A friend just received an HP 5370B that was said to be properly
working and accurate, and asked my opinion. I'm not familiar with
these, so I thought I'd ask the experts. All we've done so far is
hook it to a Tbolt that I know is operating properly.
The 5370B took hours (8 or so, which
The 10811 after 20 minutes of warmup have to be warm. You can touch physically
the oscillator, if it is not warm the oven do not work. The 100Hz off frequency
of the oscillator is more/less the frequency at ambient temperature.
One of the pin of the 10811 have to be at +24 VDC, measure it. If
Charles P. Steinmetz wrote:
A friend just received an HP 5370B that was said to be properly
working and accurate, and asked my opinion. I'm not familiar with
these, so I thought I'd ask the experts. All we've done so far is
hook it to a Tbolt that I know is operating properly.
The 5370B
Hi Charles,
Yes, the rear heatsink does run very hot, approx. 61 deg C. But do make sure
the fan is running! The unit will be damaged without the fan. Also it's
important to refrain from running the instrument too long with its top cover
removed, because the fan air doesn't properly loop
Yes, the rear heatsink does run very hot, approx. 61 deg C. But
do make sure
the fan is running! The unit will be damaged without the fan. Also it's
important to refrain from running the instrument too long with
its top cover
removed, because the fan air doesn't properly loop around and
***It does sound like the 10811's oven fuse is open, though. (The counter
won't work if there's no oscillator present at all.)***
R: oven's fuse is on +24vdc for the power part of the oven. The oscillator work
with +12 volts that is not fused. So, some time happen the oscillator work but
John Miles wrote:
...There are no such concerns with the 5370B as far as I'm aware. Nothing
in
there runs very hot except the linear regulators themselves, which are
externally heatsinked.
--clip---
John - Santa Clara designed the 5370A/B such that the fan sucks external air
It doesn't use IC regulators.
It uses a common IC reference together with a few opamps and discretes.
Bruce
Bob Camp wrote:
Hi
In an earlier thread on the 5370B checking the voltage out of the regulators
was mentioned. If you are going to open the counter up anyway, putting a DVM on
them is
Hi
In an earlier thread on the 5370B checking the voltage out of the regulators
was mentioned. If you are going to open the counter up anyway, putting a DVM on
them is probably a good idea. They do run hot and some eventually drift way out
of spec. Cheap part to replace if it's bad..
Bob
I have picked up a few of these over the years.
Seems almost everyone knows to take the oven.
Or the low quality gate oscillator is in there. Worthless and can easily be
100Hz off.
Very touchy.
Great advice from the group to check various supply voltages.
Agree on the heat sink. Its hot. Some one
Not as bad as the disaster in Northfield, MN (S of the Twin Cities)
where a guy drilling holes for Cat 5 cables broke the vacuum jar
of a Reifler clock, and nobody thought anything of it.
Actually that also apparently happened many many years ago at the Elgin Watch
Company Observatory. About
At 08:19 AM 9/14/2010, Bruce Griffiths wrote...
It doesn't use IC regulators.
Yes, it does. A7U1 (on the Oscillator Power Supply, which is apropos
to this thread) is a common 7812 3 terminal one.
___
time-nuts mailing list -- time-nuts@febo.com
Good advice Burt.
While we're on the subject of over-heating issues, on instruments with fan
filters, I'd like to mention the importance to clean their fan filters at
regular intervals.
See:
http://www.hparchive.com/Bench_Briefs/HP-Bench-Briefs-1995-01-03.pdf
Greg
-
Burt
I'm not familiar with the 5370B and I may be way off on this, but I
wanted to pass along some information regarding another piece of HP
gear that I have which ran pretty hot, too hot in my
opinion. Hopefully this will save someone else from the same grief I
went through.
I have a HP-3336A
On 9/14/2010 1:23 AM, John Miles wrote:
As Bruce suggests, you'll want to peek inside to see that you
really do have
a 10811 oscillator. If so, then it sounds like the thermal fuse
(F1, inside
the 10811) might be open.
Just short it out, or if you like, put in an NTE part with a similar temp
I wrote a long description regarding this phenomenon many moons ago. The
thermal fuses in the HP ovens do fail, mostly just because of aging, and not
because of any problems. The fuse holder contains a wax substance which is
normally hard and keeps the contacts closed. If suddenly the contacts
Thank you everyone for your comments.
