Archive for January 23rd, 2010

WWVB Antenna: Location, Location, Location

Given that the wavelength of WWVB’s 60 kHz carrier is 5 kilometers, you’d think that the position of a receiver’s ferrite bar antenna isn’t all that critical. I’ve been running a receiver hitched to a laptop atop a file cabinet, with the bar antenna a few feet away atop an adjoining bookcase.

Putting the antenna 12 cm over the top shelf surface (in a kludged cardboard holder to keep it off the wood), located on the left side of a mechanical mantel clock, produces these samples:


Glitchiness:  276 Histogram: N!qdNMKE8B8A133111..12.....1.......................
Glitchiness:  256 Histogram: O!iSMLLCC9A52215111121...1.........................
Glitchiness:  243 Histogram: V!RfKOF88D977213212...2.3..2...1...................
Glitchiness:  227 Histogram: NrfaQG6595AI66.222411.1..2.....11..................
Glitchiness:  249 Histogram: S!eXNIFB76E5432.122.1.11111........................
Glitchiness:  258 Histogram: SulWLKIIBB68433212113.1......1.....................
Glitchiness:  119 Histogram: DWJG78753AEB52.711.....23.1.....1.....11.1.........
Glitchiness:  159 Histogram: McULIE7835H72..1........332............23..........

Moving it 40 cm to the other side of the clock, the next few consecutive samples look like this:


Glitchiness:    4 Histogram: .21......3RD11..........332............223.........
Glitchiness:    4 Histogram: 11..1....3SB3.........1.63.............51..........
Glitchiness:    3 Histogram: .2.......CJC11..........251............34..........
Glitchiness:    5 Histogram: 121......9KC3...........18.........1...15..........
Glitchiness:    5 Histogram: .22......8KD3...........36.........1...33..........
Glitchiness:   11 Histogram: 131....1.3W71...........451....1.......411........4
Glitchiness:   21 Histogram: 351......6X231..1.....1.233....2....1..23.........6
Glitchiness:    6 Histogram: .21..1...7OD1......1....23211..........33..........

The first position is roughly equidistant from the apex of the corner, so the antenna is on the diagonal of a corner reflector made from the metalized aluminum foil of the exterior insulation.

I’m not sure what to make of this, other than that location is everything.

More on the histogram format there.

Memo to self: maybe display the Glitchiness on the clock before the first sync to help find a good position?

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