Am 04.03.2018 um 04:04 schrieb Richard (Rick) Karlquist:
When I was working on fiber optic communication test,
I remember hearing about lasers that were "tuned" with
variable Peltier coolers. Power consumption is critical in
a cesium standard that can run on batteries. Maybe
the power consump
Am 04.03.2018 um 03:17 schrieb David C. Partridge:
Brice said:
. Some fast CMOS devices (esp clock drivers) have an output R close to 50
ohms as they are intended to drive 50 ohm source terminated transmission
lines.
Any in particular that you'd recommend? I need to drive a 50ohm line and
> Interesting point about the heater not working vs. the XTAL having drifted
> too far.
Any logs you made of EFC percent over the past few months or years will help
verify the off-the-rail theory.
Another thing to try -- turn-off the Z3801A for a couple of hours to let it
cool. Disconnect the
Monitoring the output frequency whilst the oven "heats" up may give additional
clues as will monitoring the heater current.
Bruce
>
> On 04 March 2018 at 16:12 Tom Holmes wrote:
>
> Bob...
>
> Interesting point about the heater not working vs the XTAL having drifted
> too far. M
Bob...
Interesting point about the heater not working vs the XTAL having drifted too
far. Mine has the same symptoms as the others reported (EFC at the end of its
rope) but have not tackled it yet, figuring I'd have to dismantle the whole
thing. Certainly troubleshooting a non-operating heater
> Mine has quit achieving lock.
...
> After reading about someone else's trouble, i wonder if my OCXO has aged
> out.
Have you checked the status page? Is the GPS unit seeing satellites?
--
These are my opinions. I hate spam.
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When I was working on fiber optic communication test,
I remember hearing about lasers that were "tuned" with
variable Peltier coolers. Power consumption is critical in
a cesium standard that can run on batteries. Maybe
the power consumption of the coolers is a deal breaker.
Rick
On 3/3/2018 6:
These devices are only suitable for driving source terminated 50 ohm
transmission lines not a 50 ohm load to ground (or even 1/2Vcc) to produce CMOS
levels at the load.
If you are driving a low pass filter or similar intending to produce a sinewave
output then its somewhat easier.
Even paralle
Mine has quit achieving lock. It goes back a ways. I had it in storage for
a while. When I got it out of storage, It took about 2 weeks to lock. It
would go into holdover sometimes for no reason I could ever discover. I
lost the ability to communicate with it. Then, one of the Lucent DC/DC
converte
Thanks.
rich...@karlquist.com said:
> 2. Magnetic state selection, as used in the 5071A, would be replaced by
> optical pumping. Len Cutler was heartbroken that HP/Agilent management
> wouldn't fund this effort.
> It turns out that, even now in 2018, optical pumping is not ready for prime
> t
Brice said:
>. Some fast CMOS devices (esp clock drivers) have an output R close to 50
ohms as they are intended to drive 50 ohm source terminated transmission
lines.
Any in particular that you'd recommend? I need to drive a 50ohm line and a
single gate inverter doesn't have the grunt to do so
The attached circuit is suitable for testing the PN of various CMOS inveters
etc used as sine to CMOS converters.
Just adjust the input LC network and resistors to suit the source, frequency,
power and CMOS device Vcc.
Select the resistor in series with the CMOS output to produce a total series
Try enabling the PPS input form the "P menu.
Also, to verify that it is using the PPS input try the &a auto-tune command.
It will set the TIC and DDS tune word to to 0, collect data for for however
long you requested (an hour is a good start), then calculate the drift rate and
set the DDS tun
On 2018-03-03 3:56 PM, Tom Curlee wrote:
What I don't understand is the purpose of what looks like another coil or heater
wrapped around the Kapton printed circuit heater stuck to the inner case. This
second coil/heater is 2 layers of 1/8" thick red foam wrapped completely around
the inner c
We only use three circuits Wenzel sn65ELT35 and LTC6957. For critical
applications it is the LTC we refer to it in our designs the Bruce circuit the
only problem is solderability, my eyes. Bought 25, to poor to buy junk and not
smart enough to select something less in critical applications.
> Setting the date should update the EEPROM.
Interesting. It's not working that way on mine. If I power cycle, it both
T2 and Status page come up in Jul 1998.
Is my EEPROM worn out? Older version of firmware? ??
HEWLETT-PACKARD,Z3801A,3542A01377,3543-A
--
These are my opinions. I hat
Hystersis (exhibited by 74xx14 devices) results in AM to PM conversion which
increases as the amount of hysteresis increases.
Bruce
>
> On 04 March 2018 at 10:34 Bruce Griffiths
> wrote:
>
> Ideally one should use a Collins style optimised cascade of increasing
> bandwidth and gain
Hi
If you are simply dealing with 10 MHz sine waves (as many of us are).
— and —
It’s a “matched” application ( = you know the level / the source and converter
are tied together)
— and —
You don’t mind an L network to match increase the Vpp when it goes to the gate
— and —
Once the perfor
Ideally one should use a Collins style optimised cascade of increasing
bandwidth and gain limiting stages. The LTC6957 with its selectable input stage
bandwidth has a performance that is comparable with the Holzworth sine to CMOS
"amplifier" which is better than any comparator by itself. If the
Hello Time-Nuts,
thanks to Mark´s breakout board I was able to fire up my X72
rubidium. It seems to work fine.
