VHF-HF TRANSVERTER

This little circuit is a transmitting and receiving converter (transverter) that converts a FT290 or similar multimode handheld transciever to the 14MHz amateur band. The project is a single board module that needs an external local oscillator, for example, the VHF harmonic oscillator (or QRP VHF FM TX) LO for transverter project. It should be a relatively simple matter of scaling coils and caps to convert other bands. You may choose to omit the TX/RX switching and the TX mixer and use this unit as a receive converter giving 14MHz - 16MHz coverage on a multimode VHF receiver.

If you choose to use the full transverter circuit then you will be pleasantly surprised at the spectral purity of the transmitted signals. All unwanted spurious signals and even oscillator breakthrough are well under -75dB at the output terminal. The HF TX output from the unit is about 2mW and will give a full ten watts from my 10-Watt HF linear amplifier. The VHF rig must be of the type that also delivers +10v DC at the antenna socket on transmit. This is true of the FT290, C58 and most multimode handportables.

Read More
http://web.telia.com/~u85920178/conv/conv-00.htm