[time-nuts] RF isolation requirements for multiple GPS receivers

I want to run about 4 separate GPS units of disparate manufacture from a single antenna. My plan is to provide power for the antenna via a bias tee (power inserter) at the bottom end of the antenna's cable, then use an isolating splitter on the receiver side of the bias tee to split to the various

[time-nuts] SRS FS 740

Has any one bought the SRS FS740                                                   Bert Kehren In a message dated 11/21/2018 11:11:18 AM Eastern Standard Time, thol...@woh.rr.com writes: Thanks Steve and Tom for helping me sort that out. Much appreciated. Tom Holmes, N8ZM -Original Messag

Re: [time-nuts] RF isolation requirements for multiple GPS receivers

Hi, I am using Mini-Circuits ZN4PD1-50+. They are about 30dB in the GPS frequency band. I hang 4 receivers each off three of these mixing Motorola, Ublox, Trimble and Navspark and never had an issue. Mike > Le 27 nov. 2018 à 14:44, Dana Whitlow a écrit : > > I want to run about 4 separate

Re: [time-nuts] RF isolation requirements for multiple GPS receivers

Dana, As described in the following HP GPS splitter the isolation is > 40dB. https://www.febo.com/time-freq/gps/hp58516a/HP_58516A.pdf I use one of these 8-channel splitters. I had a bad experience using a passive splitter of the minicircuits in the 10MHz distribution in my lab.

Re: [time-nuts] RF isolation requirements for multiple GPS receivers

Hi I’ve run …. errr … lots ( > 40) of GPSDO’s on a common antenna with a single amp and passive splitters. I’ve never seen any issues. That includes cases with multiple ports un-terminated ( so not terrific isolation). Bob > On Nov 27, 2018, at 8:44 AM, Dana Whitlow wrote: > > I want to run

Re: [time-nuts] Symmetricom TS2100 Faults and Forgetfulness

Chris - Did you update this TS-2100 with HEOL Design’s replacement GPS receiver? Several time-nuts participants (and some scientific organizations) performed this update/upgrade (including me), replacing the obsolete TrimbleACE III GPS receiver. http://www.heoldesign.com/N024-GPS-receiver-board-

Re: [time-nuts] Symmetricom TS2100 Faults and Forgetfulness

Thumbs-up for the HEOL replacement receiver. I've put 'em in both my 2100's, with outstanding results. Couple that with changing out the oscillators to OCXO's, and the result is enough to keep any time-nut happy. ;-) On 27-Nov-18 09:38, Gregory Beat via time-nuts wrote: > Chris - > > Did

Re: [time-nuts] Symmetricom TS2100 Faults and Forgetfulness

A nearby university used the HEOL boards in conjunction with TS2100s. At XX:59:01 every hour the NTP servers were off by one second. Updating the TS2100 to the latest available firmware cured the problem. On Tue, Nov 27, 2018 at 11:54 AM Bruce Lane wrote: > Thumbs-up for the HEOL replac

[time-nuts] WWV/H Doppler Shift

I’ve been monitoring the Doppler shift of WWV/H and CHU for a while now from my location 100 km / 60 mi NW of Seattle. The receiver is a QS1R, using an LTC2208 16 bit ADC, and the 125 MHz clock is provided by a Bodnar GPSDO. A Wellbrook ALA1530S+ loop antenna provides good coverage for the e

Re: [time-nuts] WWV/H Doppler Shift

Tom: Thanks! Rob: your toolchain (to borrow a phrase) produces great results. If I read the graphics right, you might be able to obtain some outstanding results from the HAARP Research Campaign 29 Nov - 03 Dec 2018. U of Alaska Fairbanks Geophysical research Institute. A thought from anothe