Hi
At least in my “unconstrained by reality” state, my thought is that the “sync”
PPS signal is there all the time.
You are as much doing a phase lock as a sync. The “PLL” only has a phase
resolution of 100 ns so once
it’s running, not much happens. Yes, this might get you into all sorts of
John,
The PD15 divider that you're using will sync to within 1 PIC instruction.
That's sounds good, but the TICC reads down to picoseconds so the 400 ns PIC
granularity will look pretty high.
There is another solution. And that is not to sync the h/w or s/w counters at
all. You just let them
Hi Bob --
It's certainly possible to synchronize the TICC timescale epoch to an
external pulse at startup. The external sync pulse would have to
simultaneously reset (a) the picDIV and (b) the coarse (100us) counter
in the Arduino. The signals to do that are available, so it's a
worthwhile
I'm selling my remaining Z3801A. Months ago, I replaced the original
GPS module with a more sensitive Oncore VP. At that time, I also
replaced several suspect capacitors on the DC-DC converter board.
Everything has been 100% since. The RS-232 mod was done long ago.
A serial cable and a 24 VDC
Hi
Ok, so the guess was fairly close :)
How about a connector to allow an external PPS to reset the internal 10 MHz
divider? That way all
the data is “in sync” with the house standard. If I want to know that my GPSDO
is +32.751 ns off from
the house standard, I just look at the data on a
Good guess. The 10 MHz reference drives all the logic on the board, and
particularly the counter that maintains a local timescale in 100us
increments; the TDC7200 interpolates between the 100us ticks to stamp
incoming events on channel A and/or B with picosecond precision. The
stamps on both
Hi Luciano --
Glad to hear that!
The capability you asked for already exists (great minds think alike...)
In timestamp mode, the TICC will output the stamps for each channel
independently, measured against the common 10 MHz reference. So if both
channels are active, you'll see a bunch of
Hi
Without doing a bunch of actual *work* I’m not sure what is inside the guts of
the board. Being
lazy I’ll just guess ….
There appears to be a 10 MHz time base input and a pair of measurement inputs.
In a lot us will
be comparing to a “house standard”. That standard has a pps output that
Hi
Pin 5 is the EFC reference pin. It may (or may not) have a voltage on it. If
there is a
voltage on it, it’s a voltage that the original OEM customer found useful. It
may (or may not)
have a series resistor to match up with an OEM specified trim pot.
Bob
> On Nov 27, 2016, at 2:04 AM, Dave
Hi
You have a system with cascaded gains and noise figures. The “front end” of the
GPSDO is
in the antenna. The cable is between the front end of the receiver and the rest
of the “radio”.
With a cascaded noise figure situation, as long as the noise figure of the
first stage is low (it is)
Hi John,
I have planned to buy two TICC.
An interesting feature would be to be able to do two simultaneous acquisitions,
and Timelab as real time display,using the two indipendent input channels and
the 10Mhz clock as single reference.
Luciano
www.timeok.it
From "time-nuts"
>Most GPS antennas have an LNA built-in, making cable loss less significant.
>Doesn't your antenna have that?
Sure, specs says:
- Amplifier Gain: 26 dB +/- 3 dB
- Maximum Noise Figure:≤ 2.5 dB @ +25°C including pre-selector
I still have to search a command to check signal strength.
>For a long
tract...@ihug.co.nz said:
> I thought it may be a reference supply for the EFC pin- with a 12.03 volt
> supply the unknown pin measures at 2.803 volts-which is usefully above the
> required EFC voltage ( ~2.4 volts) to bring it on frequency.
> But does anyone have some hard data on this
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