On 3/8/10 15:41 , bpnjensen wrote:
On Mar 8, 1:23 pm, wrote:
On Mar 7, 6:56 pm, Bob wrote:

My receiver is stable to less than a twentieth of a cycle over several months.
(Using WWV as a reference)

Operator Bob
Echo Charlie 42

What radio can do that? And what is the master oscillator consist of-
does it contain a cesium/rubidium stage?- Hide quoted text -

- Show quoted text -

I keep wondering how you'd measure such a thing. Leave it on for
several years to see if the oscillator drifts one hertz?

Not to be too precious, but that does not sound like the best use of
one's hobby dollar to me ;-)



I worked with one engineer who built a frequency standard using
WWV as a reference. He would hook that up to the air monitor and
compare our carrier to the reference when he did a proof.

With a fairly simple scope you could see the smallest differences
between the two frequencies. He plotted drift over a month at a
time. And could extrapolate out months at a time with surprising
precision.

He showed me how it would be a fairly simple implementation to
use the WWV derived reference signal to control the local
oscillator's stability outright.

When we went to AM stereo, we had a serious issue with platform
motion near the nulls of our 6 tower array. He synced to WWV to
reduce that locally, and did a presentation to the state
broadcasters association describing how platform motion could be
eliminated entirely by syncing to WWV as a standard across the
implementation.

It's not difficult to do. Requires little expense, and can be
applied to every receiver in one's stable.

It's possible for Bob's receivers to be as stable as WWV by
simply using WWV as a controlling reference.