It all harkens back to the old teletype machine. Teletypes used a
current loop interface, and to make sure that it was immediately
obvious if the interface was broken... eg. the lines were down, the
teletype was designed so that when there was current, the printer
was silent, and it was the lack
You have it 100% correct. The UT+ uses "positive" logic are the logic 1 is
5-volts but the RS-232 standard uses "negative" logic. I think the MAX232
does the conversion correctly EXCEPT if you read the RS-232 standards they
use positive logic for the control signals.
On Fri, Jul 12, 2013 at 7:
Hi Brian,
That's just strange. There are a whole lot of these MAX232 and MAX3232 devices
being sold. Hmm, I'm looking at the UT+ User's Guide, and it lists the voltage
levels as follows. These would imply that an inverter is necessary, right?
Could it be that someone programmed your PIC ups
Hi Bob,
Here is my experience. I had a PIC that output RS232 at 0-5 volt
levels. It actually worked with my computer directly. When I added a
MAX 232 to make the levels something like -10/+10 volts. It didn't
work. That's because the MAX232 inverts the polarity. Look at the data
sheet,
Hi Brian,
I don't understand. Are you saying that I need to add still more parts to get
an RS-232 to TTL adapter to work? Here's the circuit for what I'm currently
using, and it looks like it's inverter based. I'm not using it, because it's
the only one I have and I want to keep it available
Bob said {the 10811 will run fine without the outer oven}
What I've seen is that a dual oven 10811 will run even **finer** and have up
to 100 times less sensitivity to normal room temperature changes with a
simple outer oven controller and a few mods.
In 2010 I compared the performance of a T
Hi Chris,
I ordered a similar one today, along with a 10ft Male-Male serial cable. I'm
looking forward to getting the hardware finished. I put a ZIF on the VE2ZAZ
board, so next I'll probably be playing with the software. Someone on the list
talked about FLL vs PLL with this card, so I'll ex
Max 232's invert the polarity. You have to follow with an inverting
gate if the TTL stuff worked.
Brian
On 7/13/2013 00:27, Chris Albertson wrote:
I have a UT+ I bought a TTL-RS232 converter on eBay the converter is built
into a DB-9 socket. It uses male header pins for conniption, the sam
I have a UT+ I bought a TTL-RS232 converter on eBay the converter is built
into a DB-9 socket. It uses male header pins for conniption, the same
kind of pins as on the UT+
Look at item # 330838910970 on eBay. It is almost exactly what I have,
lots of people sell them. It is just the max232 ch
The altidutes don't match because each is relative to something different.
The GPS is likely referenced to the WGS84 spheroid and the one on the USGS
top map is mean sea level. Check up what is is relative to there can be a
lot of difference.
On Fri, Jul 12, 2013 at 12:56 PM, Jim Sanford wrote
Jim
My guess would be the antenna does not have a clear view, high lead loss.
Or the mask angel is set to something crazy.
Paul
WB8TSL
On Fri, Jul 12, 2013 at 3:56 PM, Jim Sanford wrote:
> All:
> My Nortel receiver has been running for 6 days now. I am running the Lady
> Heather software, but
All:
My Nortel receiver has been running for 6 days now. I am running the
Lady Heather software, but also have TBOLTMON. It shows my position
fairly well, but I have seen a negative altitude, and am currently
seeing 1565' altitude. Based on local maps and the GPS in the car, I
believe the a
Hi Didier, well sorry about that, I thought I sent that to my work mate Scott!
But your reply is most helpful.
If I could find a survey mark around here I could work it out from the council
plans.
I have 1/2 dozen GPSDO and elevation is all over the place.
marki
-Original Message-
From:
ma...@non-stop.com.au said:
> When I try to enter my antenna location as per surveyor:
> -33.763698
> 151.092111
> With this scpi command: :GPS:POS S,+33,+79,3.69800E+001,E,+151,+9,+2.11100E+0
> 01,+9.45600E+001
> For some reason, the Z3816A displays this:
> LAT S 33:59:36.980
> LON
You cannot enter minutes and seconds of degrees greater than 59. The
correct coords:
-33... is 33 deg 45 minutes and 49.3128 seconds (S 33 45' 49.3128")
151... is 151 deg 5' 31.596"
On Fri, Jul 12, 2013 at 7:51 PM, Mark C. Stephens wrote:
> When I try to enter my antenna location as per surveyo
Remember that coordinates are absolute, but altitude is relative to the ground.
GPS knows your distance to the center of the earth, but it can only calculate
your altitude if it knows where the ground or sea is at your location. There
are several different earth models GPS receivers use to calcu
When I try to enter my antenna location as per surveyor:
-33.763698
151.092111
With this scpi command:
:GPS:POS S,+33,+79,3.69800E+001,E,+151,+9,+2.11100E+001,+9.45600E+001
For some reason, the Z3816A displays this:
LAT S 33:59:36.980
LON E 151:09:21.110
Which is correct except the so
Hi
The "outer oven" on that version is simply a warmup heater. If it's operating
properly, it drops out in normal operation. Put another way - the 10811 will
run fine without it.
