[ntp:questions] Re: improving WWVB reception
jerryg at total.net
Mon Aug 4 16:50:04 UTC 2003
I have a GE clock that is very good. It is also using WWV. These
clocks generally scan the base frequencies and lock in on the best of
Your problem is that in your studio, the unit is not seeing the signal,
which I realize is also your conclusion. It is possible to open the
radio, and add on an antenna wire of some sort. If the signal is not
present in your location, all you will add is noise in to its front end.
You would have to work out the front end circuit of the clock receiver,
to determine the best place to pick off to put a piece of wire to act as
a simple antenna. The only drawback is that soldering to the circuit,
you may also detune it a bit because of the stray capacitance of the
added antenna wire, and also the soldering itself. There is no added RF
input amplifier stage to offer isolation to the front end for any
external antenna connection.
It would be recommended in any case to put a capacitor of about 47 pF in
series with the added wire at the antenna solder point. This is to give
DC isolation. The 47 pF will easily pass frequencies from 5 mHz to 20
mHz which is the scanning range of these clocks.
The front end of these clocks are using MosFet devices. If there is any
static electricity, this can cause damage. Care must be taken to not
touch the bare end of the wire with the fingers. Use insulated wire
only. A small gauge of about AWG 22 to AWG 26 stranded wire should be
adequate. A length of about 6 to 10 feet should be okay.
If all of this detunes the front end due to having no input isolation,
then the reception will infact be worsened.
If you want something very good. Leitch, and Torpey Time make
professional clock systems that are designed to work from GPS. There
are a number of other companies that also make these. You put up a
small antenna about the size of a large donut in an area where it can
see the sky. There is a 52 ohm foam coax cable that runs back to the
clock receiver. The receiver has a digital packet output to run studio
type clocks. The output time accuracy is in the parts per trillion. As
a starter you need the receiver, antenna, cable, and 1 clock display
At the TV station, we are using the Torpey system for our precision time
keeping. This one is excellent.
Jerry Greenberg GLG Technologies GLG
"Chris Campbell" <chris-google at pobox.com> wrote in message
news:bglodn$qgr$1 at xuxa.iecc.com...
I recently bought this clock:
for use in a radio studio. We're going to do a fancier timekeeping
solution after our studio move next year but for now this is good
Well, it would be if it worked. The clock synchronizes with WWVB
every night, and I had it working on my engineering bench. But with
it mounted on my air studio wall, it won't sync. I've tried three
different positions -- mounted flat on west, north and east walls. In
each position, I left it there for about a week to see if it would
I'm in Atlanta, so WWVB is generally west from me. I don't know how
the internal antenna element is oriented, but I assume it's parallel
to the big flat dimension of the clock, so either east or west should
have worked best. Obviously the building is attenuating the signal,
but I really want it to work in that room, so I've got to find a way
to improve the signal reception without moving the clock much from
where it's at.
So, does anyone have any experience with opening these clocks up and
adding an antenna? What kind of antenna should I use, and how should
I orient it?
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