Hi
If a simple GPS outage makes the GPSDO go bonkers, there is something
else involved. Noise jamming or flying saucers over the antenna should just shut
down the receiver. When it locks back up again, the disciplining should
resume. If it goes into a death spiral that pretty strongly suggests t
Hi
> On Sep 28, 2017, at 6:59 PM, Mark Sims wrote:
>
> I suspect that it is either temperature related (the funkiness starts around
> when the temperature reaches a minimum) or related to the way the
> disciplining parameters are hacked to get the extended time constant.
Like it or not, mo
Hi
A lot depends on how the output stage in the OCXO was designed. Unless
you know the details of “what’s inside” it’s best to terminate it in the
specified
impedance.
One example: Tuned tank in the collector of the output stage driving a matching
network. Terminate it properly and the stage
Hi
> On Sep 23, 2017, at 9:39 PM, Hal Murray wrote:
>
>
> kb...@n1k.org said:
>> If the main use is feeding test gear (and not direct synthesis) an Rb may do
>> pretty well. Most instruments assume a dirty reference signal and clean it
>> up internally.
>
> What's the bandwidth on the typic
Hi
If the main use is feeding test gear (and not direct synthesis) an Rb may do
pretty well. Most
instruments assume a dirty reference signal and clean it up internally.
1 Hz at 20 GHz is 5x10^-11 most sources you measure up there will not be stable
to 1Hz
at a 1 second gate. The Rb will be i
Hi
> On Sep 22, 2017, at 3:01 PM, Attila Kinali wrote:
>
> On Fri, 22 Sep 2017 11:50:29 -0400
> Bob kb8tq wrote:
>
>> Given the noise levels of typical Rb’s - use XOR gates as the mixers.
>
> Right. That makes it a lot more robust than using a diode mixer.
>
ave really
awful phase noise and spurs. That’s not true of all small Rb’s, but buying
them new in small volume at $2K each is not something most of us
are interested in doing ….
Lots of fun
Bob
> On Sep 22, 2017, at 9:37 AM, Attila Kinali wrote:
>
> On Wed, 20 Sep 2017 10:21:51 -0400
Hi
> On Sep 20, 2017, at 8:39 AM, Attila Kinali wrote:
>
> On Tue, 19 Sep 2017 18:09:16 + (UTC)
> Stephan Flor via time-nuts wrote:
>
>> Hi everyone,I'm new to this list, and I wanted to get the opinion of some
>> mere experienced people on my project idea.I just got a Symmetricom X72 Rb
Hi
There is a surprisingly high range of currents pulled by various GPS antennas.
In some
cases the wider the voltage range, the higher the current. Some antennas can
pull as much as
150 ma. There are GPSDO’s that trigger over current at 30 ma ….
The “easy” approach is to run the receiver into
Hi
The gotcha is that the 3801 is an “ask for it / get it” protocol. If you don’t
get the query formatted correctly, there will be no data coming back. It’s not
like some other GPSDO’s that just yack all the time.
Bob
> On Sep 16, 2017, at 9:27 AM, Brad Stockdale wrote:
>
> From what I recall
Hi
Well if people are looking for those willing to “adopt” a stray 5065A or two,
I’ll certainly toss my name onto
that list !! :)
Back in the era HP did these designs, things like surface mount were still a
bit new. They had some
very legitimate questions about packaging and published a few p
Hi
It’s been a *long* time since the 709 or 741 were “best” in any regard. I would
not go with
socketed parts. I’ve seen more problems from sockets than from the parts that
go into them.
Semiconductor quality / reliability has come a *long* way since the 1960’s.
How to redesign the board mostl
Hi
Standard generic drill:
1) Swap RX and TX (or check with a voltmeter)
2) Cycle through the normal set of baud rates
3) Double check the jumpers on the 422 to 232 conversion
4) Check with a terminal program, typing in the *IDN? query by hand
Yes it’s sort of a mix and match of what’s above. T
Hi
Quick and simple on the XOR doubler:
Buffer up your square wave. Output goes direct to one input of the XOR. Other
input goes through a filter to give you a phase shift. Low pass is one option.
Band
pass is another option. Both benefit from being tunable. Net result is that you
can get
the s
do with a more linear regulation. Never the less, it's kind of
> nice.
