To be able to make the RSSI out modification the receiver must be opened
The 3.5mm steres jack have originally VIDEO and AUDIO and GROUND, marked here with V A G
Remove the AUDIO out capacitor and solder it to a near ground pad, now it is keept here and will not be lost.
Pin 7 of the receiver module is the RSSI out signal, to protect the rssi out from damage or overloading I have added a 1k resistor
I prefer MELF type resistors for jobs like this, they are not as fragile as normal thick film resistors
the extra wire added is wire-wrap type, thinn and easy to handle.
The two aliminium pads I have added is for cooling of the internal regulators, not normally needed if receiver is used outdoor
With this heatsink added I can now use this receiver indoor for 24hr usage and dont have to think about how hot it is.
maybe it is just me that is crasy and like to keep all electronics as cold as possible.
more about this receiver and the transmitter that match it is here : link
This RSSI out modification is made so the receiver can be used with diversity systems
and so I can read out how strong the radio rignal is.
Thomas Scherrer OZ2CPU March 2009