Hi,
C field will not get you on frequency with what you read right now, are you
sure you are on the right peak?
Bert Kehren
___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
Hi Gerard,I'm not fully set up at the moment but if you've had no better offers
I may be able to help.I'm located in Cambridge. My equipment includes a
Thunderbolt GPSDO, two Efratom FRK-L Rubidiums, Oncore VP GPS, Phillips PM6654
time interval counter, Odetics satsync 325
GPSDO, Datum
Hi,
let me start out with a disclaimer, I have sold several HP 5061A through a
friend on ebay including the two recent HP 5062C's, the reason I do not do
it direct is, he does it full time and he has the ability to get them
packed professional. We have had no complaints all where tested and
Bert-
I would be willing to take a chance on a used tube if the price was
right.
Please keep me in mind as I have been looking for a used Cs tube.
-Brian, WA1ZMS
Forest, VA
On Feb 27, 2010, at 6:21 AM, ewkeh...@aol.com wrote:
Hi,
let me start out with a disclaimer, I have sold several HP
Gerard PG5G wrote:
Hello all,
First post here, so I'll start with a quick introduction. I trained as
an electronic engineer but don't work in that field any more, which has
given me the appetite back to do some electronic engineering as a
hobby. I have been a licensed ham for
Hi
What I'm talking about here is a common mode choke on the +12 volt supply. They
are pretty common items. Just about every TV or commercial switcher has one on
the power line. Some switchers have them on the outputs as well.
Two independent windings are put on the same core. The DC current
Gerard you have some great comments already and welcome back to the
electronics hobby.
A couple of things.
Curious about whats on the board etc.
Here would be my thoughts.
If the same 10 MC signal thats the reference is also the input.
Then any funny numbers are the process leftovers or jitter.
I
now all seeme to work properly except probalily A9 .
with loop open , at J6 of A7 board I will have minimum 137Hz signal
when the frequency is exatly , but the signal grow if I move osc
frequency , this should be indicate all work good . the problem is when
I close the loop , the frequency
I am in the process of designing a DMTD system. As an experiment to do
basic measurements on the chosen mixer, I used a capacitor (0.01 uF) in
series to ground with a 47 ohm metal film resistor. Where the capacitor
and resistor meets, another resistor is attached (390 ohms) that goes to
Hi
A couple of things to try:
Just drop a 0.01 uf to ground directly on the output of the mixer.
Take the 390 to ground up to 3.9K ohms.
Depending on your mixer either / both may help or hurt.
You also may be able to run slightly more power into the mixer. More power may
also smoke the
Simplified summery of all the past N.S. in this thread
The Tbolt needs a very clean and stable +12 volt supply to get the best
possible performance.
The -12 +5 supplies are not very critical.
For the +12 volt supply, use one as good as you can,
For the -12V (-8 to -13) +5V (+-5%) power,
Brian Kirby wrote:
I am in the process of designing a DMTD system. As an experiment to
do basic measurements on the chosen mixer, I used a capacitor (0.01
uF) in series to ground with a 47 ohm metal film resistor. Where the
capacitor and resistor meets, another resistor is attached (390
Dear time-nuts,
I've just bought a used LPRO-101 which should get a permanent home
inside an instrument rack. I've also found a very nice 1U high metal
case, and a fitting 24V 1U power supply - leaving plenty of room for a
distribution amp and a microcontroller to log things like lamp and
Hi
1mm is pretty thin for a heat sink made of steel. You might consider an
aluminum plate around 4 mm thick and the length and width of the case to act as
a heat spreader.
The LPRO probably already has the tape on the bottom of it. The tape may be in
fine shape. If it's not, scrape off what
Hi
Assuming that the junction of the back to back diodes goes trough a chunk of
coax to get to the counter:
You are forming a low pass filter with the 10K resistor and the coax
capacitance. The LT1037 is quite happy driving a 600 ohm load. You could easily
drop the impedance at that point
The LT1037 is shown with a gain of ~1690x, if this amplifier is used to
amplify the beat frequency signal, it will saturate.
Opamp recovery from saturation is poorly documented and may be very slow.
It would be better to use some diodes in the amplifier feedback network
to limit the large
I agree that thats not really an effective heat sink.
On Sat, Feb 27, 2010 at 6:12 PM, Bob Camp li...@rtty.us wrote:
Hi
1mm is pretty thin for a heat sink made of steel. You might consider an
aluminum plate around 4 mm thick and the length and width of the case to act
as a heat spreader.
For operation at ambient temperatures up to 50C the manual states that a
baseplate heatsink with a thermal resistance of 2C/W or lower is required.
Bruce
paul swed wrote:
I agree that thats not really an effective heat sink.
On Sat, Feb 27, 2010 at 6:12 PM, Bob Campli...@rtty.us wrote:
Hi
Another option for cooling the LPRO would be a fan in combination with a heat
sink.. That's not my favorite way to go, but it should take care of the cooling.
Bob
On Feb 27, 2010, at 6:51 PM, Bruce Griffiths wrote:
For operation at ambient temperatures up to 50C the manual states that a
Hi
The gotcha here is that saturation / slew limiting is one of the few things
that will give you *better* data than the oscillators are really doing. Most
error sources have the nice property of making things worse.
