Re: [time-nuts] GPS Antenna Feed Line Decision

On 09/02/2017 02:57 PM, Clay Autery wrote: > Having decision-making problems for the materials for my GPS main > feedline. Going to use a TM LMR stock, just can't decide how big to go > with it... I have a modest 26dB antenna on a six feet pole of plastic piping, the piping is strapped to my

Re: [time-nuts] GPS Antenna Feed Line Decision

On 9/3/17 3:41 PM, Charles Steinmetz wrote: Attila wrote: The supplies for LNAs are usually quite benign given two constraints: * * * 1) Low frequency (0Hz to bandwidth of signal) noise is low * * * But 1) is a bit harder as it also includes 1/f noise, temperature, (upstream)

Re: [time-nuts] GPS Antenna Feed Line Decision

I work with a broadcast station. We just had a HD FM radio transmitter upgrade done. In the upgrade package from GatesAir was a GPS antenna with a F fitting. The provided feedline was RG-223 with a TNC on one end and a SMA on the other. Also provided was a TNC to F adapter. The new exciter has

Re: [time-nuts] GPS Antenna Feed Line Decision

One of my "Hockey Puck" antennas has about 50' of RG-174 on it and I have seen no problems locking up. 73, Dick, W1KSZ Sent from Outlook From: time-nuts on behalf of William H. Fite

[time-nuts] Huber 1399.17.0048

I acquired a Huber+Suhner GPS / GSM Type 1399.17.0048 antenna at a local Hamfest. It has N connectors. Does anyone know its specs ? Bill R --- This email has been checked for viruses by Avast antivirus software. https://www.avast.com/antivirus

Re: [time-nuts] GPS Antenna Feed Line Decision

Attila wrote: The supplies for LNAs are usually quite benign given two constraints: * * * 1) Low frequency (0Hz to bandwidth of signal) noise is low * * * But 1) is a bit harder as it also includes 1/f noise, temperature, (upstream) supply and load effects. The LT3042 is better

Re: [time-nuts] GPS Antenna Feed Line Decision

On 09/03/2017 06:02 PM, Bill Byrom wrote: For precision timing measurements, I would think that there would be concern about the double reflections of a badly mismatched low loss transmission line (such as using 75 ohm line in a 50 ohm environment). The re-reflected signal will act similar to

Re: [time-nuts] GPS Antenna Feed Line Decision

For precision timing measurements, I would think that there would be concern about the double reflections of a badly mismatched low loss transmission line (such as using 75 ohm line in a 50 ohm environment). The re-reflected signal will act similar to multipath (as a delayed aggressor) on all

Re: [time-nuts] GPS Antenna Feed Line Decision

On Sun, 3 Sep 2017 12:32:31 -0500 Clay Autery wrote: > - I saw in some aviation references where pilots claimed that they > achieved "better performance" by running their antennas at higher > voltages.  (Overclocking the antenna amp?  Who knows.)  But it piqued my > interest,

[time-nuts] 1pps isolation

Hi TOSLINK devices may be one way to provide galvanic isolation through an optical connection. One possible solution can be seen here: Bo ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe,

Re: [time-nuts] GPS Antenna Feed Line Decision

Hi. The last time I looked at upgrading my GPS antenna feed line (I'm currently using RG58 style cable) I spent some time looking at the temperature vs propagation delay characteristics of various cables. I also picked up a spool of cloned "LMR400 style" cable but ended up using that for my

Re: [time-nuts] GPS Antenna Feed Line Decision

Thank you for your response.  Again, money is not the issue or priority.  Knowing that I am getting the best signal within reason (my reason  ) Tangentially, you have provided me with the information I require.  As I do not know what I will hang off the end of that antenna in the future and I am

Re: [time-nuts] GPS Antenna Feed Line Decision

Actually haven't settled on an exact solution yet, Gilles.  The power supply will likely become part of the observations/experiment that prompted me to use the external supply in the first place. - All of the devices WANT to supply the antenna.  2 are nominal 5VDC, 1 supplies nominal 3.3VDC... 

Re: [time-nuts] GPS Antenna Feed Line Decision

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

Re: [time-nuts] GPS Antenna Feed Line Decision

Clay LMR-400 is probably the best compromise , I doubt you will see any useful improvement in system performance as a result of the improved 1.5db loss characteristics of the larger cables. Losses due to atmospherics, ionospherics and multi-path will be an orders of magnitude  higher than the

Re: [time-nuts] GPS Antenna Feed Line Decision

Hi There is no need to feed the 58516 or the antenna with any sort of super power supply. It’s just a simple RF amplifier in there. It’s designed to be feed off of the bias supply coming out of a GPS module. If a module has a dedicated 78L05 style regulator on it, it’s one of the better ones ….

Re: [time-nuts] GPS Antenna Feed Line Decision

On 9/2/2017 4:48 PM, Clay Autery wrote: Thanks for the response... Not sure why you and the other guy both recommended RG-6 75-Ohm cable and F-connectors, when the nominal impedance of literally everything else in the system is 50 Ohm, including the antenna and the HP GPS Distribution Amp 

Re: [time-nuts] GPS Antenna Feed Line Decision

On Sat, 2 Sep 2017 18:48:52 -0500 Clay Autery wrote: > Not sure why you and the other guy both recommended RG-6 75-Ohm cable > and F-connectors, when the nominal impedance of literally everything > else in the system is 50 Ohm, including the antenna and the HP GPS >

Re: [time-nuts] GPS Antenna Feed Line Decision

Hi Clay, Intersting subject. What design for ultra stable/clean power supply are you using please ? Thx, Gilles. > On Sep 2, 2017, at 22:47, Clay Autery wrote: > > PCTEL GPS-TMG-HR-26NCM Antenna. >

Re: [time-nuts] GPS Antenna Feed Line Decision

Thanks for the response... Not sure why you and the other guy both recommended RG-6 75-Ohm cable and F-connectors, when the nominal impedance of literally everything else in the system is 50 Ohm, including the antenna and the HP GPS Distribution Amp  And then adding N to F adapters? Doesn't

Re: [time-nuts] GPS Antenna Feed Line Decision

HP 58516A GPS L1 Disribution Amplifier ( 4-way with external power supply input) __ Clay Autery, KY5G On 9/2/2017 3:38 PM, Pete Lancashire wrote: > What are you using for a distribution amplifier ? > > On Sat, Sep 2, 2017 at 11:57 AM, Clay Autery wrote: >

Re: [time-nuts] GPS Antenna Feed Line Decision

PCTEL GPS-TMG-HR-26NCM Antenna.  http://www.neobits.com/pctel_maxrad_gps_tmg_hr_26ncm_high_rejection_gps_p2769137.htm Can't say what the gain tolerances are, but it appears to be a pretty decent quality part. The distribution amp is an HP 58516A GPS L1 Distribution Amp with the external power