I'm trying to get a radio clock to sync up with WWVB (60 kHz out of
Colorado). In the place that I want to place the clock, I can not get
it to sync, even at night when the signal is stronger.

Inside the clock is a small ferrite-core loopstick antenna. I figured
out which way the gain pattern pointed on the thing (i.e. not along
the axis of the ferrite rod) and tried positioning the clock for
maximum signal, but no luck.

So now I'd like to try a better antenna. I won't have the time to
make one myself, and I'd probably do it badly anyway. It seems that I
should be able to buy an antenna for this fairly cheaply (thank you to
my capitalist exploiter overlords!), but I can't find one. Ideally,
one designed for WWVB's 60 kHz would be great, but I'll settle for
anything really, as long as it claims to have some decent gain at 60
kHz.

This clock is going inside a building, inside two layers of cinder
block / concrete walls, so it's possible that I just won't be able to
get a signal in there no matter what I use. The
external-antenna-and-a-wire-run concept is the next step, but I'd
rather not to that unless I have to. We're moving out of that
facility in a few months so that would be wasted labor.

What are some sources for loopstick antennas?

On another note, in searching this forum, someone said:

An LF loopstick antenna wound on a 1/2 inch diameter rod is *much*
less efficient than a 1-meter square air loop

Assuming I have the space, am I better off trying this with a few big
loops of wire instead of a small ferrite loopstick? What are the
rules of thumb for comparing the two types of loop antennas?

Thanks!

Hi Chris,
try to make a rectangular coil, about 1 ft x 1 ft, some 30 turns wound
by a fairly thin magnet wire (#25 to #30). Bring it into resonance at
60 kHz by a capacitor, some 8000 - 10000 pF. Place the coil
vertically, aiming to the transmitter, and place the clock to its
center. You do not need any mods of the clock. The signal should be
significantly stronger.

BR from Ivan

(Chris Campbell) wrote in message om...
I'm trying to get a radio clock to sync up with WWVB (60 kHz out of
Colorado). In the place that I want to place the clock, I can not get
it to sync, even at night when the signal is stronger.

Inside the clock is a small ferrite-core loopstick antenna. I figured
out which way the gain pattern pointed on the thing (i.e. not along
the axis of the ferrite rod) and tried positioning the clock for
maximum signal, but no luck. ...

Ivan wrote:
try to make a rectangular coil, about 1 ft x 1 ft, some 30 turns wound
by a fairly thin magnet wire (#25 to #30). Bring it into resonance at
60 kHz by a capacitor, some 8000 - 10000 pF. Place the coil
vertically, aiming to the transmitter, and place the clock to its
center. You do not need any mods of the clock. The signal should be
significantly stronger.

Now, just so I understand you correctly, you're saying I don't
actually connect this loop antenna to the clock? I just place the
clock in the center of it, and the loop antenna (I guess) induces a
stronger signal in the clock's internal antenna? Wow, I'd love that.
As for the loop ends, I just connect them together across the cap?

And when you say "vertically, aiming to the transmitter", you mean
that the plane of the loop intersects with the transmitting station,
right? That is, I don't point the *face* of the loop at the
transmitter, I point the edge towards it. Right?


So, anyway, I'm making an antenna. Alright I downloaded and
played with Reg's program and have a configuration that might work
well.

Can I stack wire turns, and if not, why not? It seems that all the
designs have the wire turns lined up next to each other like:

*****

and never

*****
*****
*****

Is there something about keeping each loop *exactly* the same
circumferential length (not even 0.2% difference) that dramatically
affects loop antenna performance? Or some other affect?

I'd like to fill a 5mm x 5mm cross section with wire turns, which
means stacking them.

On 22 Jan 2004 12:29:08 -0800, (Chris Campbell)
wrote:

Ivan wrote:
try to make a rectangular coil, about 1 ft x 1 ft, some 30 turns wound
by a fairly thin magnet wire (#25 to #30). Bring it into resonance at
60 kHz by a capacitor, some 8000 - 10000 pF. Place the coil
vertically, aiming to the transmitter, and place the clock to its
center. You do not need any mods of the clock. The signal should be
significantly stronger.

