Shawn writes:
> Question 2: Should I just replace the fan with a 24V unit and put a 10-
> 20 ohm resistor inline to lower the speed? (probably the better choice
> but I'd love to hear your suggestions.)
I would replace the fan and see if I could get one with PWM control input ?
--
Poul
Hey Guys,
Have a couple questions.
First background:
Still refurbing some Efratom MRT Rb units, mostly filter caps and a
bridge rectifier or two, plus SLA batteries.
One of the units is a rack mount high temperature model, the FRK unit
is external to the power supply chassis and has a fan on it
A couple of years back, we started to explore using Laser Diode with a FRK.
Started by looking at shorter time constant for the loop and found that 0.055
seconds gave best AV. Longer time constant for Laser control. Also using
external reference for tuning. Using HP 70 000 Optical Plug in to cha
Hi
One thing we often miss as we shop for these Rb’s on eBay ….
$2K is a pretty typical single piece price for these devices. They sell for a
lot more new than the prices we see for 10 or 20 year old “scrap” parts.
Indeed the volume price to OEM’s is a bit below half that number. Still,
it is
Speaking of aspirational, for those interested in time travel (that
comes under "time nuts", no? ;-) ) there is this:
https://www.oreillyauto.com/flux-500.html
David N1HAC
On 4/3/21 11:10 AM, David Witten wrote:
It seems to be aspirational.
It has been on the SparkX page for a long time now.
It seems to be aspirational.
It has been on the SparkX page for a long time now.
Dave
> Date: Sat, 03 Apr 2021 07:15:13 +
> From: "Poul-Henning Kamp"
> Subject: [time-nuts] Sparkfun lists SA.35m
> To: Discussion of precise time and frequency measurement
>
> Message-ID: <81790.16174
Hi,
What you do is that you servo the semicondoctor laser to the transition,
as you do that with sufficiently narrow laser you can utilize the CBT
mode operation which has additional benefit rather than just replacing
the rubidium lamp with a semiconductor laser. Getting a laser in 780 nm
range is
Dana Whitlow writes:
> I knew about the use of the VCSEL, but I'd bet a good dinner that it's not a
> Rubidium laser!
I dont see anybody claiming that ?
It is a laser interrogated rubidum frequency standard.
The crucial part of the "Theory of Operation" is:
The MAC is a passiv
I knew about the use of the VCSEL, but I'd bet a good dinner that it's not a
Rubidium laser! Last I heard, none of the elements in that corner of the
periodic table were semiconductors, and it's hard to imagine a vapor-based
VCSEL.
Dana
On Sat, Apr 3, 2021 at 7:31 AM Lux, Jim wrote:
> On 4/3/
On 4/3/21 4:22 AM, Dana Whitlow wrote:
"rubidium laser" ???
Dana
I don't know about the MAC, but the CSAC uses a VCSEL to shine through
the gas cell.
The MAC is a pretty big thing compared to the CSAC - it's in the usual
2x2" package and draws 5-8W (after warmup)
On Sat, Apr 3, 2021 at
"rubidium laser" ???
Dana
On Sat, Apr 3, 2021 at 2:15 AM Poul-Henning Kamp wrote:
> I know it's not a particular outstanding atomic clock, but I was still
> surprised to see that Sparkfun lists the SA.35m for $1995...
>
> https://www.sparkfun.com/products/14830
>
> Not in stock though.
I know it's not a particular outstanding atomic clock, but I was still
surprised to see that Sparkfun lists the SA.35m for $1995...
https://www.sparkfun.com/products/14830
Not in stock though...
--
Poul-Henning Kamp | UNIX since Zilog Zeus 3.20
p...@freebsd.org | TCP/IP si
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