BeagleScanSpec

This project satisfies several goals:

A personal multi-band radio frequencies receiver for enjoying tuning in many varied signals

A wide coverage Spectrum Analyser on the cheap.

A POES NOAA weather satellite image receiver.

My development Hardware includes:

BeagleBoard revC2

TinCanTools Trainer board (1.8vDC to 5vDC voltage translation)

Phillips FM1236F H-3 digital tuner ( easy to get, cheap)

Interfacing to the various receivers is done with I2C and USB.

I2C interfacing can be easily done with 1.8vDC to 5vDC voltage translators.

Some additional circuitry will provide wideband and narrowband reception for two purposes.

NOAA POES weather satellite reception in the 137.00 – 138.00 MHz band requires a 35 KHz audio bandwidth.

A interface to the digital tuner is made off the spare IF out port. A SA605 receiver IC with a PLL VCO and band pass filters picks off the second IF signal pin of the tuner and converts to the 35kHZ wide audio spectrum for recording. This satellite signal is saved as a .wav file for later decoding.

A wider bandwidth output range will provide a RF spectrum analyser. The digital tuner 45.75 mHZ output is down converted to a 455 kHZ signal for display with the BeagleBoard. The PLL VCO mentioned will provide center frequency selection.

This project includes a Software Defined Radio (SDR) that covers the frequency range 1.8 MHz through 30 MHz. Coverage is selected in one of four bands.

1. Band 0: 160m – Continuous coverage from 1.8 to 2.0 MHz

2. Band 1: 80m and 40m – Continuous coverage from 3.5 to 7.3 MHz

3. Band 2: 30m, 20m, and 17m – Continuous coverage from 10.1 to 18.168 MHz

4. Band 3: 15m, 12m, and 10m – Continuous coverage from 21.0 to 29.7 MHz

This receiver implements a quadrature sampling detector to produce low frequency I and Q signals for connection to the stereo line in inputs of the BeagleBoard or a PC sound card.

And a standard digital Television tuner covering:

FM band 76.00 to 108.00 MHz, Mono / Stereo

Low band 55.25 to 160.00 MHz

Mid band 160.00 to 442.00 MHz

High band 442.00 to 801.25 MHz

NOAA POES / APT satellite reception and Spectrum analyser signals will be extracted from a 2nd IF sound output of the digital tuner and SDR.

Software:

NOAA POES satellite signal recording to audio .wav file.

Simple satellite image display. (APT decoding)

FM mono/stereo tuner application. (search, tune, store)

General coverage receiver programs. (scan, tune, observe signals).

More detailed information along with progress reports and images is available from the link below.