On 03/24/2010 03:18 PM, Magnus Danielson wrote:
Fellow time-nuts,
...
Second, anything I should keep in mind as I power one up?
...
Cheers,
Magnus
There's a bit of discussion in the archives about the need for a heat
sink, and also about the whether it's necessary to anneal the case in a
They spend most of the article on LEO hazards, but this is a geo-sync orbit.
Leigh/WA5ZNU
At 06:32 PM 5/3/2010, Dave hartzell wrote...
And it gets even more interesting. Here's more backstory and detail...
http://www.msnbc.msn.com/id/36919374/ns/technology_and_science-space/
On 02/02/2010 10:18 AM, Ralph Smith wrote:
It should also port to Linux easily with minimal tweaking. I just don't
have a Linux box available.
Ralph
I have tboltd running on Ubuntu 9 Linux. I have not yet tried the ntp
part, but LadyHeather 3.00 Beta (running under Wine) connects.
On 05/06/2010 12:29 PM, Arthur Dent wrote:
But now here is the finding. The monitor board has the 7805 SMD version and
I was feeding from +12Volt and after a while the SMD voltage regulator
overheated
and started to drop the voltage and it was the reason to receive/display
garbled
I had a bunch of them and gave them away. For XY resolution I couldn't
get better than 100m. And since it's not a Jupiter, no 10KHz output. I
went to WSW and checked one there and it was the same part I got from China.
Leigh/WA5ZNU
I've seen a number of references to documents claiming to
You're right about the current. I just checked it with my DMM and got
45ma. My inline power meter must not be that it's not that accurate at
the low end.
The display works; the backlight works; the processor must be doing
something since it prints a variety of messages. It's the RS232 that
As part of the SF Bay Area Maker Faire this weekend, I'll be showing a
Thunderbolt GPSDO and a FE-5680A Rubidium disciplined oscillator, both
connected to a $25 flea-market oscilloscope.
The demo is part of a hands-on things to do with oscilloscopes. In this
experiment, we'll have visitors use a
Thanks for thinking about and commenting on my project. The goal is to
show how you can use a scope in interesting ways. One of the ways is to
show that you can measure fraction PPB in stable, periodic signals, and
you don't need a $5000 LeCroy, just a stopwatch and a few minutes.
The
Can you really get a useful scope for $25? What's it like?
It's 30 Mhz dual-trace analog Tek scope, a bit fuzzy looking. But it
gets the point across that you don't need a high-end scope to do these
measurements, just basic skills and thought.
Here's someone who made the hard-drive
I fixed my fluke.l monitor.
This evening I got mail today from Bob Mokia:
The problem is too much volts on CPU (8051F330D).
Must have diodes 1n4148 etc at D1 and D2. Drop cpu volts to 3.6volts.
Maximum volts from data sheet is 4.2 volts.
D1, D2, and D3 are zero-ohm SMT resistors in
Is that Daughter-Board soldered in or plugged in ?
It looks like it's plugged into the connector but I can't
get it to budge and I really don't want to apply too much
force and wind up breaking it.
Thanks, Dick, W1KSZ
I believe it's soldered. I was able to do my mod using through-hold
There will likely be one of these at the Electronics Flea Market in
Cupertino, CA this Saturday. I saw it last month with a $20 price tag,
but my guess is that if you can lift it it's yours. it's the one with the
stack of neon blubs for each digit. (Somewhere I have one in a garage as
well...)
At the local flea market, I picked up what appears to be an Efratom
FRS-C. It is marked TTL internally. It has the passive connector
board, but not the active board with the 15 MHz synthesizer on it.
Mine is marked TTL internally. The service manual has a chart showing
the differences
Mike S wrote:
It sounds like you made the changes to the A4 oscillator board, but not
the ones to the A3 power supply board (several inductors, resistors
and caps). I found that using a 1 uF for C16, instead of the
documented 0.1 uF, gives a better signal.
See the top of page A-15 in the
...
[snip]
If you need a sine wave output but don't want to change anything inside,
just add a lowpass filter.
A 5th order LPF (three inductors/ 2 caps or vice versa) should give you
a clean sine wave output.
Just add a coupling cap to remove the DC component.
Adrian
_
Thank you,
Thank you, Didier.
That pretty much sums it up. I was aware of the signal level issue but
didn't consider that passband ripple would be temperature sensitive. It's
fun learning to think in the long time domain.
In the meantime I've found a 10 mbit ethernet ISA card in my office and
will follow
This is close to the project I showed at the SF Bay Area Maker Faire
in May.
I showed fractional ppb difference measurements using a $25 flea market
scope.
The photo below is by a former NIST Cs fountain researcher who stopped by:
...
I use Peter G3PLX's SBSpectrum as the analyser, where you can trim the
sample rate in tiny steps. It also has a frequency resolution of 25mHz,
which is more than adequate for HF. My combination has won FMCs, but I
still can't resolve 0.01Hz off-air.
...
73,
Murray ZL1BPU
You might
On 07/29/2010 03:57 PM, Mark Sims wrote:
Yes, there is a time sync command that causes the program to set the system
clock at periodic intervals or whenever it differs from GPS by a given amount.
I'm still out on the Project From Hell Mark II and I don't remember all the
gory details... I
I would do the same ..
-pete
Please count me in for $10 plus shipping for qty 2, if anybody's counting.
Leigh/WA5ZNU
On Sun, Aug 1, 2010 at 11:03 PM, Heathkid heath...@heathkid.com wrote:
Stanley,
Would you be willing to do another group buy? Â I'll send you enough $
for
10 of them via
I've ordered the mouser project and skipped the parts that won't ship
until 2011. So we're in the same boat.
