Can I use electrolytic capacitor for tuning a common emitter amplifier?

[obrien135]

If I use a transformer in the collector circuit of a common emmittor amplifier to match impedance and a capacitor on it's primary to tune the amp to a certain frequency, is it OK for that capacitor to be electrolytic? The frequency is 3MHz.

 

[keith1200rs]

capacitor question

No. The inductor voltage will swing both ways (i.e. the collector voltage will go above the positive rail) so the capacitor must be unpolarised.

Keith