Another discussion on Desheng R-333, one-time conversion of the Motorcycle modification machine

Said it is the type of machine, from a few days to use the experience and find the point of information!

Actually listen down, this machine's amplitude modulation part does have "enhance" the place, mainly in the sensitivity, through and several one-time variable frequency pointer machine and digital display comparison, indeed has the promotion, especially uses the tie rod antenna, has approached the BCL machine level, let me to its interest greatly increases.
In general, the purpose of the machine is to eat dry squeeze net existing hardware capabilities, this machine in a very common single-chip radio chip with some "tricks", amplitude modulation performance, and is not accidental.

One of the tricks is a double quad variable capacitors, medium wave FM with one, short wave alone with one, this "trick" is very trickery, on one hand to reduce the complexity of medium and short wave switching, on the other hand, the short-wave part independently, can be adjusted separately.
The second trick is to take advantage of the large volume of the machine features, important components can be more relaxed layout, reducing the crosstalk between each other
Trick three is the amplitude modulation plus a high-frequency amplification, although only a simple amplification circuit, but the sensitivity is improved
The trick is to use the reverse-paranoid capacitive effect of the common transistor-based polar collector, acting as a varactor diode to be used, and the circuit diagram is as follows:

This frequency fine-tuning is very easy to adjust and smooth than tuning, compensating for some gear transmission mechanism easily adjusted "too" shortcomings
Trick Five, the two-gear tuning mechanism partially suppresses the rebound during tuning

Another discussion on Desheng R-333, one-time conversion of the Motorcycle modification machine