WWVB decoder circuit
 

In article , (Scott Dorsey)
writes:

If you build your own, make sure you use nixie tubes. That's important.

And in the true Ham tradition, be sure to scrounge them from a defunct HRO-600
:-)
Ripping off an old HP freq counter is second-best.

Real content: I used to listen to WWVB on a huge old Navy regen RX (RAL or the
like?) and could get it day or night on a Sloper antenna. Nothing I own now is
sensitive enough down there to pick it up. The signal is pretty weak and I am
really amazed at the little clocks that can get it. I bought one on sale from
Rat Shack and it doesn't lock on until late at night.

BTW, whatever you buy or build, be sure that it displays seconds. Seems a
waste to have a precision clock that doesn't show them. My Rat Shack clock
does not, but I know it's dead-on because the minutes digit flips just as WWV
(10 or 15 MHz) does its "beep."
-- Mike K.

Oscar loves trash, but hates Spam! Delete him to reply to me.

"Mike Knudsen" wrote in message
...
In article , (Scott Dorsey)
writes:
[...] I used to listen to WWVB on a huge old Navy regen RX (RAL or the
like?) and could get it day or night on a Sloper antenna. Nothing I own
now is
sensitive enough down there to pick it up. [...]

Be careful with this. I haev an ICOM 706 which I have been listening to
350kHz beacons and I suspect sensitivity is not an issue. The receive is
not selective enough to keep out much noise. Below about 200KHz I heae
locam AM broadcase stations. Some kind of IM or something. I want to build
some kind of a low / band pass filter to see if it makes a diff. The
specific antenna can also make a diff. I'm using a 40M dipole.
-- Regards,
Steve N, K,9;d, c. i My email has no u's.

On Tue, 9 Mar 2004 14:01:40 -0600, "Steve Nosko"
wrote:

Be careful with this. I haev an ICOM 706 which I have been listening to
350kHz beacons and I suspect sensitivity is not an issue. The receive is
not selective enough to keep out much noise.

Steve -

You suspect correctly. That is why the antenna preamp for the HP 117A
VLF Comparator incorporated a magnetorestrictive 60 kHz filter with a
half-power bandwidth of 30 Hz.

Dale H. Cook, Chief Engineer, WWWR Roanoke VA, WCQV Moneta VA, WKBA
WZZI Vinton VA, WKPA WLNI WZZU Lynchburg VA, WMNA/WMNA-FM Gretna VA
http://members.cox.net/dalehcook/starcity.shtml

In article , "Steve Nosko"
writes:

Be careful with this. I haev an ICOM 706 which I have been listening to
350kHz beacons and I suspect sensitivity is not an issue. The receive is
not selective enough to keep out much noise. Below about 200KHz I heae
locam AM broadcase stations. Some kind of IM or something. I want to build
some kind of a low / band pass filter to see if it makes a diff. The
specific antenna can also make a diff. I'm using a 40M dipole.

Pretty sure that the best antenna is a loop -- a big one with lots of turns,
and a fat cap to resonate it to 60 KC. Maybe not practical. Or use a big
ferrod loopstick and wind LOTS of turns on it.

And like you say, many RX suffer from intermod and images from the BC stations.
A low-pass filter would probably help a lot. A resonant loop would of course
eliminate all that stuff.

I haven't cracked my Rat Shack clock open, but I suspect there's some kind of
loop antenna inside. --Mike K.

Oscar loves trash, but hates Spam! Delete him to reply to me.