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

Tom Van Baak tvb at LeapSecond.com
Sat Nov 11 05:42:51 EST 2017

> Rank your preferences!

I echo Magnus. In almost every photo of national timing labs you will see SR620's in use. The interface, specs, readability, and reliability are really good. Also SRS seems to support their products forever. For the curious, the full BOM and schematics are in the service manual. Note they just added the FS740 (GPSDO) but there's no update for the 620 after all these years. The downside is that they are larger, heavier, and louder than many modern instruments.

For high-performance and high-throughput the CNT-91 is my choice. Quiet, feather-light, and it's a continuous dual-edge timestamping counter with raw data output capability.

That said, when I need a quick or long-term measurement I almost always grab a HP 53132A and run it in talk-only mode, collecting data with RS232->USB. Once you get used to the 5 key (arrows & enter) UI you're all set.

About the 53230 -- When it came out I got a pair on loan from Agilent; one with and one without OCXO. When I saw how badly they handled the external REF-in and how noisy the REF-out was, I figured it was a green team that designed it and I'd give them another product life cycle to learn about precision timing. So there are no 53230A in my lab. As soon as they come out with a redesigned B version where the ext/int REF are good to 1 ps (like you'd expect with a 12 digit/s counter), I will be the first to buy one.


----- Original Message ----- 
From: "Magnus Danielson" <magnus at rubidium.dyndns.org>
To: <time-nuts at febo.com>
Cc: <magnus at rubidium.se>
Sent: Friday, November 10, 2017 11:50 AM
Subject: Re: [time-nuts] Favorite counters (current production)?


I would say CNT-99/91 and SR-620.

Bob has a point about 53230, since the others is older, but on the other 
hand, it is a bit of a gamble. There are many aspects that goes into the 
longlivety of a product, such as access to components, but also strategy 
of companies.

The CNT-90/91 an 53230 both have graphical presentation, which is very 
beneficial. The SR-620 still have better performance even being older 
than everything else.


On 11/10/2017 05:37 PM, Bob Camp wrote:
> Hi
> There is no perfect answer. I’d go with the 53230 simply because it *might* be supported
> the longest.
> Bob
>> On Nov 10, 2017, at 11:17 AM, Scott Newell <newell+timenuts at n5tnl.com> wrote:
>> What current production freq counters do people like for general time-nuttery these days? There's a chance I can get a decent counter for work, so I'm looking for suggestions. Bonus points for fanless. Don't need anything past 200 MHz or so. Prefer ethernet over USB or GPIB.
>> The SR620 looks to be pretty big and a little dated. The 53230A seems to have better specs and screen than the Tek/Fluke FCA3k series. Am I missing any?
>> Rank your preferences!
>> -- 
>> newell  N5TNL

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