Assuming I wanted to reverse engineer 13FSK, what steps would I take to begin reverse engineering it? I have seen tools such as inspectrum and baudline that can help me view the raw signals, but I am unsure as to how to reverse engineer the 13FSK and then build a way to receive and transmit data using 13FSK.
$\begingroup$
$\endgroup$
8
-
1$\begingroup$ FYI, unless the name is being misused "13FSK" just means that it's frequency-shift modulation with 13 distinct frequencies. What you need to know after that is the coding, the meaning of those 13 symbols. $\endgroup$– Kevin Reid AG6YO ♦Apr 4, 2016 at 3:54
-
$\begingroup$ Correct. Do you have any ideas on how to figure out the actual data? $\endgroup$– user6451Apr 4, 2016 at 4:15
-
1$\begingroup$ You'll probably need more to go on, like having some message with some idea of what it should contain. $\endgroup$– Phil Frost - W8IIApr 4, 2016 at 11:35
-
$\begingroup$ I agree - first you will want some information about who is transmitting it, and that may give clues as to the content. There is not enough information in this question to give a definitive answer. $\endgroup$– SDsolarMar 29, 2017 at 5:21
-
1$\begingroup$ Welcome to Amateur Radio. Please take a moment for the tour at ham.stackexchange.com/Tour Note that since this database will be around for years we generally don't assume that raw links will hold their value - so please edit this and provide a rough explanation of what people might find if they follow this link. If you do so you are more likely to turn around the voting on this one. $\endgroup$– SDsolarJun 30, 2017 at 15:18
|
Show 3 more comments
2 Answers
$\begingroup$
$\endgroup$
To reverse engineer anything, you need a sample to look at. Can you generate valid 13FSK signals? If so, then you need to capture it.
Also, you'll need manipulate the transmitted payload so you can compare "before and after" to see what changed.
$\begingroup$
$\endgroup$
If you mean you are looking at something like Pactor 3 or 4 ... then good luck.
I did have a look at this a few years ago after buying a very expensive (but functional) Pactor 3 Modem....
I apologize that this is not a more constructive comment. However such Digital transmissions are usually compressed (possibly using commercial algorithms) and may additionally use proprietary codecs.
