Re: [time-nuts] TruePosition on the Arduino

Yes, It is easy if you have an Arduino handy. Write a scratch to try EVERY address one at a time. Print the currently attempted address top the screen In fact there is a pre-written sketch in the IDE's I2C examples folder. You can run that and it will report what it finds. It just tries

Re: [time-nuts] GPScon running on Raspberry Pi 3b

it looks to me like Olgierdhas a working INTEL linux os running on the Pi3. He installed Wine on the Intel Linux not on the ARM Linux It looks like maybe Michael has an ARM version of linux running native on the Pi3 Wine will not run on that If you need to run Wine, you need to fist have an

Re: [time-nuts] GPS discipline oscillator vs phase lock

On 6/20/17 4:22 PM, Hal Murray wrote: jim...@earthlink.net said: sequential tone ranging: by putting a "ranging tone" at, say, 1 MHz, on the carrier Thanks. The part that attracted my attention was your "spectrally pure signal" for the VCO. Typically a maser at the ground station - that

Re: [time-nuts] TruePosition on the Arduino

Has anyone been able to get the Packrat software to work with a display? I have been successful getting the Arduino board to initialize the Trueposition board but can't get the display right. The problem seems to be getting the I2C addressing correct. There are several 16x2 line displays

Re: [time-nuts] Plate Tectonics was: GPS Antenna on Tower.

Hi Attila: I have a web page devoted to finding true North. http://www.prc68.com/I/North.shtml There are many ways. Here's on that uses the north star. The first step is to sight the North Star (assuming you are in the Northern hemisphere. But the North star currently is at: dec: +89°15' 51"

Re: [time-nuts] GPS Antenna on Tower.

How do the GPS control/monitoring stations handle Earth tides? My guess is they have another nearby antenna that they can link up to VLBI data. -- These are my opinions. I hate spam. ___ time-nuts mailing list -- time-nuts@febo.com To

Re: [time-nuts] GPS Antenna on Tower.

Hi Earth tides are at least as crazy a topic as time. There are formulas that will let you incorporate the effect of Pluto on solid Earth tides. Bob > On Jun 20, 2017, at 7:21 PM, Peter Vince wrote: > > Hi Mark, > > This is all new information to me - and

Re: [time-nuts] GPS discipline oscillator vs phase lock

jim...@earthlink.net said: > sequential tone ranging: by putting a "ranging tone" at, say, 1 MHz, on the > carrier Thanks. The part that attracted my attention was your "spectrally pure signal" for the VCO. I think the answer I was fishing for is that the modulation has to be easy to filter

Re: [time-nuts] HP 4815 Vector Impedance Analyzer repair

Rick, I have two, one I repaired yesterday using parts from the second. Since acquiring both of them about 4yrs ago, I’ve had to repair the “working” unit five times including the first time when I picked it up. Unlike other HP equipment I own, this thing hasn’t been as reliable. Luckily

Re: [time-nuts] GPS Antenna on Tower.

Hi Mark, This is all new information to me - and fascinating! Have you just "calculated" the offsets (using known values from somewhere), or "measured" it by very long term averaging of the GPS position information? Peter Vince On 20 June 2017 at 17:34, Mark Sims

Re: [time-nuts] CRT for Tracor 527A

A suggestion. $300 does seem a lot for a gamble. But if it really gets bad you can buy any scope and plumb it in and get what you need. Clearly an OK answer. But a thought none the less. Regards Paul WB8TSL On Tue, Jun 20, 2017 at 6:06 PM, Clint Jay wrote: > A little extra

Re: [time-nuts] SR620/PM66xx/CNT-90 input stages

Attila wrote: Now, if the downstream circuit would be low impedance, I could understand that, but the sink is a comparator with a high impedance input (only a few µA input current). I am sure the engineers had a good reason to add those amplifiers, but I cannot guess why. Would someone be so

[time-nuts] GPS Antenna on Tower.

I just added the ability to calculate solid earth tides and the vertical gravity offset due to the sun and moon to Lady Heather. The lat/lon offset is typically around +/- 60 cm per day.Vertical offset is around +/- 180mm. Depending upon the day and where you are, the swings are not

Re: [time-nuts] GPScon running on Raspberry Pi 3b

Hi Michel, I installed Wine (Windows compatibility layer) within the ExaGear. After the installation of the ExaGear on a Raspberry Pi one gets a new icon on the desktop that just starts a session of Debian-8. Trying command "$ arch" returns "i686" beauty! What I did (within this Debian

Re: [time-nuts] ebay posting

Bert Kehren via time-nuts wrote: Since I have a Tracor 527E I am not going to bid on the following link. I have bought two items with very good results and have nothing to do with the seller. I suspect based on his location that this is NASA material. The unit has a FRK Rb in it. Bert Kehren

Re: [time-nuts] HP 4815 Vector Impedance Analyzer repair

The first thing I would do is replace all the power supply electrolytic capacitors on the internal boards.  If I remember correctly, the boards are plugged in and the replacing the capacitors is quite easy.  In my unit, at least one capacitor was shorted and was pulling down a power supply. 

