Hi,
On that note we have Rick Karlquists article showing how he replaced the
traditional syntheis chain with an oscillator at the target frequency,
locked to the lower frequency. Benefit is in the phase-noise.
This was from the fine work on the 5071A.
This approach can be used for rubidiums
Typically External Cavity diode lasers use either the Littrow or the
Littman-Metcalf configurations.
A typical Littrow configuration is:
http://www.moglabs.com/uploads/2/4/2/1/24212474/manual_ecd_rev4.20.pdf
Alternatively a cat eye external cavity can be used:
discharge tubes
> On Apr 12, 2017, at 2:18 PM, jimlux <jim...@earthlink.net> wrote:
>
>> On 4/12/17 10:28 AM, Dave B via time-nuts wrote:
>>> On 12/04/17 17:00, jimlux wrote:
>>>
>>> Subject: Re: [time-nuts] Re. DIY atomic "resonator&q
Hi
There are papers from the mid 90’s talking about improving the GPS Rb’s. Those
parts are
as far as I know the best “production” Rb’s out there. The main comment seems
to be that
phase noise (in it’s various forms) is a major contributor to the stability of
the Rb’s….
Bob
> On Apr 12,
Many decades ago, QST had an article about the
"Monode" RF noise generator. No it wasn't an
April Fools joke; the Monode is simply a light
bulb. You can probably download the article
from the arrl.org web site.
HP used to sell a fluorescent tube embedded in
a waveguide as a noise source.
Hi
*All* incandescent lamps emit RF ….. They are a resistive device that is heated
to well above
room temperature. People do use them in simple noise figure meters. The
inductance of the
filament in a typical bulb restricts the bandwidth a bit. The are designs from
at least the 1960’s
Looking back at the dialog I started on Rb’s and the repeated returns to
that subject allow me to make some comments, observations and
recommendations.. I stayed on purpose away from participating but learned a
lot. It also
resulted in some off list dialogs with members working on the
On Wed, Apr 12, 2017 at 11:18:00AM -0700, jimlux wrote:
> Yep. There's been a fair amount of work over the past decades on using
> modulated reflectors for measuring antenna patterns (e.g. on phased
> arrays). You can have a diode/dipole suspended by resistive leads (with
> an impedance of
Some incandescent lamps can emit RF.
http://www.rexophone.com/?p=1081
http://www.radiomuseum.org/forum/rustika_lightbulb_fm_measurements.html
On Tue, 11 Apr 2017 18:09:52 +, you wrote:
>Apparently fluorescent tubes continuously emit a lot of other microwave
>signals. I once built a
On 4/12/17 10:28 AM, Dave B via time-nuts wrote:
On 12/04/17 17:00, jimlux wrote:
Subject: Re: [time-nuts] Re. DIY atomic "resonator"
Message-ID: <b3926cda-b4ff-2508-1be6-57c2fecf0...@earthlink.net>
Content-Type: text/plain; charset=utf-8; format=flowed
On 4/11/17 11:09 AM,
On 12/04/17 17:00, "Tom Van Baak" wrote:
> It turns out that OP (Andre) would like the readings of his vintage Black
> Star (UK) Nova 2400[X] 8-digit 2.4 GHz bench frequency counter to be accurate
> and stable to the 8th digit. That's all. The internal XO or TCXO is not good
> enough for that
On 12/04/17 17:00, jimlux wrote:
> Subject: Re: [time-nuts] Re. DIY atomic "resonator"
> Message-ID: <b3926cda-b4ff-2508-1be6-57c2fecf0...@earthlink.net>
> Content-Type: text/plain; charset=utf-8; format=flowed
>
> On 4/11/17 11:09 AM, Mark Sims wrote:
>> Appa
or to build his own
> atomic clock from scratch. It's just an 8 digit counter.
>
> /tvb
>
> - Original Message -
> From: "Andre" <an...@lanoe.net>
> To: <time-nuts@febo.com>
> Sent: Tuesday, April 11, 2017 12:31 AM
> Subject: [time-nuts] Re. DIY
I investigated police radar stuff a long time ago, and for a while had
an old X band unit shaped just like a searchlight, with analog meter.
What I learned then was that even on the newer units, the tuning fork
was specified to provide an independent means to verify the accuracy of
the unit in
But it is as Richard said and after he sent it I remembered reading about
it in the "Quantum beat".