>
> Now, I wonder where that oven went, I'd love to get it running. :)
> You always learn something. :)
>
> Cheers,
> Magnus
>
> On 09/07/2017 05:30 PM, Bob kb8tq wrote:
>> Hi
Hi
The 115VAC power suggests that it dates back a ways. The 100KC frequency
suggests
the same thing. It could easily be a 100 KHz crystal in a simple thermostat
controlled oven.
In that case, the stability would not be anything super duper.
Your guess of 0.001 Hz gives a 1x10^-8 sort of numb
Hi
> On Sep 5, 2017, at 10:23 PM, Hal Murray wrote:
>
> Was
> Subject: Re: [time-nuts] GPS Antenna Feed Line Decision
>
> kb...@n1k.org said:
>> There is pretty much no experiment you could run that would show a
>> difference between the two. With a normal GPS, the “front end” of the radio
>>
Hi
> On Sep 5, 2017, at 5:19 PM, Charles Steinmetz wrote:
>
> Mike wrote:
>
>> I tried to see if there was any difference in the signal quality reported by
>> Motorola UT+ and U-Blox Neo 6M (not timing grade but has a good 1PPS) over
>> 30m of 2 different cable types.
>> I only had RG58(75 Oh
Hi
> On Sep 5, 2017, at 6:06 AM, Hal Murray wrote:
>
>
> Clay Autery said:
>> I will use something better than RG-59 or RG-6 (even if it is only "better"
>> in my opinion).
>
> Crazy thought department. Can you also run a parallel run of RG-6 and run
> some tests to see if you can measure
Hi
> On Sep 4, 2017, at 10:32 PM, Nick Sayer via time-nuts
> wrote:
>
> I happened to be at Powell's bookstore in Portland the day after the eclipse
> and came across this book and wound up buying it. It's attraction to me was
> the same that I felt growing up watching the documentaries hoste
Hi
A lot depends on just which outfit you buy your attenuators from. There
certainly *are* outfits out there that supply you just over 20 db RL when
the spec is 20. They also don’t charge very much for their attenuators ….
Bob
> On Sep 4, 2017, at 4:53 PM, jimlux wrote:
>
> On 9/4/17 1:18 PM,
Hi
If you are running into a TBolt, it’s got an F connector and 75 ohm cable
spec’d already …. The 50 ohm / 75 ohm thing didn’t seem to bother
Trimble. They certainly looked at it before going that way ….
Bob
> On Sep 4, 2017, at 12:31 AM, Ian Stirling wrote:
>
> On 09/02/2017 02:57 PM, Clay
Hi
The bigger issue with unsuspended cables is wind and weather. It’s not just a
static weight issue.
When the wind blows the cable jerks around. You very much want to tie it off
against the mast. You
also want a strain relief loop at the antenna.
Bob
> On Sep 3, 2017, at 10:44 AM, Artek Man
amp will be mounted near the devices such that amp to
>> device jumpers will all be < 1 meter/3.28 feet. Likely a lot less. ALL
>> Times N-connectors until reaching a connector TM doesn't make.
>>
>> __
>> Clay Autery, KY5G
>>
&g
Hi
Modern distribution amp chips are likely to be sub 2 db NF. Gain is generally
just a bit more than
the loss through any post filtering and the passive power splitter after it.
Bob
> On Sep 2, 2017, at 7:02 PM, Wes wrote:
>
> This is just a cascaded noise figure situation.
>
> The first s
Hi
A lot depends on what comes after the feed cable. The “disto amp” will
determine
a lot. You likely need 10 db of net gain in front of it to keep things running
ok. For an
antenna that is *really* 26 db (as opposed to 26 db +/- 6 db), that would come
out to
16 db of feed line loss. This isn’
Hi
For something like a 1:1 transformer, you actually don’t need all that super a
ferrite.
Essentially all the current flow balances between the windings so you don’t
have a
lot of (effective) mag field in the core. Going with a lower frequency / higher
permeability
core “forces” any residual
> between LH and PC all receive only - no handshaking that would get messed up
> with a split Y serial cable?
>
> Jerry, NY2KW
>
> -Original Message-
> From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of Bob kb8tq
> Sent: Wednesday, August 30, 201
ems with my Prolific
>>> adapters failing, usually after an "update" - particularly Windows - I
>>> switched to FTDI adapters and have never had a problem since.
