[time-nuts] HP53132A vs SR625

SAIDJACK at aol.com SAIDJACK at aol.com
Thu Feb 7 20:17:28 EST 2013

rent one of each if you can before you make your choice. I have both, and  
the HP unit is much easier to use once you know which button sequence to 
push to  get more than just "Frequency/Time-Interval" type measurements - these 
can be  single-button events on the HP unit.
Even offsetting and normalizing frequencies becomes very easy after a  
couple of days of using the unit, there is no setting that takes me longer than  
about 5 seconds to set up, so while not perfect, the user interface can be  
learned easily. I find the SR620 to have too many buttons(!) I always find  
myself searching for just that one button. Anyways, more buttons are just 
more  things that can fail. If you are a pilot, and have used a Garmin 430W  
GPS in your life, then the HP user interface is no challenge whatsoever and  
seems very easy to use..
The SR-620 has it's advantages, especially when you just do one single type 
 of measurement, but for me it has a huge number of disadvantages, and I 
mostly  use the 53132A for that reason:
1) I paid quite a bit of money and I had it "calibrated" and fixed by SRS,  
and it still exhibits a significant frequency offset with a "perfect" 
reference  and "perfect" DUT!!!
SRS says a small frequency error is "normal", well that prevents me from  
using the unit as a frequency counter, for me it's only useful as a relative  
display frequency counter. HP doesn't have such a frequency error, so no  
worries there.
2) The SRS unit is soooo loud that it's totally annoying and unacceptable  
for long measurements. Many folks reported this here before. It's just bad.  
Whining like crazy.
3) The SRS unit is 19" wide, huge, heavy, and clunky. I need my  counter 
portable, only the HP unit will do
4) The SRS unit has a much lower MTBF because of all the parts inside, and  
it needs finicky adjustments, see item 1) above. The HP unit either works, 
or is  just dead. Not much to adjust. Different technology generation. And 
the coolness  factor: a nice florescent tube display is so much more modern 
looking than those  clunky old 7-segment LED's..
5) The SRS unit is usually $1000 more than the HP unit, and you don't know  
how good the unit is you are buying because of all of the calibration 
stuff.  Usually there is no hit-or-miss issue with the HP units, they either 
work, or  are dead.
That said, the HP unit doesn't measure well at 10MHz, so I mostly use a  
divide-by-two to get one more digit of resolution out of it, and it's time  
interval resolution is not as good as the SR620. But for time interval  
measurements I use a Wavecrest DTS unit that blows the SR620 and the HP out  of 
the water anyways..
In a message dated 2/7/2013 16:39:04 Pacific Standard Time, ba6it at 163.com  

Hello  Dear Group:

I am very glad to see so many replies in  the morning, and I am very 
grateful to every time nuts gave me useful  information, your proposal has 
strengthened my determination, in fact, I am  also very like SR625, So I will to 
find and buy a good shape SR625 for my new  time interval measure instrument.

Thanks again for everyone's  advice, which is very useful to make a choice 
for me. Sorry for not reply  everyone's mail. 

Best Regards!

Hui  Zhang

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