The cheap probes probably lack the resistive inner conductor in their
interconnecting coaxial cables.
This results in a poorly damped transient response.
Bruce
Eric Garner wrote:
I too, fell for the siren song of cheap Chinese probes. 2 years after
I bought 4 of them, only one has not failed.
Chris Albertson wrote:
On Wed, Mar 16, 2011 at 11:00 PM, jimlux wrote:
Could you make the measurement in, say, 48 hours.. A portable setup might be
reasonable with a 10-20km baseline.
Before you can even think about building a long baseline radio
receiver the first goal is to be abl
I'm inclined to agree. (I'm not sure I'd want to use my Thunderbolt as the
reference oscillator for an instrument that had 20 ps of resolution, nor would
I trust the long term accuracy of an ocxo without being able to compare it to a
reference such as an gpsdo.)
Sent from my iPad
On 2011-0
The last answers actually the best considering the base system initial
investment. If you are in that league a TBolt is not much at all.
On Thu, Mar 17, 2011 at 10:30 PM, J. L. Trantham wrote:
> Personally, I would get both.
>
> Joe
>
> -Original Message-
> From: time-nuts-boun...@febo.c
My opinion is that first you need to tell more about how you
are going to use this counter. For work in the shop where
a distributed reference is always available then no need
to buy any extra option. Second idea is that if it is most
used in the shop but occasionally in the field then consider
wh
Personally, I would get both.
Joe
-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On
Behalf Of J. L. Trantham
Sent: Thursday, March 17, 2011 9:24 PM
To: 'Discussion of precise time and frequency measurement'
Subject: Re: [time-nuts] Equipment questi
On Thu, Mar 17, 2011 at 6:50 PM, Wolfgang wrote:
> .. What I'd really
> like to do is to make up my mind based on educated opinions on this list
> whether the built-in OXCO option offers any advantage at all compared
> to standard clock + good external reference.
Using a OXCO allows the instrume
Depends on what you want. Stability or accuracy? Bench or portable? The
TBolt or another GPSDO will certainly be accurate. Probably fairly stable
as well. However, if you need portability, the OCXO is the only way to go.
You will have to look at the stability measurements of the OCXO versus th
WELL,
All I saw was three responses one of which (I) suggested the opposite.
BillWB6BNQ
Wolfgang wrote:
> On Friday 18 March 2011, Greg Broburg wrote:
> > I have a 53131 and 53181. There were several TB options.
> > I dont have a manual for the 53230A. If you could, see what
> > the option
Unfortunately in the first round of the thread you did not say what you are
actually doing with the system and whats important to you. Sooo you get our
best guesses.
They are free after all. :-) But they are also reasonably educated.
On Thu, Mar 17, 2011 at 9:50 PM, Wolfgang wrote:
> On Friday 1
On Friday 18 March 2011, Greg Broburg wrote:
> I have a 53131 and 53181. There were several TB options.
> I dont have a manual for the 53230A. If you could, see what
> the option TB assembly PNs are, then go looking for these
> assemblies. Mine just dropped in and did the autocal right
> off. I pai
Hi Wolfgang,
I would go with the highest stability OCXO they offer. That would provide the
best portable functionality if you take it out of your work place. Nothing is
more aggravating then having to lug a ton of extra junk around if you have to
travel to a remote place to do work.
Even if you
I have a 53131 and 53181. There were several TB options.
I dont have a manual for the 53230A. If you could, see what
the option TB assembly PNs are, then go looking for these
assemblies. Mine just dropped in and did the autocal right
off. I paid 300 to upgrade the 53181. The autocal using a
DAC wo
Welcome to the group Wolfgang
My thinking would be go with the T bolt at a fraction of the cost of the
oven.
See if that takes care of your needs. If not add the oscillator later?
Regards
Paul.
On Thu, Mar 17, 2011 at 8:59 PM, Wolfgang wrote:
> Hi,
>
> I'm new on this list.
>
> Right now, I'm p
Hi,
I'm new on this list.
Right now, I'm planning to buy a brand new Agilent 53230A frequency
counter (350 MHz, 20 ps, 12 digits/s, 2500 EUR).
I'm wondering whether it is worth investing into a built-in OXCO timebase
option when ordering the 53230A since that adds 950 EUR.
