[time-nuts] FE-5680A arrived

[J. L. Trantham]

Try setting your scope to a relatively slow speed, 50 mSec/cm or so, set it
to trigger on the appropriate channel, positive slope, turn off 'Auto'
trigger thus just getting a sweep only if triggered, then adjust the trigger
sensitivity to see if you see a sweep go across the screen once per second.
If so, turn the intensity up very high and move the sweep speed to 1 uSec/cm
and look very closely at the very first part of the trace, about 5 V above
the base line.  Should be a 1 uSec wide pulse across the screen only once
per second (thus the need to turn up the intensity of the display).

I used a 10X probe on pin 6 to measure this (10 Meg Input Impedance).

Hope this helps.

Joe

-----Original Message-----
From: time-nuts-bounces at febo.com [mailto:time-nuts-bounces at febo.com] On
Behalf Of Joseph Gray
Sent: Wednesday, January 11, 2012 12:11 AM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] FE-5680A arrived


I'm not seeing a PPS on either of these. All I see is about 17 mV P-P of
noise that looks like a multi-stepped sine wave. I'm using a TDS 340 scope.

Joe Gray
W5JG

On Tue, Jan 10, 2012 at 10:30 PM, J. L. Trantham <jltran at att.net> wrote:
> I confess!
>
> I, too, could not resist the opportunity to 'commune' with the members 
> of the list with these Rb units.
>
> I ordered two of the FE-5680A units ($36 ea. including shipping) from 
> the same supplier with amazing speed (order date 1/4, arrival date 1/9 
> to NW Florida).
>
> They were marked 'FE-5680A UN 70021' 'S/N 0405-72179' and 'FE-5680A UN 
> 71920' 'S/N 0413-75933'.
>
> I promptly came home, constructed a DB9 female connector, with the 
> connections as specified in recent postings, and both units were up 
> and locked with extremely close agreement with my TBolt and Z3816A in 
> under 5 minutes.  Pin 6 had a 1 uSec wide, 5 Volt, 1 PPS, pulse.  I 
> did not explore pins 8 or 9, the RS232 pins.  I guess I'll have to go 
> back through the list to see what, exactly, I can do with these.
>
> They, too, were packed with bubble wrap individually and then 
> together, and in a plain envelope that was placed in a UPS plastic 
> envelope.  However, they arrived without damage, and, amazingly, very 
> promptly.
>
> Not sure what, exactly, I will do with them yet, but they will 
> certainly have many possible roles.
>
> Joe
> WB4BPP
>
>
>
> -----Original Message-----
> From: time-nuts-bounces at febo.com [mailto:time-nuts-bounces at febo.com] 
> On Behalf Of Joseph Gray
> Sent: Tuesday, January 10, 2012 8:04 PM
> To: Discussion of precise time and frequency measurement
> Subject: [time-nuts] FE-5680A arrived
>
> With all the talk on the list about these things, and considering the 
> price, I could no longer resist temptation and ordered two from 
> nichegeek.
>
> First, I was amazed at the speed at which I received these units. The 
> order was placed last Friday, the shipment went out late Saturday and 
> I received them today (Tuesday). In my experience, it has always taken 
> two weeks or more to receive anything from China. I couldn't believe I 
> got these in just three days.
>
> BTW, I paid $38 each with the free shipping. An outstanding deal IMO. 
> I also received the semi-useless freebies.
>
> My only quibble so far is that both units were packed in nothing more 
> than a large envelope, with a thin layer of bubble wrap added. Nothing 
> is dented or rattling around, so hopefully they are OK. I'm just about 
> to wire up a cable and power them on, so I'll know soon.
>
> The units I got have numbers of UN 71xxx and UN 78xxx. I don't know 
> exactly what this means, but according to the ebay sellers, they are 
> claiming that 6xxxx and 7xxxx numbers indicate newer units. Can anyone 
> decipher this number sequence?
>
> Joe Gray
> W5JG
>
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to 
> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.
>
>
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to 
> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.
>

_______________________________________________
time-nuts mailing list -- time-nuts at febo.com
To unsubscribe, go to
https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.