The trick is to get that accurate frequencies sideband to land on the RB or
CS frequency. Just 1 sideband. So using a large step synthesizer and then
another to get the finer detail is a reasonable
On 4/11/17 11:09 AM, Mark Sims wrote:
Apparently fluorescent tubes continuously emit a lot of other microwave signals. I once
built a homodyne doppler "speed" radar kit (used a coffee can for the
antenna). The way you calibrated it was to point it at a florescent tube and and adjust
the
clock from scratch. It's just an 8 digit counter.
/tvb
- Original Message -
From: "Andre" <an...@lanoe.net>
To: <time-nuts@febo.com>
Sent: Tuesday, April 11, 2017 12:31 AM
Subject: [time-nuts] Re. DIY atomic "resonator"
> Hi all.
>
> As a first st
Apparently fluorescent tubes continuously emit a lot of other microwave
signals. I once built a homodyne doppler "speed" radar kit (used a coffee can
for the antenna). The way you calibrated it was to point it at a florescent
tube and and adjust the reading to a specific value.
Hi
If you make the cells in the basement (or even in most factories) the ability
to have a wide range
synthesizer will come in handy. The whole “6.834xxx GHz” thing is dependent on
a number of variables.
It is not at all uncommon to produce cells that come out 10’s or 100’s of KHz
off of the
You always want two frequency sources. One generates a carrier
frequency offset many MHz from 6.834 GHz and the other frequency
source modulates the carrier with a sideband that is at the
exact ~6.834 GHz frequency that finds the atomic line. The
sideband is in turn modulated with audio to find
When I read about the frequency generation in the Rb or CS there are
normally many numbers associated with the actual frequency. Down to at
least the 1 Hz level. Many of these PLLs are intended for multi-KHz steps.
I speculate you might need 2 PLLs one thats very fine in I hz increments
that gets
On 4/11/17 9:22 AM, Magnus Danielson and Rick Karlquist wrote:
This is in the category of projects where if you were qualified
to do it, your time is far too valuable to do it for the amount
of money you would save.
This is the type of project you do not to save any money, but to spend
and
the are 6GHc synthesizer chips from ADI available see here
http://www.analog.com/en/analog-dialogue/articles/design-a-direct-6-ghz-local-oscillator.html
73
KJ6UHN
Alex
On 4/11/2017 8:29 AM, Attila Kinali wrote:
On Tue, 11 Apr 2017 07:31:01 +
Andre wrote:
Has anyone
YES SDRs [step Recovery Diodes] is hard to find today, but there many--
PIN -- diodes, which exhibits that effect, even some standard rectifier
diodes could be used for, despite of that Magnus is right, today are
better solutions available e.g. PLLs with 10GHz prescalers
73
KJ6UHN
Alex
On
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] Re. DIY atomic "resonator"
Hi
If you are going to do a Rb, probably the best place to start is with a
salvaged physics package out of one of the telecom Rb’s. That would let you get
the “easy bits” worked out on
Hi
If you are going to do a Rb, probably the best place to start is with a
salvaged physics
package out of one of the telecom Rb’s. That would let you get the “easy bits”
worked
out on your side of the design. It would also let you lear how to address a
few of the
more complex items sorted
On 04/11/2017 05:54 PM, Richard (Rick) Karlquist wrote:
On 4/11/2017 12:31 AM, Andre wrote:
Has anyone else either built an atomic clock around a bare Rb lamp
module "core" or attempted
Not a DIY project, but I was the RF designer on the HP 10816 rubidium
standard, which never made it
On Tue, 11 Apr 2017 07:31:01 +
Andre wrote:
> Has anyone else either built an atomic clock around a bare Rb lamp module
> "core" or attempted
>
> to make a hydrogen maser?
Building my own Rb vapor cell standard or H-maser is on my list
of Things-I-have-to-do-before-I-die
On 4/11/2017 12:31 AM, Andre wrote:
Has anyone else either built an atomic clock around a bare Rb lamp module
"core" or attempted
Not a DIY project, but I was the RF designer on the HP 10816 rubidium
standard, which never made it to product introduction (a half dozen
working pilot run
Andre
Now I know your location. So your questions make more sense to me.
With respect to home brewing atomic standards. There have been numerous
threads on time-nuts around this.
The fact is technology has obsoleted so many technologies that things like
Rb references can be had far cheaper used
Hi all.
As a first step, I wanted to build a specific hydrogen line (1.420 GHz) preamp.
Seems that some fluorescent tube starters do emit a very brief burst at around
1.4 GHz
during a specific portion of the initial switch-on surge when cold and actually
observed this here.
Also relevant,
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