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Receive.doc
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1988-08-10
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59 lines
Receiving SSTV:
The most inportant thing you need to know in order to receive SSTV is
what mode is the other party sending?
There are many, many formats of SSTV supported by the AVT system, and
unfortunately it is difficult to help you on this one from the manual.
If you are a HAM, you can always simply ASK the other party. If you are
an SWL, then you must listen very carefully and try to figure it out
from the conversation of the parties involved in the active transmission
and reception fo these modes.
A small bit of help is this; For many of the Robot Color modes, they often
simply say, "this will be 36" or "here comes a 12". Most modes are referred
to by their speed, and very often no mention is made of whether it will
be a color or black and white shot. Again, you kind of need to listen
carefully to see what's going on.
To actually initiate receive is very easy. You press the appropriate
button on the AVT's on-screen control panel for the speed, and then the
mode, and then press the recieve button.
Any receive mode, including FAX, can be aborted by pressing the left mouse
button during receive. However, in FAX, you must hold the button down for
a period of time greater than 6 lines of FAX video at the scane rate
you are using. Simply put, hold the button for at LEAST 6 seconds and the
program will quit receiving.
Some receive modes wait until they "hear" an incoming signal before
actually DOING anything. The AVT modes are an example of this. Until an
Initiate sequence is receieved from the station that is the source of the
image, nothing will happen.
When receiving FAX, you can "phase" the image by pressing the left mouse
button for a SHORT period of time during reception of a signal. Phasing the
FAX image essentially means you are aligning it to match the left edge of
your screen.
This version of the program does not autostart when it hears a FAX signal;
instead, it begins receive immediately when you press the receive button.
It is a virtual certainty that you will begin reception with an image that
is NOT properly horizontally aligned; If this is so, tap the left mouse
button until the image is positioned correctly.
It may take several tries to learn how to do this effectively, but it is
time well spent.
Each receive mode has a set of characteristics unique to itself; It will
take you some time to become proficient at recognizing the various types
of signals from the way that they sound, but that's part of the fun.
With any other system besides the AVT system, you wouldn't have the option;
instead, many times SSTV images would fly by and there would be no WAY
for you to receive them. You made the right choice!