On 2014-01-27 23:32, Don Latham wrote:
Mike S
On 1/27/2014 1:33 PM, Robert Atkinson wrote:
I looked at this a while ago. The spec only defines transmission
levels, it does NOT specify receive thresholds.
It certainly does...
2.1.3 For data interchange circuits, the signal shall be
On Sun, 05 Jan 2014 13:35:43 -0800
Hal Murray hmur...@megapathdsl.net wrote:
att...@kinali.ch said:
Also keep in mind that RS-232 relies on the voltage going negative to encode
a 1. I.e. getting 0V is not enough and might only work by chance with some
RS-232 receivers.
I think there
On 27.01.2014 15:08, Attila Kinali wrote:
In practice, the receiver chip only has one power supply. It would take
extra work to make the switching threshold below ground.
That's not correct. Standard transceiver chips (like the MAX232 family)
have an integrated charge pump to get a negative
OK I can add something here.
Yes the spec is correct. But modern receiver chips actually can work with
single side signals. You have to look at the specs of the chip to see what
they will do.
Granted noise immunity is much lower but for most of us in the 10' run
distance its good enough. I operate
.
Robert G8RPI.
From: paul swed paulsw...@gmail.com
To: Discussion of precise time and frequency measurement time-nuts@febo.com
Sent: Monday, 27 January 2014, 14:44
Subject: Re: [time-nuts] Trimble Thunderbolt 1pps
OK I can add something here.
Yes the spec
I pointed out a while ago that the modern chips like the MAX232 have a
positive receiver threshold so TTL drive is fine for short runs.
73,
David
On 1/27/14 10:35 AM, Javier Herrero wrote:
On 27.01.2014 15:08, Attila Kinali wrote:
In practice, the receiver chip only has one power supply.
Specs or not. In real life most computers will accept a TTL level
serial signal. They will also accept one with RS232 levels.
The thing to keep straight is the RS232 uses negative logic for data,
positive logic for control lines and TTL is always positive logic.
You may need some inverters.
So
.
From: Javier Herrero jherr...@hvsistemas.es
To: Discussion of precise time and frequency measurement time-nuts@febo.com
Sent: Monday, 27 January 2014, 15:35
Subject: Re: [time-nuts] Trimble Thunderbolt 1pps
On 27.01.2014 15:08, Attila Kinali wrote:
In practice, the receiver chip only has one
On 27.01.2014 19:33, Robert Atkinson wrote:
All the receiver chips I've looked at, ancient and modern, have only positive
thresholds. Most have single supplies and clamp the input at 1 diode drop
negative WRT common after an input current limiting resistor, see the MC1489
datasheet.
Hello,
On 2014-01-27 12:43, Javier Herrero wrote:
On 27.01.2014 19:33, Robert Atkinson wrote:
All the receiver chips I've looked at, ancient and modern, have only positive
thresholds. Most have single supplies and clamp the input at 1 diode drop
negative WRT common after an input current limiting
On 1/27/2014 1:33 PM, Robert Atkinson wrote:
I looked at this a while ago. The spec only defines transmission levels, it
does NOT specify receive thresholds.
It certainly does...
2.1.3 For data interchange circuits, the signal shall be considered in
the marking condition when the voltage on
we, maybe needed if you're running an ASR-33 teletype. . .
Don
Mike S
On 1/27/2014 1:33 PM, Robert Atkinson wrote:
I looked at this a while ago. The spec only defines transmission
levels, it does NOT specify receive thresholds.
It certainly does...
2.1.3 For data interchange circuits,
-nuts@febo.com
Sent: Tuesday, 28 January 2014, 2:01
Subject: Re: [time-nuts] Trimble Thunderbolt 1pps
On 1/27/2014 1:33 PM, Robert Atkinson wrote:
I looked at this a while ago. The spec only defines transmission levels, it
does NOT specify receive thresholds.
It certainly does...
2.1.3
I may have posted this link before. It is on topic, even though I was using
coax cable:
http://ko4bb.com/Test_Equipment/CoaxCableMatching.php
It would be easy to do the same experiment with cat-5 cable. I would expect the
pictures to look somewhat similar.
Didier KO4BB
Tom Van Baak
att...@kinali.ch said:
Also keep in mind that RS-232 relies on the voltage going negative to encode
a 1. I.e. getting 0V is not enough and might only work by chance with some
RS-232 receivers.
I think there are 2 parts to this discussion. What do the specs say, and
what actually happens in
Interesting discussion re getting the 1PPS into a PC to synchronise a
timing program.