>>>>
>>>> Ken
>>>> WA2LBI
>>>>
>>>>
>>>>
Hi
I would blame the usual “coms error” stuff and dig into that. Bum
cable / loose cable is number one on that list. Connectors (on either
end) coming unsoldered from the pc board would be next ….
Bob
> On Aug 29, 2017, at 10:30 AM, Jerry wrote:
>
> Need some more help figuring out why Lady He
Hi
The older GPS units had a downconverter in the antenna and passed an IF
frequency
back to the receiver. There also was an era when the standard antenna was fed
12V
(rather than 5V) and had 50 db of gain (rather than 20 to 30 db). Most modern
hockey
pucks will be unhappy with 12V.
Bob
>
Hi
Oddly enough we were in the process of wine tasting as the eclipse happened on
the
other side of the cloud bank. We noticed no disruption in the timing of our
sips ….
Bob
> On Aug 22, 2017, at 3:58 PM, Mike Cook wrote:
>
> Hi you guys over the pond.
>
> Don’t be shy.
> Did anyone measu
Hi
A lot of the OEM’s seem to be going with a large multi layer PCB as the
“heatsink” for
the lightweight Rb’s. Apparently they have enough airflow through their racks
that this
works ok for them. In that case, I think I’d prefer some sort of “cheap” SMD
PC mount
connector. Faster to assembl
Hi
Located just outside Bordeaux ….. ROAD TRIP
I don’t think there’s been much mentioned about them before. It’s interesting
that their
main sales thrust so far seems to be China and India.
Bob
> On Aug 19, 2017, at 3:04 PM, Ole Petter Ronningen
> wrote:
>
> Hello
>
> I just stumbled
Hi
10 MHz sine output would be pretty high up on my list of “pins to send
someplace else …”
Bob
> On Aug 17, 2017, at 5:36 PM, Mark Sims wrote:
>
> Cable has a DB-25 on the other end. X72 uses 26 pins. So logically it would
> be pin 26 that is missing... 10 MHz sine wave output... nobod
as good
> in the polar area as at the equator. The inclination of orbits was a
> compromise for better service while not requiring atomic clocks at the
> receiver.
>
> Cheers,
> Magnus
>
> On 08/15/2017 06:34 PM, Bob kb8tq wrote:
>> Hi
>> The “degradation at
I
>
>
>
>
> On Tue, Aug 15, 2017 at 12:44 PM, Bob kb8tq wrote:
>
>> Hi
>>
>> In the case of a spoof, the target is likely one specific vehicle. You
>> care about the
>> armored car with the big pile of gold bars in it. The objective is not to
>
Hi
In the case of a spoof, the target is likely one specific vehicle. You care
about the
armored car with the big pile of gold bars in it. The objective is not to get
him to
drive into a bridge abutment. It’s to get him to turn left on the wrong road.
You tailor
the spoof so everything “make
Hi
The “degradation at the poles” thing was very well understood in the 1970’s when
they came up with the orbit plan. The questions about performance started being
asked quite early. The earliest answer I recall hearing (in the late 70’s) was
that polar
operations were not a big part of the syst
Hi
If you are at ICBM mid course altitudes, there are a *lot* of sat’s visible ….
(at least compared to being on the ground).
Bob
> On Aug 14, 2017, at 9:04 PM, jimlux wrote:
>
> On 8/14/17 5:12 PM, Bob kb8tq wrote:
>> Hi
>>
>> At the time all this was figured ou
Hi
At the time all this was figured out, the idea of the military needing nav at
the poles
was pretty far fetched. They accepted a bit of degradation in those regions as
a result
of this thinking.
Bob
> On Aug 14, 2017, at 7:45 PM, Hal Murray wrote:
>
>
> The satellite orbits only go so far
is spoof be as easy as recording the real signal and playing it
> back (louder) delayed by about 120 seconds? (Assuming you want to shift
> things to the East.) (Also assume you have a relatively unsophisticated GPS
> nav receiver.)
>
> --- Graham
>
> ==
>
> On Mon,
Hi
> On Aug 14, 2017, at 2:13 PM, Chris Albertson
> wrote:
>
> The trouble with spoofing location is that in theory every ship is using
> more than one method of navigation. They would notice their GPS is acting
> up and turn it off.