Leigh/Wa5ZNU
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) and highest quality parts? Please send a link.
Thank you in advance.
Has anyone started updating the project to include substitutes?
73 Brice KA8MAV
- Original Message - From: Leigh L. Klotz, Jr. WA5ZNU
le...@wa5znu.org
To: Discussion of precise time and frequency measurement
time-nuts
I tried water, then isopropyl, but what worked was a quick cleaning
with a white eraser.
Leigh/WA5ZNU
On 08/06/2010 08:15 AM, Ed Palmer wrote:
You mean they are tinned? I received my two boards a couple of days
ago. I thought that they missed the tinning solution. There's just
an
Now that Dan Schultz has kindly provided me with the elusive 74AC175PC, I
still need a programmed PIC for the PICTIC II. Is there are thread where
we're gathering together for another kind soul to distribute them?
Leigh.
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time-nuts mailing list
without regard to setting up the bboard or not, I'd recommend creating an
archive of time-nuts at Nabble. Nabble is more easily searchable than the
standard mailman type archives, and it has a bboard format, and people can
use accounts there and post back to the list. It's all transparent to the
WeirdStuff has tbolts, no case, no info about firmware version, for $75.
They were $495 but I sent them a note saying it wasn't a competitive
price and they lowered it and they appear to be selling out quickly.
http://www.weirdstuff.com/cgi-bin/category.cgi?item=29654
Also on their
Is anyone familiar with the hazards of an undervoltage supply on an FE 5680A?
I've seen reports of users running it at a more commonly available 13.2V
instead of 15V.
What module might be most affected? The lamp?
Thanks,
Leigh.
___
time-nuts
. Klotz, Jr WA5ZNU wrote:
I've attached an SMA connector to my FE-5680A and built an external
linear power supply with a TO-3 7815.
I ran the device today for about half an hour, and used an infrared
sensing thermometer to measure the external case temperature.
It got up to 48 C externally
Yes, thank you to all.
I'll go ahead with the heat sink on the bottom and consider a fan nearby.
Leigh/WA5ZNU
I think we've all learned from this. Good info about the Efratom unit,
and sounds as though we should aim for around 38C with the FEI units as
well. The FE-5680 looks to be easier to
run of device may want
to investigate that.
Leigh.
Bruce Griffiths wrote:
Leigh L. Klotz, Jr WA5ZNU wrote:
So far I've seen
http://www.dd1us.de/Downloads/precise%20reference%20frequency%20rev%200_4.pdf
If the case is Mu metal or similar then the modification shown in the
above
For reference, Ridge Equipment has a photo of one of this year's crop of
FE-5680A mounted to a large aluminum plate.
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItemitem=330233071735
http://i43.tinypic.com/126cpcp.jpg
Leigh/WA5ZNU
Almost all rubidium standards DO specify the use of some form of a
It's fluke.l not flukel who I've dealt with quite recently, and many
other more venerable folks on this list have commented on as well.
Leigh.
Is this good value, and a trusted seller?
I went looking for Fluke1 as listed earlier on here for these devices
(Thunderbolt GPS disciplined referenced
I use this on Linux:
cd ~klotz/.wine/drive_c/Program Files/Heather
wine heather.exe /IP=localhost:45000 /TW=250
I use Ralph Smith's tboltd so heather connects to a TCP port, but you
can also just give a COM port to connect on the line above.
The /TW=250 gives reasonable performance without
Are you doing DGPS?
An an alterative to the roll-your-own SDR, tou can build a direct
conversion small receiver or IF converter with a SA602 chip, which
contains a Gilbert cell mixer and a local oscillator.
Here is a board that will do most of what you want, if you're willing to
live with the
I have an HP-5216A that I got at the local flea market. One tube is bad
and one driver.
I found the drivers (they're special HP chips), but now I see it has
about 10mA leakage current to ground. I've removed everything on the
primary side and it seems to be the transformer. There's a slight
And vacuum tube equipment using indirectly-heated cathodes:
http://www.cpii.com/docs/related/23/Basic%20Tube%20Design.pdf
Operating techniques that are proper for filamentary tubes are not
necessarily
correct for tubes with indirectly heated cathode emitters. In
particular, the opera-
tion of
In 1984 we had a QBUS-based 68000 (dual 68K, due to the paging flaw)
that ran 9-track tapes off the end and gained about a good fraction of
an hour a day on its clock. We complained to the vendor and they
swapped CPU boards for us. Tapes worked fine, and the clock was more
accurate, but
I got a demo of a national network quality (and price) digital TV
encoder from a ham friend in the industry.
It took about 6 seconds delay itself to encode images. The compression
has a lot of state and multiple heuristic systems as well (face
trackers, for example).
Leigh/WA5ZNU
On
On 01/13/2012 01:22 AM, Javier Herrero wrote:
For providing ntp, probably the best way is to use ntp :)
Ralph Smith did a good integration for BSD NTP. I patched it and wrote
some startup and monitoring scripts for it for Ubuntu.
See http://wa5znu.org/2011/08/tbolt/
I run Heather under
Based on Mark Sims updates to Heather v5.0 I've updated Ralph Smith's
NTP daemon to handle the rollover. I haven't updated the gpsd.
https://wa5znu.org/2011/08/tbolt/
It's not as ambitious as Mark's update; this one doesn't read system
time so it will have to be recompiled again in about 20
of this issue.
Could you check the source tarball? I just downloaded it and it appears to be
the unmodified version of my code from 2010.
Ralph
AB4RS
Sent from my iPhone
On Aug 1, 2017, at 2:42 AM, Leigh L. Klotz, Jr WA5ZNU <le...@wa5znu.org> wrote:
Based on Mark Sims updates to Heather v5.
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