Now, just so I understand you correctly, you're saying I don't
actually connect this loop antenna to the clock?

Correct.

I just place the
clock in the center of it, and the loop antenna (I guess) induces a
stronger signal in the clock's internal antenna?

Yup.

Wow, I'd love that.
As for the loop ends, I just connect them together across the cap?

You got it.

And when you say "vertically, aiming to the transmitter", you mean
that the plane of the loop intersects with the transmitting station,
right? That is, I don't point the *face* of the loop at the
transmitter, I point the edge towards it. Right?

"Towards" is a relative direction. You may have to experiment.

Hi Chris,

The ultimate explanation is that if you read the instructions
carefully, you may find they state to try on one wall, or move to
another and try again (pretty much the same advice as that above, less
all the wire and capacitors).

The "synchronization" does not always happen all at once (again, this
is undoubtedly discussed in the instructions - or used to be). You
may spend up to a week discovering the sweet spot where the receiver
responds. We have fielded many such questions as yours in the past,
and I cannot recall anyone coming back after having given up (and I
don't recall one needing an external antenna).

73's
Richard Clark, KB7QHC

Richard Clark wrote:
The ultimate explanation is that if you read the instructions
carefully, you may find they state to try on one wall, or move to
another and try again (pretty much the same advice as that above, less
all the wire and capacitors).

The "synchronization" does not always happen all at once (again, this
is undoubtedly discussed in the instructions - or used to be). You
may spend up to a week discovering the sweet spot where the receiver
responds. We have fielded many such questions as yours in the past,
and I cannot recall anyone coming back after having given up (and I
don't recall one needing an external antenna).

Oh, I'm sure lots of folks ask questions here about these clocks

Believe me, I tried and I was very patient. I tried the clock set up
in five different locations, which included several orthogonal
directions, and I left it in each position for at least 24 hours, and
probably a lot longer. I spent a month on this and I'm not
exaggerating. It was months ago (I *did* give up and my memory is
fuzzy but I know I left it up at least overnight in each position, and
for a week or more in some locations (i.e. on the bench, pointing in
different directions). I never got a sync indoors.

It's just that now I'm trying again, after having given up. Thanks
for your help and I'll try the surrounding-loop solution. Makes me
wish I'd taken that antenna design course in EE school.

On 23 Jan 2004 08:18:31 -0800, (Chris Campbell)
wrote:

It was months ago (I *did* give up and my memory is
fuzzy but I know I left it up at least overnight in each position, and
for a week or more in some locations (i.e. on the bench, pointing in
different directions). I never got a sync indoors.

It's just that now I'm trying again, after having given up. Thanks
for your help and I'll try the surrounding-loop solution. Makes me
wish I'd taken that antenna design course in EE school.

Hi Chris,

Some years ago in my Cal Lab, the antenna that I used to receive WWVL
was a 16 foot whip. I had it connected to a specialized receiver that
separated out the Naval Observatory's TOC which was a specifically
shaped pulse that occurred every 17 minutes. I used this to
synchronize my Atomic Clock to within 100nS of UTC. It was never a
simple feat, and missing that pulse meant a delay of at least 17
minutes (which was about how long the entire process took).

One question that I have failed to ask the various posters that came
here was "how do you know it hasn't synchronized?" I can imagine
there being a gross error of seconds if not minutes (which may
contribute their/your problem), but under one second variation is
difficult to confirm.

73's
Richard Clark, KB7QHC

(OK1SIP) wrote:
try to make a rectangular coil, about 1 ft x 1 ft, some 30 turns wound
by a fairly thin magnet wire (#25 to #30). Bring it into resonance at
60 kHz by a capacitor, some 8000 - 10000 pF. Place the coil
vertically, aiming to the transmitter, and place the clock to its
center. You do not need any mods of the clock. The signal should be
significantly stronger.

[I asked this a couple days ago but it was at the tail end of a longer
message so maybe that's why nobody replied.]

