Hi
It’s *lots* easier to apply it in software than to do the fun and games with
the delay line.
One of the biggest issues with the delay line approach is finding one that is
good enough
( stable, 0.1 ns resolution, wide enough range, low noise ….) to do the job.
Bob
> On Nov 10, 2020, at 4:0
Hello Time Nuts,
I've been running some tests - I just had the screen 'white-out' problem
happen again - I have a termination resistor on the SCK line (pin 13 on the
Teensy 4.1) -
so it appears this is related to the TFT screen updates - maybe a pixel
write going out of bounds. The Teensy is stil
Joe,
I mentioned those spikes in an earlier, private email as well, I think Bob is
correct, there's something going on with the sawtooth correction.
Since you're already reading the quantization error correction data from the
Ublox TIM_TP message, you might want to try "digitally" applying it.
Surplus Equipment is an interesting business.
Today, eBay auction: 233776320909
This Seattle based eBay seller: “losangelessurplus” is selling NOS (more than
10).
These Clocks derive their time from Internet (NTP) ... AND can be PoE powered !
—
Masterclock NTDS24 NTP Driven Digital Clocks (2.4 i
Graham that is the alternate approach. The new suggested KD2BD vcTCXO works
very well. Its 10 MHz and readily available. But then the old divider
chains are needed. The KD2BD method works well if you have plenty of solder.
First mixer is 50 KHz LO. Result 10 KHz IF.
10 KHz IF gain
Second Mixer is a
Bob, Thanks for that. I am going to dig!
Joe
On Tue, Nov 10, 2020 at 7:56 PM Bob kb8tq wrote:
> Hi
>
> If you are handling the sawtooth correctly, you should see no hanging
> bridges
> at all. My guess is that the spikes are coming from a problem in the
> sawtooth
> correction “stuff”. With no
Rather than using the hardware delay line, I suggest you add or subtract
(as appropriate) the sawtooth correction data directly to/from your time to
digital converter data. In the Ublox devices, the sawtooth should be
applied to the following pps pulse.
Also you might consider using the TI TDC7200
Hi
If you are handling the sawtooth correctly, you should see no hanging bridges
at all. My guess is that the spikes are coming from a problem in the sawtooth
correction “stuff”. With no correction, you *will* see a spike as is rolls
over. With
a correction error, you would also see a spike.
B
Paul:
It might be easier to relegate that function to hardware.
A simple TC-VCO that drives the sampling clock for the ADC and is steerable
for frequency/phase lock from the CPU would allow you to build a
synchronous receiver without working about locking the CPU clocking system
to anything.
---
Hi Bob,
Yes, I am - I use a Dallus digital delay line in series with the GPS 1pps
and program the delay line each second with the GPS delay estimate in the
GPS NAV message.
It works really well, jitter on the 1pps pulse is hugely reduced, but one
side effect is that those 'hanging bridges' can beco
Hi
Are you using sawtooth correction?
Bob
> On Nov 10, 2020, at 8:55 AM, Joe & Gisela Noci wrote:
>
> Hi everyone,
> Still playing with my GPSDO..The Rubidium source I was hoping to have the
> loan off did not work out, so still in the dark. I have sort of convinced
> myself to procure a reaso
Hi everyone,
Still playing with my GPSDO..The Rubidium source I was hoping to have the
loan off did not work out, so still in the dark. I have sort of convinced
myself to procure a reasonable 'proven' source, Rubidium or whatever, but
that
seems to be more easily decided than done..Or at least so i
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