You will need a good 12 volt, 2 (Minimum) - 8 (Future expansion) Ampere Regulated Power Supply. No "wall wart" please! Short circuit protection is useful, but not mandatory. Adjustable output voltage gives you additional feature, you will be able to change your transmitters output power by changing voltage of your power supply. Not bad. You can sometimes squeeze more power out of your transmitter if you raise voltage over rated voltage for your transmitter. But be careful, this is likely to destroy your output transistor, blow some capacitors or cause excessive heating. Importance of proper power supply is often underestimated. Poor power supply can cause several problems, add hum to your signal, cause interference to your neighbors (typical for AM systems where RF leaks into power lines), too low output power, unstable operation etc. Radio Shack is a good place to look for cheap stuff, as well as ham stores and ham fests.

If you prefer to build your equipment by yourself, get your soldering irons and check out these projects:

This is a simple "variable output" power supply. Now, left of this circuit would be standard line voltage transformer (110-220/18V) and a standard gretz rectifier with smoothing caps (10000uF or even better more). The heatsink of the 317 regulator must be isolated from the ground (aluminum heatsink).

If you need a stronger power supply, check:

This is a pretty strait-forward circuit. You might need to bypass C5 with a bigger capacitor (10-100uF). Diode D makes up for the BE loss of 0.7V of the 2N3055 transistor. If you need higher voltage, use 7815 instead of 7812 and connect pin 3 directly to ground. This will give you 14-14.3V on the output. I built several power supplies like that for my CB/ham stations and they work very well. Of course you have to add mains transformer and rectifier bridge + smoothing caps, just like above. Caps should be as big as possible (20000uF or more).

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