In most cases the “other method” is dead reckoning. That’s
Hi
Consider what your automotive GPS receiver does coming out of a tunnel or out
from under
a bunch of trees. It still needs to work correctly in that situation. Same
thing with
a big rain cloud “over there”. I don’t think you would want a receiver that
went nuts in those cases.
I don’t thi
HI
Since multi path is a real issue in a mobile environment, defining what an
“abnormal”
change is could be quite tricky. A reasonable “spoof” would start with feeding
the correct
data and then slowly capture the target (still with correct data). Once he is
are “in charge”
signal wise, start do
Hi
> On Aug 14, 2017, at 11:38 AM, Clint Jay wrote:
>
> All very true and yes, for a capable programmer and hardware tech it's not
> going to be an impossible task.
>
> I would still expect a turnkey solution to exist though as I can see many
> applications for not just state actors.
There ha
Hi
Time is one more thing the spoofer needs to consider. It does not eliminate the
ability to spoof, it just adds one more factor to his setup. If he’s got a
“clear” GPS
signal to base his spoof on, that gives him a timebase to use.
Bob
> On Aug 14, 2017, at 12:09 PM, Tim Shoppa wrote:
>
> B
Hi
The big(er) deal with some systems is that they offer encrypted services. If
you happen to have
access to the crypto version, that’s going to help you. As long as you are
using “public” (and thus
fully documented) modes … not a lot of difference. The same info that lets
anybody design a
re
Hi
> On Aug 12, 2017, at 9:16 AM, Laurens de Bruijn wrote:
>
> Long time listener, first time caller.
>
> I’ve been doing some background reading, but unable to find a definitive
> answer to this, grateful for links or direct input:
>
> I have
> a. 53132A (no options, internal XO, about 1pp
Hi
My guess would be that the box the TBolts connect to uses a pretty limited set
of messages. Like you,
I’d hope that the firmware on the “other end” is happy with the E version.
Bob
> On Aug 11, 2017, at 6:09 PM, Mark Sims wrote:
>
> I wonder if they have tested their system with a Thunderb
Hi
Best guess is that the “real work” on the firmware took place …errr… a bit over
19.6 years ago.
That’s a massively long time ago in terms of development tools and hardware.
Simply getting
a tool suite back up and going on the “old code” would be a big task in most
organizations. Ask
me abou
Hi
The whole “offset frequency” simulcast thing is pretty old. It most certainly
pre-dates
GPS. It’s actually old enough that the first OCXO I ever designed at Motorola
went into that kind
of system. The “time sync” thing came along a while after that.
There’s always been a lot of infrastructur
Hi
Indeed, this could be a new wave of TBolts into the market. My fear is that
those
handling it are not going to sell off the “rejects”. They’ll just toss them in
the trash.
Bob
> On Aug 10, 2017, at 8:00 PM, paul swed wrote:
>
> Just remember you are taking on E911 responsibility.
> Not th
:59 PM, paul swed wrote:
>
> Sweet. Yankee ingenuity at its best. $27K thats seriously nice.
> Almost enough to get me to code something. But then its 911 services maybe
> not.
> Regards
> Paul
> WB8TSL
>
> On Thu, Aug 10, 2017 at 7:00 PM, Bob kb8tq wrote:
>
>>
Hi
They said that hardware was swapped out.
Bob
> On Aug 10, 2017, at 6:48 PM, Chris Caudle wrote:
>
> On Thu, August 10, 2017 5:12 pm, Bob kb8tq wrote:
>> Next up is the comment that it took two weeks
>> and $27,000 to fix.
>
> I wonder if that was the cost to p
Hi
So I’m sitting at dinner focusing on a cold beverage, with the local
news running in the background. Blah blah blah … local EMS system
down for two weeks…. surprise hardware failure takes out “paging
system” … blah .. blah … blah …
So finally they pop up with the “documentation” related to t
Hi
Sounds like a lot of fun getting everything to zero out :)
One thing to watch for is hysteresis. The tempco may not be quite the same
going hot to cold as going cold to hot.
Bob
> On Aug 9, 2017, at 2:34 PM, cdel...@juno.com wrote:
>
> HP5065A +20V supply and C-field circuit mods
>
> I'm
Hi
Actually it *is* a standard Vectron part number. Once an OEM placed an order,
the specific part was issued
a 4 digit “code”. That plus the base model number made up the part number from
there on. On could debate
endlessly if it was to make reordering easier (fewer digits to make mistakes
on)
Hi
> On Aug 4, 2017, at 9:45 AM, paul swed wrote:
>
> Arthur
> Thanks for the picture. I have a TBolt also and its working just fine at
> the moment.
