Anyone built *this* PIC programmer ??

guys, I have built this programmer given here :

**broken link removed**

my problem is that the voltage between VCC and VSS comes out to be 4V instead of 5V. everything else is as it should be. any suggestions on how to get around this problem ?

Provided you have 5V at the emitter of the ZTX500, you should get about 4.8V on Vcc. At the moment you only sinking about 1mA of base current with the 7406. This is capable of sinking 30mA. You can try and decrease the value of the 4.7k resistor to switch on the transistor harder. You can safely half the value to around 2.2k and see if it improves.