bl bus2334
lb busf123
bm busf124
mb busf2334
bv busf1344
vb busf1223
fl busf1124
lf busf234
fm busf134
mf localosc
fv mixer
vf amp
lm ampflip
ml bpf
lv brf
vl hpf
mv lpf
vm attenuator
dg coupler
gd combiner
dk splitter
ug phaseshifter
gu varriableatt
uk circulator
ku pcb10
The rest of the symbols, have not yet been assigned to any components and are
available for future use:
uw kd dw wd np pn nx xn nz wu rg
gr rk kr rw wr ac ca ap pa ax nc zn zh cn xa az za hc ch hp ph hx xh so os hz to
ot iy yi ij ji iq qi
wb fg gf fk kf gl lk kl lw wl kb bw fw wf lg bg gb vw wv pr rx xr rz zr mg gm mk
km mw wm vg gv vk bk dc cd dp pd dx xd dz kv cr rp ao oa ho zd uc cu up pu ux xu
uz zu rc tj jt tq qt ty oh no on yt sj js sq qs sy ys
kg gw wg kw wk ww kk gg gk lx xl lz zl mc bc cb bp pb bx xb bz zb cm mp pm mx xm
mz zm vc lp pl fc cf fp pf fx xf fz zf lc do od uo ou ro cv vp pv vx xv vz zv cl
aj or yh nj ja aq qa ay ya hj jh hq qh hy jn nq qn ny yn
xg gz zg kc ck kp pk kx xk kz zk wc cw pg gx gc cg wp pw wx xw wz zw gp ov bo ob
fo of lo ol mo om vo dj jd dq qd dy yd uj ju uq qu uy yu rj jr rq qr ry yr
og ko ok wo ow xc cz zc px xp zz xx pp cc cp pc cx pz zp xz zx go bj jb bq qb by
yb fj jf fq qf fy yf lj jl lq ql ly yl mj jm mq qm my ym vj jv vq qv vy yv
gj jg gp pg gy yg kj jk kq qk ky yk wj jw wq qw wy yw co oc po op xo ox zo oz
oo cj jc cq qc cy yc pj jp pq qp py yp xj jx xq qx xy yx zj jz zq qz zy yz
oj jo oq qo oy yo
yy qq jj jq qj jy yj qy yq