[time-nuts] WTB: GPSDO

Tim Lister listertim at gmail.com
Tue Mar 21 21:36:51 EDT 2017

So it seems the threat of replacement and a bunch of plugging and
replugging into different computers has spurred my recalcitrant GPSDO
back into life and it is now producing output again... This leaves me
with the original problem of low sensitivity but at least I can solve
that problem by using the "replacement GPSDO" money towards connecting
a better antenna.

I have a Symmetricom 58532A GPS antenna which has a N female connector
but my 3 current GPS receivers all have SMA female connectors. If I
want to provide capacity for at least 4 receivers fed from the same
antenna, I was wondering what the best option for a splitter and where
to do the N-to-SMA conversion. I currently have a Mini-Circuits
ZAP3PD-2 power splitter which does SMA input to 3 SMA outputs. This
seems to work but the connected devices all complain of an Antenna
short, which doesn't seem good. The other popular option seems to be
the Symmetricom 58536A 1x4 splitter which would then require 3-4
N-to-SMA cables - it looks like although this has gain, it seems to be
more of "eliminating loss" than straight gain so would presumably not
overpower the receivers' frontends. Or maybe there is another more
suitable SMA splitter in the Mini Circuits confusingly extensive
catalog ?

Regarding hand-correcting oscillators, that's not really what I am
personally in this for. I am interested in the data acquisition and
analysis parts (must be the astronomy background) and so I am wanting
to use the time-nuts part to learn about how to interface
microcontrollers and ADCs and DACs and would like to measure things at
the multi-day taus. (I'd also like to be able to eventually build a
programmable delay line either to do the sawtooth correction or
perform clock steering to generate and compare my own UTC(TAL), along
with some means of displaying multiple timescales, which may involve
another construction project as available ones either seem to have NTP
servers built in or want IRIG-B or cost a fortune (unless I'm just
googling for the wrong thing)


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