Building a simple radio scanner

[Electro132]

Hi,

I would like to build a simple scanner which has a wide range of 10 000 hz to 30 000 khz or 10 000 khz to 30 000 mhz. Is there a simple circuit? I had a look and it seems like i could go with building a receiver based on these values but not sure how.

Any help is appreciated.

Thanks

 

[KrisBlueNZ]

RF scanners aren't simple! Saying that you want to build a simple scanner doesn't mean that a simple design for a scanner exists.

Also your frequency ranges are confusing. 10,000 Hz to 30,000 kHz is actually 10 kHz to 30 MHz; a ratio of three and a half decades! And 10,000 kHz to 30,000 MHz is actually 10 MHz to 30 GHz, which is well into the microwave band!

No, there isn't a simple scanner circuit. You can build a simple AM receiver operating around 1 MHz with a tuning range of about 3:1 - it's called a crystal set. Beyond that, things rapidly become more complicated.

 

[BobK]

Not to mention that even if you were able to build one, it could never match the performance of a commercially built one nor the price.

Bob

 

[hevans1944]

Software defined radios (SDR) are becoming more practical to build, and that would be my starting point for a scanner. Since the radio is defined by its software, adding a scanner function is almost trivial. However, you must define a reasonable portion of the spectrum to examine. Ten kilohertz to thirty gigahertz is a bit much, even for a commercial spectrum analyzer such as the Tektronix - RSA3408A Real-Time Spectrum Analyzer which "only" covers DC to 8 GHz.

IMHO, a 100 kilohertz to 10 megahertz SDR with a scanner function could be designed and built by a skilled amateur.

 

[davenn]

IMHO, a 100 kilohertz to 10 megahertz SDR with a scanner function could be designed and built by a skilled amateur.

Yup, an SDR radio covering that range would be a good start. Still requiring good electronics skills

Dave