[time-nuts] WWVB d-psk-r down conversion method
paulswedb at gmail.com
Tue Sep 23 11:54:04 EDT 2014
Wow. What 8 hours can do for responses.
Great comments and appreciated. A piece of the puzzle appears to have
gotten lost from the start of the process.
This down converter system. Only detects phase change. It is not intended
to be a phase locked oscillator system that replicates what the old radios
Its output flips a signal path to invert or not invert the incoming wwvb
signal that feeds the old radios.
There is no need for an instantaneous response in the flip circuit. .3-.5
seconds seems fine for the old radios. Want to see if I can get down to
Pretty sure from what I have seen so far there is no need to lock the LO
nor must it be some precise offset of 100 Hz or anything else.
In watching this on a scope with a stable local 100 Hz reference not locked
to anything. The phase changes were obvious and useful.
One of the comments in the thread was that you could use a good local
reference and adjust for the LO drift. I do believe thats the case. I am
pretty good at dividing in decades. ;-) But getting ahead of the other
criteria. Simple as possible.
OK time to fix the HP3335a that failed. Lost my LO for the moment.
On Tue, Sep 23, 2014 at 7:37 AM, Bob Camp <kb8tq at n1k.org> wrote:
> Actually stability isn’t the main problem with the progamables. The issue
> is usually phase noise ad spurs. Often they use odd multi modulo divides
> rather than a PLL. That gives them a low cost chip, but the output spectrum
> is pretty poor. Figuring out if you have a “bad one” or not is tough from
> many data sheets. It’s rare that cheap XO’s come with phase noise and spur
> On Sep 23, 2014, at 12:04 AM, Hal Murray <hmurray at megapathdsl.net> wrote:
> > paulswedb at gmail.com said:
> >> Did try lots of frequencies and divider math to come up with a simple LO
> >> scheme for 61 or 59 KHz. Messy.
> > There are companies that will make a crystal or oscillator at any
> > you want at a not silly price. Delivery is not overnight.
> > Beware: There are several companies selling instant delivery of
> > running at any frequency you want. They are using a programmable PLL so
> > won't get the stability you expect from a crystal.
> > --
> > These are my opinions. I hate spam.
> > _______________________________________________
> > time-nuts mailing list -- time-nuts at febo.com
> > To unsubscribe, go to
> > and follow the instructions there.
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to
> and follow the instructions there.
More information about the time-nuts