The alternative
Hi
The classic approach is to start with something stable as an input. A TBolt is
one example of this. Ideally you would want good phase noise in the sub 10Hz
offset range from your base oscillator. Next you PLL up an OCXO in the 60 to
120 MHz range. The idea is to get good phase noise out to a
Bringing it back on topic, I use one of these oriental probes
(switchable x1 or x10) all the time on my bench counter which has a 1
Meg Ohm input as well as 50 Ohm.
And don't mention it on the Tek scopes list :^) but the Chinese hook
tips fit a lot of tek probes...
Dan
ac6ao
_
The truth probably lies somewhere in between.
Joe
-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On
Behalf Of beale
Sent: Thursday, March 17, 2011 1:42 PM
To: time-nuts@febo.com
Subject: [time-nuts] semi-OT: comparison of two 10x scope probes (cost
I resemble that remark.
Sad but true.
Joe
-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On
Behalf Of Pete Lancashire
Sent: Thursday, March 17, 2011 11:23 AM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] Thunder
Be great if we might down load it just to look
On Thu, Mar 17, 2011 at 4:40 PM, Richard W. Solomon wrote:
> I forgot to mention, I have a scan of the manual, it's around 7 MB. The
> manual
> came in pretty poor shape, hence the scan.
>
> 73, Dick, W1KSZ
>
>
> -Original Message-
> >From: J
Very good comments by everyone.
T Tbolts all done no muss or fuss maybe a power supply but its complete.
The M12+ is really if you want to roll your own as I just did recently. I
have a HP 3801, but there is nothing like actually building the software
filters and dac control etc to make your own. A
Hi
Manson started out in Connecticut and then was bought out by Halicrafters. A
number of people at Manson decided that they didn't want to make the move to
Chicago after the buy out. The pre-move and post move Manson stuff was done
very differently, since it was done by a completely different bun
Just for fun I plotted the UT1-UTC data from the IERS Bulletin A.
Here's the raw data:
UT1-UTC
s
-0.18115
-0.18232
-0.18353
-0.1847
-0.18576
-0.18674
-0.18763
-0.18842
-0.18912
-0.1897
-0.1903
-0.19103
-0.192
-0.19324
This is from March 4 to Match 17 inclusive.
I don't know if it's a fluke, but
I forgot to mention, I have a scan of the manual, it's around 7 MB. The manual
came in pretty poor shape, hence the scan.
73, Dick, W1KSZ
-Original Message-
>From: John Ackermann N8UR
>Sent: Mar 17, 2011 1:22 PM
>To: Discussion of precise time and frequency measurement
>Cc: David Olea
I picked up a Manson RD-146 a couple of years ago to play with. After getting
that
out of my system, it sits on the shelf awaiting a new home.
It's interesting that the manual says they are a subsidiary of Hallicrafters.
73, Dick, W1KSZ
-Original Message-
>From: David Olean K1WHS
>Sen
I too, fell for the siren song of cheap Chinese probes. 2 years after
I bought 4 of them, only one has not failed. However, my 1980's
vintage probes from Tek still work dandily.
On Thu, Mar 17, 2011 at 12:47 PM, beale wrote:
> Yes, I am controlling the OCXO frequency with a voltage input (cente
Dave, I haven't seen an actual Manson standard, but I do recall that one
was listed in an ancient Tucker catalog (from the early 80s). I'm just
now unpacking my library after our move, and should soon uncover that
catalog if I still have it. Let me know if you'd like me to scan the
Manson inf
In this case a (roughly) 375 MHz reference with say 5 ps rms jitter
would do just fine. The 375 MHz is not set in stone, but I'd like to
end up with something in that ballpark.
regards,
Fred
- Original Message
From: ew
To: time-nuts@febo.com
Sent: Thu, March 17, 2011 7:42:55 PM
Subjec
Yes, I am controlling the OCXO frequency with a voltage input (center tap of
10k trimpot from +5V to ground). I hooked up my custom 26 MHz PIC divider* and
was able to trim the OCXO to match the output of my GPS 1pps signal to better
than 1E-9 (at least for short periods of time).
