Hi
Ok, so it’s not a super duper low phase noise OCXO. It’s also at a reasonably
high frequency.
I’d just drive it into a 5V tolerant input and move on. There are lots of logic
gate chips out there that will run from 3.3 and accept 5V inputs. Use something
reasonably fast and it will do a
Hi,
More than a matter of personal taste avoiding a resistive divider using a
active circuit you could benefit from its low output impedance. With a
resistive divider there could be some issues in terms of impedance matching
when a load it is present but as been said it all depends on how
I guess the question that comes to me is why is cloudflare free?
I understand why Didier does what he does for free, he's giving
back by serving a community to which he is a member. But what
is cloudflare getting in return for paying for the rent, hardware,
backbone, and electricity?
-Chuck
Following on from my question the other day about the type of
oscillator in the HP 8720D VNA, I finally got around to setting this
up on the spectrum analyzer today. Luckily, some software I wrote back
in 2008 for a friends HP 7 system was easy to modify to grab the
save the frequency. So I
Typical 10811 warm-up time is circa 10 minutes; cool-down time is actually
several times longer (since there is no active cool-downer in the case!)
More modern, smaller OCXO's will warm up and cool down more quickly.
If it's a double oven or user has added extra insulation around the basic
OCXO,
Further to my question the other day about what type of oscillator was
used in the HP 8720D VNA, fitted with the high stability oscillator
option (1D5), here is the frequency as the instrument is switched on,
after being powered off for 2-3 hours.
The oscillator appears to start too high in
Since Cloudflare has a paid service as well the working assumption is the
'free' service is more of a try before you buy and allows colleges and others
to demonstrate the value of the service so budget can be requested. I'm sure
the analytics are not as detailed as the paid version etc
drkir...@kirkbymicrowave.co.uk said:
Anyway, later today (tomorrow ??) I will post a plot of frequency vs time.
The question is though, how long is thing thing likely to take too cool?
I'd expect an exponential decay so you need to specify how close to ambient
you want to get. I'd guess a
If it were me, I'd avoid the active buffers since there is no need for them
when going from higher to lower voltage swings. The output of a
buffer/inverter is guaranteed to be at least a little less clean than what
you started with.
First, check to see if the 5V output really is a 5V signal. If
David wrote:
here is the frequency as the instrument is switched on,
after being powered off for 2-3 hours.
The oscillator appears to start too high in frequency, overshoots
downwards, then settles down.
That is a typical warmup profile for an ovenized AT-cut crystal (OCXO
with AT-cut
About 8 or 9 years ago my HP active 2 way GPS smart splitter died. After taking
off the cover, and some troubleshooting, I found that the 5 volt to 3.3 volt
regulator was open. Since it was an SMD device, and I did not have a
replacement, I just cut the device out, and, using a small piece of
I plan to run the new site for about a month to see how it is doing (I have
a 30 days try out period anyhow) and if all goes well, I will give
Cloudflare a try.
Just to let everyone know (it will be announced on the site), I will have a
50 files/day download limit initially to limit the rogue
Yes, I saw that. I doubt that I would get as much info as I get now with my
log files, but it is definitely worth a try. I will run the site from the
new host for a month to see how it does then I will probably get Cloudflare.
Thanks!
Didier KO4BB
On Tue, Sep 30, 2014 at 8:42 PM, Paul Alfille
On 10/1/2014 1:04 PM, Hal Murray wrote:
drkir...@kirkbymicrowave.co.uk said:
Anyway, later today (tomorrow ??) I will post a plot of frequency vs time.
The question is though, how long is thing thing likely to take too cool?
I'd expect an exponential decay so you need to specify how close to
I'd expect an exponential decay so you need to specify how close to ambient
you want to get. I'd guess a ballpark of 10x the warm up rate.
You can probably measure it if you have the warmup graph. Turn it off, wait
a while, turn it on, measure the freq, consult warmup graph.
Some older
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