Hi Larry,
I use a linear supply for mine.
My supply is actually a headphone amp supply kit from JayCar Electronics
here in Australia. Its basically two LM317's and a 7805 for 5v. I
changed the resistor that set the output voltage from 15v to 12v and
also selected an appropriate toroid
dropout works with a +/- 12 volt +5 volt
switcher.
Bob
-Original Message-
From: Larry McDavid
Sent: Thursday, February 10, 2011 6:46 PM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] Thunderbolt Supply
Certainly, I'd prefer a linear 3-output supply
Larry--
I use a +12 volt linear supply (an open-frame leftover) with a 7805 for the +5
rail. For -12, I use a 2 watt isolated dc-dc converter (leftover from another
project).
As others have stated, the +12 rail seems to be the noise sensitive one.
73 bob k6rtm in silicon valley
I use a 16 Volt Laptop power supply followed by Low Noise LT1764A linear
regulator for +12 and a 7805 for the logic. If you want to splurge use a
LT1764A also for the +5.. To generate the -12V a Microchip TC962 followed by
a 79L12 does a nice job. The +5 and -12 are not that critical. That
Subject: Re: [time-nuts] Thunderbolt Supply
Certainly, I'd prefer a linear 3-output supply. But, I've not found a
suitable one yet, in linear or switching. TAPR offered one in the past
but has no more. So, I'm asking for recommendations and where to get one.
Larry
On 2/10/2011 3:32 PM, J. L
That's odd. I just went to the TAPR.org web site and can still
seem to order an LPU kit for around $43 US.
I'm using a TAPR/OpenHPSDR LPU to run two Thunderbolts. The LPU
is operating on 13.6 volts off the house battery. The -12 volts
is switching, the other two voltages are linear.
I
Looks to be mostly a plot of the 5370B's noise floor at low taus.
You may need something a couple of decades better if you want to measure the
Tbolt at that tau setting.
BTW, You should NOT set the TBolt's TC to 999 sec. I have found that the
control can become somewhat unpredictable, AKA
Thanks for the comments.I did a quick check of the noise floor of the 5370b
while feeding the 10 mhz output of the tbolt to the start and stop inputs of
the 5370b with a t connector. At a tau of 10 (approx 2.5 seconds) the Allan
deviation is 1x10-11, at a tau of 100 (approx 25 seconds) it
Hi
There's pretty much nothing in a TBolt that wears out. The heat rise on the
parts on the pc board is modest and the only heated part is the OCXO.
Cooling down the OCXO actually increases the stress on it (more heater power
pulled = more stress on the heater).
Obviously you can get it to hot.
On Tue, Jan 18, 2011 at 9:16 AM, Pete Lancashire
p...@petelancashire.com wrote:
Been getting ready to build a box for the t'bolt and instead of it all
getting hotter to maintain a stable temp
is the idea of cooling with a Peltier cooler, or a mix of a Peltier
I've used Peltier cooling. It
sound like not worth it. My idea of 'cooling' was say keeping the insides
at something like 25C. Just having a 2nd TBolt as a spare would be easier
-pete
On Tue, Jan 18, 2011 at 9:41 AM, Bob Camp li...@rtty.us wrote:
Hi
There's pretty much nothing in a TBolt that wears out. The heat rise on
I've done a couple projects/contracts with them, still have a few
dozen units, power supplies,
heat pipes etc.
but I've ditched the idea. Spare T'Bolt or two should exceed my life.
-pete
On Tue, Jan 18, 2011 at 10:12 AM, Chris Albertson
albertson.ch...@gmail.com wrote:
On Tue, Jan 18, 2011 at
Peltier takes to much power and generates more heat. A fan will work
nicely.
Bert Kehren
In a message dated 1/18/2011 12:17:00 P.M. Eastern Standard Time,
p...@petelancashire.com writes:
Been getting ready to build a box for the t'bolt and instead of it all
getting hotter to maintain a
Comes down to the simple fact that it needs to know its position accurately
in order to give you good timing. I found this one out the hard way many
(many) years ago with an old single channel Trimble unit, where we had to
manually enter a known position in order to speed up acquisition. We were
...@febo.com [mailto:time-nuts-boun...@febo.com] On
Behalf Of Robert Darlington
Sent: 26 November 2010 9:23 PM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] Thunderbolt Lady Heather 48 hour precision survey
I'm running another test now and it's significantly improved
On 11/27/2010 11:33 AM, Rob Kimberley wrote:
Comes down to the simple fact that it needs to know its position accurately
in order to give you good timing. I found this one out the hard way many
(many) years ago with an old single channel Trimble unit, where we had to
manually enter a known
Hi
Of course you *do* have the excuse that you had to stop and think for a second
as to weather it *was* east or west of Greenwich ...
