[time-nuts] Favorite counters (current production)?

Tom Knox actast at hotmail.com
Sat Nov 11 13:39:15 EST 2017

The FS740 is interesting. Obviously it has a lot going for it, but what appears to be missing is graphic data display capabilities which would simply be a few line of code. Perhaps I missed something skimming through the manual.

And it appears to be a simple L1 receiver, I myself am looking forward to an instrument with these great user features backed up in an instrument using L1/L2 as well as the other GNSS constellations with carrier phase as well is simply looking at the L1 timing signal. What I also find interesting is the rubidium has the same phase noise spec as their physically impressive stand alone quartz The phase noise is very good compared to LPRO and X72 on the FS725's I have measured  with the 5MHz phase noise meeting their specs but the 10MHz seems consistently about 10dB optimistic.

All and All a real nice instrument that may soon find a place in my lab. Tramsmille has also come out recently with a similar concept but I have not seen any details.


Thomas Knox

From: time-nuts <time-nuts-bounces at febo.com> on behalf of Magnus Danielson <magnus at rubidium.dyndns.org>
Sent: Saturday, November 11, 2017 8:57 AM
To: time-nuts at febo.com
Cc: magnus at rubidium.se
Subject: Re: [time-nuts] Favorite counters (current production)?


On 11/11/2017 01:44 PM, Tom Van Baak wrote:
>> A trouble with some of these modern counters is that sometimes their
>> processing isn't as transparent as it used to be. The trouble with that
> I agree 100%. They get "too clever" for their own good and the internal design is not released. This is one reason why the TAPR TICC is so welcome. Totally open h/w and s/w. Ok, it doesn't quite compete with 20 ps full-featured high-end counters, but it's also 10x cheaper.

This is a common problem to the researchers and the time-nuts.
We can hope that the vendors reading this take notice about these needs.

> That said, I want to point out that the latest GPSDO / counter from Stanford Research continues their tradition of relatively open design. If you have an hour, go through the very detailed user manual, which includes theory of operation and BOM and schematics, just like the old days:
> http://www.thinksrs.com/downloads/PDFs/Manuals/FS740m.pdf
FS740 GPS Time and Frequency System<http://www.thinksrs.com/downloads/PDFs/Manuals/FS740m.pdf>
Stanford Research Systems FS740 GPS Time and Frequency System Certification Stanford Research Systems certifies that this product met its published specifications at ...

> http://www.thinksrs.com/downloads/PDFs/Catalog/FS740c.pdf
Frequency Standards - Stanford Research Systems<http://www.thinksrs.com/downloads/PDFs/Catalog/FS740c.pdf>
Stanford Research Systems phone (40)744-9040 www.thinSRS.com Frequency Standards FS740 — GPS Time and Frequency System

> It's rather understated: they call it a "GPS time and frequency system" but it does frequency synthesis and pulse generation, frequency counting and time tagging, stats including ADEV, etc. You can see how they combined pieces of several other products all into this one modern instrument. Perhaps there's no need for them to ever refresh the SR620 now that the FS740 exists.

Many thanks for this one, I did not know about this one, but look very

>> That said, I hope Keysight can straight it out. I'm not out to bash
>> them, but I'm not as excited about their products as I was back in the
>> HP and early Agilent days.
> Right. That's also why I mentioned that if someday there's a Keysight B version of the 53230 I'm all in. Surely someone at Keysight is looking into this. They just need someone with a time nut mentality to clear up all the loose ends. Meanwhile the FS740 is on my Christmas list.

Exactly my view. That we comment on it here, is since we learn and need
to track it. Hopefully they learn from this.

Vendors have become better at interacting again.

In the meanwhile, I hope Santa has a nice FS740 for me under the
christmas tree. Need to be nice now for a the rest of the year.

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