I am building a capacitive fan speed control using triac's for switching it is giving off excessive RF interfearance does anyone know what can be done to reduce the RF interfearance
Is that the actual circuit? Your zener and 5 volt regulator should have turned to smoke by now - there is no current limiting for the zener.
If that's a 115 VAC fan, then VT3 should be able to control the speed if some source for the internal triac is supplied. What VT1 & 2 are supposed to dodo is a bit of a mystery. But you don't get a lot of conduction through a 6.6 uF capacitor (where did you find that value? Are they Ac rated?).
There must be more circuitry controlling the optocouplers.
Possibly you could post up a verbal circuit description so we can follow how the circuit is intended to work.
they are 250v rated the 6.6 is accually 2, 3.3 Uf in parallel. it is a 3 speed control VT-1 and VT-2 are slow and medium speed it is the accual circuit I have it working it just emits a ton of RF interfearance I have not been able to figure out the source of the interfearance to correct the problem