Bob
On Nov 27, 2010, at 5:33 AM, Rob Kimberley wrote:
Comes down to the simple fact that it needs to know its position accurately
in order to give you good
Bob Camp wrote:
Hi
Of course you *do* have the excuse that you had to stop and think for a second
as to weather it *was* east or west of Greenwich ...
Bob
Is it not both? It was a few degrees west, but a mere 359.5 degrees east.
___
time-nuts
...@febo.com] On
Behalf Of jimlux
Sent: 27 November 2010 3:31 PM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] Thunderbolt Lady Heather 48 hour precision survey
Bob Camp wrote:
Hi
Of course you *do* have the excuse that you had to stop and think for a
second
-
From: time-nuts-bounces at febo.com [mailto:time-nuts-bounces at febo.com]
On
Behalf Of Robert Darlington
Sent: 26 November 2010 9:23 PM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] Thunderbolt Lady Heather 48 hour precision survey
I'm running another test
...@febo.com [mailto:time-nuts-boun...@febo.com] On
Behalf Of jimlux
Sent: 27 November 2010 3:31 PM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] Thunderbolt Lady Heather 48 hour precision survey
Bob Camp wrote:
Hi
Of course you *do* have the excuse
-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On
Behalf Of jimlux
Sent: 27 November 2010 3:31 PM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] Thunderbolt Lady Heather 48 hour precision survey
Bob Camp wrote:
Hi
Of course you *do* have the excuse that you
:15 AM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] Thunderbolt Lady Heather 48 hour precision survey
Right, For best performance, in fix mode operation, for a Tbolt, you don't
want to run at zero (or 5) degrees.
This is just one test in a series of necessary
.?
Joe
-Original Message-
From: time-nuts-bounces at febo.com [mailto:time-nuts-bounces at febo.com]
On
Behalf Of WarrenS
Sent: Saturday, November 27, 2010 11:15 AM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] Thunderbolt Lady Heather 48 hour precision
Sent: 26 November 2010 9:23 PM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] Thunderbolt Lady Heather 48 hour precision
survey
I'm running another test now and it's significantly improved after the 48
hour survey. Before I'd see several degree swings over
: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On
Behalf Of William H. Fite
Sent: 27 November 2010 6:07 PM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] Thunderbolt Lady Heather 48 hour precision survey
Interesting. I had my tbolt mask set at 10
On Fri, Nov 26, 2010 at 6:41 AM, Robert Darlington rdarling...@gmail.comwrote:
I keep it in a styrofoam beer cooler surrounded with bottled water in a
draft free area and it's been all over the map.
Robert-
Are you doing this for temperature stability? How stable is it?
Dave
I'm running another test now and it's significantly improved after the 48
hour survey. Before I'd see several degree swings over the course of an
hour, now it's more like 1.1 degrees in the last 8 hours. The problem here
is I didn't do anything to the styrofoam box, but the idea was to keep
There is an EEPROM that can be used to store parameter such as the
initial DAC voltage, position, etc. but it's not automatic. Have you
explicitly saved the position (or auto stored it) after the survey is
complete? If you don't do this then it will have to do a survey on every
startup and
I had the same problem with my Thunderbolt shortly after I got it and the
problem turned out to be the power supply had gone bad and the voltages
supplied to the tbolt were way off (but close enough to give a ~10Mhz 1pps
signal). I would suggest checking each pin on the plug and make sure the
I bought two TAPR ThunderBolts and on one of them
the serial port would quit communicating after a
while. There was no response to any command, only
removing the power and then restoring power would
get it talking again. My power supply was okay.
I opened the T-Bolt and inspected the solder
NOTE: If you boot Windows with your ThunderBolt
connected to the Com port, Windows will think it
is a serial mouse and grab the port. It can lead
to some interesting Windows behavior as the T-Bolt
outputs data.
Mike - AA8K
Easy fix. Add the following to your Boot.ini file. Obviously,
Hi
Temperature moved about 8 C. That's enough to get a bad solder joint going.
