Hi,
I fail to see what the benefit is of removing this unless a better temp
compensation scheme is used. It is not likely to interfer with the external
loop as it reduces the midterm noise that is systematic. It does add some
higher rate noise but that is quantization errors of the systematics
Because the 96K attachment needs moderator approval I am sending it again
without attachment. It is the one I posted before and shows clearly the
frequency jumps. So here is the rest of it.
Magnus
Sorry but I disagree with your statement. First and foremost we have to
accept that these devi
Hi Scott,
I reviewed the material at the N5TNL site and it leaves me wondering.
There are at least three different and separate temperature controlling
areas inside the FEI-5680. One of which has cannot be messed with due
to the fact that it is inherent in its design. That would be the
pos
Hi
Most of these lightweight Rb’s do the same thing. They watch the oven current
on one or the other section and try to guess the external temperature. Based on
that guess they do a simple temperature correction on the unit. The older
analog units feed a DC signal into the EFC. The newer digita
On Sat, Jun 28, 2014 at 4:32 AM, wb6bnq wrote:
> wicking surface. The final question is how much, if any, external oil
> cooling would be necessary. That would have to be experimentally
> determined. The mineral oil, by the way, has a higher flash point then the
> container and is electrically
On Fri, Jun 27, 2014 at 11:34 PM, DaveH wrote:
>
> I also searched for "Lightning" and found nothing about detecting nearby
> strikes, only about protection. Searched from around 1980 back through
> 1940.
>
There are a number of products on the market that make use of lightning
detection and ran
QST lightning radar. But what a mess you get with google and every
lightning and radar TV station in the US.
Oh well if your replacing TVs every few years whats a few more opamps?
Now how does a poor man build something for what started this whole thread?
Time for me to hop off this thread.
Regards
Thanks Bob for putting it in perspective, 0.05 C is very doable, looks like
it is also used in some OCXO's.
Bert Kehren
PS on a related subject I just pulled PROCEEDINGS OF THE ANNUAL SYMPOSIUM
ON FREQUENCY CONLTROL ATLANTIC CITY in the late 70's did attend a few
because of my involvement in
At 04:32 AM 6/28/2014, wb6bnq wrote:
monitoring process ? In other words have you traced out the
connections to see what is driving the pin you think is the temperature input ?
No. I've only traced back from the ADC input to the voltage divider.
The next big question is have you monitored t
I can only answer some of your questions. The tuning word is modified by
the temperature but if it came back to the same oven current it will again
have the same tuning word to the DDS.
Since we have not fount a temperature sensor they most likely use oven
current that Bob mentioned.
If you d
Will someone beside us use heat pipe. Would love to have an impendent
input. What does it take to get a test going. Scott has done a lot of work, how
about some one else step up to the plate. There are a lot of time nuts out
there with the 5680A,many for the first time will have a very good
Hidden on the backplane of the Nortel (trimble) units is a SCPI interface known
as the " Serial Interface to CDMA system"
It is RS485 standard but I usually tap into the TTL I/O of the transceiver chip.
This is the standard SCPI interface.
E
D
C
B
A
1
+24/-48Vdc
+24/-48Vdc
+24/-48Vdc
There is actually a lot of information on lightening observation. If you
have access to a university library. Some public libraries have on-line
databases you can search too. Google is not so good at this as most of
the papers are in journals where you need a subscription, or more likely a
libr
A PDF of the 1960 book can be found here:
http://www.sciencemadness.org/library/books/projects_for_the_amateur_scienti
st.pdf
Dave
> -Original Message-
> From: time-nuts-boun...@febo.com
> [mailto:time-nuts-boun...@febo.com] On Behalf Of Larry McDavid
> Sent: Friday, June 27, 2014 22:4
Hi guys,
This is my first posting. I think I’m a Time Nut, at least my friends tell me
I am. I’m trying to get my old Tracor 599J phase locking receiver working
again. It used to work great, but since 2012 has not worked, as you all are
probably aware. I discovered an article on the web tha
There's an interesting (and on topic) project in that book starting on page
335, discussing a home-made Magnetic Resonance Spectrometer. I wonder if any
time-nuts have constructed such a device, and what potential accuracy it would
have?
Bob - AE6RV
From: D
Hi,
I have spent several hours on the internet searching for an article
about frequency multiplication techniques
(doublers/triplers). I found it and read it about a month ago on my
mobile but I didn't save the article.
Now I want to read the article again but I'm not able to find it anymore.
I find that very puzzling. I was a subscriber to QST from some time in 1957
until into the 1960s. I didn't have a subscription to Scientific American
so I couldn't have confused them. I suppose the article has been lost or
somehow escaped being entered into the searchable database.
Regards.
Yes, that is precisely the device I built; I was in high school at the
time but had been a licensed ham for 5 years and built much of my own
equipment. My father had access to a machine shop and helped with the
soft iron pole pieces and a few other items but I built all the
electronics. And, i
John wrote:
I discovered an article on the web that uses an AD835 multiplier
chip to square the WWVB signal * * *. I built a five section
synchronous filter tuned to 60 KHz to get rid of interference and
its output feeds the 835 chip. This all works fine. * * * the
599J won't tune tha
I built the Van de Graaff generator / electron accelerator with a buddy for
a high-school science project. My Dad was a physicist so was able to borrow
a vacuum system and not have to make that part.
