60 kHz 5 kilometers
2.5 mHz 120 meters
5.0 mHz 60 meters
10.0 mHz 30 meters
15.0 mHz 20 meters
20.0 mHz 15 meters
confusedpenguin wrote:I remember buying an atomic clock years ago, and the manual stated that it would sometimes take up to a few hours to set itself, depending on signal strength. I would set it up and leave it for a while and come back later to see if it has made any progress.
Khali wrote:At this point it comes down to geography or interference of some type. Out side of some unknown iron ore vein it seems geography is not the likely culprit. Interference is possible but the only things I can think of that might cause it would be the cell tower or power lines in the area.
just brew it! wrote:Surely there are NTP-enabled clocks with WiFi for less than the $350 they're asking for the one PenGun linked? Crap, I can build an entire frikkin' PC for less than that! Nearly everyone has WiFi these days, it seems like this would be a no-brainer!
PenGun wrote:just brew it! wrote:Surely there are NTP-enabled clocks with WiFi for less than the $350 they're asking for the one PenGun linked? Crap, I can build an entire frikkin' PC for less than that! Nearly everyone has WiFi these days, it seems like this would be a no-brainer!
That was the first on the google list. I'm sure there are cheaper ones.
Khali wrote:Its not so much I want it to work. The problem is getting to be that any clock you look at while shopping has this as a feature and some you can't even set the time yourself. I see the day coming when a simple clocked will be dumbed down so people won't have to, or be able to, set the time.
New product designers focus on getting their products to work in high population area's like cities because that's where the most money is to be earned. Those of us that live in small towns and rural areas are a secondary thought, if we get thought about at all. It takes years for some things to make it out to these areas. The atomic clock signal is just a minor example.
Khali wrote:I talked to a friend that lives in the closest town from here, two miles away in the same valley, and he can not get the signal either. I guess its a running joke in town that when the town wide garage sale day rolls around you can find one of these clocks for sale at about 75% of the garage sales.
Khali wrote:OK, for those interested I did some more research and finally found a answer. I talked to a cousin who is big into HAM radios and has been for years. From what I can tell by looking on the internet after talking to him, he has the right answer. He says that the atomic clock radio signal will only go about 1200 miles before weakening enough to lose the ground hugging feature. You can pick it up out to 2000 miles or so before it weakens to the point it would be useless. Past the 1200 mile point you would have to be on a flat plane or on a hill to pick it up reliably. The 1200 mile limit puts it right at the Illinois/Indiana state line. That puts me about 150 miles out side the reliable signal limit, living down in a valley is just the icing on the cake.
Khali wrote:So if you live east of the Mississippi river chances are the signal will not be reliable. The farther east the worse it gets. If your close to one of the cities on the East coast your totally out of luck due to distance and interfering signals that come with high populated areas.
Khali wrote:There were plans to build a second transmitter in the east at the Redstone Arsenal in Huntsville, Alabama, but it got quashed by the Marshall Space Flight Center objecting to having such a high power transmitter so near to their operations.
WWVB's Colorado location makes the signal weakest on the U.S. east coast, where urban density also produces considerable interference. In 2009, NIST raised the possibility of adding a second time code transmitter, on the east coast, to improve signal reception there and provide a certain amount of robustness to the overall system should weather or other causes render one transmitter site inoperative. Such a transmitter would use the same time code, but a different frequency.
Use of 40 kHz would permit use of dual-frequency time code receivers already produced for the Japanese JJY transmitters. With the decommissioning of the Swiss longwave time station HBG at 75 kHz, that frequency is potentially also available.
Plans were made to install the transmitter on the grounds of the Redstone Arsenal in Huntsville, Alabama, but the Marshall Space Flight Center objected to having such a high power transmitter so near to their operations. Funding, which was allocated as part of the 2009 ARRA "stimulus bill", expired before the impasse could be resolved, and it is now unlikely to be built.
Two other possibilities were explored in 2012. One was to add a second transmission frequency at the current transmitter site. While it would not have helped signal strength, it would have reduced the incidence of interference and (frequency-dependent) multipath fading.
None of the ideas for a second transmitter were implemented.
Instead, WWVB added phase modulation to the WWVB carrier in 2012. This required no additional transmitters or antennas. The modulation scheme is broadly similar to that used by time signal station DCF77. A receiver that decodes the phase modulation can have greater processing gain, allowing usable reception at a lower received signal-to-noise ratio than the amplitude modulation time code. The scheme is more fully described in a later section in this article.
Users browsing this forum: No registered users and 7 guests