Quote Originally Posted by Luciano View Post
If you do so we will know if somebody else is transmitting on the same frequency.
Everyone in Europe is transmitting on that frequency. It's the only one allowed for this type of use. There are restrictions on how often & how long you can transmit because so many share the frequency. Allowing 25mW when everyone uses the same band is sure to lead to problems.

An RSSI output, in and of itself, may be of little help as noise can generate a high RSSI - it depends on the details of both the circuit and the methodology - it's not equivalent to CD on FSK. With the RWS superregenerative receivers, I measure the modulation depth (difference between the pulse and following space) of the lead-in pulse which has proven to be a good proxy for signal strength.

Recording or viewing the data output line is the best way to determine whether it's random noise or a signal (or signals) from the transmitter (or other transmitters). It's easy to do by recording with a soundcard and viewing it in a soundfile editor or with soundcard oscilloscope software (Google Virtins) or even the Parallax USB oscilloscope. The data output will be audible. You can even distinguish noise from signal by listening to it with a sound card.

You can also grasp why a relatively long lead-in pulse is needed by looking at a the output in graphical form. The noise pulses tend to be of short duration so a long lead-in makes it easy to separate wheat from chaff..