Bob
On Jul 12, 2013, at 1:41 PM, Mark C. Stephens wrote:
> Sure, Maybe there is a market for a run of them ;)
>
Sure, Maybe there is a market for a run of them ;)
-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf
Of Azelio Boriani
Sent: Saturday, 13 July 2013 1:38 AM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] 108
Hi Chris,
Thanks. Our setup is a bit different. My oscillator is the Trimble 34310-T
and I'm using an Oncore UT+ receiver board. What are you using for your
RS-232-TTL converter? I'm looking for one that will look relatively "clean"
when I get it mounted on the back of this HP 37203A box..
Hi Bob.
My configuration is:
- HP 10811-60111 10 Mhz oscillator
- Trimble Resolution-T GPS card
- VE2ZAZ controller board
- homebrew power supplies
- RS232 switchable between GPS and VE2ZAZ controller
- little e-bay puck GPS antenna on the top of
The periodic +/- might be caused by periodic error in the PPS. The UT+ has
an error "sawtooth" function. That is the error is the PPS is left to
accumulate and then it is reset. So if you DAC counts goes up and down on
a few seconds or few tens of seconds period it could be tracking the error
i
Hi
You will need to fine tune the firmware settings for that OCXO.
Bob
On Jul 12, 2013, at 11:27 AM, Bob Stewart wrote:
> Hi Bob,
>
> OK, you got me: time as in about 120 minutes. =) It's mostly "+", with the
> occasional "-" for about an hour or so. Then, it wavers back and forth
> bet
Hi Azelio
I'm not tracking it with a counter. The VE2ZAZ board I mentioned in my post
has a serial port interface. Every 32 seconds you get a line of tracking
information, which includes the right 4 digits of the hex count of how many
oscillator transitions occurred during the previous 16 s
Is it enough if I have a schematic to send? But first let me find it...
On Fri, Jul 12, 2013 at 5:13 PM, Mark C. Stephens wrote:
> I have a spare 10811 double oven, is there a homebrew outer oven controller
> floating around?
>
>
> -Marki
>
> ___
> tim
Hi Chris,
Thanks for the feedback. Do you happen to know the parameters you have setup
for yours? Just wondering what you are using for the "F", "M", and "S"
parameters. What kind of receiver are you driving yours with, and do you have
it in "position hold" mode?
Bob
>_
Hi Bob,
OK, you got me: time as in about 120 minutes. =) It's mostly "+", with the
occasional "-" for about an hour or so. Then, it wavers back and forth between
"+" and "-", but the long term trend is still very slowly "+". So, I guess
the OCXO needs more time to "settle in"? My OCXO is
I have a spare 10811 double oven, is there a homebrew outer oven controller
floating around?
-Marki
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and follow the instructi
Scotty, need some help figuring out my elevation.
I noticed all the smartclocks are surveying wrong.
The only one correct is the thunderbolt.
Interesting.
Once I figure out the string to enter the correct co-ords into the Z38xx's but
I am still troubled by the elevation variable.
-marki
-
Hi
On Jul 11, 2013, at 11:59 PM, Bob Stewart wrote:
> After ham-fistedly breaking a few things, I've finally got my GPSDO working.
> (does happy dance) Now that it's had some time to warm up
Time as in minutes, or as in a couple of days? If you look at the plot in the
QEX article, a day or s
The thing is, when a SLA is being charged at the float charge voltage
range... 13.8V for a 12V SLA, it isn't all that low impedance. Remove the
charger, and it will almost instantly drop to 13.2V. At best, the SLA
is behaving as a very ugly high ESR electrolytic capacitor.
If you want low noise
Interesting idea.
Capacity equates to about 115mAH (.310WH / 2.7V) and thats to zero output, so
not an endurance option.
Robert G8RPI
From: David
To: time-nuts@febo.com
Sent: Thursday, 11 July 2013, 22:17
Subject: Re: [time-nuts] Lead acid battery noise leve
G'Day Mark,
Yes as suggested, Gal. pipe works for me, you can get short threaded
lengths at Bunnings. (Just like the plastic Ag. pipe you are using now. A
few "U Clamps" and you in business.
Regards Scott
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No, it doesn't depend on the timing mode. What reference are you
using? That is, your counter is using its internal reference or else.
On Fri, Jul 12, 2013 at 5:59 AM, Bob Stewart wrote:
> After ham-fistedly breaking a few things, I've finally got my GPSDO working.
> (does happy dance) Now that
Its just over 10 years since I've used lead acid batteries as the lo
noise power option for a low phase noise reference source use in the
development of a jitter measurement instrument , we used discrete regs
rather than '317s etc, it worked fine but I can't pass on the details.
I still have t
The instruments I have used that employed an internal battery supply
were meant to run off the batteries only intermittently. But that isn't
the case for the OCXO. So the comparison has to be made with trickled
charged batteries versus a power supply. But once we get to trickle
charging, NiCads
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