Bob
On Feb 27, 2010, at 6:40 PM, Bruce Griffiths wrote:
The LT1037 is
At 07:01 PM 2/27/2010, Bruce Griffiths wrote...
For the 5370A attenuating the 5V CMOS signal to a 1V...
For the 5370A attenuating the 5V CMOS signal to a 2V...
ITYM 5370B for the second part.
___
time-nuts mailing list -- time-nuts@febo.com
To
Oops! a small correction (2nd paragraph):
For the 5370A attenuating the 5V CMOS signal to a 1V swing with the threshold
set to 0.5V is close to optimum.
An input signal with limits of 0V and +1.4V with a trigger threshold of 0.7V is
the maximum usable (for high performance).
An input signal
What else is going to be in the rack? If your 1U enclosure is packed in
tight between other devices there might be no cooling at all. You might
need a fan to move some air.
I don't know if you can find something like this, but I scavenged heat
sinks from an old Compaq DL760 server that
Hi
Which *still* carefully avoids the issue of how .
Bob
On Feb 27, 2010, at 8:52 PM, Bruce Griffiths wrote:
Oops! a small correction (2nd paragraph):
For the 5370A attenuating the 5V CMOS signal to a 1V swing with the threshold
set to 0.5V is close to optimum.
An input signal with
Mike S wrote:
At 07:01 PM 2/27/2010, Bruce Griffiths wrote...
For the 5370A attenuating the 5V CMOS signal to a 1V...
For the 5370A attenuating the 5V CMOS signal to a 2V...
ITYM 5370B for the second part.
Yes, a result of cutting and pasting.
Bruce
HI
Running the LPRO from a supply below 19 volts is a good idea. As you raise the
voltage into the unit, a lot of the energy simply goes into heat. Not a good
thing when you have a marginal heatsink in the first place.
Bob
On Feb 27, 2010, at 8:56 PM, Ed Palmer wrote:
What else is going to
1) One method with 5V CMOS is to add a resistive voltage divider at the
CMOS driver output with a 50 ohm output impedance at the tap that drives
the 5370A/B input.
2) If one has a 5V 50 ohm driver (eg Thunderbolt PPS output) use a 50
ohm attenuator at the 5370A/B input.
For a 5370A an
Hi
AC cmos will easily drive an L pad to match a 50 ohm cable at these levels.
That's true at either 3.3 or at 5.0 volts. There are a lot of cmos families out
there that beat AC for speed and match the output drive capability.
Bob
On Feb 27, 2010, at 9:12 PM, Bruce Griffiths wrote:
1) One
If one is feeling paranoid about ground loop noise (and wishes to avoid
transformers, optoisolators , or fibre optics), etc one could always use
an LVDS driver with a batter powered(?) LVDS to CMOS receiver/translator
right at the 5370A/B input BNC connector.
This may be useful for a DMTD
Hi
Gee, LVDS what an unusual approach :)
It would be nice if these instruments had a balanced input. Common mode noise
is indeed an issue in a lot of cases.
Of course wrapping the coax headed to the counter 10X around a fairly large
core can help things a bit.
Bob
On Feb 27, 2010, at
In general, what about the old National damn fast and super damn fast
LH0032 LH0033? I used to use a lot of those in my designs many years ago.
- Mike
Mike B. Feher, N4FS
89 Arnold Blvd.
Howell, NJ, 07731
732-886-5960
___
time-nuts mailing list
Since the input amplifier and trigger circuit are located on a small
daughter board it wouldn't be too difficult to replace this with an LVDS
to CML stage.
The only remaining isue would be what input connector to use (twinax??,
SATA??).
Bruce
Bob Camp wrote:
Hi
Gee, LVDS what an unusual
Hi
I don't even have the counter and already we're butchering it
The big issue is suitable twin-ax connectors and cable. I have both, but they
are *big*. They never really made it into the world of miniature connectors and
miniature cable.
Shielded twisted pair would be another option.
Mike Feher wrote:
In general, what about the old National damn fast and super damn fast
LH0032 LH0033? I used to use a lot of those in my designs many years ago.
- Mike
Mike B. Feher, N4FS
89 Arnold Blvd.
Howell, NJ, 07731
732-886-5960
The LH0032 was a fast FET input opamp.
I presume you
Actually there are miniature twinax style connectors, for example:
http://www.amphenolrf.com/products/twinbnc.asp?N=0sid=4B8860805409E17F;
http://www.amphenolrf.com/products/twinbnc.asp?N=0sid=4B8860805409E17F;
Bruce
Bob Camp wrote:
Hi
I don't even have the counter and already we're
Hi
Sure never seen any of them on any gear in my junk pile.
I also never seen a customer ask for them as an output connector on an
oscillator. I wonder how common they actually are.
Bob
On Feb 27, 2010, at 9:59 PM, Bruce Griffiths wrote:
Actually there are miniature twinax style
You could look at a surplus F16 (probably wont fit in your garage
though) or similar STP was heavily used in MIL STD 1553 avionics buses.
