Re: [time-nuts] Raspberry Pi NTP server

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

Re: [time-nuts] HP 5316B External Reference

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

Re: [time-nuts] HP 5316B External Reference

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

Re: [time-nuts] FTS 4065A schematics?

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

Re: [time-nuts] PDIP package 100 MHz decade dividers

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

Re: [time-nuts] HP 5316B External Reference

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

Re: [time-nuts] Raspberry Pi NTP server

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

Re: [time-nuts] HP 5316B External Reference

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?

Re: [time-nuts] HP 5316B External Reference

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] FTS 4065A schematics?

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

[time-nuts] HP 5316B External Reference

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

Re: [time-nuts] PDIP package 100 MHz decade dividers

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

Re: [time-nuts] PDIP package 100 MHz decade dividers

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

Re: [time-nuts] Raspberry Pi NTP server

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).