I use WSPR for ham radio and was wondering how to do this.
Can you tell me which (Windows) time synch programs can use the 1PPS on
DCD of the RS232 interface please?
Next step would be to build a variable
On Sat, Jan 4, 2014 at 12:36 AM, David J Taylor
david-tay...@blueyonder.co.uk wrote:
Interesting discussion re getting the 1PPS into a PC to synchronise a
timing program.
I use WSPR for ham radio and was wondering how to do this.
Can you tell me which (Windows) time synch programs can use
Since I had a couple of spare RS-232 driver gates, I built a simple PPS
extender/level shifter in my Thunderbolt Monitor kit. It is not as general
purpose (not configurable) as the Fat PPS kit from TAPR, but it works well for
the Thunderbolt. You could easily build the circuit on a piece of
albertson.ch...@gmail.com said:
Where those using the cat-5 wire as a twisted pair? If sothat's cheating
Yes. I was thinking that 4 pairs would be Rx, Tx, PPS, and power. If I need
Ethernet, I'll pull another Cat-5.
--
These are my opinions. I hate spam.
On Sat, Jan 4, 2014 at 12:05 PM, Hal Murray hmur...@megapathdsl.net wrote:
albertson.ch...@gmail.com said:
Where those using the cat-5 wire as a twisted pair? If sothat's
cheating
Yes. I was thinking that 4 pairs would be Rx, Tx, PPS, and power. If I
need
Ethernet, I'll pull another
and frequency measurement
time-nuts@febo.com /divdivRubrik: Re: [time-nuts] Trimble Thunderbolt
1pps /divdiv
/divOn Sat, Jan 4, 2014 at 12:05 PM, Hal Murray hmur...@megapathdsl.net
wrote:
albertson.ch...@gmail.com said:
Where those using the cat-5 wire as a twisted pair? If sothat's
cheating
Pulse quality of single-ended RS232 over unbalanced twisted pair is going
to be pretty bad beyond a few feet. If you want to transport the 1pps over
twisted pair there are a couple of options:
Hi Brian,
I suspect this is true at one level, but what would be helpful to to *quantify*
it. What
On Sat, Jan 4, 2014 at 1:51 PM, Tom Van Baak t...@leapsecond.com wrote:
Pulse quality of single-ended RS232 over unbalanced twisted pair is going
to be pretty bad beyond a few feet. If you want to transport the 1pps
over
twisted pair there are a couple of options:
Hi Brian,
I suspect
On Sat, Jan 4, 2014 at 3:51 PM, Tom Van Baak t...@leapsecond.com wrote:
Pulse quality of single-ended RS232 over unbalanced twisted pair is going
to be pretty bad beyond a few feet. If you want to transport the 1pps
over
twisted pair there are a couple of options:
Hi Brian,
I suspect
Does the Trimble Thunderbolt provide 1pps on DCD of the RS232 interface?
--
Brian Lloyd, WB6RQN/J79BPL
706 Flightline Drive
Spring Branch, TX 78070
br...@lloyd.com
+1.916.877.5067
___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to
No. The serial port is just three wires, the PPS signal is TTL level on
one of the BNC connectors.You will have to level sift it to re-232
voltage levels and then make a costom cable
On Fri, Jan 3, 2014 at 7:50 AM, Brian Lloyd br...@lloyd.com wrote:
Does the Trimble Thunderbolt provide
On Fri, Jan 3, 2014 at 11:35 AM, Chris Albertson
albertson.ch...@gmail.comwrote:
No. The serial port is just three wires, the PPS signal is TTL level on
one of the BNC connectors.You will have to level sift it to re-232
voltage levels and then make a costom cable
Thank you. No problem.
Does the Trimble Thunderbolt provide 1pps on DCD of the RS232 interface?
No, but you can open it up and add a wire. That will give you CMOS rather
than RS232, but it works. (Or at least, it works for me and I've never heard
a good story where it didn't work.)
One problem is that the PPS
The TTL level PPS did not work for me when I tried to drive a long cable.
I used the MAX232 level converter chip to level shift.
Do check the polarity. If you get it wrong it will appear to work but the
timing will biased by the pulse width. (the falling edges is used if you
get it wrong.
albertson.ch...@gmail.com said:
The TTL level PPS did not work for me when I tried to drive a long cable.
I used the MAX232 level converter chip to level shift.
Thanks.
How long was the cable?
How solid was the driver? (How much of the problem was long cable vs weak
driver?)
