Dick,
I also ordered an LCD monitor from fluke.l (beneath an LPRO Rubidium).
For Lady Heather, do I have to add a switch between the monitor and the
PC, or does the monitor have an additional RS232 port to feed through
the PC communication automatically?
Frank
Hi Bob,
I have the correct DIL 74175 so I can untick that item.
Steve
On 07/08/2010, Bob Camp li...@rtty.us wrote:
Hi
As far as I know all the parts are correct except the 74175. It is the soic
version.
Bob
On Aug 6, 2010, at 7:16 PM, Steve Rooke sar10...@gmail.com wrote:
Bob,
For Lady Heather, do I have to add a switch between the monitor and the
PC, or does the monitor have an additional RS232 port to feed through
the PC communication automatically?
++
I just soldered the monitor lead to the transmit pin on the T-bolt's RS232
Hi
I strongly recommend checking your local inventory (dare I say junk box.) off a
lot of the parts. Stuff like bypass caps likely something you have.
Bob
On Aug 7, 2010, at 5:10 AM, Steve Rooke sar10...@gmail.com wrote:
Hi Bob,
I have the correct DIL 74175 so I can untick that item.
Hi Bob,
Oh, I'll be doing that, for sure, as I expect most if not all the
passives are in the junk-box. It's just finding them, my filing
system seems to be having a bit of a meltdown of late and I'm
frequently in the state of know I have something, somewhere, but I
can't for the life of me find
Hi Steve:
In the movie Zero Effect Daryl Zero says:
Now, a few words on looking for things. When you go looking for
something specific, your chances of finding it are very bad. Because of
all the things in the world, you're only looking for one of them. When
you go looking for anything at
Brooke Clarke posted this quote, which I really like:
Now, a few words on looking for things. When you go looking for
something specific, your chances of finding it are very bad. Because of
all the things in the world, you're only looking for one of them. When
you go looking for anything at
On 08/08/2010, Brooke Clarke bro...@pacific.net wrote:
Hi Steve:
In the movie Zero Effect Daryl Zero says:
Now, a few words on looking for things. When you go looking for
something specific, your chances of finding it are very bad. Because of
all the things in the world, you're only looking
What your saying is that it is a form of selective blindness where the
brain filters out an item it does not want to see but if your looking
for something specifically, I wonder why this happens. I have
experienced this many times, I try to find something that I had just a
moment ago and cannot
Are you sure it was there all the time? The same thing happens to me.
I wonder about these things. :^)
Joe
-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On
Behalf Of Steve Rooke
Sent: Saturday, August 07, 2010 9:56 AM
To: Discussion of precise
Perhaps its the fairies at the bottom of my garden :)
Steve
On 08/08/2010, J. L. Trantham jlt...@att.net wrote:
Are you sure it was there all the time? The same thing happens to me.
I wonder about these things. :^)
Joe
-Original Message-
From: time-nuts-boun...@febo.com
Hello all -
first of all, I would like to thank you for the many replies I got regarding my
first posting a couple of weeks ago where I described my homebrew Rubidium
oscillator based on an LPRO-101.
During the last couple of days I found enough spare time to dig deeper into
some issues. In
ulm...@vaxman.de wrote:
blinked. This problem was eventually solved by driving the LED with a discrete
transistor instead of a free 74AC14 gate and decoupling this driver with an
RC-combination.
CMOS logic gates have a totem pole output that is famous for overlap
where both transistors on
On 08/07/2010 07:31 PM, Richard (Rick) Karlquist wrote:
ulm...@vaxman.de wrote:
blinked. This problem was eventually solved by driving the LED with a
discrete
transistor instead of a free 74AC14 gate and decoupling this driver
with an
RC-combination.
CMOS logic gates have a totem pole output
Without naming names, I want to suggest that if anyone on this list is
going to ship IC chips in the future (DIP in particular), that they
either use the hard plastic tube the chips come in, or put the chips
inside a box. Antistatic foam inside a padded envelope results in very
flat pancakes. Just
Just an FYI guys, the PIC chips are shipping in the hard anti-static tubes.