Re: [time-nuts] CRT for Tracor 527A

A little extra heater voltage and allowing the tube to 'cook' a while can help as can a CRT rejuvenator but the cathode is usually tiny on a mono tube and from experience with television repairs back in the dawn of my career, they very rarely last any length of time after rejuvenation before

Re: [time-nuts] CRT for Tracor 527A

Hi: Yes, there are Cathode "Rejuvenators" that can sometimes give a CRT some more lift. This is a problem with all test equipment that uses CRTs. There are LCD replacements for the CRT in some HP equipment, like the 8566 SA. -- Have Fun, Brooke Clarke http://www.PRC68.com

Re: [time-nuts] SR620/PM66xx/CNT-90 input stages

If the source impendance at dc is 10k at dc a bias current of a few microamp produces a dc offset of tens of millivolts which may be an issue if the signal amplitude is low and has a low slew rate. Bruce > > On 21 June 2017 at 09:11 Charles Steinmetz wrote: > >

Re: [time-nuts] CRT for Tracor 527A

Hello to the group. I was not going to comment on the thread. But realized I should. A caution on CRTs is that if they have been around a long time they may have very poor emissions. Even if new. Cathode pollutes over time. Just saying don't be to surprised if you don't get what you paid for. Best

Re: [time-nuts] Plate Tectonics was: GPS Antenna on Tower.

On Tue, 20 Jun 2017 13:29:24 -0700 Brooke Clarke wrote: > Original Message > > I have wondered how geologists are able to measure tectonic plate > > movements in the earths surface to a couple cm's when the sensors from > > what I see/read they are nothing

Re: [time-nuts] CRT for Tracor 527A

Not rare but uncommon. I gave the one I have away a couple years ago. Ask on a few of he military/boatanchor lists, I've had pretty good luck. -pete On Tue, Jun 20, 2017 at 2:01 PM, David C. Partridge < david.partri...@perdrix.co.uk> wrote: > Trying a long shot here, I'm looking for a 1" CRT

Re: [time-nuts] HP 4815 Vector Impedance Analyzer repair

There's a guy on eBay who sells HP stuff (and other) who does certified calibrations and repairs of HP stuff... can't be that hard to find... KN5U is his eBay ID (and call sign?) He calibrated my HP freq counter before sending it to me after I won it on one of his auctions...

[time-nuts] CRT for Tracor 527A

Trying a long shot here, I'm looking for a 1" CRT type 1EP1 (or 1EP11, or?) for a Tracor 527A Frequency Difference Meter. I did spot some on eBay but the vendor had a rather high opinion of their worth :) at over 300 dollars Anyone got one to spare? Thanks Dave

[time-nuts] Plate Tectonics was: GPS Antenna on Tower.

Hi Bryan: The first data on tectonic plate movement came from the Latitude Observatories. The Longitude problem was solved fairly quickly by Harrison's clocks but the uncertainty of an observatories latitude because of wobble of the pole took much longer and was addressed by a hand full of

Re: [time-nuts] HP 4815 Vector Impedance Analyzer repair

Rick Sorry to say I do not know but I do remember an article in EDN I think. The ground connections were riveted and essentially made poor contact after many years. Drilling them out and putting normal screws nuts and lovking lugs in evidently really restored the units. Regards Paul WB8TSL On

Re: [time-nuts] GPS Antenna on Tower.

I have wondered how geologists are able to measure tectonic plate movements in the earths surface to a couple cm's when the sensors from what I see/read they are nothing more than sensors in concrete boxes?. I believe they use various technologies such as Very Long Baseline

[time-nuts] HP 4815 Vector Impedance Analyzer repair

I have a non-functional HP 4815, don't know if it is the probe or the box. A long time ago, there was a fellow named George Standford (something like that) who repaired these. My old contact information for him is no good. Does anyone know if he is still in business, or if there is any other

Re: [time-nuts] TBolt help...

You are not the only one that has experienced that problem happened to my friend Juerg today too and a while back to me Bert Kehren In a message dated 6/20/2017 1:15:34 P.M. Eastern Daylight Time, dave.mall...@gmail.com writes: hi many thanks to all! it was much simpler: the pins in

Re: [time-nuts] TBolt help...

hi many thanks to all! it was much simpler: the pins in the power plug on the Tbolt had gradually slid up in the connector block till the -12 disconnected. all this in a closed insulated box on the wall!!! humbled and happy 73, dave mallery, k5en On Mon, Jun 19, 2017 at 7:12 PM, J. L.

Re: [time-nuts] GPS Antenna on Tower.

I thought there was kind of a rule about EXCLUDING sats on or near the horizon... __ Clay Autery, KY5G On 6/20/2017 8:27 AM, "Björn Gabrielsson" wrote: > Hi Thorbjörn, > > To bad this particula antenna has surrounding buildings (and maybe trees) > that mask low elevation

[time-nuts] ebay posting

Since I have a Tracor 527E I am not going to bid on the following link. I have bought two items with very good results and have nothing to do with the seller. I suspect based on his location that this is NASA material. The unit has a FRK Rb in it. Bert Kehren

Re: [time-nuts] GPS Antenna on Tower.

