Re: [time-nuts] How can I measure GPS Antenna quality?

Mark wrote: The tricky bit is interpolating signal levels between logged points (there is a display options for showing the raw signal level data). Heather interpolates between adjacent azimuth points at each elevation angle. I always wondered about the "filled in" (interpolated) plot.

Re: [time-nuts] Best replacement for Trimble Bullet antenna

I bought a Gilsson marine antenna and an 8 port amplified splitter on eBay. The antenna is mounted on the roof of my garage, where it has visibility easily down to 20 degrees except to the North where there is an obstruction (but that doesn’t matter). The coax is 10 meters of whatever came with

[time-nuts] How can I measure GPS Antenna quality?

The colored signal level vs az/el plot follows that convention... outer edge is the horizon, center point is zenith (90 degrees above the horizon). Color represents the average signal level seen at a given point in the sky. The tricky bit is interpolating signal levels between logged

Re: [time-nuts] Fwd: Best replacement for Trimble Bullet antenna

With roof mounted antenna practical issuers are important. 1) Do birds like to tech on it, they will it then can find a way to stand on top of it. They poop on whatever they perch on. 2) Same with snow in some places 3) Can you route the lead wire down the mast? Some antenna mount to a pipe

Re: [time-nuts] Re; Do reflections up/down the antenna cable cause a problem with GPS

On 11/22/16 4:36 AM, John Ponsonby wrote: Remember that for a microwave LNA the condition for optimum noise figure is not the same as the condition for the input to be matched. Thus one doesn't expect the input of a good LNA to be matched to 50Ω. (Dr John Ponsonby) this is also true for

Re: [time-nuts] How can I measure GPS Antenna quality?

On 11/22/16 10:13 AM, Mark Sims wrote: Attached is a screen shot from Lady Heather showing various antenna signal displays. The antenna was a cheap GPS/GLONASS patch antenna (mounted on a 3 foot ground level tripod ) connected to a rather nice NVS-08 receiver tracking GPS, SBAS, and GLONASS

Re: [time-nuts] Do reflections up/down the antenna cable cause a problem with GPS?

Hi, I agree. In general, you have one 50=>75 transmission loss, cable damping, one 75=>50 reflection, cable damping, a 75=>50 reflection, cable damping, 75=>50 transmission for the direct path of 50=>75 transmission, cable damping 75=>50 transmission. Thus, the reflection will be two cable

[time-nuts] Commercial avionics GPS bruohaha

http://gpsworld.com/faa-suspends-approval-of-certain-navworx-ads-b-units/ -- Dave manu...@artekmanuals.com www.ArtekManuals.com ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to

Re: [time-nuts] How phase stable is rg59 or alternate coax

Note that partial air core (9913) and foam dielectric is better than solid polyethylene. David N1HAC On 11/21/16 5:39 PM, Mark Spencer wrote: At one point I contemplated running Andrews "Heliax" for my GPS antenna. Part of the rationale was due to the data presented in page 2 of the

Re: [time-nuts] Do reflections up/down the antenna cable cause a problem with GPS?

Hi Relay based attenuator. Oddly enough I have data on more than one generator :) (ouch indeed if it’s not being paid for on somebody else’s credit card) Bob > On Nov 22, 2016, at 10:50 AM, Scott Stobbe wrote: > > Ouch! Relay stepped attenuator? Or solid state

[time-nuts] How can I measure GPS Antenna quality?

That screen is one of the features in the next (5.0) release. If you click the mouse on one of the signal level maps in that display, it will zoom that one to full screen. Besides the normal "zoom" keyboard commands, with the 5.0 release you can also zoom the clock/watch/sat map/signal

[time-nuts] Fwd: Best replacement for Trimble Bullet antenna

I have a used version of the subject antenna, which is still quite operational. However, I recently needed either a way to tie into reception from this antenna or purchase additional antennas. Given the cost of active patch antennas, I tried one from Adafruit. While comparing reception on a

Re: [time-nuts] How can I measure GPS Antenna quality?

Mark, Was that screen invoked from the LH application or via command line? I don't see a mention of something similar on the LH help pop-up. 73/jeff/ac0c www.ac0c.com alpha-charlie-zero-charlie -Original Message- From: Mark Sims Sent: Tuesday, November 22, 2016 12:13 PM To:

[time-nuts] How can I measure GPS Antenna quality?

Attached is a screen shot from Lady Heather showing various antenna signal displays. The antenna was a cheap GPS/GLONASS patch antenna (mounted on a 3 foot ground level tripod ) connected to a rather nice NVS-08 receiver tracking GPS, SBAS, and GLONASS satellites (typically around 22 sats).

Re: [time-nuts] 53132 replacement fan

Is the original fan controlled by a temperature sensor? That is the best way to control noise because the fan runs at lower RPM most of the time and high speed only when needed. So the airflow and noise is only as much as is required, They make retrofit kits, fans with sensors most for use in

Re: [time-nuts] Logging SPAD pulses on synced devices (was: Linux PPS clues?)

Hi, Do a SPI bus do this job correctly? I'd have the clock on one line and the pulses logged on a second line. Like CLK for clock pulses and MOSI/MISO for serial logging of pulses. I'd avoid I2C because of addressing packets. Best Regards, Ilia On 11/05/16 04:48, Casey L. Jones wrote: Yes,

Re: [time-nuts] 53132 replacement fan

On Sun, 20 Nov 2016 14:14:02 -0500, John Ackermann N8UR wrote: > Does anyone have a part number for the 53132 fan (or equivalent)? Mine > is getting pretty noisy. > > Thanks! > John I got this one for my '132 http://www.ebay.com/itm/111317257709 Sunon HA40201V4-999 Axial-Lüfter 40x40x20mm

Re: [time-nuts] Do reflections up/down the antenna cable cause a problem with GPS?

Ouch! Relay stepped attenuator? Or solid state components? On Mon, Nov 21, 2016 at 11:00 PM Bob Camp wrote: > Hi > > There are packages you can put on a fairly standard HP signal generator > that will > do the mismatch stuff without spending all the money Sperient wants for > one

[time-nuts] Re; Do reflections up/down the antenna cable cause a problem with GPS

Remember that for a microwave LNA the condition for optimum noise figure is not the same as the condition for the input to be matched. Thus one doesn't expect the input of a good LNA to be matched to 50Ω. (Dr John Ponsonby) ___ time-nuts mailing list

Re: [time-nuts] Do reflections up/down the antenna cable cause aproblem with GPS?

From: Dr. David Kirkby (Kirkby Microwave Ltd) Anything not immediately absorbed by the GPS receiver is going to be reflected back up the coax, and could be reflected multiple times. = Only if the sending impedance of the LNA in the antenna is well off

Re: [time-nuts] 53132 replacement fan

I will point out that I have rejuvenated many a fan by peeling off the round label covering the bearing and adding a small amount of oil. David N1HAC On 11/21/16 12:57 PM, jimlux wrote: On 11/21/16 6:39 AM, Charles Steinmetz wrote: Tom wrote: EFB0412MD Airflow 7.17 CFM 6300 RPM Noise 24