Friday 28 March 2014

AM receiver with TA7642

From Kent Electronics l ordered and received some TA7642 Integrated Circuits for 0.75 euro each. These linear circuits in TO92 housing are designed for medium wave AM reception.








The internet provides lots of circuits with the Ferranti TA7642. For example this simple design:

Note: contacts 1 and 3 on TA7642 / contacts 5 and 6 on LM386 swapped
 

What’s possible with this small IC.  How about (V)LF reception or CW/SSB decoding ?



I found some time to solder the circuit above. To be honest, the results were rather dissapointing. Could receive 2 MW stations and in the evening 4. But there was no good separation of the stations (bad selectivity). I used an SMD version of the LM386. It will be hard to discover it on the photo below.





5 comments:

  1. Impossible! That circuit does not fit in such a small blob ;-)

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  2. The good old ZN414, aka MK484, YS414 and ... TA7642.

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  3. me too, handy, useful for a solar radio, but poor performer overall. john

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  4. Buen dia,ud deberia usar una configuracion tipo regenerativa,esto incrementará considerablemente la sensibilidad,y deberia tambien aumentsr el numero de espiras psra aumentsr el q del circuito.saludos

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