I am trying to understand the problem with harmonics on the 10 MHz output.
If you use it to drive the external input of another instrument, it won't be a
problem, more likely it will probably help since the instrument will convert
that signal to a square wave more appropriate to driving digital
On 11/15/11 3:06 PM, Alan Melia wrote:
Another approach to filtering is a 10.7 MHz IF filter... they're common,
fairly wide band, but not too wide. Can't say much about the tempco.
Minicircuits BLP-10.7 or BLP-15 for instance
or BBP-10.7 (which is about 2 MHz wide)
__
Whilst Advantest offers a cut down version of this manual on their web site
this may well be the only high quality scan of the complete manual you'll
ever see, so enjoy:-)
I've scanned and resized the A5/A4 printed manual in high enough
resolution to enable it to be printed out as A4/A3, or
On Tue, Nov 15, 2011 at 4:25 PM, beale wrote:
> Sylvain Munaut wrote:
>> It's not generated from a DDS. It's from a xilinx PLD,
I think the DDS is implemented inside the PLD.
Sying "that is not a DDS, it's a PLD, is like saying "That is not an
amplifier, it is a transistor."
In the description
After a lifetime of collecting and hoarding I'm finally snowed under and
virtually unable to move, so I'm starting to have a long overdue major clear
out of surplus test gear and radio equipment.
Some is fully working and some definitely of "project" status and, if
nobody has any objections,
Sylvain Munaut wrote:
> It's not generated from a DDS. It's from a xilinx PLD, then through an L and
> then through a C to the RF connector.
> The signal at the L output is fairly sinusoidal (at least monotonic near the
> crossing), but after the cap, it's like that ...
While I'm waiting for my
I may be mistaken but that does not look like harmonic distortion to me.
the frequency "imposed" on the 10MHz sine-wave is around 140MHz, this sounds
like the VCO frequency in the Rb loop. The corner frequency of the filter
could be a long way away from 10MHz in that case with maybe minimal
> I would rather say DDS generated and poorly filtered
It's not generated from a DDS. It's from a xilinx PLD, then through a
L and then through a C to the RF connector. The signal at the L output
is fairly sinusoidal (at least monotonic near the crossing), but after
the cap, it's like that ...
Ch
I would rather say DDS generated and poorly filtered
--Mensaje original--
De: David VanHorn
Remitente: time-nuts-boun...@febo.com
Para: Discussion of precise time and frequency measurement
Responder a: Discussion of precise time and frequency measurement
Asunto: Re: [time-nuts] FE 5680A "ne
* This is at the RF connector : http://i.imgur.com/Bg3SK.png
That's just nasty and indescriptible.
Close in impedance discontinuity?
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Hi,
> If the problem is only harmonics (cleaning up a square wave), a simple LC
> low pass filter with a cutoff midway between the fundamental and second
> harmonic might be a better choice because it minimizes the tempco-related
> phase shift that either a high Q filter, or one with a cutoff near
Monumental! Really amazing...
On Tue, Nov 15, 2011 at 10:07 PM, Kit Scally wrote:
> Fellow Nutters,
>
> Unbelieveable as it seems, this isn't OT.
> Cast your eyes on this rare 14th century "digital" clock. Not a skerrick
> of Rb to be found.
> Answers on the back of a postcard to ...
>
> Kit
>
If the problem is only harmonics (cleaning up a square wave), a simple
LC low pass filter with a cutoff midway between the fundamental and
second harmonic might be a better choice because it minimizes the
tempco-related phase shift that either a high Q filter, or one with a
cutoff near the desi
Robert wrote:
One "off the shelf" or more likely out of the junk box option is to
use the filter components from a 10Mb/s ethernet card. They work
quite well but might introduce some temperature related phase shifts.
As others have pointed out here in the past, to minimize phase and
amplitud
I like his "NO timewaster" disclaimer. I've been yelling that at people
around the office :-)
On Tue, Nov 15, 2011 at 3:57 PM, Javier Herrero wrote:
> El 15/11/2011 20:09, Peter Gottlieb escribió:
>
>
>>Ebay seller "nichegeek" will take $35.00 shipped for these units. You
>>can't buy a
El 15/11/2011 20:09, Peter Gottlieb escribió:
Ebay seller "nichegeek" will take $35.00 shipped for these units. You
can't buy a good OXCO for that. These are the ones which are more
suited for digital purposes.
I could not resist to buy one from him last sunday... but at 37.99, n
Now that's a deal! I just snared one from his $37.99/Free Shipping
offer. Seven left under that one when I looked a minute ago.
Happy timing.
*** REPLY SEPARATOR ***
On 15-Nov-11 at 13:09 Peter Gottlieb wrote:
>Ebay seller "nichegeek" will take $35.00 shipped f
Ebay seller "nichegeek" will take $35.00 shipped for these units. You
can't buy a good OXCO for that. These are the ones which are more
suited for digital purposes.
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Hi,
One "off the shelf" or more likely out of the junk box option is to use the
filter components from a 10Mb/s ethernet card. They work quite well but might
introduce some temperature related phase shifts.
Robert G8RPI.
From: Sylvain Munaut <246...@gmail.com>
As noted by others, the internal Rb locked signals of some FEI units are not
especially nice sine waves.
One way to profitably use them is to operate an external DDS generator. The
phase noise of the source will afffect the result, but not the harmonics. I
have an FE-5680B which has an internal
Hi
By their nature, rubidium's run hot. Hot parts have shorter lives than they
would at a lower temperature. Figure on a 5 year life after you get them and
be happy when they last for 10 years. If really need to be *sure* you have a
standard that's good for 10 years, buy three and put two in stora
You can add a crystal filter using a common 10 MHz crystal in series
with a low noise, high impedance amplifier. Terminate the input side
with about 50 ohms, and set the Q of the filter with the load
impedance. Since you're only worried about harmonics, the Q can be
fairly low, making the exact
Hi all,
As noted somewhere on the list, the 10 MHz output of the newer version
units is less filtered than before.
The output at the internal RF connector is even worse (there is some
more filtering going on inside the DB9 itself).
I'm looking for ways to clean up that 10 MHz output, preferrably
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