| Welcome to the W1VLF 9 Kilohertz Experiment Page |
Rescue Electronics Surplus
9 Kilohertz
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The objective of this project or experiment, is to propagate a signal on a frequency of less than 9 Kilohertz to the farthest possible distance.
The reality may be the only contact that I make to is to Jay W1VD located 5 Kilometers away.
Still... The project must go on.
The reality may be the only contact that I make to is to Jay W1VD located 5 Kilometers away.
Still... The project must go on.
Thank you to Stefan/DK7FC, for the inspiration to start this project. Thank you to all the folks on Lowfer Reflectors that have answered many
basic questions for me. And thank you to Jay W1VD for all his time and patience during this endeavor, and it has just begun HI HI
basic questions for me. And thank you to Jay W1VD for all his time and patience during this endeavor, and it has just begun HI HI
| Take a look at Stefan/DK7FC 8.97KHz Page He started us on this journey |
| The former for the resonating coil. A commonly available concrete tube Inexpensive, light, and readily available Dimension are 12.75" diameter, Length is 48" Material is cardboard.. Dielectric or Losses problems do you think? |
| Tube is supported on both end by wooden supports with a .625" threaded rod acting as an axle. The tube is centered on the axle by rotating the tube and observing for symmetry in on the outsider diameter. |
| Here we see a very happy and very tired OM W1VLF taking a break from winding W1VLF appears happy because he is approaching the 50% point of winding this coil. Rotating the tube with 1 hand and aligning the wire with the other . Total winding time was approximately 4 hours. |
| The completed coil located in the very messy shop of W1VLF The coil is actually wound tighter than picture would suggest. There was a lot of dust present during the winding process.. I am not sure why. |
| The completed coil side view. |
| The other end of the coil .. for what ever it's worth!! |
| Shooting down the axis of the completed coil See I told you that was dust and not loose windings. |
| 178.8 Millihenries R = 60 Ohms All that work for a lousy 178 Mhy. This very close to what I expected. Obviously this will have to be augmented by a considerable amount of antenna "C" and a more "L" "Q" values will be posted later. |
| Coil in temporary location inside the shack. Sitting on Styrofoam insulator. This is a very noisy coil!! My head hurts Initial tests proved out well on the 5 KM path Also note the makeshift PVC tube in the center of the coil |
PVC Column is held in place by PVC Tee. Column reaches to the bottom of the coil and is filled with ferrite rods of unknown Mu
Sliding the column in and out of coil will adjust "L" to achieve resonance. The ferrite rods arc between each other, but it seems consistent and does
not appear to affect to cause resonance to change. This is part of noise emitting from this Coil.
Sliding the column in and out of coil will adjust "L" to achieve resonance. The ferrite rods arc between each other, but it seems consistent and does
not appear to affect to cause resonance to change. This is part of noise emitting from this Coil.
279 mhy is the value of "L" with the ferrite column inserted and adjusted to resonance. Also the ferrite rods get very hot when keyed
down for 30 minutes or more, lots of wasted power here. 10 feet below the top hat is another ferrite rod column with 84 mhy of
inductance. Both the "L" at the antenna and the will be all air coils when I am finished. Still need to build a Variometer for tuning
down for 30 minutes or more, lots of wasted power here. 10 feet below the top hat is another ferrite rod column with 84 mhy of
inductance. Both the "L" at the antenna and the will be all air coils when I am finished. Still need to build a Variometer for tuning
| Screen capture of W1VLF 8.97 Khz station from the W1VD Grabber. Jay is located at 5 Km distant from my QTH Triangle wave generated by HP 3336 set to sweep 2 Hz at 20 second rate QRSS 10 with power out of amplifier approx 50 watts Note the nice signal trace Thank you again Jay for all the help without which this project would not be possible |
| Friday April 16 2010 TEST |
The new coil has been completed and was taken outside for the first test run. This coil is 277 Mhy and in combination with the old 12" diameter
coil of 177 Mhy, force resonance to 8890 Hz. Until I finish the variometer this frequency is where my transmissions will take place. Signal using
50 watts is more than 6 db better than previous transmissions. Why ?? Removed the ferrite rods in old coil to bring up inductance, now
everything is air core. Transmissions are still using 50 watts. The other change made to drive the loading coil array with 20 turns of wire at the
base of the blue coil. 20 turns was arbitrarily picked as a starting point. The eliminated the need for a ferrite matching transformer.
coil of 177 Mhy, force resonance to 8890 Hz. Until I finish the variometer this frequency is where my transmissions will take place. Signal using
50 watts is more than 6 db better than previous transmissions. Why ?? Removed the ferrite rods in old coil to bring up inductance, now
everything is air core. Transmissions are still using 50 watts. The other change made to drive the loading coil array with 20 turns of wire at the
base of the blue coil. 20 turns was arbitrarily picked as a starting point. The eliminated the need for a ferrite matching transformer.
Here is a capture from W1VD using QRSS 3 Distance is 5 KM , antenna current was approx 200 ma , Power driving the coil 50 watts. You can
see the difference between this capture and the one above using QRSS 10 Signal is much stronger now.
see the difference between this capture and the one above using QRSS 10 Signal is much stronger now.
| Take a look at Roger Lapthorne's G3XBM Below 9 Khz Page DX records Frequency used and more |
| Updated on April 17 2010 |
| The W1VLF 129' tower located at FN31LS. The tower is about 65 feet taller than the surrounding trees. From this view the Antenna wire and the top hat wires cannot really be seen that well. This view does give a pretty good idea of the what is around the antenna wire. The antenna consists of 173' of #12 wire that slopes from the rear deck of the house and is pulled to the near the top of the tower by a rope and pulley arrangement. Currently there are 2 top hat wires wire which slope away from the tower toward the viewer. The wires are roughly 150' long each and terminate 60' and 40 feet above the ground. The total antenna "C" = approx 950 pF I am hoping to add 2 more top hat wires out over the trees but I am not sure if this will be of any benefit because of losses in the trees. These wires could be as long as 200' each with out touching the trees as the if I keep the ends at 70' above ground |
Close up views of the antenna wires and top hat wires. Because of the angle of the sloping wires even
with a close up view it is difficult to imagine the wire configuration.
with a close up view it is difficult to imagine the wire configuration.