Bob
On Sep 27, 2010, at 11:19 PM, Peter Putnam pico.2...@sbcglobal.net wrote:
Greetings,
I have posted two plots graciously provided for me by Lady Heather, showing
strange behavior in my recently acquired
See http;//www.ko4bb.com/Test_Equipment/Thunderbolt/PulseStreching/
Didier KO4BB
Sent from my Verizon Wireless BlackBerry
-Original Message-
From: Arthur Dent golgarfrinc...@yahoo.com
Sender: time-nuts-boun...@febo.com
Date: Sun, 26 Sep 2010 05:07:50
To: time-nuts@febo.com
Reply-To:
I was thinking of modifying my Tbolt to put the 1 PPS on one of the unused
RS-232 leads. It just seems like it would be really convenient to have
that signal available to import into a computer.
NTP expects the PPS signal on pin 1, DCD.
It looks like it's not going to be quite as simple
Hal Murray wrote:
I was thinking of modifying my Tbolt to put the 1 PPS on one of the unused
RS-232 leads. It just seems like it would be really convenient to have
that signal available to import into a computer.
NTP expects the PPS signal on pin 1, DCD.
It looks like it's not
Problem 2: Because you connected the TTL-level 1 PPS to the RS-232, you
may find that not all computers will recognize it. A computer that
actually followed the RS-232 rules wouldn't see it at all. I don't know if
any modern computer actually follows those rules.
I've never had any
Between Tboltmon and Ladyheather, you'll see that your unit either works or it
doesn't. My bet is that it will work just fine, even if the antenna is indoors-
and then you won't be able to stop watching it (esp. with lady heather) for at
least a few hours... Have fun!
Dave
- Original
Hello,
On Mon, Sep 20, 2010 at 12:21 PM, d.sei...@comcast.net wrote:
Between Tboltmon and Ladyheather, you'll see that your unit either works or
it doesn't. My bet is that it will work just fine, even if the antenna is
indoors- and then you won't be able to stop watching it (esp. with lady
, 20 Sep 2010 12:31:09 +0200
From: francesco messineo francesco.messi...@gmail.com
Subject: Re: [time-nuts] Thunderbolt initial check out?
To: Discussion of precise time and frequency measurement
time-nuts@febo.com
Message-ID:
aanlktimqjxpyhxrref3xsx03rhg_b35b9qop_efdy...@mail.gmail.com
Russell,
Load TBoltMon on your computer, connect the TBolt to the Serial Port,
connect the antenna, connect the power supply (make sure of the correct
connections), fire up your computer, then turn on the TBolt, double click
the TBoltMon icon, select the appropriate port, and just watch what
Hi
The unit you get may be set up for some strange location. It's possible you
will need to reset it to factory defaults before it will do it's thing.
Lady Heather is a good program to dig into a TBolt with. It's free...
Bob
On Sep 19, 2010, at 6:47 PM, russell wrote:
This is my first
On Sep 19, 2010, at 4:38 PM, Bob Camp wrote:
Lady Heather is a good program to dig into a TBolt with. It's free...
It also plots oscillator and PPS error (the oscillator error plot may be off by
default). If the error plots look good and both signals can be seen at the BNC
outputs with an
Your biggest problem may be to find the COM port that your TBolt is
connected to.
You may have to configure the port to the baud rate etc of the Tbolt
(or visa versa)
A Tbolt will work OK with a USB-to-Serial port converter but you have
to find the port
allocation and baud rate.
I once
mspencer12...@yahoo.ca said:
Would any one be able to point me towards a web site that shows the power
supply pinout for the bare thunderbolt board (without the power supply
board.)
http://www.leapsecond.com/pages/tbolt/power.htm
--
These are my opinions, not necessarily my employer's.
Thanks that is very helpfull.
- Original Message
From: Roberto Barrios rbarri...@msn.com
To: time-nuts@febo.com
Sent: Fri, September 10, 2010 10:50:51 PM
Subject: [time-nuts] RE: Thunderbolt power supply hookup
Hi Mark,
You will find that and lots of other very interesting info at
Thanks that all makes sense and power up went ok.
- Original Message
From: Hal Murray hmur...@megapathdsl.net
To: Discussion of precise time and frequency measurement time-nuts@febo.com
Sent: Fri, September 10, 2010 11:04:21 PM
Subject: Re: [time-nuts] Thunderbolt power supply hookup
From: Hal Murray hmur...@megapathdsl.net
To: Discussion of precise time and frequency measurement time-
n...@febo.com
Sent: Fri, September 10, 2010 11:04:21 PM
Subject: Re: [time-nuts] Thunderbolt power supply hookup
mspencer12...@yahoo.ca said:
Would any one be able to point me towards a web
The default parameters are a compromise. The thunderbolt was originally used
to provide time and frequency, though I understand not always frequency, for
cellsites. Though heated and air conditioned, I suspect they had pretty good
temperature swings. Also, the sky view was not always optimum. It
think
that was the wrong decision, but that's what they went with.