Can I stack wire turns, and if not, why not? It seems that all the
designs have the wire turns lined up next to each other like:

*****

and never

*****
*****
*****

Is there something about keeping each loop *exactly* the same
circumferential length (not even 0.2% difference) that dramatically
affects loop antenna performance? Or some other affect?

I'd like to fill a 5mm x 5mm cross section around the perimeter of the
clock with wire turns, which means stacking them.

Chris:

I thought someone else would answer, but here it is: For highest Q you want
the minimum capacitance between start and end, so what you suggest will
work, but try to actually make the layers carefully so the outside layers
don't collapse down to the first.

--
Crazy George
Remove N O and S P A M imbedded in return address
"Chris Campbell" wrote in message
om...
(OK1SIP) wrote:
try to make a rectangular coil, about 1 ft x 1 ft, some 30 turns wound
by a fairly thin magnet wire (#25 to #30). Bring it into resonance at
60 kHz by a capacitor, some 8000 - 10000 pF. Place the coil
vertically, aiming to the transmitter, and place the clock to its
center. You do not need any mods of the clock. The signal should be
significantly stronger.

[I asked this a couple days ago but it was at the tail end of a longer
message so maybe that's why nobody replied.]

Can I stack wire turns, and if not, why not? It seems that all the
designs have the wire turns lined up next to each other like:

*****

and never

*****
*****
*****

Is there something about keeping each loop *exactly* the same
circumferential length (not even 0.2% difference) that dramatically
affects loop antenna performance? Or some other affect?

I'd like to fill a 5mm x 5mm cross section around the perimeter of the
clock with wire turns, which means stacking them.

To design small, VLF to HF, multi-turn loop antennas, download program
RJELOOP3 in a few seconds and run immediately.

Sides of square, number of turns, spacing between turns, value of tuning
capacitor, and other data.
----
.................................................. ..........
Regards from Reg, G4FGQ
For Free Radio Design Software go to
http://www.btinternet.com/~g4fgq.regp

Where are you? I'm in Illinois and just got one of the clocks. I know it
helps you not not a bit for me to say mine sync'ed up quickly, but everybody
says that kinda' stuff (:-)..

Don't think there is anything to buy... Make is the only way.

The instructions for mine say that it only listens at certain times and can
take a few _DAYS_ to sync up. That seems strange to me...oh well.

Ivan's passive loop is a VERY good idea - easy.

I don't think cinder block walls will matter.

Search for "lowfer". I wanted to actually hear WWVB and do a little SWLing
for NDBs (300-500KHz) w/ my new IC 706 and did some snooping. A good loop
takes a little bit of work.
--
Steve N, K,9;d, c. i My email has no u's.


"Chris Campbell" wrote in message
m...
I'm trying to get a radio clock to sync up with WWVB (60 kHz out of
Colorado). In the place that I want to place the clock, I can not get
it to sync, even at night when the signal is stronger.

Inside the clock is a small ferrite-core loopstick antenna. I figured
out which way the gain pattern pointed on the thing (i.e. not along
the axis of the ferrite rod) and tried positioning the clock for
maximum signal, but no luck.

So now I'd like to try a better antenna. I won't have the time to
make one myself, and I'd probably do it badly anyway. It seems that I
should be able to buy an antenna for this fairly cheaply (thank you to
my capitalist exploiter overlords!), but I can't find one. Ideally,
one designed for WWVB's 60 kHz would be great, but I'll settle for
anything really, as long as it claims to have some decent gain at 60
kHz.

This clock is going inside a building, inside two layers of cinder
block / concrete walls, so it's possible that I just won't be able to
get a signal in there no matter what I use. The
external-antenna-and-a-wire-run concept is the next step, but I'd
rather not to that unless I have to. We're moving out of that
facility in a few months so that would be wasted labor.

What are some sources for loopstick antennas?

On another note, in searching this forum, someone said:

An LF loopstick antenna wound on a 1/2 inch diameter rod is *much*
less efficient than a 1-meter square air loop

Assuming I have the space, am I better off trying this with a few big
loops of wire instead of a small ferrite loopstick? What are the
rules of thumb for comparing the two types of loop antennas?

Thanks!