Re: [time-nuts] time-nuts Digest, Vol 187, Issue 13
Hi Chris,
You might would want to try and calibrate the (T)ime (O)ffset as per
page 32 of the Operation and Service Manual and then write that value
with the TO! command.
Saving TimeOffset with user command only works from firmware version 3.23
and higher - mine is 3.21 and therefore only possible with a factory
command. But I think that's not necessarily the problem, but more important
is the TS parameter which should normally be around 14000.
Christoph
Am Mo., 10. Feb. 2020 um 18:00 Uhr schrieb <time-nuts-request@lists.febo.com
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Today's Topics:
1. Lady Heather Question (Don@True-Cal)
2. Re: Help with BG7TBL 2015-07-08 GPSDO>Fixed! (Patrick Murphy)
3. Re: Using a common power supply among few time standards
(Taka Kamiya)
4. PRS10 (Christoph Guenther)
5. Re: PRS10 (Chris Burford)
6. Tbolt and LOCK indicator - is it there? (Taka Kamiya)
7. Re: eLoran (paul swed)
8. Re: Help with BG7TBL 2015-07-08 GPSDO>Fixed! (Gary Woods)
9. Re: Tbolt and LOCK indicator - is it there? (Bob kb8tq)
Message: 1
Date: Sun, 9 Feb 2020 15:29:49 -0600
From: "Don@True-Cal" truecalservices@gmail.com
To: "'Discussion of precise time and frequency measurement'"
time-nuts@lists.febo.com
Subject: [time-nuts] Lady Heather Question
Message-ID: 047f01d5df90$0fad7bd0$2f087370$@gmail.com
Content-Type: text/plain; charset="us-ascii"
I am using LH on a classic Thunderbolt (actually several) that uses the
MV89
OCXO retrofitted. I typically use a DAC TC of 1200-1800 seconds to really
smooth things out. I want to do a LH 48-hr precision survey and have a
couple of questions about that process. 1) Do I need to manually change
the
TC to something substantially lower so the forced position error offset
scan
results are more responsive or does LH make all necessary parameter changes
before starting the process? 2) I have always been confused at the
completion of the precision survey process rather I need to manually enter
the coordinates last displayed in the screen log of does LH do this
automatically? In other words, what exactly are the steps after the survey
has completed? Thanks for any help.
Don
Message: 2
Date: Sun, 9 Feb 2020 18:10:36 -0600
From: Patrick Murphy fgdhrtey@gmail.com
To: Discussion of precise time and frequency measurement
time-nuts@lists.febo.com
Subject: Re: [time-nuts] Help with BG7TBL 2015-07-08 GPSDO>Fixed!
Message-ID:
<CAG1UqTizi71enZ11Rj3hwrhwDT7QF8xPmL7biMB9ap=
bZg6HEg@mail.gmail.com>
Content-Type: text/plain; charset="UTF-8"
Great news! And even better sleuthing. I'm just curious - what piece of kit
is the MAX3232 installed in? I'm trying to figure out is it is the DCE or
the DTE end.
Thanks!
-Pat (KG5YPQ)
On Sun, Feb 9, 2020 at 10:15 AM Gary Woods garygarlic@earthlink.net
wrote:
Once I found the datasheet for the RS-232 interface, I found the TX
data was checking in but not out, and the circuitry that makes -V in
the MAX3232 wasn't working.
Replaced it * and all is well; Lady Heather is giving me nice maps of
satellites passing by, and 2nsec excursions on a graph. So now my
ancient Davis counter has a really really good timebase and I can
tweak my ham rig to within a fraction of a cycle of right. Hardly a
"time nuts" level of accuracy, but good enough!
Thanks, all!*Lengthy digresssion involving my Navy vocabulary omitted.
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Message: 3
Date: Mon, 10 Feb 2020 05:11:23 +0000 (UTC)
From: Taka Kamiya tkamiya9@yahoo.com
To: Discussion of precise time and frequency measurement
time-nuts@lists.febo.com
Subject: Re: [time-nuts] Using a common power supply among few time
standards
Message-ID: 1351448730.629365.1581311483259@mail.yahoo.com
Content-Type: text/plain; charset=UTF-8
I spent last two days boxing? up LPRO-101 into a 2U rack case.? It has Rb,
dist amp, interface for LED, and EFC knob on front.? While doing so, I gave
power supply concern I have been discussing careful thought.? I believe I
came to something that is workable and fits my needs.?
I started with 24V linear power supply (open frame type).? This is the
only power supply in the box.? From there, it branches to Rb, a small dist
amp, and a simple interface circuit.? Dist amp is 12V rated and interface
is 5V.? I modified the dist amp by including a 3 terminal regulator.? Now,
it's a 24V device.? I crated a 5V source right at Rb's interface board to
be used as EFC power.? This is the only purpose of this branch.? I also
created a separate 5V for the simple interface circuit. The reason for two
5V supply is that I didn't want to mix the source for EFC and digital
circuit together.