> But one day it may not. As several people have mentioned lightnings an
> issue.
>
> So going down the crazy thought path for a moment.
> It app
Hi
> On Jul 31, 2017, at 3:32 PM, Didier Juges wrote:
>
> The Thunderbolt is well known for not having the best sensitivity among GPS
> receivers. It seems that timing receivers in general, particularly those of
> the same generation as the Thunderbolt are not as sensitive as navigation
> (possi
Hi
Trimble, even on supported products, is pretty firm about a service contract
being in place for updates.
The only exception seems to be security related patches. There have been a lot
of examples of this
over the years ….AFIK, there isn’t even a “public” firmware loader for the
TBolt.
Inde
Hi
> On Jul 27, 2017, at 8:01 PM, Attila Kinali wrote:
>
> On Thu, 27 Jul 2017 17:49:14 -0500
> Didier Juges wrote:
>
>> I cannot imagine a work around since the problem stems from the GPS service
>> only identifying the current date within a particular 1024 weeks epoch
>> unless the governme
t aware there was any special need
> beyond that? Right?
> Regards
> Paul
> WB8TSL
>
> On Mon, Jul 24, 2017 at 8:12 PM, Bob kb8tq wrote:
>
>> Hi
>>
>> The TBolt is a great unit !!
>>
>> The main source of temperature impact is the DAC /
Hi
The TBolt is a great unit !!
The main source of temperature impact is the DAC / Voltage reference. Since
that is a
“distributed” circuit, the temperature control also needs to cover more than
just the backplate.
Bob
> On Jul 24, 2017, at 6:37 PM, Norm n3ykf wrote:
>
> Hi all!
>
> Al
Hi
I’d bet that the “learning” about atomic clocks is not the only thing going on.
Like any
organization, they aren’t really very excited about talking about problems they
have not
solved yet.
Bob
> On Jul 22, 2017, at 8:37 PM, Mark Sims wrote:
>
> Does anybody know why it is taking so long
Hi
Not in the least bit uncommon propagation at those frequencies and this time
of year.
Bob
> On Jul 16, 2017, at 8:44 PM, Clay Autery wrote:
>
> Prop shifted... I tuned to it before I left for Home Depot at 1600 hrs
> CST, and it was strong It was GONE by 1830 hrs.
>
> ___
dard was
> solved because the Volt is defined to be whatever the Josephson array
> produces. Yes expensive because to runs at nearly absolute zero.
>
> On Sun, Jul 16, 2017 at 4:10 PM, Bob kb8tq wrote:
>
>> Hi
>>
>>> On Jul 16, 2017, at 6:33 PM, Richard (Ri
Hi
> On Jul 16, 2017, at 6:33 PM, Richard (Rick) Karlquist
> wrote:
>
>
>
> On 7/16/2017 1:51 PM, Bob kb8tq wrote:
>> Hi
>> One gotcha with any ADC or DAC is going to be the reference. There, you are
>> in the same
>> “get what you pay for” dilemm
Hi
One gotcha with any ADC or DAC is going to be the reference. There, you are in
the same
“get what you pay for” dilemma. Stable and noisy, can do. Quiet and not very
stable, can do.
Both stable and quiet, not so easy if you want it cheap.
Noise can also be the sigma delta ADC’s weak point.
sult will be observable.
Bob
>
>
> On Thursday, July 13, 2017, Bob kb8tq wrote:
>
>> Hi
>>
>> I think we are both taking it as a given that the eclipse’s impact on the
>> ionosphere will
>> be “visible” even with a fairly simple setup. I guess that
t and then make a bold claim when and where the eclipse was,
>> like capturing a trace through a cloud chamber. Having done all that you
>> can "look in the back of the book" for the actual eclipse path to see how
>> right you were.
>>
>> /tvb
>>
>&
Hi
If one perhaps knew the path of the eclipse in advance *and* had a GPS timing
receiver that
could be set somehow to look at a single satellite….. all one would need is a
means of comparing
the output to a stable reference to *possibly* observe something interesting.
More or less: You know
Hi
I’ll put that on my calendar right away :)
Yet another potential bug to check for in MJD code ….
