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Antenna for receiving WWV/10MHz: am I asking too much?
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October 11th 07, 05:49 PM posted to rec.radio.amateur.antenna
Jim Lux
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First recorded activity by RadioBanter: Mar 2007
Posts: 801
Antenna for receiving WWV/10MHz: am I asking too much?
Jon Kåre Hellan wrote:
(Geoffrey S. Mendelson) writes:
Frnak McKenney wrote:
Not sure what you could be referring to... other than the three
computers, 25" monitor, printer, Atmel AVR development board (8MHz
clock), flourescent desk lamp, and overhead I-look-like-an-
incandescent flourescent helix... all within 3 feet of the antenna
and clock. grin!
With all that hardware, wouldn't NTP (internet time) be a better option? Or if
you are not too deep into steel and concrete a GPS receiver?
Sounds like OP is really interested in bringing his father's WWV clock
to life.
But if correct time is the objective, ntp is easy. Over the internet
it is supposed to be accurate to tens of milliseconds. On our network,
1 - 5 ms is typical, but I suppose it is quite well behaved.
A GPS intended for timing gives better than 100 ms accuracy off the
cable. It can discipline ntp on a computer to typically 1 - 10 us
accuracy.
It looks like the Garmin GPS 18lvc us the timing GPS of choice for
hobbyists. You need a pulse per second (PPS) signal. There are other
GPS dongles which don't have PPS on the plug, but you can find the signal on
the circuit board.
More info at TAPR: "http://www.tapr.org". See also the timekeepers
mailing list archive:
"http://fortytwo.ch/mailman/pipermail/timekeepers/".
John Ackerman N8UR is an authority on timing and ham radio.
Why not take the GPS disciplined oscillator (e.g. a Z8301) and use that
to synthesize a fake WWV signal (which you could program up in the AVR),
and radiate that to your MACII. You can easily divide down the 10 MHz
from the oscillator to generate all the needed modulations for WWV (the
tones, ticks, and 100 Hz timecode). Synthesizing the voice
announcements might be a bit more challenging grin "At the tone,
Coordinated Universal Time is...." You could even have a switch to
change back and forth between WWV and WWVH.
But again - this is probably not what you're really after :-)
73
LA4RT Jon
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