The following is an email message sent out to the PSN-L mailing list 
regarding WWVB receivers. Last updated 8/23/98

-Larry Cochrane

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Date: 1/13/98
From: Charles R. Patton, Editor, Geo-Monitor

The Temic  clock part is really a series of three parts of which seem 
to be the same with only a difference of number of pins in the packaged 
part.  Of interest is that the app note shows two ways to use them with 
one 60 KHz crystal or two crystals for the IF. In none of the  radio 
clocks I've seen, have they used the two crystal version--only one.  
Cost, no doubt, but there is a significant improvement in performance 
with two. As I've mentioned before, the Oregon Scientific "Time Machine" 
and the Klockit analog movement unit all use the same RF decoder it 
would appear.  However, just before I found out about the Temic chip, I 
had depotted a Klockit board, and the chip nomenclature doesn't look like
it fits the Temic brand.  I know Integrated Display Co in Hong Kong 
builds the Oregon Scientific line, and is big enough to have a custom 
design done, and since Radio Shack imports a bunch, they may be using 
the same chip.  Be that as it may, Of the units I have examined, the Oregon 
Scientific and the Klockit and information on one other brand from another 
experimenter I've talked to, they all have the 4 wire scheme just as Larry 
describes for the Radio Shack unit  -- power, ground, signal out, and 
inhibit.  So if you want to start with something cheaper, get the Klockit 
unit, it's only $30 and has the same capability--you just have to slice 
and dice the circuit board a bit to get those four connections -- but it 
really isn't too hard as the RF section is confined to one end of the board.  
Be careful about the load you place on the signal out line. The chip runs 
on only a few microamps, so basically can't drive anything. I would suggest 
the use of a CMOS buffer (inverter or such) between the data signal and your 
computer input.  I don't know the impedance of the line on Larry's board, 
but running from 5V will help the driving capability somewhat.

I've known about the Temic chips for some time and  I'm in the process of 
building up just boards to be interfaced to the computer.  I have 4 
samples of the Temic SMT chips in my possession that I got last month, 
and just got in the 60 KHz crystals last weekend (Digi-Key  SE3320-ND 
cylinder type watch crystals made by Epson for $1.35 each singles). Rather 
than use ferrite rod antennas, I'm going to use a small loop, which is more 
available and repeatable and should increase the sensitivity to boot because 
the effective antenna height of the various clocks is very small because they 
use such small antenna rods.

I'll let you know how it works out when I finish.

Charles R. Patton, Editor, Geo-Monitor
patton@iinet.com

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Date: 8/24/98
From: Larry Cochrane

I found this link on making a WWVB antenna and receiver.

http://www.lakeweb.com/dbLabs/wwvb.html

-Larry Cochrane