Bruce wrote:
Open the lid and check that it actually has a 10811A rather than a
simple gate oscillator.
We have so far refrained from opening it to preserve the right of
return. Did HP ship 5370Bs with lesser oscillators than the
10811? I had assumed
You're welcome Peter. I'm glad I was able to finally provide
something useful. :)
Hopefully others found it an interesting read as well. I have two
Thunderbolts and am trying to figure out how far apart I should mount
the antennas. Further apart reduces the changes of multpath to both
I did a number of professional GPS installations in the 90's, mainly for
Telco sync and NTP work. Where there were more than one antenna required, we
used to install at different ends of the building, to minimise risk from
lightning strikes etc.
Rob K
-Original Message-
From:
Charles, all HP 5370Bs were shipped with 5E-10/day OCXOs. So you should
hopefully find a 10811 in there, or possibly a 10544.
Greg
- Original Message -
From: Charles P. Steinmetz charles_steinm...@lavabit.com
To: Discussion of precise time and frequency measurement
time-nuts@febo.com
Speaking of filters.
Thanks for putting the HP brief up. They are always a good read.
Especially since these days I can afford that gear.
That said many if not all of the filter material is degenerated.
Its soft and sticky. At a min get rid of it.
My environments clean so I leave them out.
Have
Maybe early ones but I believe Bs were shipped with the gate osc and the
10811s were opt.
On Tue, Sep 14, 2010 at 12:57 PM, Greg Burnett gb...@comcast.net wrote:
Charles, all HP 5370Bs were shipped with 5E-10/day OCXOs. So you should
hopefully find a 10811 in there, or possibly a 10544.
Greg
Yeah, good advice to get rid of the fan filter material, Paul. With the HP
8568B 8566B, Signal Analysis Division (SAD) weighed the pros and cons of
keeping the instrument clean vs. risk of over-heating if the fan filters
were not kept clean. They decided in favor of reduced risk of heat
I guess with humor, I clean up 20 years of stuff on/in the gear. Almost
always straight off.
Reason. That forces a very good inspection. You find all kinds of clues as
to what might be up. Burnt caps, resistors, loose wires and such.
Other thing I do is measure all supplies while cold looking for
Hello,
My 1986 HP catalog do not show a high stability oscillator as an option
for the 5370B, and from the time base aging effects graphs it appears to
have a 1E-8/month oscillator. My 1996 catalog also do not shown this as
an option, but the specs for the 5370B are so sparse that they even
On 09/14/2010 07:59 PM, paul swed wrote:
Maybe early ones but I believe Bs were shipped with the gate osc and the
10811s were opt.
Which makes sense if you consider that for many lab/production uses you
hook it up to a distributed 10 MHz and why pay for a 10811 you never
use? The gate
http://mpqu.livejournal.com/42997.html 35781
___
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.
The HP 5370B's timebase specs are stated on page 1-4 of the Operating and
Service Manual, available for download at:
Mike S wrote:
At 08:19 AM 9/14/2010, Bruce Griffiths wrote...
It doesn't use IC regulators.
Yes, it does. A7U1 (on the Oscillator Power Supply, which is apropos
to this thread) is a common 7812 3 terminal one.
The oscillator regulator shouldn't run hot since the current for the
10811A
On 9/14/2010 8:28 AM, Dan Rae wrote:
I hate to disagree with John who knows a heck of lot more than I ever
will, but in this case it will protect the oven from cooking up if the
control circuit fails with the heater full on, which can happen.
I did have a 5370B with a 10811 that had a bad
Has anyone built / seen / bought a small simulator for WWVB?
I live near Boston, and the WWVB signal is pretty marginal around
here. MSF on the same frequency isn't that far away, and local
noise is pretty fierce. So now and then one of my WWVB listeners
(like my generally nice Junghans
Circuit Cellar did an article.
Feburary 2010 #235 Page 38.
This was a WWV simulator for a 2 part article the 2nd being a receiver.
73s
Randall ZL2RJP
-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On
Behalf Of Bob Clements
Sent: Wednesday, 15
On 09/14/2010 11:10 PM, Bob Clements wrote:
Has anyone built / seen / bought a small simulator for WWVB?
I live near Boston, and the WWVB signal is pretty marginal around
here. MSF on the same frequency isn't that far away, and local
noise is pretty fierce. So now and then one of my WWVB
It should not be hard.
