The transmitter uses 2 MPSH10 (equiv BF494 or NTE229) transistors in a double-ended free-running voltage controlled oscillator (VCO) operating at half the output frequency on each side and combined at L2, which is tuned to the 2nd harmonic of the VCO and covers the 88-108 MHz range. A standard 9 volt battery is used for power and fits inside the tin. The mono audio input circuit is totally passive with 70us pre-emphasis provided and the audio quality is great.
Build Accurate LC Meter and start making your own coils and inductors. This LC Meter allows to measure incredibly small inductances making it perfect tool for making all types of RF coils. LC Meter can measure inductances starting from 10nH - 1000nH, 1uH - 1000uH, 1mH - 100mH and capacitances from 0.1pF up to 900nF. The circuit includes an auto ranging and reset function to make sure the readings are as accurate as possible ... [more]