2011 09:33:14
To: Discussion of precise time and frequency measurement
Reply-To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] FE-5680A Results so far
Artifacts from the TDS210, not from the Rb.
On Thu, Dec 29, 2011 at 8:14 AM, mike cook wrote:
>
I got twenty 10 MHz rocks from a guy in China a while ago.
It was just a few dollars for 21 pieces. The original purpose
was to build a 10 MHz TRF receiver.
I don't think any of my legacy signal generators are stable enough to
characterize these rocks, but the 5680a should do nicely with a bit
o
Just FYI, this current batch of FE-5680As has a different RF
architecture than the old ones - one of the most notable changes is
that although they still have a DDS in them it's not in the output
path anymore - the VCXO now runs at 60MHz, and this is divided down
(in a CPLD) to produce the 10MHz ou
Tried crystal lattice filters, their bw is usually too large (1 to 2khz)
I would use a simple pll, such as an exor gate driving a single gate vcxo with
<10hz bw. Most crystal oscillators would improve the noise from the dds.
So you could do this with four parts:
Nc7sz86 exor gate driven by the
On Thu, Dec 29, 2011 at 10:37 AM, Said Jackson wrote:
> Good enough as a portable frequency counter reference, as the offset can be
> compensated, and the output is fairly stable...
>
> These units could really use gps disciplining and a crystal post filter.
>
> Great stuff for $40, new they mus
I gave my 5680a several firm whacks with a backscratcher and it did not
seem to flinch.
On the other hand I've used taps with a jeweler's screwdriver to fine
tune my counter's timebase.
On 12/29/2011 10:37 AM, Said Jackson wrote:
Hello Mike,
We measured a couple of these 5680As on a tsc5125a
Hello Mike,
We measured a couple of these 5680As on a tsc5125a analyzer. With different
quality supplies.
Very noisy buggers, huge number of spurs and very high noise floor -130dBc or
so if I recall correctly. Thats probably the jitter you are seeing. Probably
due to the dds generating the out
On Wed, Dec 28, 2011 at 11:14 PM, mike cook wrote:
>
> 1) What is the expected 10MHz peak to peak voltage. FEI doc seems to
> indicate 0,5V but I am getting only 200mv.
> 2) What is the sensitivity to 15V input level. I am only measuring 14,722
> (stable) on Pin1.
> 3) Could this low input volta
Le 29/12/2011 09:28, Chris Albertson a écrit :
1) What is the expected 10MHz peak to peak voltage. FEI doc seems to
indicate 0,5V but I am getting only 200mv.
I'm getting a lot more, about 2V peak to peak. What are you loading it
with, I'm using a 10X scope probe. How are you measuring the
Artifacts from the TDS210, not from the Rb.
On Thu, Dec 29, 2011 at 8:14 AM, mike cook wrote:
> Hi,
> Just got my cheapo 5680A. It was accompanied by a little teddy bear
> clutching a L7805CV !
>
> Got a couple of questions.
>
> 1) What is the expected 10MHz peak to peak voltage. FEI doc seems
On Wed, Dec 28, 2011 at 11:14 PM, mike cook wrote:
> Hi,
> Just got my cheapo 5680A. It was accompanied by a little teddy bear
> clutching a L7805CV !
>
> Got a couple of questions.
>
> 1) What is the expected 10MHz peak to peak voltage. FEI doc seems to
> indicate 0,5V but I am getting only 20
Hi,
Just got my cheapo 5680A. It was accompanied by a little teddy bear
clutching a L7805CV !
Got a couple of questions.
1) What is the expected 10MHz peak to peak voltage. FEI doc seems to
indicate 0,5V but I am getting only 200mv.
2) What is the sensitivity to 15V input level. I am only m
that went by?
If so, that might be a beginning.
Joe
-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@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-nu
. (a
100ns cycle per sec = 1e-7 freq offset)
ws
****
*********
[time-nuts] FE-5680A Results so far
Chris Albertson albertson.chris at gmail.com
Wed Dec 28 18:21:54 UTC 2011
Just got my fe5680 yesterday. Seems to work but the fe5680 is the most
accurate reference I have. So how to t
Chuck Forsberg WA7KGX N2469R wrote:
I haven't checked it, but the FE5680A has 1pps on pin 6.
There is no documented way to sync the FE5680A 1pps to an external
reference.
You could set an extreme value in the freq offset and wait for the 1pps
to drift
into place.
On mine if you put in extre
> 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 assume you have a GPS with PPS.
Get one of TVB's picPETs. (or do it yourself) Clock it
ffset)
ws
*****
[time-nuts] FE-5680A Results so far
Chris Albertson albertson.chris at gmail.com
Wed Dec 28 18:21:54 UTC 2011
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
Thunderbol
I haven't checked it, but the FE5680A has 1pps on pin 6.
There is no documented way to sync the FE5680A 1pps to an external
reference.
You could set an extreme value in the freq offset and wait for the 1pps
to drift
into place.
Measurements of the delay between 1pps signals depend on the accu
Chris Albertson wrote:
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?
Going to have to get a Thunderbolt. I have an Oncore UT+ the provides
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
: [time-nuts] FE-5680A Results so far
I had the elevation and signal level masks set too tight
on the Tbolt. It ran out of birds and freaked out.
--
Chuck Forsberg WA7KGX N2469R c...@omen.com www.omen.com
Developer of Industrial ZMODEM(Tm) for Embedded Applications
Omen Technology Inc
I had the elevation and signal level masks set too tight
on the Tbolt. It ran out of birds and freaked out.
--
Chuck Forsberg WA7KGX N2469R c...@omen.com www.omen.com
Developer of Industrial ZMODEM(Tm) for Embedded Applications
Omen Technology Inc "The High Reliability Software"
102
I just got back from running an other test on my 5680 and for 24 days now
it has been reading consistently 9.944 MHz! I average over 1000
seconds because feeding two Tbolts into a Tracor 527E I do see up to +_2 E-11
changes off and on, and one runs all my instruments. I am waiting for
After a few days of fooling around it appears my $38.00 Rb frequency
standard
is meeting its specs except for the current draw on the 5 volt supply.
The attached plot shows phase readings between the Rb and a ThunderBolt made
by a Racal-Dana 1992 counter read out by Fedora Linux 16 and a Nationa
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