From: Bob Camp li...@rtty.us
To: Discussion of precise time and frequency measurement
time-nuts@febo.com
Sent: Friday, September 27, 2013 1:11 PM
Subject: Re: [time-nuts] Shielding a DAC line - WWV
Hi
If you already know that the standard is within 50 ppb, then it only can
drift 50
From: Bob Stewart b...@evoria.net
To: Discussion of precise time and frequency measurement time-nuts@febo.com
Sent: Thursday, September 26, 2013 6:13 PM
Subject: Re: [time-nuts] Shielding a DAC line
Hi Bob,
I should have mentioned that I added a new 5MHz output, and the coax ran
From: Bob Stewart b...@evoria.net
To: Discussion of precise time and frequency measurement time-nuts@febo.com
Sent: Thursday, September 26, 2013 6:13 PM
Subject: Re: [time-nuts] Shielding a DAC line
Hi Bob,
I should have mentioned that I added
.
What do you think?
Bob
From: Bob Camp li...@rtty.us
To: Discussion of precise time and frequency measurement time-nuts@febo.com
Sent: Friday, September 27, 2013 4:30 AM
Subject: Re: [time-nuts] Shielding a DAC line - WWV
Hi
One hertz at 20 MHz is indeed 50
.
What do you think?
Bob
From: Bob Camp li...@rtty.us
To: Discussion of precise time and frequency measurement time-nuts@febo.com
Sent: Friday, September 27, 2013 4:30 AM
Subject: Re: [time-nuts] Shielding a DAC line - WWV
Hi
One hertz at 20 MHz is indeed 50
From: Bob Camp li...@rtty.us
To: Discussion of precise time and frequency measurement time-nuts@febo.com
Sent: Friday, September 27, 2013 4:30 AM
Subject: Re: [time-nuts] Shielding a DAC line - WWV
Hi
One hertz at 20 MHz is indeed 50 ppb. On a practical basis
.)
Bob
From: Bob Camp li...@rtty.us
To: Discussion of precise time and frequency measurement time-nuts@febo.com
Sent: Friday, September 27, 2013 1:11 PM
Subject: Re: [time-nuts] Shielding a DAC line - WWV
Hi
If you already know that the standard is within 50
of precise time and frequency measurement time-nuts@febo.com
Sent: Friday, September 27, 2013 1:11 PM
Subject: Re: [time-nuts] Shielding a DAC line - WWV
Hi
If you already know that the standard is within 50 ppb, then it only can
drift 50 nanoseconds per second. If you check it every
li...@rtty.us said:
Anything under 100 ppb relative to WWVB is probably closer than the
ionosphere will let you get under normal conditions. You can indeed get a
zero beat, but that's not always a guarantee that the carrier isn't moving
around at some odd rate. Far better to use WWVB. The LF
From: Bob Camp li...@rtty.us
To: Discussion of precise time and frequency measurement time-nuts@febo.com
Sent: Friday, September 27, 2013 1:35 PM
Subject: Re: [time-nuts] Shielding a DAC line - WWV
Hi
Anything under 100 ppb relative to WWVB is probably closer than
I made some minor hardware changes to my GPSDO today and I see that it's locked
to a new DAC voltage about 21mV higher. So, I was wondering about shielding
the short run to the OCXO. I have immediately available RG-174 and I'm putting
that in. But, should this be some sort of steel shelled
Hi
I suspect that you have a ground offset between the OCXO's ground return and
the DAC's ground reference. The signal *should* be DC, Shielding it won't hurt,
but it really should not help much. If anything is an issue a simple R/C
filter at the OCXO pin should nuke it better than coax will.
measurement time-nuts@febo.com
Sent: Thursday, September 26, 2013 7:54 PM
Subject: Re: [time-nuts] Shielding a DAC line
Hi
I suspect that you have a ground offset between the OCXO's ground return and
the DAC's ground reference. The signal *should* be DC, Shielding it won't
hurt, but it really should
, 2013 6:13 PM
Subject: Re: [time-nuts] Shielding a DAC line
Hi Bob,
I should have mentioned that I added a new 5MHz output, and the coax ran within
1/8 of the single DAC wire going to the OCXO. I don't think anything else
changed, but of course there could be some flake of something on the DAC
, September 26, 2013 8:24 PM
Subject: Re: [time-nuts] Shielding a DAC line
This is off topic but I'm unsure how to do it properly.
I am trying to 'discipline' a couple of sources. I zero beat with 20 MHz WWV
but can't tell the difference between fading and the beat, so I am stuck in
the vicinity of 1
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