Hi,
I was doing some phase noise measurements today at a friends place.
The Rapco 1804M was about -110 dBc/Hz at 10 kHz. It was 30 dB higher up
from the HP5065A, which was some 10 dB higher than the BVA. On the other
hand, when viewing the ADEV and TDEV, it became apparent that the Rapco
has
Good point Bob, in my humble opinion Low Noise is about -115 @ 1 Hz dropping
to about -165 @ 10KHz for 5 MHz about 3dB higher for 10MHz. Which from my
testing will tax the noise floors of a fair number of application specific
products.
It is true that most of these distribution amps sold today
Hi
On Jan 5, 2015, at 6:33 PM, Li Ang lll...@gmail.com wrote:
Hi Bob,
There are 2 oscillator on board, one 8MHz for MCU one 125MHz for FPGA.
I've took it down from the board, and changed MCU to use internal RC
oscillator for MCU and PLL to mutilply refclk to 200MHz for FPGA.
I will try
Hi,
If you have a stable delay of 198 ns, and we can't figure out why it is
bad, bad, bad, then just calibrate it and compensate for it.
I would be curious to figure out where it is. I don't have the full
system insight right now. It sounds like you need two coarse count
cycles (I think you
Hi
On Jan 5, 2015, at 6:26 PM, Li Ang lll...@gmail.com wrote:
Hi
I've confirmed that it's 198ns between start and stop with my racal dana
1992. I've spent days to learn how to compensate this 2ns in Quartus.
However, it's not something easy for me to do.
It’s not something that anybody
Actually, I dont want to ask my colledge for help. Everytime ,for each
guy I ask for help, I need expain the entire system and principle of a
frequency counter to him. They just keep asking questions instead of
answering mine.
In defense of the hardware guys, there are a lot of questions
Hi,
With a multiturn pot and a 78L05 I can get a 0 to 5V EFC to tune
an OCXO on desired freq. But... maybe other voltage regulators
or other scheme have better temp stability than the old 78L05.
Before I crawl lost in new'ish fancy regulator land does anybody
know the killer solution/IC for
Hello,
As I am in the process of creation of my own Nixie clocks. And it
probably good time frame to clarify one thing about leap seconds. In my
project I am using GPS module as an option to have current UTC time and
also to have 1PPS signal to do auto-adjustment for external RTC module.
On 4 January 2015 at 02:37, Bob Camp kb...@n1k.org wrote:
Hi
On Jan 3, 2015, at 6:09 PM, Dr. David Kirkby (Kirkby Microwave Ltd)
drkir...@kirkbymicrowave.co.uk wrote:
I was looking to make a 10 MHz distribution amp to feed test equipment with
the output of a GPSDO.
I see this
Dave wrote:
At 50 MHz, the loss from the common port is 12.8 dB, and the isolation
between two ports sets of ports is either 38 or 48 dB
To get the worst-case output-to-output isolation, you need to test
two output ports that are electrically adjacent (i.e., that share the
same last 2:1
Hi Bob, That is the issue, it doesn't.
(the 2,3 different types I would like to use none of them have it, so I will
be making a small pcb with the trimpot and the regulator and some
capacitors etc).
Luis Cupido.
ct1dmk
On 1/7/2015 1:09 AM, Bob Stewart wrote:
Does your oscillator have a VRef
Does your oscillator have a VRef output? If so, use that instead of a
regulator. It's cleaner and usually temperature compensated.
Bob
From: ct1dmk ct1...@gmail.com
To: Discussion of precise time and frequency measurement time-nuts@febo.com
Sent: Tuesday, January 6, 2015 6:40 PM
Here's a nixie clock using javascript. It includes a leap second count down
which is now active:
http://leapsecond.com/java/nixie.htm
For your project, any GPS module with 1PPS output is a start. Those with NMEA
output are problematic. First, there is no advanced notice that a leap second
Just to say, the comment on the graphs that the VNA covers 50 MHz to 20
MHz, is obviously wrong. My 8720D covers 50 MHz to 20 GHz.
I do have another couple of VNAs here that cover 10 MHz. I will do some
more measurements, with a more suitable VNA when I have both splitters here
and some time for
On 7 Jan 2015 00:23, d0ct0r t...@patoka.org wrote:
Hello,
The same question is for UNIX epoch time. How computers knows if it is
necessary to add leap seconds ?
During the event, the kernel raw time (assuming UTC) will go from
23:59:58.9 straight to 00:00:00.0 when removing
Hi Magnus
You are right, I could compensate it in the software. I've tried that.
The software sets sig=ref=10MHz and measures start-to-stop time t1. Then,
it sets sig=ref=5MHz and measures time t2. With t1 t2, I could get the
time difference between the start path and the stop path. Repeat it
Hi Bob,
Actually, I dont want to ask my colledge for help. Everytime ,for each
guy I ask for help, I need expain the entire system and principle of a
frequency counter to him. They just keep asking questions instead of
answering mine. :(
The 2 MV89As are powered by the same power supply
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