KA7OEI - Remote Antenna For 60 KHz (WWVB) Reception > 자유게시판

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The pictures on this net web page have been taken during this more moderen repair, after the unit had been in steady service for 12-thirteen years. Click on small footage for larger view in separate browser/tab. Drill two holes holes by way of the diameter of the PVC pipe to assist the small loop in the right orientation. At the underside of the loop was welded a small plate of steel as may be seen close to the left aspect in the underside image of Figure 1. This plate was welded in the middle of the loop, reverse the hole at the highest and such that when the plate was bolted to the side of the utility field, it held the loop upright. Working with him, I sketched out the design for a shielded loop and the consequence was that visible in Figure 1. Since he was useful with a welder and had loads of pieces around it was a natural to make it out of scrap items of 1/2" electrical conduit and utilizing a conduit bender he original a "sq. loop" that was about 18" (45cm) on a facet as proven in the picture. When the loop was made with a conduit bender, the two ends of the loop were introduced shut collectively, however not touching, and this hole is coated by the black tape/tubing seen at the highest of the loop in the picture!

To ensure that this to work nevertheless, there must be a gap in the shield or else it will merely "quick out" the impinging magnetic subject from the specified sign and for causes mechanical, electrical and symmetrical, it is best that this hole be right in the middle of the loop. Note that an attic install is not going to work well when you've got aluminum-skinned insulation on the underside of the roof (or a metallic roof). For obtain-solely APRS monitoring or igate responsibility, the smaller model will work as nicely as the larger one. By adjusting the resonant frequencies of the loops, there's additionally no purpose why it couldn't also be used for the Japanese forty kHz JJY or the German 77.5 kHz DFC77 sign as nicely! The reply is a bit tough as any system involving potentially involving radio frequencies is topic to FCC guidelines. For personal use, one would take care to avoid doing something that could trigger interference and considering the frequencies concerned, one may moderately be assured that a system like this can be usually incapable of doing so - even if it have been to malfunction in some bizarre means!

Being that this was a fashionable constructing of steel and bolstered concrete development, and since it was full of digital devices corresponding to computer systems, fluorescent lights, etc. neither of those receivers ever managed to get a ok sign to synchronize themselves to the 60 kHz time sign being transmitted from Fort Collins, Colorado by the NIST station, WWVB even though the sign from that station right here in the Salt Lake area is sort of robust. I've occasionally been requested "Where can I get a system like this"? Were a system like this to be actively marketed and bought then it can be incumbent on the manufacturer/vendor to assure correct FCC compliance - a process that can be each costly and arduous! In instances like this the X-3.0 is the better Cable. This may simply not do for really lengthy Cables (just like the 5m I'll need sooner or later for the link from my Pre to my Mono-block Amp's (beneath growth). I didn't want the antenna to be tunable since it is going to function on a single spot frequency (10.149 MHz) permanently. Top: The rooftop-mounted 60 kHz shielded loop antenna. A loop antenna has a "determine 8" pattern and thus has two nulls and a level of directionality.

The 10-foot piece of pipe is minimize into two pieces after which rejoined with a pipe cross-tee, allowing the antenna to be disassembled to fit into the trunk of a car. I have now setteled down to two basic Versions of this Cable. The calculator referred to above is now downloadable from this webpage. I calculated the required capacitance required to resonate the loop at 10.15 MHz using the calculator referred to above, and got down to create an affordable mounted-value capacitor with 4-5 KV breakdown voltage. I'm measuring the Cables Capacitance. It isn't very hygienical (don't inform individuals that actually purchase these Cables yeah?) but the only dependable stripper I've discovered are my teeth. Since I've written the last two Interconnect Articles I had each some suggestions from you, the Readers and have made a number of more Cables myself. All however one Cable where variations of the XLO Geometry, which I've determined to name X-Cable (as a result of crossing conductors making many, copper conductor meter cable many X's down the length of the Cable). Solder one finish to one of many holes in the flange of a coax socket. The quantity denotes the gap between the begin and finish of 1 full flip around the core.