--
These
The line driver was a TTL inverter chip I was going through about 50 or
60 feet of cat-5 wire.
TTL level serial is always marginal, the specs say it should not work but
it does work most of the time.
I found a soave of DB9 connectors that have built-in MAX232 chips on ebay
for under $5. I use
On Fri, 3 Jan 2014 13:12:52 -0800
Chris Albertson albertson.ch...@gmail.com wrote:
The TTL level PPS did not work for me when I tried to drive a long cable.
I used the MAX232 level converter chip to level shift.
Do check the polarity. If you get it wrong it will appear to work but the
albertson.ch...@gmail.com said:
The line driver was a TTL inverter chip I was going through about 50 or
60 feet of cat-5 wire. TTL level serial is always marginal, the specs say it
should not work but it does work most of the time.
Modern CMOS chips work much better than real TTL. Some CMOS
Hal,
Your plots don't show the wave being reflected by the cable end, and bouncing
back and forth.. Until settling down.
Without an end-termination the improperly terminated output of the Thunderbolt
will cause the signal to bounce back and forth..
If there is a 50 ohms termination, there
saidj...@aol.com said:
Your plots don't show the wave being reflected by the cable end, and
bouncing back and forth.. Until settling down.
Yes. I'll put up some nasty pictures if anybody wants an ugly example.
For that set of graphs, I tried to get rid of that sort of junk. I was
working
Hi Hal,
still pretty impressive results, thanks for sharing the data.
bye,
Said
In a message dated 1/3/2014 17:10:13 Pacific Standard Time,
hmur...@megapathdsl.net writes:
saidj...@aol.com said:
Your plots don't show the wave being reflected by the cable end, and
bouncing back and
Interesting discussion re getting the 1PPS into a PC to synchronise a
timing program.
I use WSPR for ham radio and was wondering how to do this.
Can you tell me which (Windows) time synch programs can use the 1PPS on
DCD of the RS232 interface please?
Next step would be to build a variable
Can you tell me which (Windows) time synch programs can use the 1PPS
on DCD of the RS232 interface please?
To answer my own question:
Here's one...
http://www.visualgps.net/NMEATime/default.htm
There are a few others listed at
http://www.gpskit.nl/links-en.htm
Zim
On Fri, Jan 3, 2014 at 8:32 PM, Graeme Zimmer gzim...@wideband.net.auwrote:
Can you tell me which (Windows) time synch programs can use the 1PPS on
DCD of the RS232 interface please?
To answer my own question:
Here's one...
http://www.visualgps.net/NMEATime/default.htm
There are a few
Where those using the cat-5 wire as a twisted pair? If sothat's cheating
I was truing to send an RS232 signal down a cat 5 cable. That means Tx, Rx
Gnd and DCD. You need four wires for that, ethernet uses the other two
pair.I was using the pairs Ethernet does not use.
The solution was to
Unless you bring the 1pps in and synchronize with that, you are
probably better off just running NTP.
Yes, that is the idea.
I often don't have access to the Internet when running WSPR.
eg when operating portable in remote areas or marine.
Thanks . Zim
On Fri, 29 Aug 2008 22:21:43 -0400, Pieter Ibelings wrote:
Hi All,
I got a Trimble Thunderbold from Ebay and I am having trouble triggering the
HP 53131A. The 1PPS output shows a 10us pulse of 1 Volt into a high
impedance probe. This seems low to me. Should it be 5 volts? Maybe the
output
and frequency measurement
time-nuts@febo.com
Sent: Saturday, August 30, 2008 10:12 AM
Subject: Re: [time-nuts] Trimble Thunderbolt 1PPS TTL level?
On Fri, 29 Aug 2008 22:21:43 -0400, Pieter Ibelings wrote:
Hi All,
I got a Trimble Thunderbold from Ebay and I am having trouble triggering
the
HP 53131A
Hi All,
I got a Trimble Thunderbold from Ebay and I am having trouble triggering the
HP 53131A. The 1PPS output shows a 10us pulse of 1 Volt into a high
impedance probe. This seems low to me. Should it be 5 volts? Maybe the
output 74AC04 is toast?
Pieter, N4IP
Have you tried terminating it with 50ohms? That was the trick for mine.
Scott
Pieter Ibelings wrote:
Hi All,
I got a Trimble Thunderbold from Ebay and I am having trouble triggering the
HP 53131A. The 1PPS output shows a 10us pulse of 1 Volt into a high
impedance probe. This
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