![best vlf receiver best vlf receiver](https://www.robkalmeijer.nl/techniek/electronica/radiotechniek/hambladen/ar/1989/12/page10/fig1.jpg)
When the diagonals are set with 60 degree angles between them the distance from each paddle to the next will be 0.75 meters and the length of a turn will be 6 X 0.75 = 4.5 meters. The paddies should extend exactly one inch beyond the ends of the 57 inch long diagonals so the distance between the ends is exactly 59 inches which is 1.5 meters. I used #10 brass flat head wood screws 3/4" long to mount the paddles on the diagonals. These offsets produce a hexagonal frame that will lay flat and the winding will not zigzag. The paddle drawings show how the three countersunk holes for the mounting screws are centered on two paddles, offset 5/8" to the right on two paddles and offset 5/8" to the left on the other two. Then you can measure how wide 24 turns will be. The plywood paddles are 6-inches long and the width of 24 turns of whatever size wire you use so you should buy the wire first. I used 5/16-18 threaded brass rod and brass nuts and washers to prevent rust. A hole is drilled in the centers of the three diagonals and they are fastened together with a bolt. Each diagonal is cut to be exactly 57 inches long. The diagonals are 1" X 2" nominal, actual size 5/8" X.1 3/8", wood from Home Depot or any lumber supply house. The drawing above shows how the hexagonal frame is shaped lice a paddle wheel with the six'/4 inch plywood paddles mounted all facing in the same direction on the ends of three diagonals. If you follow these directions you will have a nice looking single layer loop that will have no zigzags but a less carefully made frame will probably work just as well provided you maintain the dimensions fairly close. They are connected directly across the loop leads and do not need to be protected.īelow are instructions for making a hexagonal frame for the loop antenna receiver. The tuning capacitors for the loop are not mounted on the board. After removing the flux, candle wax is dripped on the amplifier board to cover it completely and protect it from rain. It is usually a mixture of Ethyl either, Acetone and alcohol. Some other radio and electronics stores do carry it. First, all soldering flux must be removed from the circuit board with flux remover, something Radio Shack no longer carries. Two things are necessary to protect the receiver from the weather. It is not necessary to put the receiver in a weatherproof box.
#BEST VLF RECEIVER HOW TO#
Below the chart is a simplified diagram of how to hook the parts of the receiver together. The chart below shows an interference-free recording of the signal from NAA in Cutler, Maine, USA transmitting on 24 kHz that I made in Orlando, Florida, USA with the loop antenna 8 meters (27 feet) from the nearest 60 Hz electrical wiring. This loop antenna receiver is meant to be located outdoors so it can be placed as far as possible from electrical wiring which is the source of most if not all of the interference that plagues SES receivers. The receiver has a pass band of less than 500 Hz which compares favorably with other SES (Sudden Enhancement if Signal) receivers in use today.
![best vlf receiver best vlf receiver](https://physicsopenlab.org/wp-content/uploads/2020/05/VLFRec3.jpg)
The low resistance of the #14 wire gives the loop a high Q, about 400 compared to about 20 for small loop antennas wound with #26 wire that are used by most SID observers. It is the LC resonant circuit for the receiver and owes its success to being a large high-Q loop with much greater aperture than small loop antennas usually used with sudden ionospheric disturbance (SID) receivers. I call this a "Loop Antenna Receiver" because the loop is the receiver. There is plenty of signal to make up for any lost on the transmission line.
#BEST VLF RECEIVER DRIVER#
There is no need to match this transmission line to the recorder driver because the signal has already been amplified 900 X. After the signal is amplified 900 times it is sent over a transmission line consisting of ordinary 4-wire telephone wire to a recorder driver. The receiver is built right on the loop antenna so there is no need for a transmission line between the antenna and the receiver. I meet the second requirement by eliminating the transmission line altogether. I meet the first requirements by building a hexagonal loop antenna that measures 1.5 meters (59 inches) across the diagonals and winding it with 24 turns of # 14 stranded copper wire. The design is based on the principle known to all amateur radio operators that the most important part of a transmitting or receiving system is a good antenna and a well matched transmission line. The loop antenna that goes with it will take another day to build from stuff you can buy at Home Depot or a similar store. You can build it in one afternoon from about $10 worth of Radio Shack parts. Here is an updated version of the simple VLF receiver first described in the April SID Supplement of the Solar Bulletin. A Simple, Easy to Build VLF Receiver to Detect Solar Flares and Gamma Ray Bursts - From the October 2002 Solar Bulletin