Bob
-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On
Behalf Of John Green
Sent: Wednesday, June 16, 2010 9:32 AM
To: time-nuts@febo.com
Subject: Re: [time-nuts] Thunderbolt test
One time did 0.8 , 1.0 and 1.2 at 100 seconds and did not see much change.
Its in the works one day to play with it some more, when I have more
TIME
Brian
Peter Vince wrote:
Have you played with the damping factor Brian?
Peter
___
Have you played with the damping factor Brian?
Peter
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and follow the instructions there.
Hi
The monitor programs should let you know where the DAC voltage is on your unit.
If it's 1.9 Hz high and in the center of DAC range, that's fine.
Since you have no alarms popping up, I'd guess that the problem has to be
pretty close to the GPS front end. The previously mentioned RF amp is a
Hi
The vertical axis on the plot is pretty tough to read. What is the scale?
Bob
On Jun 11, 2010, at 8:43 AM, Donal G wrote:
Hi Guys,
I bought a Thunderbolt device recently. I have done some
10Mhz frequency tests in comparison to a Cesium reference.
Attached is MTIE plot. Have any of
HI Bob,
10 nanoseconds at the bottom, up to 10 microseconds at the top,
in three logarithmic sections.
Donal: Is the time-constant at its default of 100 seconds, and was the
above plot taken shortly after turning it on? There has been lots of
talk on here about tweaking the performance.
Hi
Ok, then the TBolt is running 100 to 200 ns for a tau of 12 seconds to 280K
seconds.
Without looking at the raw data it's tough to see what's going on. The numbers
are 5 to 10X worse than I would have expected them to be.
One of the monitor programs (like Lady Heather) might be useful
I changed the disciplining time constant on my Thunderbolts and you can
improve it (over the 100 second default). I changed it to 200 sec, then
ran a day, the 300 sec, ran another day, etc.
One unit was best at 400 seconds, the other unit at 600 seconds. What
you should see is less movement
In a message dated 10/06/2010 23:34:05 GMT Daylight Time,
hol...@hotmail.com writes:
I'm not sure of the required power spec, but 28V may be too low. These
were meant to run off a telco power bus (nominal 48V).
I run mine at 40V (from a Tek PS503A mounted in a TM501 mainframe, unit
Hi Steve,
I don't know what the issue is, but my experience was very similar. My Tbolt
is the same (or very similar) to yours and worked fine for a few years off and
on. When Lady Heather became available, I took it out again. It worked great
with the antenna indoors in my lab for
Hi
I would certainly check the solder connections to the RF and power connectors
on the PC board. Some of them apparently didn't get a real good solder job when
they were new.
Bob
On Jun 10, 2010, at 3:09 PM, Steve wrote:
Hi all,
I have used a Trimble Thunderbolt for several years as a
In a message dated 10/06/2010 20:14:40 GMT Daylight Time,
stev...@suddenlink.net writes:
Input voltage to the poor performing unit is about 28VDC. I did the
tboltmon.exe Factory Reset with no discernible difference in
performance. It is the Thunderbolt model in the aluminum housing with
My understanding is that you have the older red box. Manual for the red box
is there:
http://www.ko4bb.com/Manuals/05%29_GPS_Timing/Trimble/Trimble_-_Thunderbolt/
ThunderBolt_Datasheet_%28red_box%29.pdf
The power spec is 24V nominal, 18V min to 36V max
Mine has been running off a small open
The TB has an error flag if there is no antenna connected (open) or if it is
shorted. The tboltmon PC software reports these flags, and so does my GPSMon
firmware in the fluke.l monitor.
It is possible but unlikely that there would be something wrong with the bias
circuit that would not be
The voltages I measure are 11.8, -12.3 and 4.9VDC. Those measurements
are with the unit operating and the power supplies under normal load.
There is 4.7VDC on the feed to the antenna, that is with the coax
attached to the Thunderbolt.
Arthur's suggestion that something is amiss in the RF
Hi
I suspect that the unit puts out an ok 10 MHz signal. That would suggest that
the +12 and likely the +5 supplies are ok. If the monitor software can talk to
it, that's another indication that the +/-12 and +5 are fairly close to
working.