FW is 5.19.
As far as I understand from the (rather crappy) manual, I
should be able to discipline it to 1pps, but I wasn´t lucky
using the commands from the manual.
I switched t
Rick,
On 03/03/2018 03:30 PM, Richard (Rick) Karlquist wrote:
> I asked the CBT manager at Microsemi about this
> rumor and he disavowed any knowledge of this.
> He told me they were making 8 a week (not clear
> if this is just 5071A's, or includes replacement
> CBT's). I don't remember the produ
Hi
First off some basics about OCXO’s.
In a single oven design, you have a heater that warms up the entire crystal and
the guts of the oscillator. It is on all the time and
it gets things up to a temperature that makes sense for a given crystal. It can
be adjusted based on manufacturing data o
In the 5071A, we squared up an 80 MHz clock with a 74AC04 gate
capacitively coupled with resistive bias to set it at half
the supply current; not a resistor from input to output as
you often see.
Ever since the LT1016 came out, it has been the "easy" way
to square up a sine wave. Easy != high pe
Since the Z3801A is being discussed, I thought I'd ask about an issue I'm
having with my unit. I use my Z3801 as my working lab standard for the usual
pieces of RF test equipment. In the past year or so I've had the unit drop out
of lock and go into standby mode. Resetting/cycling power would
Hi
There’s a big chunk of sales under the “not semiconductor” side of Microsemi.
It may
not be big compared to an $8 billion sell price, but it’s not a trivial part of
the company.
Exactly what happens to things like the 5071 … we’ll see …..
How the sales policies of one or the other company
Look at the LPRO manual. They have a couple of circuits that uses a single
CMOS gate with a capacitively coupled input. Wenzel has some very similar
circuits on their web site (search for "Wenzel squarer").
My HP-531xx counter calibrator board uses on as the input squarer (with a
74HCT86 as
I don't know about the VHC family, buy the LVC1G family can drive 24 mA.
My interface boards for connecting the LPFRS/LPRO or the TS-RFS to my BNC/SMA
connector board has a PICDIV for making a 1PPS signal and uses a 74LVC1G125 to
buffer it. Also my PRS10 interface uses one to buffer the 1PPS ou
Search for ultra fast comparator yields TL3016 and AD8611, claims to be
faster pin compatible replacements. I have found low parasitic capacitance
on the outputs of these types of comparators is important, and I have used
balanced hysteresis (use positive feedback from both + and - outputs). I
hav
There is an announcement of the impending purchase on the Microchip website.
>From my perspective this is a good thing as I've been eyeing some of the
microsemi semiconductor products for some time for use in various designs
of mine and this is likely to make those products easier to incorporate d
Setting the date should update the EEPROM.
---
> I think the second power down in there resets the date.
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and f
You might consider using MC74VHC1GT14 or MC74VHC1G14 (Schmitt trigger inverting
buffers) depending on the exact voltage levels.
They are fast (74AC logic fast) single gate devices in SC70 (SOT-353) or
SOT23-5 case and can drive 25mA output if needed.
I've seen documents saying that using fast l
Gentlemen,
I have so far been using LT1016 as a pulse shaper and also whenever I needed
toconvert a sine wave into TTL Logic levels. Some hysteresis and all the
decouplingand layout precautions as recommended by LT.
Are there any similar or better alternatives out there that could be usedthat
It's not just that you need to have small signal Thevenin source
impedance << 50 ohms, you also need to be able to
deliver sufficient current, at the rated logic
voltage swing of the device. If the device is swinging
rail to rail, and you drive a 50 ohm load through a
50 ohm resistor in series wi
The manager many not know but the market does and there have been announcements
and the stock is up and for the day the fifth most active of all US markets. At
2 pm #2 Bert Kehren
Sent from my Galaxy Tab® A
Original message From: "Richard (Rick) Karlquist"
Date: 3/3/18 9:
I asked the CBT manager at Microsemi about this
rumor and he disavowed any knowledge of this.
He told me they were making 8 a week (not clear
if this is just 5071A's, or includes replacement
CBT's). I don't remember the production ever
being anywhere near this level. The reason
for the relativel
Using this to buffer output from an LPRO (74VHC1G14 (Schmitt trigger 3.3V
TTL compatible)), or an Efratom 105243-003 10MHz OCXO with CMS output
(74VHC1GU04 CMOS levels) in a 10MHz mod for the KS-24019 RFTGm-II.
To match well to 50R bandpass I want to add a series resistor to the output
but don't k
Just a change to the last part of the name then ;)
https://www.ft.com/content/10192a2a-1d99-11e8-956a-43db76e69936
"semi" -> "chip"
On Sat, Jan 27, 2018 at 1:27 AM, Clint Jay wrote:
> Perhaps of interest to the list
>
> https://www.theregister.co.uk/2018/01/25/microsemi/
>
> --
> Clint.
>
> *No
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