I bought 10 of each from here:
http://www.elexp.com/ics_icst.htm
They were easy to cut up with a utility knife without shattering and I
bought 150 of their rubber stoppers for the ends. They had very inexpensive
I would like to thank everybody involved on this list who have made it
possible to get the necessary parts distributed.
For me these are Stanley (for the boards), Nigel (for the 74ac175) and
Poul Henning (for shipping the boards inside Europe)
And of course Richard who was willing to share his
Mea culpa. However, I did propose the option of choosing flat rate
boxes in lieu of the envelopes, and no one replied with such a request.
This was actually Bob Camp's idea, and he was the only one who
specifically asked for this packing method. It costs substantially more,
but apparently is
You do not need a switch, the T-Bolt Monitor only reads what's coming from the
T-Bolt, you just need to wire two connectors in parallel, and as long as Lady
Heather uses the same T-SIP protocol, which I believe is the case, you should
be OK.
Didier KO4BB
--Original Message--
From: Dr.
On Sun, 8 Aug 2010 02:38:53 +1200, Steve Rooke sar10...@gmail.com
wrote:
Well, that does make a lot of sense, it's just a pity that searching
for the item you want frequently ends up fruitless but I agree that if
you search for anything, your sure to find it.
Senior moments are lifesavers; after
Hi all,
I have a Seimens master clock with a Reiffler pendulum. A lovely piece
of work that used to provide time services in the 40s.
Being a master clock it has contacts that open and close on each
pendulum swing and so I can monitor it's accuracy quite easily using
gps and my 5370B.
I've
A high voltage opamp (or a low voltage opamp with a discrete output
stage with a voltage gain of at least 2) with -3V and + 30V supplies is
perhaps the simplest method.
The opamp merely senses the current flowing in a current sensing
resistor and regulates this voltage drop to equal the output
Since it's inside a closed loop, the design is uncritical.
One option is a high voltage Op-Amp with +/- 25 to 30 VDC supplies. You
would set the OA gain to about 10, so 2.5 V in would yield 25 V out. and
sum in a negative offset voltage so that +2.5 from the DAC yields 0.0 V
out. I'd use
Hi,
the range of the adjustment is probably far wider than you would ever
need
as you will be applying it continuously instead of over a few hours
to correct the clock to the latest
observations.
So all you need is an amplifier run off + and - 15 Volts with enough
gain for the DAC output.
The 60mA load current would be problematic for most common opamps
without an output buffer stage.
High voltage opamps are relatively rare.
Bruce
J. Forster wrote:
Since it's inside a closed loop, the design is uncritical.
One option is a high voltage Op-Amp with +/- 25 to 30 VDC supplies.
A high voltage opamp (or a low voltage opamp with a discrete output
stage with a voltage gain of at least 2) with -3V and + 30V supplies is
perhaps the simplest method.
The opamp merely senses the current flowing in a current sensing
resistor and regulates this voltage drop to equal the output
OK. You know better.
BTW, op-amp noise is essentially irrelevant in this application, and the
C's across the FB resistors limit slew rates so there is no significant
dI/dt to cause voltage spikes.
-John
Your naive stabilisation scheme wont work, try simulating it.
741's are
J. Forster wrote:
OK. You know better.
BTW, op-amp noise is essentially irrelevant in this application, and the
C's across the FB resistors limit slew rates so there is no significant
dI/dt to cause voltage spikes.
Noise is never irrelevant.
You havent shown that its insignificant either.
Jim Said:
It also has a coil mounted near the pendulum and a fixed magnet on the
pendulum bar and this coil connects to a box down below with a meter
and a knob. They are labeled in sec/day. The electronics in the box
are not clear (being quite old) but by measuring the current in the
coil it
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