I think that a problem with the GPS front end /
Hi Bob,
I took a look at the 10MHz output. The unit had been unpowered on my
bench for an hour or so. It took about 10 minutes to stabilize at 1.9Hz
on the high side of 10MHz as measured on a GPS-referenced counter.
Oscilloscope indicates a level of about +12dBm and a clean looking sine
and frequency measurement
time-nuts@febo.com
Sent: Monday, May 24, 2010 7:10 PM
Subject: Re: [time-nuts] Thunderbolt, Rb, Scopes at SF Bay Maker Faire this
weekend
I received some messages asking how the demo went, so I'll summarize here.
If you weren't originally interested in this demo
I hope it is a LONG show with a lot of patent people.
This is way above the typical WWV stuff.
Any good adjusted RB with a correctly set up Tbolt will take 2.5 hrs to do
the 360.
Delta 1e-11 = 10,000 sec for 100 ns change.
I understand it is not what your desired goal is,
But would be much
Hi
The rubidium should tune over a +/- 1x10^-9 range. A nanosecond per second
isn't all that hard to spot. At 10 MHz you'll do a full 360 in 100 seconds.
Bob
On May 20, 2010, at 5:57 PM, WarrenS wrote:
I hope it is a LONG show with a lot of patent people.
This is way above the typical
True,
I did not consider they may want to Mis-Tune something to its limit
Why not use a good OXCO, with a pot connected to its EFC?
Now that would make a good demo and show some practical use, and only need to
wait around a sec or so.
and it would be much more fun than watching the RB drift
Hi
You can tune it from easy to impossible and still know where it is for
judging purposes. Sounds like a pretty good way to do it.
Bob
On May 20, 2010, at 6:18 PM, WarrenS wrote:
True,
I did not consider they may want to Mis-Tune something to its limit
Why not use a good OXCO, with
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
Tomorrow, the school demo will be a paper scope made out of a yard stick, a
marker, and wall-chart paper: one student holds the oscillating yard stick,
a second pulls the paper steadily, and a third times it. Afterward, they
count peaks and divide by time.
Neat. Scopes are fun.
The
Hi
The point is that you can indeed get into trouble before the internal regulator
drops out. How much trouble depends on the design of the heater.
Bob
On Apr 26, 2010, at 8:26 PM, Arthur Dent wrote:
Bob Camp-In addition to the influence of the voltage on the oscillator, the
voltage
On 26/04/2010 09:02, Ed Palmer wrote:
In the Thunderbolt the +12 runs the oscillator. Won't an unregulated,
but relatively steady, +12 supply degrade the performance of the
oscillator or does the Tbolt have a built-in regulator to deal with this?
There is some interesting reading on this
Please excuse the individual message.
Tom Van Baak, I sent you a direct reply about my
Thunderbolt quitting and I suspect that e-mail is
being filtered somewhere. I have been using your
tvb LeapSecond address.
Please reply to my a...@comcast.net and aa8k.arrl.net
addresses, in case Comcast
Hi
The simple answer is that there is no regulator in the TBolt between the OCXO
and the +12 supply. A well regulated supply is a good idea.
The common suggestion is to run a ~ +15 supply and regulate it to +12 at the
TBolt. Depending on the regulator you use, You might be able to get away
Hi Paul,
Yes, I've read that page a couple of times, but it doesn't say whether
the Ault, Meanwell, or Acopian power supplies have a 'regulated' or a
'close enough' +12 supply. I think that the two variable power supplies
would be well regulated. I can pretty well guarantee that the ATX
Hi
I'd say those are all pretty safe guesses with any modern OCXO. The drop out
on the internal regulator is likely to be well below anything we would put
on the +12 supply.
The Trimble spec on the TBolt shows a +/- 10% tolerance on the +12V supply.
From that I'd assume you could run the unit
Hi Bob,
Where did you find that 10% spec? I looked in the Tbolt book and the
data sheet but didn't see it.
Ed
Bob Camp wrote:
Hi
I'd say those are all pretty safe guesses with any modern OCXO. The drop out
on the internal regulator is likely to be well below anything we would put
on the
Hi
That's where I found it.
