Don't know if this is correct place for this but here goes:

Horizontal divisions are 2ms.

It´s the inverted output from a tsop1736.

Having trouble on identifyng correct protcol since all protocolls from [Link: sbprojects.com] have or a Leader pulse, or a start bit .
However this one start's with a short pulse.

It's from a Set Top Box, of Scientific AtlantabBrand, that somepeople say uses RC6.

Any ideias?

Thank You

It will help if you can capture of a complete signal, and calculate/post the overall duration (time). Also measure the modulation frequency of the signal before it runs through the decoder.

If the waveform above is an accurate representation of the beginning of an IR signal, it is not RC6, but it plausibly is RC5.

By the way, normally we try to measure the durations of burst pairs. Witha complete set of durations from one or more signals, it is usually practical to infer the protocol. A partial pictorial snapshot doesn't really have enough information.

If i keep pressing the button it repeats itself every 100ms

it also seems like RC5 to me, but if so, the start bit is 0, instead of usual 1, and there is no toggle bit.

also, there is a strong variation in pulse width. around 20/30%.

Tks for input