Lost to a guy who had done a ruby laser - this was back in 1966.
Dave
> -Original Message--
Mike,
A frequency offset is just a long term shift from nominal rate.
Wander is "slow" variations and jitter is "fast" variations of phase.
The separation between "slow" and "fast" is a bit arbitrary, but the 10
Hz division-line is handy as it describes different sources, where
wander is the i
Hello all:
Rencently I bought a second-hand HP8568B Spectrum Analyzer, it kind of
vintage but works well. Only problem is its time base lost accurate. When I use
it measured my HP Z3801A output (locked to GPS), the center frequency read is
9.12MHz, about 88Hz diffrence. So I decide to us
On 6/28/2014 6:48 PM, Hui Zhang wrote:
Hello all:
Rencently I bought a second-hand HP8568B Spectrum Analyzer, it kind of vintage but works well. Only problem is its time base lost accurate. When I use it measured my HP Z3801A output (locked to GPS), the center frequency read is 9.12MHz,
Hi Hui...
The first thought is that you are tied to the resolution of the span divided by
the number of displayed points -1. Try a narrower span. If you look at the
absolute accuracy spec that error may be within the '66's capability.
Also, I believe there is a marker counter function that will
Hi Tommy:
I used each span to do my test, they are also have frequency diffrence,
the 42Hz is result of 1kHz span. I also use marker counter function, sometime
I use 'peak serach' function, it will gave me a peak value, very helpful. I am
thinking about the reason you and Alex talked about
Are you using the normal marker or the frequency counter marker? The
counter marker should be accurate, while the frequency displayed for the
normal marker position will not be. You may be able to improve the normal
marker's accuracy in narrow spans if you run the shift-W self-calibration
routine
Hello Alex:
Thanks for you quickly reply, yes I use same source as EXT reference and
input signal, it also has 42Hz error. Do you mean even I use EXT reference the
intenal 10Mhz time base still need work? If so, I really need calibrate and
readjusted it (HP 10811).
Hui Zhang
At 201
Back on the topic of lightening,
a destructive side of lightening can occur with between-cloud strikes.
Beneath a cloud with a hefty charge on it there is a counter charge, a
reflection,
on the earths surface. This will have the same amount of charge but in inverse
polarity.
When the charge in th
Certainly the point of an external reference is to replace the internal
reference with one more accurate, so when external is selected the internal is
out of the picture. However it is my understanding that not all of the
oscillators in the signal path are locked to either reference in the '66.
namic...@gmail.com said:
> Fibre optic would seem to be the answer for protection.
Assuming I use fibers for the data, how do I safely get power to the other
end?
--
These are my opinions. I hate spam.
___
time-nuts mailing list -- time-nuts@fe
On 6/28/2014 6:48 PM, Hui Zhang wrote:
Hello all:
Rencently I bought a second-hand HP8568B Spectrum Analyzer, it kind of vintage but works well. Only problem is its time base lost accurate. When I use it measured my HP Z3801A output (locked to GPS), the center frequency read is 9.12MHz,
Use a local solar cell and battery power supply.
If it is self contained it should not attract lightning.
Cheers,
Neville Michie
On 29/06/2014, at 1:13 PM, Hal Murray wrote:
>
> namic...@gmail.com said:
>> Fibre optic would seem to be the answer for protection.
>
> Assuming I use fibers for t
Batteries or PV system. Depending on what you want to run on the remote end,
you might be able to find a used solar powered shed light and use the parts.
Something like this for $20:
http://www.harborfreight.com/solar-shed-light-95573.html
If you find a unit whose batteries are failing, you can
On Sat, Jun 28, 2014 at 6:55 PM, DaveH wrote:
> I built the Van de Graaff generator / electron accelerator with a buddy for
> a high-school science project. My Dad was a physicist so was able to
> borrow
> a vacuum system and not have to make that part.
>
> Lost to a guy who had done a ruby lase
On Sat, Jun 28, 2014 at 10:13 PM, Hal Murray
wrote:
>
> namic...@gmail.com said:
> > Fibre optic would seem to be the answer for protection.
>
> Assuming I use fibers for the data, how do I safely get power to the other
> end?
>
I recommend a kite, wet string, and a Leyden jar.
--
Brian Lloyd
In message <1411dfb1.542.146e54f3eac.coremail.ba...@163.com>, "Hui Zhang"
writes:
>Hello all:
>do I need a calibration after I used external 10Mhz stand?
At the very least you need to run the "blue key" + "W" calbration if you change
to
or from external reference, because that is entirely base
>> That sounds complicated and messy but may be easier than it appears. An
>> appropriate container would be:
>
>
> It does sound messy. I don't think I'm willing to dunk one of my units.
This reminds me of the old Cray-2 super computer. The entire machine
about a half dozen racks were flooded
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