Bob
-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On
Behalf Of Arthur Dent
Sent: Monday, April 26, 2010 4:01 PM
To: time-nuts@febo.com
Subject: [time-nuts] Thunderbolt Power Supply Question
Ed Palmer-Where did you
Arthur Dent wrote:
The +12VDC supply (internal to the sealed oscillator) supplies both the oven
and the oscillator circuits. I think you'll find that internally this +12VDC
goes to the heater circuit as well as through a regulator to the oscillator
which is running on something like +7VDC.
Hi Robert,
Robert Atkinson wrote:
Hi Ed,The better quality industral power supplies normally have a regulator for each rail. Some specifications will put a minimum load requirement on the primary supply though.
You're right that better quality power supplies have regulation on all
outputs. I
Hi Arthur Bob:
Okay, it's official. I'm blind. I don't know how I missed that.
Thanks for pointing it out.
Ed
Bob Camp wrote:
Hi
That's where I found it.
Bob
-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On
Behalf Of Arthur Dent
Sent:
Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On
Behalf Of Ed Palmer
Sent: Monday, April 26, 2010 5:25 PM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] Thunderbolt Power Supply Question
Hi Robert,
Robert Atkinson wrote:
Hi Ed
measurement
Subject: Re: [time-nuts] Thunderbolt Power Supply Question
Hi Robert,
Robert Atkinson wrote:
Hi Ed,The better quality industral power supplies normally have a
regulator for each rail. Some specifications will put a minimum load
requirement on the primary supply though.
You're right
Hi
In addition to the influence of the voltage on the oscillator, the voltage
change also impacts the temperature control circuit. Most OCXO's control
current through the heater rather than power in the heater. As you drop
voltage, the power being controlled drops. The net effect is a change
Please excuse the individual message.
Tom, I sent you a direct reply over 24 hours ago, and
I suspect that e-mail from me to you is being filtered,
as I also sent you a direct e-mail on 6/April about
my Thunderbolt problem. I have been using your
tvb leapsecond address.
Yes, I'd appreciate
Do anyone have a troubleshooting suggestion?
I've been having a chronic problem with one of the TAPR
Thunderbolts that I bought; it just stops communicating.
I have to power it down and back on to talk to it.
I originally attributed it to my PC's RS-232 interface,
but since I have gotten the
Do anyone have a troubleshooting suggestion?
Cold solder joint on RS232 connector.
Stanley
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Hello Maury,
A Lady Heather screen grab would be helpful in understanding the issue.
How is the power supply doing ?
I once had a flakey power supply that gave me abnormal readings.
Stan, W1LE Cape Cod
msproul wrote:
I have a Tbolt (labeled Rev. E, 5/31/05) that seems to be working
It sounds like you have a Tbolt with the newer rev E (or greater) temp
sensor chip... which is not totally compatible with the tbolt firmware.
Dallas Semiconductor changed the DS1620 chip design and made it so the Tbolt
cannot do high resolution temperature readings.
That's a dramatic and impressive difference Mark! Were the other
choke-rings similarly better than the ordinary conical, or was this
one heads and shoulders better than the rest? I was just wondering if
it was the choke-ring concept that gave the major improvement, with
this one just being
Good information to know, if one is doing survey work.
But some NON-Nut needs to ask, SO WHAT?
A 3 foot error may cause + - 3ns of additional phase time error, which is
well below the short term GPS noise level.
If that is averaged over the 500 or so second TC loop or the 48 hrs supper
survey
I use one like eBay item 290369619357. I have it attached to the corner of
my workshop roof which is under a canopy of trees. It is connected through
about 25 feet of Belden 9913F7 and it works like a champ. Relatively
inexpensive if it gets taken out by a storm.
Joe
-Original
Hi
That's quite an antenna. 10 lbs and 14 diameter
Bob
On Mar 11, 2010, at 11:29 PM, Mark Sims wrote:
It doesn't get any better than Ebay item 270262189976... I've tested a
couple dozen antennas and nothing comes close to what it does... It's big.
It's pricey (but FAR less than
Looks like a standard choke ring antenna.
Bruce
Bob Camp wrote:
Hi
That's quite an antenna. 10 lbs and 14 diameter
Bob
On Mar 11, 2010, at 11:29 PM, Mark Sims wrote:
It doesn't get any better than Ebay item 270262189976... I've tested a couple
dozen antennas and nothing comes
Mark wrote:
It doesn't get any better than Ebay item 270262189976... I've
tested a couple dozen antennas and nothing comes close to what it
does... It's big. It's pricey (but FAR less than the $2000+
original cost). It's good.
On Mark's advice, I got one of these a few months ago. It
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
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,
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