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

2017-09-02 Thread Bill Hawkins
My HP conical antennas had N connectors, so I used 50 feet of RG-8. Z3801 receivers never had a problem. RG-8 is a sturdy cable, which may be the primary consideration for a 38 foot drop unsupported through the mast. Don't have any comparison to lighter cable, though. Bill Hawkins

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

2017-09-02 Thread William H. Fite
True, though a friend of mine used LMR-400. On Saturday, September 2, 2017, Mark Sims wrote: > Cheap RG-59 cable coax is more than sufficient for 50 .. 150+ feet (unless > you are doing geodetic level GPS work). It is recommended by several GPSDO > makers. The 50/75 ohm

[time-nuts] GPS Antenna Feed Line Decision

2017-09-02 Thread Mark Sims
Cheap RG-59 cable coax is more than sufficient for 50 .. 150+ feet (unless you are doing geodetic level GPS work). It is recommended by several GPSDO makers. The 50/75 ohm mismatch is not an issue. No need to waste money on fancy pants artisanal luxury coax.

[time-nuts] Symmetricom SA22.c temperature sensitivity

2017-09-02 Thread Mark Sims
I connected a Tbolt to the 1PPS input of a Symmetricom SA22.c rubidium oscillator and ran Heather's software discipling code on it. For some strange reason, you do get better performance using a clean 1PPS rather than the crappiest one you can find ;-) Anyway some interesting results came

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

2017-09-02 Thread Bob kb8tq
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

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

2017-09-02 Thread Mike Naruta AA8K
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... 26 dB 5vdc antenna on top of a 38 foot mast. Feed will come down the inside/center of mast and exit

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

2017-09-02 Thread Wes
This is just a cascaded noise figure situation. The first stage is the antenna (preamp) which has 26 dB gain (assumed) and an unknown noise figure. Assume it's a dB or so. Let the second stage gain be a negative value equal to the cable loss and the second stage noise figure be equal to the

Re: [time-nuts] SA22.c and Lady Heather

2017-09-02 Thread Dave Mallery
hi on the 2011 or newer items, they include this link calibration data plot. i received a printed one with the unit. dave On Sat, Sep 2, 2017 at 6:55 AM, Mark Sims wrote: > The data that RDR showed was from the SA22.c

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

2017-09-02 Thread Pete Lancashire
What are you using for a distribution amplifier ? On Sat, Sep 2, 2017 at 11:57 AM, 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... > > 26 dB 5vdc

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

2017-09-02 Thread Bob kb8tq
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

[time-nuts] GPS Antenna Feed Line Decision

2017-09-02 Thread Clay Autery
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... 26 dB 5vdc antenna on top of a 38 foot mast.  Feed will come down the inside/center of mast and exit near the bottom, thence routed through a window

Re: [time-nuts] Datum Cesium Plus (CS PLUS) manuals

2017-09-02 Thread Ed Palmer
Not the manual, just the datasheet. Hope it's useful. https://web.archive.org/web/20030316131651/http://www.datum.com:80/pdfs-ttm/cesium_plus.pdf Ed On 2017-09-02 10:00 AM, Maarten wrote: Hi All, I recently acquired a number of these but don't have any manuals for

[time-nuts] SA22.c and Lady Heather

2017-09-02 Thread Mark Sims
The data that RDR showed was from the SA22.c "w" command. I think he was just using a terminal program. Attached is a screen dump of Heather doing a software disciplining algorithm on a SA22.c (using the dev board as an interface). The 1PPS reference that I am using is the nosiest one that I

[time-nuts] Datum Cesium Plus (CS PLUS) manuals

2017-09-02 Thread Maarten
Hi All, I recently acquired a number of these but don't have any manuals for them. Does anyone on the list know where I can get User and or Service manuals? Kind regards Maarten VK6MP ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe,