MODIFYING THE ACCU-KEYER FOR CCW
                                               BY RALPH E.
TYRRELL
                                               
        The Accu-keyer may be modified as follows for CCW. My
Accu-keyer has memory and you should load the memory in CW
position or you may end up with short dashes.        NEWS ABOUT
THE PETIT FILTER          Ray Petit reports that printed circuit
boards for the Petit filter are now out of stock. He is not
planning to order more from the manufacturer at this time. He and
Woody discussed possible revisions and it appears that a revised
and corrected version will be prepared. One idea under
consideration is to make the filter output frequency independent
of the pulse period and using a 555 to control the output
frequency, thereby allowing the user to set the output frequency
at any frequency he wishes. Anyone who has suggestions, please
pass them on to Woody or Ray.  5-6 MHz SYNTHESIZER          Ray
Petit has indicated that he will make PC boards for the 5-6 MHz
synthesizer with 100 Hz steps (CCWN 76:65) available if there is
a reasonable demand for them. Those of you who are interested,
please drop Ray a note.  COMMENTS ON USING WWVB                   
                             BY DON GROSS, W3QVC                  
                                       Narrower bandwidths or VHF
use of CCW are possible if we can use more accurate frequency
standards. Standards with precision to one part in 10-8 are now
available either as surplus units (at about $50), or for the
patient homebrewer. (See pp. 118-126 of the Summer, 1975 VHF
Communications.)          The problem is that WWV is not stable
enough at long distances to set such a standard to better than
one part in 10-7. One way of solving that problem is to use the
60 kHz signal of WWVB. It can be used to develop a precise time
interval for a digital frequency counter that can then count the
output of the standard we wish to set. (See, for instance, pp.
28-34 of the March, 1976 Ham Radio) have developed a WWVB
receiver that will count, under normal conditions, a 10 MHz
output derived from my secondary standard, to two parts in 10-7.
This is with 100 seconds counting intervals. I use a filter with
a 0.1 Hz bandwidth, which really improves the signal to noise
ratio at a distance of 1300 miles' I hope to describe this
receiver in an article in a ham radio journal.