Bob
> On Jul 13, 2017, at 1:51 PM, Peter Vince wrote:
>
> 2038 could be an "interesting" year - on the 22nd of April, the MJD hits
> 65535 (2^16-1) !
>
>
> On 12 July 2017 at 13:19, Tom Van
Hi
> On Jul 12, 2017, at 4:02 PM, Gregory Beat wrote:
>
> A palindrome is a word, phrase, number, or other sequence of characters which
> reads the same backward as forward, such as the words: madam, racecar, or
> tattarrattat.
>
> Palindrome Days start with July 10, through July 19.
> https
HI
> On Jul 12, 2017, at 3:27 PM, Tom Van Baak wrote:
>
> 2 items:
>
> 1) I ran across another link related to lunar timing. Last year Carroll Alley
> died (89). To me he's famous for his cesium and H-maser relativity
> experimence in the 1970's. But he was also the PI for the Apollo Lunar La
Hi
There may well be multiple EEROM’s in the 53181 and 5313x counters. At least
when I have blown up the EEPROM in them, it comes back with a error. I haven’t
blown any up since the early 1980’s so I don’t quite remember the exact error
message involved. Had it simply failed silently, I would h
Hi
I’ve swapped out the GPS on a couple of them. Not 100% sure what went wrong.
Swapping out a cheap GPS was a pretty easy decision compared to trying to
board level troubleshoot an undocumented GPS. When the swap out fixed the
problem,
I moved on.
Bob
> On Jul 11, 2017, at 6:27 PM, Hal Murr
Hi
People *have* been known to sort MiniCircuits parts and use the “extras” in
something else. A certain major oscillator manufacturer once bought a bunch
of RPD-1’s , sorted them for the “one in a hundred” examples, and then returned
the rest for credit…… Somehow I doubt HP didi it quite that wa
Hi
> On Jul 9, 2017, at 9:35 AM, Francesco Messineo
> wrote:
>
> On Sun, Jul 9, 2017 at 2:15 AM, Mark Sims wrote:
>
>>
>> So far my design is tending towards: 10MHz ref input -> Minicircuits
>> doubler -> Wenzel squarer -> 74AC74 divider -> 74AC04 buffer -> level
>> shifter. The doubler
merely claims 100ps absolute accuracy is possible
> with the 5370A/B.
>
>
>
> On Sat, Jul 8, 2017 at 7:48 PM, Bob kb8tq wrote:
>
>> Hi
>>
>> Based on a quick read of the use of the device, they seem to be relying on
>> it to be << 100 ps
>> off
Hi
Based on a quick read of the use of the device, they seem to be relying on it
to be << 100 ps
off from “ideal”. How much it being non-ideal matters …. not clear. If you are
correcting for various errors
and eliminating both unknown source errors and destination errors it likely
gets messy.
Hi
Good means whatever the 5313x needs for calibration. If that is four signals
that are
crossing zero within < 10 ps of the “correct time” then that is the definition
of good in this case.
Rise time delay, fall time delay are rarely the same in logic gates.
Propagation inside a chip to
poin
Hi
> On Jul 8, 2017, at 1:31 PM, Tom Van Baak wrote:
>
> Mark writes:
>
>> lots of luck finding one of those
>
> Actually, you can get J06 HP-59992A calibrators on eBay. You might have to
> wait a while but I've seen them frequently over time. Note that eBay has an
> automatic search notific
Hi
This may be “inside” the envelope for something like a PIC. If not it’s a
pretty
easy task for any of the sub $10 FPGA boards. Given the relatively small
audience, tacking an extra connector or three onto something might be the
better option.
The big unknown (at least to me) is how close t
Hi
Not in a commercial system ….
Bob
> On Jul 7, 2017, at 6:14 PM, Hal Murray wrote:
>
>
> kb...@n1k.org said:
>> Consider that in 1974, I could buy a nice new car for less than what a
>> decent packaged 16 bit DAC cost. Go back into the 1960’s and you are up
>> into the “several new cars”
Hi
> On Jul 7, 2017, at 4:51 PM, Tim Lister wrote:
>
> Three recent papers from the APOLLO project showed up on my VoxCharta
> summary of arxiv.org which may be of interest to the time-nuts
> community. They are to do with improving the precision and absolute
> calibration of the lunar laser ra
Hi
The 58532’s are good antennas. They have nice tight filters in them to reject
crud outside the GPS band. They also have enough gain for any modern GPS
module without having so much that you get into overload issues. The bad
news is that if you want to run Glonass, the filter is tight enough
Hi
Are you trying to contact them via the “info” email or some other way? A lot of
companies
have issues with their contact email setups ….
