[time-nuts] FE-5680A Results so far

J. L. Trantham jltran at att.net
Wed Dec 28 20:17:02 EST 2011

Is it possible to feed the FE5680 to an external input reference of the
5328A (I presume it has one) then use the FE5680 as the source whose
frequency/intervals is to be read and then use the Oncore UT+ as both the
'Start' and 'Stop' to count the number of intervals (cycles) that went by?

If so, that might be a beginning.


-----Original Message-----
From: time-nuts-bounces at febo.com [mailto:time-nuts-bounces at febo.com] On
Behalf Of Chris Albertson
Sent: Wednesday, December 28, 2011 12:22 PM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] FE-5680A Results so far

Just got my fe5680 yesterday.   Seems to work but the fe5680 is the most
accurate reference I have.  So how to test it?   I plan to buy a
Thunderbolt but until then, anyone have any creative ideas?

I have an HP5328A with unknown calibration.  It reads 10,000,026 Hz
I have an FCC 1 kit I assembled a few years ago and it says 9,999,993 Hz.
(I can make the FCC1 read exactly 10MHz if I place it on top of the hot
FE5680, the FCC1 is very temperature sensitive.
My old Tek scope says the period is "about" 0.1 uS and the sine wave looks
pretty good.

BTW, 5 VDC is 76.5 mA with RS232 not connected.    15 VDC is 1.5 ~ 0.8 A.
 The unit does get warm.  A 3/16 x 5 x 16 inch aluminum plate worked is a
"good enough" heat sink.

Going to have to get a Thunderbolt.  I have an Oncore UT+ the provides a
good pulse per second but that will not help

Chris Albertson
Redondo Beach, California
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