"Fred McKenzie" wrote in message
...

Another approach is to add a converter stage between the 4000khz antenna
and
the antenna input connector of the tuner. Such a converter might have a
4000khz preamplifier stage, a converter stage and a local oscillator
stage. If
the local oscillator were crystal controlled, you might be able to tune
the
frequency on the AM dial, with frequency determined by adding a constant.

This is the best approach. It's best to use an AM car radio that has
analogue tuning for this sort of thing. A crystal for 5 MHz would be OK - 4
MHz would come up at 1000 kHz on the dial.

An excellent project is a converter using 4 & 5 MHz crystals and a tunable
front end. This will give you a receiver that tunes continuously between 3.5
and 7.5 MHz in 4 bands. You will need a double tuned circuit at the front
end to resonate over this range. Add a 455 kHz BFO for SSB.


73, Peter