Joe,
Interesting tests.
So, in your previous problem, loss of -12V caused loss of communication
while in your recent tests, you didn't lose communication, regardless of
whether the -12V failure was open or grounded. Okay, now I'm totally
confused!
Regarding the frequency / locking
Fellow time-nuts,
I was just asked to assist on the debugging on a Accubeat AR-40A. He has
serial port interface, but not knowing the commands it's a bit hard to
get started. He has 2 working and 1 failing, so comparing readings is
possible.
Does anyone has manuals for it? I looked at the
Hi Magnus,
Have you tried contacting AccuBeat?
I believe that Avi Stern is still with them. Try him, I'm sure he will be
able to help (and please give him my kind regards).
Rob Kimberley
-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On
Behalf
Hi Rob,
On 05/12/2012 11:59 AM, Rob Kimberley wrote:
Hi Magnus,
Have you tried contacting AccuBeat?
Not yet.
I believe that Avi Stern is still with them. Try him, I'm sure he will be
able to help (and please give him my kind regards).
OK, will try to contact him then.
Cheers,
Magnus
Ed,
Looking back on the message, I see your confusion. I guess a better
descriptor is 'TBolt Failure' rather than 'failure to communicate'.
Clearly, under both scenarios, it was communicating, as indicated by the
'green' COM 1, though not in all areas.
I did not notice the DAC or EFC voltage
I'd suggest that when the -12V line is open leakage currents allow it to become
positive causing problems (parasitic diodes conducting etc), while if it is
tied to ground only the -12V specific functions fail.
Robert G8RPI.
From: Ed Palmer
Ooops, thanks for the correction...
Then I assume that if the voltage is too low for the negative reference
headroom, severe stability problems could result.
Didier KO4BB
--Original Message--
From: Mark Sims
Sender: time-nuts-boun...@febo.com
To: Time-Nuts
ReplyTo: Time-Nuts
Subject:
It sounds like the -12V supply is used to generate the DAC low voltage
reference. If it is floating, the DAC output will be unstable. If it is at a
solid voltage, the DAC output will be stable. The standard EFC range for a
tbolt is -5V to +5V, but since almost all Tbolts are running the
Hi
I have never fully traced out the DAC on the TBolt. I have gone far enough to
see that it's a sum of several sort of circuit. My guess is that they sum and
then measure the result with a good ADC. If so, the DAC would likely function
fine as long as the ADC was not impacted by the loss of
On 05/12/2012 03:37 PM, Mark Sims wrote:
It sounds like the -12V supply is used to generate the DAC low voltage
reference. If it is floating, the DAC output will be unstable. If it is at a
solid voltage, the DAC output will be stable. The standard EFC range for a
tbolt is -5V to +5V,
Thanks everyone!
On 05/12/2012 03:37 PM, Mark Sims wrote:
It sounds like the -12V supply is used to generate the DAC low voltage
reference. If it is floating, the DAC output will be unstable. If it
is at a solid voltage, the DAC output will be stable. The standard EFC
range for a tbolt
Our friends from Old Cathay sell two versions of the Trimble Resolution timing
receiver: the -T and the -SMT.
The -T is a 12 channel receiver built of discrete components on both sides of
the PCB. It is spec'd at +/-20 ns accuracy (the sawtooth correction range).
It can be set up operate
Today I 'failed' the -12 V supply again and got screen captures of the
TBoltMon GUI with the TBolt operating normally, -12V failed short and -12V
failed open.
I used a 5372A referenced to a Z3816A to measure the 10 MHz output frequency
of the TBolt for normal operation followed by -12V failed
Hi,
I fround this site this evening:
http://w140.com/tekwiki/wiki/Main_Page
The scans are not as good as some commercial pones, but the price is
right. It has manuals that are not available on BAMA or the other sites I
checked.
Best,
-John
Those of you going to the Dayton Hamvention next weekend should be aware that
there will be other Time Nuts (and a Volt Nut or two) to be found there. Don't
be surprised if you see the Febo administrator himself relaxing in the flea
market beside the trailer in spaces 1901-1904. If you go past,
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