From: Steven Sommars
[]
Why bother with GPS/USB? Sometimes I use laptops. Few laptops today
directly support PPS/serial.
I just checked with Dell and found zero laptops with native RS232.
Thanks for posting your measurements, Steven.
If you can find a laptop with a
Thank you Paul.
On 7/11/2020 6:59 PM, paul swed wrote:
Wes many of the HP sig gens and counters use that method I might guess
starting in the 70s. They all lock very well to the external reference and
are as good as the external reference is.
One gotcha. It seems some people pull the oscillators
Thanks for your insights Rick.
The manual specifically states: "The HP 5316B does not actually use the
external input signal for a time base but locks-on to the signal with an
injection-lock-multiplier. The external signal must be 1,5, or 10 MHz"
My only experience with injection locking
Jim
I do not have a 4065. But a 4060 and it uses a +31V supply. Its derived
from the common 24V supply by a DC/DC up converter. The tantalum caps had
burst and eaten many traces and parts. No real way to repair that damage
though I seriously tried. When that all failed, I simply introduced a nice
3
Hi Perrier
https://www.y-ic.es/datasheet/3b/74F569SC.pdf will work
73
KJ6UHN
Alex
On 7/11/2020 3:00 PM, Perry Sandeen via time-nuts wrote:
Learned List,
On previous posts I was looking for a PDIP package 100 MHz decade divider.
Reading just the front of the data sheet I thought that the 74LS1
Wes many of the HP sig gens and counters use that method I might guess
starting in the 70s. They all lock very well to the external reference and
are as good as the external reference is.
One gotcha. It seems some people pull the oscillators to sell on auction
sites. So if its missing thats a bit o
On 7/11/20 1:30 PM, Steven Sommars wrote:
Using GPIO with an RPi is a good direction, of course. That wasn't my
question. Some data may help explain.
Configuration =
RPi4 (raspbian buster)
Uputronics RPi GPS board (includes PPS) connected to GPIO pins. This
is the time of day sour
On 7/11/2020 3:51 PM, Wes wrote:
As I understand it this counter has an external reference input that
isn't used directly as the time base but injection locks the internal
time base. Does anyone here know how well this works. Is using a GPSDO
as a reference a worthwhile accuracy improvement?
Hi
The “typical” HP counter for many decades has phase locked an internal
oscillator to
the external reference. I have not seen any designs that use injection locking.
Given the
somewhat crazy math associated with injection locking, this is not a big
surprise.
By modern standards the 5316 is
Time Nuts-
Another project - have an FTS 4065A cesium beam reference with what appears to
be a short in the -34V supply line. I have the 4065C Operators Guide, which has
partial schematics. However, the C version apparently has only a +34V main
supply, whereas the A version has both + and -34V.
As I understand it this counter has an external reference input that isn't used
directly as the time base but injection locks the internal time base. Does
anyone here know how well this works. Is using a GPSDO as a reference a
worthwhile accuracy improvement?
Wes Stewart N7WS
_
Hi
HC is the *slower* version of AC. If it makes it to 50 MHz, you are doing well
…..
Bob
> On Jul 11, 2020, at 6:00 PM, Perry Sandeen via time-nuts
> wrote:
>
> Learned List,
> On previous posts I was looking for a PDIP package 100 MHz decade divider.
> Reading just the front of the data s
The 74XX160/74XX162 is the decade divider that runs at maximum
clock rate for the chip. Meaning no external feedback is
necessary to make it work at divide by 5/10.
The 74XX161/74XX163 can only divide by powers of 2 at maximum
clock rate. You have to add feedback to divide by 5 and THAT
is what
Using GPIO with an RPi is a good direction, of course. That wasn't my
question. Some data may help explain.
Configuration =
RPi4 (raspbian buster)
Uputronics RPi GPS board (includes PPS) connected to GPIO pins. This
is the time of day source for the RPi4. (via GPSD+chrony).
Navis
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