Hi Thorbjörn, To bad this particula antenna has surrounding buildings (and maybe trees) that mask low elevation satellites. -- Björn > http://www.sp.se/en/index/resources/GNSS/Sidor/default.aspx > Have a look at the best receiving antenna I know about. > > The tower must have cooling tubes

Re: [time-nuts] GPScon running on Raspberry Pi 3b

Neat! I just happen to be playing with a Pi this week as a class assignment (retirement is wonderful - finally going back to college). I downloaded Lady Heather, compiled it, and got it to come up and run. Nothing that I can plug in this week though, but it looks good. I also installed QEMU in

Re: [time-nuts] GPS Antenna on Tower.

Try again ..., Since 1cm of motion is equivalent to 30 ps, there's probably not much point in putting your GNSS antenna on a geodetic monument if all you care about is timing. But it does matter if you're trying to track continental drift. Michael On Tue, 20 Jun 2017 at 10:44 pm, Michael

Re: [time-nuts] GPS Antenna on Tower.

Since 1cm of motion is equivalent to 30ps, there's probably not On Tue, 20 Jun 2017 at 10:11 pm, Didier Juges wrote: > If that is not time-nutty, I do not know what will :) > > On Jun 20, 2017 7:04 AM, "jimlux" wrote: > > > > > for geodetic

Re: [time-nuts] GPS Antenna on Tower.

It was bright sunshine and 46 degrees C here in the desert near Tucson, Arizona yesterday. It would take a lot of cooling to keep that solar collector (radome) cool. Wes Stewart On 6/19/2017 9:42 PM, Thorbjørn Pedersen wrote: http://www.sp.se/en/index/resources/GNSS/Sidor/default.aspx Have

Re: [time-nuts] GPS Antenna on Tower.

LOL!!! My first reaction to reading the drill for sub-subterranean GPS mast was... Wonder if I could borrow Shappell's little drilling rig to do THAT hole and the vertical wells for the geo-thermal cooling loops? Followed closely by... Wonder what kind and number of Sorbothan, et al. dampers

Re: [time-nuts] Halcyon OFS

I've learned NEVER to start a new task on "Friday afternoon", unless I want to work on that task thru Monday morning. __ Clay Autery, KY5G On 6/20/2017 3:36 AM, Stephen Tompsett wrote: > It's a Friday afternoon job! WOW!!! That was a LOT to trim off!!!

Re: [time-nuts] GPS Antenna on Tower.

On 6/20/17 5:11 AM, Didier Juges wrote: If that is not time-nutty, I do not know what will :) if you're a "real time-nut" you drill your own holes - you buy a surplus drilling rig, refurbish it, figure out how to work it (maybe there's a "drill-nuts" list?), etc. But at least the station

Re: [time-nuts] GPS Antenna on Tower.

If that is not time-nutty, I do not know what will :) On Jun 20, 2017 7:04 AM, "jimlux" wrote: > > for geodetic measurements, they drill a hole down to bedrock, and run a > pipe down to anchor the antenna to the bedrock. > > "All holes shall be drilled straight enough so

Re: [time-nuts] SR620 TCXO calibration

On 19 June 2017 at 21:43, David C. Partridge wrote: > Yes please. ... > OK, the code is here http://www.kirkbymicrowave.co.uk/tmp/srs-0.02.tar.gz Note 1) It has only be tested on Solaris SPARC, with a National Instruments GPIB card. 2) I would expect it to run

Re: [time-nuts] GPS Antenna on Tower.

for geodetic measurements, they drill a hole down to bedrock, and run a pipe down to anchor the antenna to the bedrock. "All holes shall be drilled straight enough so that PVC casing can be installed in the top 15.5 ft of each hole, and that the steel pipe can be freely lowered, not forced,

Re: [time-nuts] SR620/PM66xx/CNT-90 input stages

Its somewhat difficult to achieve a 1Megohm input with just a bipolar comparator input stage especially if AC coupling is required. Bruce > > On 20 June 2017 at 19:20 Attila Kinali wrote: > > Hi, > > I had a look at the PM668x[1] and CNT-90[2] schematics

Re: [time-nuts] SR620/PM66xx/CNT-90 input stages

Hi I think the purpose is to get high input impedance for high frequency signal. The input impedance of comparator is high at low frequency range only. Li Ang / BI7LNQ ---Original--- From: "Attila Kinali" Date: 2017/6/20 15:20:44 To: "Discussion of precise time and frequency

Re: [time-nuts] Halcyon OFS

It's a Friday afternoon job! On 19/06/2017 18:26, Clint Jay wrote: > It seems I have a hybrid, on the front panel it's an OFS-1, on the serial > number label it's an OFS-1A and on the PCB it's an OFS-2. > > http://imgur.com/a/brRou > > On 19 June 2017 at 17:40, Ole Stender Nielsen

[time-nuts] SR620/PM66xx/CNT-90 input stages

Hi, I had a look at the PM668x[1] and CNT-90[2] schematics yesterday and noticed one thing: The input stages are strikingly similar to the SR620[3] (down to the parts used) and all of them have a gain 1 amplifier infront of the comparator. The PM668x service manual explicitly calls it "impedance