Pretty quickly, I found out going from 24V to 5V incurs huge loss
resulting in heat and death of 3 terminal regulator for that branch.? EFC
circuit was fine but digital interface board killed the regulator. Put a
heat sink on it and issue is resolved.? A bit surprising but it shouldn't
be....? The circuit only uses 25mA or so but voltage drop is huge.
Basically, I'm doing the same thing S100 bus computers did.? I will have
to consider use of small smp board for large voltage drops.? I didn't this
time, as its noise profile is not known to me.? Can't really go wrong with
linear regulators.? My only remaining concern is if regulator fails short,
then what happens??? It will kill the particular device, which I'm fine
with, but what else?? Perhaps simple fuse is in order for every branch.?
This method is a lot simpler than hap-haphazardly creating multiple
voltage at power supply and routing all over the place.? It became
impossible to trace ground loops.? Above method makes it really easy as, as
far as power supply is concerned, everything is a 24V device.
Thanks everyone for discussions.? I learned a lot in this process.
(Mr.) Taka Kamiya
KB4EMF / ex JF2DKG
On Saturday, February 8, 2020, 9:52:02 PM EST, Charles Steinmetz <
csteinmetz@yandex.com> wrote:
Chris wrote:
How about using the open frame linear supplies like the ones from Power
One or Lambda?
I have had very good results with Deltron open-frame linear supplies.
They have selectable mains voltage and low output noise (1mVrms/5mVp-p).
? I have used many (i.e., hundreds) of the Model W303E triple-output
supply.? These have one, 5v/8A section and two sections, each selectable
between 5v/12v/15v at 0.7A/1.7A/1.5A.? [NOTE there is an overall 55W
output limit, so they will not do all of that at once.]? Each section
can be adjusted +/- 5%.? These show up regularly on ebay.
As for switchers, I have been satisfied with the performance of
Integrated Power Designs (IPD) products.? [IPD is a different company
than Power Designs, who made some of the best lab and bench power
supplies of the 1960s through 1990s.]? One in particular may be of
interest to time nuts: the Model SRW-65-4006.? This is a four-output
supply (5v/5A, 24v/1A, and +/-15v/2A) [NOTE again, there is a 65W
overall limit, so it won't do all of that at once].? It is available
open-frame or with a chassis and cover.? For installation close to other
circuitry, and particularly inside a piece of equipment, I strongly
recommend the model with both chassis and cover (options CH and CO).
Check ebay and look at distributors.
Assume you will need to post-filter the switcher output, either with L/C
filters or low noise linear regulators.? Note that I did not say "LDOs".
? I don't know why, but everyone seems to be stuck on LDOs these days.
Active regulators (including LDOs) always perform better with more
headroom (up to 4v or so).? The only excuse for designing LDO is if you
have a gun to your head from a power budget you can't otherwise control.
? [Here, "LDO" is mostly a matter of how you use the part, not of its
claimed capabilities -- "LDO" regulators work much better with at least
4v of headroom.]
Best regards,
Charles
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Message: 4
Date: Mon, 10 Feb 2020 10:10:37 +0100
From: Christoph Guenther chguenther1@googlemail.com
To: time-nuts@lists.febo.com
Subject: [time-nuts] PRS10
Message-ID:
<CAApZC99wwWSuKJ-r7p3pm7=w6m-t_K1qj1p0GVtURYqJD0+m=
Q@mail.gmail.com>
Content-Type: text/plain; charset="utf-8"
PRS10 - Help Wanted !!!
My PRS10 v.3.21 sends "SYNTAX ERROR" in the TT string for TT values above
approx. 999999640 (ext. 1PPS input active). LadyHeather therefore shows no
negative TTs. Only when the TT gets smaller does LH also show more negative
values than approx. -360ns, otherwise 0 or positive. If you read the other
parameters, you will find that TO = 0 and TS = 12000, PS = 200 (unlikely
that these round values are correct ). If 1PPS output and input are
connected, TT = 1855 is output. This value should be saved with TO as
-1855. A full recall (RC1) also brought no change. Attached is an LH screen
printout.
Do you have any ideas on how I can fix the problem? The part has the
customer PN: 123-44101-06. Could these strange parameters possibly be
related to this PN? Does anyone have such a PRS10 v. 3.21 with this PN and
could he send me his values (TO, TS, PS)?
Support from SRS is unfortunately not really available because I did not
buy the device directly from them - thanks SRS !!! -
Does anyone know the factory access code (will of course be treated
confidentially) to write the correct values in the device?
I would be very grateful if there was a ?PRS10 professional? who could help
me. For direct answers, I can also be reached at verochris@web.de.
Thank you very much
Christoph