These parts
I have a vintage HP 106B crystal oscillator. It has been sitting around for a
few years and I just recently found a schematic for it. It was enough so I
could dig in and check things out. The first thing I tried when I got it was to
run the unit on external power as the internal PS seemed to be
On Wed, Mar 16, 2011 at 11:00 PM, jimlux wrote:
> Could you make the measurement in, say, 48 hours.. A portable setup might be
> reasonable with a 10-20km baseline.
Before you can even think about building a long baseline radio
receiver the first goal is to be able to detect a quasar with just o
At 01:41 PM 3/17/2011, beale wrote:
output of a 26 MHz Pletronics OCXO in a 14DIP can (by the way these
go for $2 online, the cheapest OCXO I've seen). This was just a
quick casual comparison, not to be taken too seriously.
That's a great price for any OCXO. Do they have EFC? (I can't tell
It depends what your definition of low jitter is. There are low noise CRO's
coupled with a PLL that will do a credible job. You may also considder a
multiple of 375 if a good CRO is available and devide it down. Look for close
in phase noise. Plenty of good PLL's available since you will not hav
I am always loosing the little hook adaptor on the end of my scope probes so I
went looking for replacements. I noticed that I could buy a pair of complete
"100 MHz" probes including tip and ground clip online for $13 shipped from
Shenzen China. Didn't expect much, but this application was for
I like to know which !PPS is better because I use modified Shera units
contrlling Rbs. Tbolt does not do it.directly.
Bert Kehren
-Ursprüngliche Mitteilung-
Von: Chris Albertson
An: Discussion of precise time and frequency measurement
Verschickt: Do., 17. Mrz. 2011, 13:45
With regard to your mentioning of "a reference is not 10MHz" ...
Suppose one is after a good quality ~ 375 MHz reference with low
jitter and high frequency accuracy, what would be the best bang
for buck time-nut approved way be?
For now I would settle for a 370 MHz reference, which would be
obtai
On Thu, Mar 17, 2011 at 8:58 AM, Tijd Dingen wrote:
> Same here. A GPSDO like the thunderbolt is really nice from a system
> integration point of view. Buy an easy thingy kit on ebay, and you have
> your 10 MHz reference. However, cannot a lot be gained from using a
> more up-to-date design with n
Folks,
I have received the following announcement:
___
The MoD has informed Ofcom of the following GPS jamming exercise:
Dates: Jamming will be conducted on a maximum of 3 week-days in the period
10-21 July 2011.Times: 0900 -1730 BST.
Location:
A 'real' timenuts GPS setup would have a T'bolt, or HP etc. Then a
minimum of 3 or 4
other GPS receivers.
On Thu, Mar 17, 2011 at 8:58 AM, Tijd Dingen wrote:
> Same here. A GPSDO like the thunderbolt is really nice from a system
> integration point of view. Buy an easy thingy kit on ebay, and you
Same here. A GPSDO like the thunderbolt is really nice from a system
integration point of view. Buy an easy thingy kit on ebay, and you have
your 10 MHz reference. However, cannot a lot be gained from using a
more up-to-date design with newer gps engine?
On the one hand we have a thunderbolt whic
When I made a 1PPS GPS interface to a one pulse per minute impulse clock
movement, I used a 74LS90 divide by 10 followed by a 74LS92 in combination
with a 74LS20 as a divide by 6. I also used the circuit to drive two Nixie
tubes to provide a seconds display. More details if you are interested.
Not that I have ever seen.
But today there are a lot of easy ways to achieve this.
Traditional was a divide by 10 and 6. Typically two chips.
Today a few lines of code in basic or any other language you like into a 8
pin PIC.
4 total wires clk in pulse out and VCC and ground.
But if you want a pul
Hello,
I need to produce a pulse per minute, derived from 10 MHz or 1 pps.
So a divide by 60 if 1 pps is used.
Does anyone make such a divider? That would save me from designing my own.
Regards
Steve
___
time-nuts mailing list -- time-nuts@febo.co
I also would like to know the answer to that question if you use the 1 PPS
of the Tbolt versus the M12 or maybe a later model affordable GPS engine.
Bert Kehren
In a message dated 3/16/2011 11:18:23 P.M. Eastern Daylight Time,
albertson.ch...@gmail.com writes:
On Wed, Mar 16, 2011 at 8:
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