Bob
> On Jul 5, 2017, at 3:28 AM, Achim Vollhardt wrote:
>
> Fellow Time-Nutters,
>
> I am trying to get in contact with Jackson Labs but without any su
Hi
If you go back in the archives a few years, there are extensive discussions of
the various
alignment steps on a 5070A or B. They are a highly recommend read if you are
getting
ready to dig into one of these counters.
Bob
> On Jul 3, 2017, at 10:13 AM, Gary Neilson wrote:
>
> I have a 53
the unity gain
> buffers or would any normal garden variety op-amp work?
> Wentzel used the 310 in his buffers, and those are a bit special, being a
> bipolar amp with 2nA input bias current.
>
>
> BR.
> Thomas
>
>
>
> 2017-06-28 18:08 GMT+02:00 Bob kb8tq :
>
Hi
Ok, let’s back up a bit:
There are two basic regions when measuring a phase locked oscillator. You
can be “inside” the loop bandwidth or “outside”. Yes it’s a bit more complex
than that, but go with the idea for now. Inside the bandwidth, everything about
the PLL can / may matter. It can and
Hi
I’m not claiming Lemo’s are any cheaper or easier to get than the uber D’s. At
least they
give a bit better density.
Bob
> On Jun 26, 2017, at 9:19 PM, Christopher Hoover wrote:
>
> On Sun, Jun 25, 2017 at 2:53 PM, Bob kb8tq wrote:
>
>> Hi
>>
>> Cost a fo
Hi
It’s mainly a matter of causality. If you have an anomalous reading, there is
likely a “findable” reason
for it. Finding that reason probably gives you useful information about the
design and how to
improve it.
Bob
> On Jun 26, 2017, at 4:17 PM, William H. Fite wrote:
>
> On Monday, June
Hi
Cost a fortune *and* can easily get you into 12 week delivery times ….
Bob
> On Jun 25, 2017, at 4:37 PM, Poul-Henning Kamp wrote:
>
>
> In message <1317347843.1873959.1498418740...@mail.yahoo.com>, Ulf Kylenfall
> via
> time-nuts writes:
>
>> Why not take a look at mixed D-Sub c
Hi
The simple answer is that it’s much more simple than that :)
The 4100 and 6100 both run a very rudimentary serial command set. It’s
not quite SCPI, but that’s the idea. With a simple terminal program (any
terminal program ..) you can bash in the four or five lines that get it doing
what you
Hi
If you have a phase noise under vibration requirement, you do *not* want to use
the “D connector” setup. Go with an SMA ….
Bob
> On Jun 24, 2017, at 7:54 PM, Didier Juges wrote:
>
> I have been forced to use micro-D by a customer on a military power supply,
> not even space rated, it was we
Hi
It’s an LPRO Rb. I’ve always gotten good stuff from that seller. Like any Rb,
the
phase noise and spurs are not good enough for most microwave applications. If
you
are into high dynamic range HF SDR, they will impact that as well.
Bob
> On Jun 23, 2017, at 4:47 AM, Roman wrote:
>
> Hi gro
much
> the term 'time' in this discussion here ;-) .
>
> kind regards
> Arnold, DK2WT
>
>
> Am 23.06.2017 um 01:33 schrieb Bob kb8tq:
>> Hi
>>
>> You can get and use PP’s at 30 to 50A in a 12V circuit without frying them
>> or the cable they a
Hi
You can get and use PP’s at 30 to 50A in a 12V circuit without frying them or
the cable they are
attached to. Doing the same with a “Cannon” connector is not at all easy ….You
can also bump up
to the larger PP’s and get into a couple of hundred amps.
Bob
> On Jun 22, 2017, at 6:54 PM, Arn
Hi
There are some really nice aircraft grade connectors that only cost about $250
each (as in
$500 a pair) that take care of all sorts of issues :)
For my money, Power Poles do just fine.
Bob
> On Jun 22, 2017, at 3:19 AM, Tom Van Baak wrote:
>
> Wes, Don,
>
> I am quite surprised at the n
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