Seconded. Did both last August and it was great. The amount of restored
hardware that's operational is impressive and docents are knowledgeable.
If you get to the computing museum, having a chat with whoever is in the
Colossus gallery is worth your time.
Admission to BP is £17.75 and the
As expected, on the leap second the display on the 8183 showed 6:59:60 (the
8183-A showed 23:59:60), but the TV400 displayed 7:00:00 at that moment.
The TV400 remained one second ahead until it displayed 7:00:03 for a two-
second period, then from 7:00:04 forward it was properly synced.
On
Should I make it a habbit of TDRing my GPS antennas, receivers and
splitters?
Cheers,
Magnus
I think that question ties into some of the other responses to the original
post. The value of doing the TDR measurement would probably depend on your
cable lengths and how likely you think it is
snip
And it's not clear that there's actually loss due to mismatch. Most
antennas/preamps/receivers don't have exactly 50 ohm impedances. 75/50
is only 1.5:1, and there's an awful lot of antennas and receivers out
there that only claim 2:1 VSWR. The usual spec for the antenna is
1.5:1,
Fat fingers. Replace test with rest.
snip
And it's not clear that there's actually loss due to mismatch. Most
antennas/preamps/receivers don't have exactly 50 ohm impedances. 75/50
is only 1.5:1, and there's an awful lot of antennas and receivers out
there that only claim 2:1 VSWR. The
I can't help you with the outboard monitor, but I can help with the haywire /
mouse situation.
Windows thinks that the serial port has a mouse connected because of the 1 /
second transmissions from the T-Bolt. At boot time Win looks for serial mice
and it gets fooled by seeing something
Edgardo,
Two possibilities: Cathode poisoning or bad tantalum caps. I'm not sure if
cathode poisoning is really the correct term for this effect, but it's
similar. There have been a number of tutorials out there about rejuvenating VF
displays.
The one I have direct experience with is bad
- snip -
Two possibilities: Cathode poisoning or bad tantalum caps. I'm not sure if
cathode poisoning is really the correct term for this effect, but it's
similar. There have been a number of tutorials out there about rejuvenating VF
displays.
- snip -
It appears that the military parts
Thank you to all of the respondents. There is a lot of great information in
the replies. Based on more interaction with our customer it's looking like we
may need to send the unit(s) out to a facility that specializes in this area.
Best regards,
John
-Original Message-
From:
Thank you very much for the thorough reply.
Best Regards,
John
From: saidj...@aol.com [mailto:saidj...@aol.com]
Sent: Wednesday, October 31, 2012 3:17 PM
To: John Lofgren; time-nuts@febo.com
Subject: Re: GPS receiver testing
John,
thanks for your email, I am replying to Time Nuts as well
The 0.5 W and + 10 dBm numbers in the specs don't work out. +10 dBm is 10 mW.
I suspect that the 1/2 watt is really the DC input power.
And, I'd agree about the range. +10 dBm into a dipole at 10 meters gets you
about -44 dBm at the receiver antenna in a free-space model. That's really
snip
I would hence believe that a 50 Hz flicker must be pretty close to the edge of
what can be perceived, so I'm having trouble believing that a flicker at more
than twice that rate would be perceptible at all by anyone.
snip
Oh, but it is. A couple of years ago I bought one of the Chinese 30
Unfortunately I don't have that article, anymore, but I remember the basics
from it. The author used one of the Radio Shack piezo sounder elements as the
pickup. It was one of the 3 wire styles designed for an external oscillator
circuit. I think it might have been around 1 cm diameter.
The
@febo.com
Cc: John Lofgren
Subject: Re: time-nuts Digest, Vol 95, Issue 74
I'm learning a bunch here about filters and pcb techniques. Got one
question that I'm hoping somebody could help me out with:
Date: Thu, 21 Jun 2012 13:39:01 +
From: John Lofgren jlofg...@lsr.com
One thing we have found
The inductors used in this board look like multilayer ceramic chip types. They
actually have a fairly low stray field around them and they're wound around
an axis that's perpendicular to the PCB. Most of the solenoidal coupling will
be in the axis normal to the board. While rotating
This place has them, plus some other stuff that may be of interest to RF types
building outdoor devices:
http://www.sealingdevices.com/products/gore-vents
Unfortunately it looks like you need to ask for a quote, so they may not be
open to small orders.
Also, McMaster Carr has an assortment of
One feature of the Agilent and Rohde scopes (maybe Tek, too?) that can help in
some situations is segmented memory. It allows you to capture periodic or
random events with the full sample rate but to ignore all the dead time between
events. For each trigger it stores one sweep with a time
Check the archives on this one. There have been several discussions in the
past about high heatsink temperatures. Some users have added external fans to
them to get the temperature down.
-John
-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On
I believe so. I don't own a 5370B, but I remember the thread.
What I was thinking of starts here:
http://www.febo.com/pipermail/time-nuts/2010-September/050384.html
Or the complete thread is available here:
http://answerpot.com/showthread.php?1285452-Questions+about+HP+5370B
-John
I did the same thing when I first tested mine. I mounted the regulator and a
pair of SMA jacks right to the board it came with using the big board copper as
the heat sink for the regulator. I didn't want to build a driver for the LED
so I wired it directly (with resistor, of course). Dim and
There have been discussions in the past about ways to reduce regulator output
noise or clean-up oscillator or voltage reference power supplies. Here's an
article from Design Ideas in Electronic Design that looks promising. It has
pretty decent rejection even at 1 Hz.
There's a system that the motorcycle guys call the Whitworth Inch, but I think
may be more correctly called Whitworth Measure. It's an old British system
that was used on their motorcycles and possibly cars, too. There's a whole
subculture of people trading in Whitworth tools for BSA and
fortunately, everything in the lab(basement) is on UPSs so in theory
the input voltages to the equipment should be pretty constant and I
was already planning on using a linear supply.
Be careful, there. Most consumer type UPSs are not line regulators. When
there is sufficiently high line
Thank you.
A good friend of mine is a huge Bob Pease fan and also a devout non-wearer of
seat belts. He's already used-up one of his nine lives on an accident where he
wasn't belted-in.
Hopefully this unfortunate reminder will cause him to change his mind about
belt use.
-John
with your unit?
On Thu, May 5, 2011 at 5:50 PM, John Lofgren jlofg...@lsr.com wrote:
I don't think so. All of the chips that have date codes I can decipher are
from late 1984, or earlier.
I probably should have been more specific, too. It's a model 285-202/NC
with a serial number of 011710
Does anybody have any information available for a Kode (Odetics) model 285 Time
Code Unit? I've checked the usual places (google, BAMA, Didier's site, etc.)
and haven't come up with anything. I see that this question was asked in 2008
and 2009, also. Just checking to see if anything new has
thats misspelled) help.
Can you tell if its newer then 1994?
Regards
On Thu, May 5, 2011 at 4:54 PM, John Lofgren jlofg...@lsr.com wrote:
Does anybody have any information available for a Kode (Odetics) model 285
Time Code Unit? I've checked the usual places (google, BAMA, Didier's site,
etc
Hi Jim,
Try Serialmon:
http://www.serialmon.com/
It has a NMEA packet decoder built in.
- John
-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf
Of Jim Mandaville
Sent: Thursday, January 07, 2010 8:42 PM
To: Discussion of precise time
28 matches
Mail list logo