Bruce
Bob Camp wrote:
Hi
Sure never seen any of them on any gear in my junk pile.
I also never seen a customer ask for them as an output connector on an
Hi
MIght have to move a few things in the shed to fin in an F16.
If they were used in quantity there aught to be cable and connectors out there.
The only reason I have the stuff I do is good old IBM and their approach to
networking back in the old days. It would be tough to properly drive an
Bob Camp li...@rtty.us wrote:
Hi
MIght have to move a few things in the shed to fin in an F16.
If they were used in quantity there aught to be cable and connectors
out there. The only reason I have the stuff I do is good old IBM and
their approach to networking back in the old days. It
Hi
R-390 and / or R-390A
Not a lot of IBM stuff here. I can fit in a F-16 only because I've avoided the
IBM stuff
Bob
On Feb 27, 2010, at 10:18 PM, Larry Snyder wrote:
Bob Camp li...@rtty.us wrote:
Hi
MIght have to move a few things in the shed to fin in an F16.
If they were used
R-390 or S/390?
The R-390 receiver (designed by Collins) is probably worth more today than an
S390. ;-)
___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow
here is a two center pin type of BNC, presumably for a balanced twisted
pair or twin ax type cable.
The shape of the dielectric allows proper mechanical mating.
Stan, W1LE Cape Cod
Bob Camp wrote:
Hi
I don't even have the counter and already we're butchering it
The big issue is
I need the red plastic digit cover/window [approximately 1 3/4 x 14 3/4]
to complete the repair of a HP 5370 counter/timer. I don't care if it says
5370A or B. I assume that no major change occurred other than the
unit identifier changing. Perhaps someone can correct me if I am wrong in
I have a bnc type connector with two pins inside the shield on a FTS cesium
standard labeled DS1 must be a phone industry jack.
Stanley
- Original Message
From: Bob Camp li...@rtty.us
To: Discussion of precise time and frequency measurement time-nuts@febo.com
Sent: Sat, February 27,
Arthur Dent golgarfrinc...@yahoo.com wrote:
R-390 or S/390?
The R-390 receiver (designed by Collins) is probably worth more today
than an S390. ;-)
Good point, and I apologize for the smart remark. I've worked with
both (and a Z900 Cu box is pretty quick :-)
-ls-
Mike Feher wrote:
In general, what about the old National damn fast and super damn fast
LH0032 LH0033? I used to use a lot of those in my designs many years ago.
- Mike
Gotta really decouple the power supplies on those puppies...
___
time-nuts
Bob Camp wrote:
Hi
Sure never seen any of them on any gear in my junk pile.
I also never seen a customer ask for them as an output connector on an
oscillator. I wonder how common they actually are.
Bob
On Feb 27, 2010, at 9:59 PM, Bruce Griffiths wrote:
Actually there are miniature
These were used on some measuring instruments to provide a balance
'guarded' input.
The shield around the balanced conductors provided a ground between
the DUT and the measuring equipment that was not connected to the input.
IIRC this was for very low level signals.
73
Glenn
WB4UIV
At 10:06
found a picture of the Twin BNC here: http://drawings.amphenolrf.com/pdf/172.pdf
___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.
If it's the one that I think it is... look closely at the photo. The shafts
on two of the pots are sheared off at the panel. These are the display update
control and the external arming level control. These were custom HP pots with
a funky (and delicate) switch. They had brittle
The values in the schematics are wrong for the op amp gain. The drawing
was from an earlier drawing where I made a preamp to start checks on the
mixers, and I sent it to you (Bruce G). Thats when you determined I did
not have enough gain to get near the noise floor. The THAT1512/1646 ICs
Hi the gang,
Why the Digest of this group is sent evey one or two hours?
The digest objective is to receive not too often in one message a bunch
of them, very usefull when you forward your emails to your mobile phone,
here with this group I receive very often a digest with only few
messages,
Quoth Pierre-François (f5bqp_pfm) at 2010-02-28 16:55...
Why the Digest of this group is sent evey one or two hours?
Most mailing list softwares send either at a set interval OR when a
certain number of messages are received - whichever happens first.
This prevents a very busy system from
Most mailing list softwares send either at a set interval OR when a
certain number of messages are received - whichever happens first.
Or when the digest gets bigger than N bytes.
--
These are my opinions, not necessarily my employer's. I hate spam.
Is that buttermilk or blueberry batter? :-)
Don
- Original Message -
From: Bruce Griffiths bruce.griffi...@xtra.co.nz
To: Discussion of precise time and frequency measurement
time-nuts@febo.com
Sent: Saturday, February 27, 2010 7:32 PM
Subject: Re: [time-nuts] Achieving maximum
I've fixed shafts like this carefully with plastic swizzle sticks and super
glue. Did I say carefully? a little dab'll do ya...
Don
- Original Message -
From: Mark Sims hol...@hotmail.com
To: time-nuts@febo.com
Sent: Saturday, February 27, 2010 10:10 PM
Subject: [time-nuts] Achieving
56 matches
Mail list logo
