Hello Bruce,
I agree. The DAC reference is an LM7805CT regulator with 0.8mV/C (typ.)
temperature coefficient. Considering that typical Oscillators (MTI units for
example) have about +-20Hz deviation per 5V - this alone - excluding the
Opamps
tempco, would lead to a temperature drift
Hello Bruce, Hello Said
despite the fact that the author is a ham radio colleage of mine I agree
completly to what both of you said.
Obviously, the longer you integrate the 1PPS GPS signal for,
the better the accuracy will be. But the drawback of this
is that the longer the integration time
Colin,
if you need the maintainence manual as well, send me your email address.
bye
Ulrich Bangert
-Ursprüngliche Nachricht-
Von: [EMAIL PROTECTED]
[mailto:[EMAIL PROTECTED] Im Auftrag von David Forbes
Gesendet: Samstag, 21. Oktober 2006 06:57
An: Discussion of precise time and
Tks Bruce
I did wonder why on earth he didn't use a timing rx-and that raised
questions re the remainder of the design, but I've not had a chance to
read it through completely as yet. My initial impression was that too
many corners were being cut. Said's comment re the 7805 tempco was
another
Said et al,
Although everything said in this thread is accurate, I guess I find
myself a little reluctant to just trash the author and the project out
of hand. He is obviously a hobbyist without a lot of precision timing
theory in his back pocket (hey, I'll place myself in that category, I
learn
Well said, Randy.
It wasn't my intention when I asked for comments to trash anybody or
anything. In the somewhat 'rarefied atmosphere' of this forum I doubt
that any comments made were intended to be anything other than
objective.
I guess the ultimate question is whether or not the claimed
I think it'd be great to see Dr. Griffiths' list of issues in a letter to
QEX, sans a couple of the more, er, editorial comments. This would give
the author a chance to respond, and alert other builders of opportunities
for improvement.
Some of the concerns may not be major issues (e.g., it
John,
I agree. I think it was the, er comments that seemed a little much.
All EXCELLENT points, and as you say I am sure the author would
appreciate any helpful comments. I'm sure he would like to make his next
version even better.
That's what this forum is all about..
Randy
John Miles wrote:
I think it'd be great to see Dr. Griffiths' list of issues in a letter to
QEX, sans a couple of the more, er, editorial comments. This would give
the author a chance to respond, and alert other builders of opportunities
for improvement.
Some of the concerns may not be
In message [EMAIL PROTECTED],
Randy Warner writes:
Said et al,
Although everything said in this thread is accurate, I guess I find
myself a little reluctant to just trash the author and the project out
of hand. He is obviously a hobbyist without a lot of precision timing
theory in his back
John Miles [EMAIL PROTECTED] wrote:
Some of the concerns may not be major issues (e.g., it seems safe to say
that the FLL action will correct for drift caused by the 7805's tempco,
unless you plan to dump a can of R134a on it), but others are worth bringing
to the magazine's attention. If
[EMAIL PROTECTED] (Tim Shoppa) wrote:
Having seen some bad vibes unfold through the channels of the
letters column and other communications with editors, I think that
BY FAR the most useful thing to do would be to contribute an
improvement (preferably with schematic) rather than a lengthy
Tim Shoppa wrote:
John Miles [EMAIL PROTECTED] wrote:
Some of the concerns may not be major issues (e.g., it seems safe to say
that the FLL action will correct for drift caused by the 7805's tempco,
unless you plan to dump a can of R134a on it), but others are worth bringing
to the
thanks for volentering sounds like you know what it takes to make a good one
and set up the webpage..
tom w0kgw
- Original Message -
From: Dr Bruce Griffiths [EMAIL PROTECTED]
To: Discussion of precise time and frequency measurement
time-nuts@febo.com
Sent: Saturday,
OK, here is my problem. I do not think it is a unique problem, based on
recent mail :-)
I have read about the Allan Deviation and I understand the principle,
even though the nuances between the 3 basic Allan deviations escape me
at the moment, but I am sure it will come once I re-read the Help
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