Wondered if anyone had seen some sort of gadget that would look to see
if there was a 10 Mhz signal and switch a relay (or provide some other
output) in the absence? I would like to cook up some sort of fail over
switch without having to do much actual work. :)
73/jeff/ac0c
Hi
One thing to watch on the TBolts - the ocxo’s used in them got better as the
years went by. An early one likely will not do quite as well as a later one.
They
also updated the firmware as time went by, same basic issue - later is probably
better ….
Bob
> On Feb 4, 2019, at 8:51 PM,
There have been some Trimble Thunderbolts over on that auction site
that were being sold for $80 each (not surplus Telcom ones).
I grabbed two and they work.
My antenna was a "hockey puck" style antenna sitting on the window
sash, facing South.
73, Dick, W1KSZ
Sent from
On Feb 4, 2019, at 14:25, Achim Gratz wrote:
> The Si5351 needs something between 25MHz and 27MHz as reference.
That isn't true. Even the B version works just fine with a OCXO input
directly. See my thread here:
Hi
The bumps you are seeing are likely due to some sort of filtering in the EFC
input
to the oscillator you are trying to lock up. 100 Hz is not all that uncommon
for a filter
cap rolling off noise on the EFC line. Indeed it can be from other things, it’s
just a guess….
Bob
> On Feb 4, 2019,
Said at JLT isn't currently on the list so I'll forward his input:
--
. It looks like you are measuring the output of the OCXO or TCXO
inside the LN Rb. That unit has a tempco spec of 20ppb over its operating
temperature, the Rubidium is much much better of course (up to
[typo in subject corrected]
John Ackermann N8UR writes:
> On 2/3/19 11:48 AM, Achim Gratz wrote:
> I've been playing with the SiLabs 53xx series chips. There are two
> that are quite interesting for time-nuts.
I am really trying to go for the octal output parts. :-)
I'd rather use the
Paul
The keyword is GPSDO - GPS disciplined oscillator. The vast majority of
these will give a 10MHz output. The long term accuracy is the same as
the GPS navigation system, which for most purposes is similar to that of
national standards. GPSDOs are more stable than most rubidium
I played around with this today, recording 5 minute runs: freerunning, P/10
gain, P gain, 10x P gain (where P is some unknown value...)
I then added either a 1M/100n or 500k/100n integrator which really only
shows in the TDEV-plot, not in the PN-plot.
https://photos.app.goo.gl/V9xL5MkVsL6RLRXJ7
