Description:
This low cost, 60 kHz WWVB
receiver was designed to allow decoding of the time code
signals sent out by NIST. An outdoor loop antenna drives
this TRF receiver that consists IF amplifiers and high Q, LC
bandpass filters that keep interfering noise to a minimum.
An analog AGC system drives the dual gate MOSFET IF
transistors keeping the signal at an optimum value for
proper time code decoding. A remote PIC Microcontroller with
an LCD Display is used to display the decoded time
information. PSpice was used to optimize the signal path and
bandpass filters by capturing actual WWVB waveforms from a
digital oscilloscope and replaying them in PSpice into
simulated circuits.
- No conversion, TRF
design.
- Low noise, Dual Gate
MOSFET IF amplifiers featuring: High Q, 60 kHz LC
bandpass filters.
- AGC control for > 70
dB dynamic range.
- AGC output for signal
tracking and propagation studies.
- Signal / Power LED's for
quick operator feedback.
- Digital data output to a
remote PIC Microcontroller and LCD time display.
- Outdoor loop antenna for
interference free reception.
- Very low cost.
- Single 12 VDC power
supply.
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