We used 2N4142 NPN transistors in our receiver.Ĭ7 = 470 uF. Q1, Q2, Q3, Q4 = 2N4124, or 2N3904 NPN small signal transistors. Stormwise part # AMVC-384 $ 20.00 each + s/h. Wire in as shown in the diagram and photos. NOTE: Do not omit RFC1, it provides the needed signal blocking to force the received signals into the Q2 audio detector stage. RFC1 = 144 turns # 28 wire wound on separate FE core. Don't overdrive it, you'll loose headroom on signal strength measurements, but feel free to experiment, depending on your needs. NOTE: 元: 1 turn is -ALL- that is needed to effectively couple the BFO signal into the FE core. Note L2: 12 turns works well from 10 KHz - 300 KHz with FE part. L2 = 12 turns # 22 copper magnet wire wound on FE. NOTE: In our receiver we changed L1 to 2 turns on 06-26-2015, giving much better selectivity performance. NOTE L1: Selectivity is the ability of the receiver to separate stations on the dial. L1 = 4 turns # 22 copper magnet wire wound on FE. Tuned Antenna required: Any Stormwise SER22T antenna for use in bands between between 10 KHz to 300 KHz.įE = Stormwise VLF-LF Transformer Core # 1 $ 7.00 each + s/h. A sudden drop in recorded signal strength at night indicates you may have recoreded an astronomical event. You can also watch WWVB fade out an hour before local sunrise, and signal level increases at night an hour after sunset each day. Monitoring WWVB's signal strength can allow detection of solar flares, x-ray bursts, gamma ray bursts, or other space events that greatly disturb the ionosphere, causing a sudden drop or increase in signal strength.
#Build vlf receiver full#
At night this effect dissipates and WWVB comes up to full signal strength. The signal from WWVB fades or is weaker during the daytime due to solar atmospheric ionisation. The receiver has a signal strength DC output available to allow recording of received signal strength to a chart recorder app. The intended application of this receiver is to monitor signal strength of time code station WWVB at 60 KHz.
#Build vlf receiver movie#
View 12 second movie of receiver working on breadboard, receiving WWVB 60 KHz time signal station.īuild this sensitive 4-transistor VLF-LF Radio Receiver for 10 KHz - 300 KHz.
![build vlf receiver build vlf receiver](https://portia.astrophysik.uni-kiel.de/~koeppen/VLF/images/VLF3schema.jpg)
We will move it to a permanent box with soldered connections. This is how we built it at first for testing. It works even when built like this on a solderless breadboard. View 1 minute movie of completed receiver, working and receiving WWVB 60 KHz time signal station. See at the bottom of the page the data we collected. We used this VLF receiver to 'view' the big American solar eclipse of 2017.