If you are considering building a beacon transmitter, there are projects for automatic keyers and oscillators.

Fig I The circuit diagram for on operational amplifier ver sion oj the VLF receiver. The next step is to obtain a means for recording the voltages from the FGM-3 and VLF. There are also some audio amplifier boards that could be used as the headphone amp for a Natural Radio Receiver. TheCA-3240 is a I win CA-3I4U, much like a 1458 is like a twin 741. REMOTE TUNED ACTIVE ANTENNA/CORNELL (2 BD SET).Here are some of the projects I found that might appeal to Natural Radio Experimenters: Looking at this list is also an easy way to find a reference for project you may have read about a few years ago, but can’t remember where you saw it. It’s worth spending some time looking through the listings, as having a circuit board makes construction a homebrew project much easier. Therefore, it might take a little research to find out the details of the project. The listing on the website for each project board includes the magazine and issue where the article was published, but there is really no other description of the project other than the title. Far Circuits has produced circuit boards over the years for many construction projects appearing in QST, 73, and other electronics publications. If you are interested, the website address is:Īnother source for boards of interest to the VLF and Natural Radio experimenter is Far Circuits. The American Radio Relay League (ARRL) is the national association for amateur radio, connecting hams around the U.S. The INSPIRE project sells their VLF-3 receiver kits for $120. Here are some sources for project boards and kits. PublicationReference ArticleBoard PriceHYCAS IF AMP by Wes Hayward and Jeff Damm8.00THE TT2 SURFACE MOUNT TRANSMITTER4.0073s Feb99A 40 METER RECEIVER BY THOMAS DUNCUN (2 BD SET)14. Receivers are of two basic types: E-Field and H-Field. The only real complexity that needs be added to a receiver is low-pass filtering on the front end to prevent overloading by strong out-of-band signals, and some form of filtering to get rid of the annoying hum and buzz from power mains that plagues the Natural Radio listener. (There are naturally occurring signals that extend above and especially below the range of human hearing, but the most common signals are within the range of our hearing.) At its simplest, a Natural Radio receiver is a high-gain audio amplifier with an antenna on the input and headphones or a speaker on the output. All that is necessary is to amplify the signal and convert it from a radio wave to audio so that it can be heard. Natural Radio signals occur within the range of human nearing so no frequency conversion or demodulation is necessary.

Gyrator vlf receiver