I, like you live near Boston. So I built the carrier generator for testing
WWVB receivers.
Essentially divide ref freq to 20kc X 3 to 60 Khz.
I did not modulate it because I was trouble shooting a frequency lock
problem.
That said modulating it with the IRIGb code would be
Randall said:
Circuit Cellar did an article.
Feburary 2010 #235 Page 38.
This was a WWV simulator for a 2 part article the 2nd being a receiver.
73s
Randall ZL2RJP
Yup, I read that. It didn't have the RF part of the TX.
Magnus said:
If you don't need a precision carrier, but
Maybe a PIC to do the modulations trains and a serial interface to set it
up. In all about 3-4 chips. Should not be too hard.
Why do you need more than one chip?
Why can't the PIC generate the 60 KHz signal by bit banging a couple of pins?
I'm thinking of a 2 or 3 bit D/A with 2 or 3 more
I hate to disagree with John who knows a heck of lot more than I ever
will, but in this case it will protect the oven from cooking up if the
control circuit fails with the heater full on, which can happen.
That might be plausible if the thermal fuse were anywhere near the oven
mass. However,
Hal said:
I wonder what the range would be using 2 feet of wire for an
antenna. Do you want to fix your neighbors clocks too?
I don't think any of my neighbors do time better than a
millisecond. So as long as the data comes from the main server,
(and I get DUT1 right) I should go
On 09/14/2010 11:49 PM, Hal Murray wrote:
Maybe a PIC to do the modulations trains and a serial interface to set it
up. In all about 3-4 chips. Should not be too hard.
Why do you need more than one chip?
Why can't the PIC generate the 60 KHz signal by bit banging a couple of pins?
I'm
Page 8-112 of the 5370B manual shows a 10811
http://cp.literature.agilent.com/litweb/pdf/05370-90031.pdf
cheers,
ian
Date: Tue, 14 Sep 2010 13:28:47 -0600
From: Greg Burnett gb...@comcast.net
Subject: Re: [time-nuts] Questions about HP 5370B
To: Discussion of precise time and frequency
Hal said:
The NIST web page is here:
http://www.nist.gov/physlab/div847/grp40/wwvb.cfm
I assume you can find the fine print there, but they probably aren't easily
machine readable.
Um, that's just a general description -- not the current values.
Or did I miss something?
/Rcc
I designed and built a similar thing a while back, which emulated the
full VNG time code (which could be decoded by 'Radio Clock' and other
clock software).
My unit was GPS locked, using two microcontrollers, but it wouldn't need
to be that complex for setting clocks/watches. It generated all the
On 9/14/2010 5:27 PM, Hal Murray wrote:
Is there a secret NTP++ protocol that I've
missed out on?
Yes, but I can't tell you ;-)
--
mailto:o...@ozindfw.net
Oz
POB 93167
Southlake, TX 76092 (Near DFW Airport)
___
time-nuts mailing list
There is a good trouble-shooting tree in the 10811 manual that addresses
these issues.
I had a 10811 where the oven would not come on. I found the thermal fuse
open and even ordered the replacement part from HP. It was only a couple
bucks IIRC. I also found some close ones for only a few
Um, that's just a general description -- not the current values. Or did I
miss something?
Here is a table of leap seconds.
ftp://time.nist.gov/pub/leap-seconds.list
It gets updated every 6 months or so and contains a use-by date inside so you
know when you need to get a new one. The
Hi
A little guess work:
Over a 10 year period something like one in 1,000 to 1 in 10,000 10811's fail.
Of those, less than 1 in 1,000 are controller run away. Of the controller run
away's 1 in 10 might be stopped by the thermal fuse. That puts you at a 1 in
1,000,000 to 1 in 10,000,000 chance
Has anyone built / seen / bought a small simulator for WWVB?
An example of a PC-based WWVB simulator is here:
http://www.leapsecond.com/notes/wwvb1.htm
http://www.leapsecond.com/notes/wwvb2.htm
You can take the output of this and drive hardware:
http://www.leapsecond.com/tools/tco1.c
Good use for an old case.
My irig clock uses and old truetime dc468 sat recvr case.
I find them these days at hamfests for $5.
Very nice display.
On Tue, Sep 14, 2010 at 6:36 PM, Murray Greenman
murray.green...@rakon.comwrote:
I designed and built a similar thing a while back, which emulated
48 matches
Mail list logo
