[time-nuts] GPS splitter measurements

bg at lysator.liu.se bg at lysator.liu.se
Fri Oct 12 01:45:42 EDT 2012


Paul,

> Azelio,
> Not at all the satellite splitters can be smart or passive. I use a
> passive
> so it has 1 dc path. But all of the other ports have dc blocks built in.
> The smarter units will direct the highest DC to the antenna. Its really
> diodes and I stay clear of those. To smart for there own good.

The S14WI chose the lowest port with a DC present. (smarter than diods...
;-))

> Plus with 3.3v and 5 v... it gets messy. I actually use the whole thing as
> a passive. Have a line amp ahead of the splitter to make up for splitter
> loss. Feed it with its own supply that also feeds the antenna.

> On some gps units you do have to add a dc load to trick them into
> believing
> an antenna is connected.

This is included in (all) decent splitters. The load is usually 200ohms.
The S14WI will actually remove the load towards the receivers when it
detects a short/open condition towards the antenna.

> Regards
> Paul
> WB8TSL
>
> On Thu, Oct 11, 2012 at 7:15 PM, Azelio Boriani
> <azelio.boriani at screen.it>wrote:
>
>> To test this kind of items, you have to play with DC-blocks and
>> bias-tees.
>> Rather tedious but necessary. I know as at times I have to test
>> questionable GPS antennae that return after lightning strikes.
>>
>> On Fri, Oct 12, 2012 at 1:09 AM, paul swed <paulswedb at gmail.com> wrote:
>>
>> > Magnus what would the possibility be of measuring an 8 way satellite
>> > splitter? The $7 wonders with dc pass through. That looks like a very
>> nice
>> > network analyzer you have.
>> > Regards
>> > Paul
>> > WB8TSL
>> >
>> > On Thu, Oct 11, 2012 at 7:05 PM, Magnus Danielson <
>> > magnus at rubidium.dyndns.org> wrote:
>> >
>> > > On 10/12/2012 12:16 AM, Azelio Boriani wrote:
>> > >
>> > >> Please take care that the S14WI is "smart": if it doesn't sense a
>> DC
>> > >> current on the antenna port then it reports that to the user ports
>> and I
>> > >> think it can even power off the internal amplifier, this can
>> account
>> for
>> > >> the observed loss instead of the gain.
>> > >>
>> > >
>> > > I did consider this. but did not have the time and energy to follow
>> that
>> > > up at the time. It was only when I got home that I could dig up the
>> > > datasheet and manual of the S14WI. Didn't want to fry it in the lab.
>> > >
>> > > I rather do an incomplete lab quick and safe. I reports warts and
>> all.
>> > >
>> > > I'll see if I get time to re-do it tomorrow.
>> > >
>> > > Regardless, I want to get things going. More people than me should
>> be
>> > able
>> > > to do this.
>> > >
>> > >
>> > > Cheers,
>> > > Magnus
>> > >
>> > > ______________________________**_________________
>> > > time-nuts mailing list -- time-nuts at febo.com
>> > > To unsubscribe, go to https://www.febo.com/cgi-bin/**
>> > > mailman/listinfo/time-nuts<
>> > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts>
>> > > and follow the instructions there.
>> > >
>> > _______________________________________________
>> > time-nuts mailing list -- time-nuts at febo.com
>> > To unsubscribe, go to
>> > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
>> > and follow the instructions there.
>> >
>> _______________________________________________
>> time-nuts mailing list -- time-nuts at febo.com
>> To unsubscribe, go to
>> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
>> and follow the instructions there.
>>
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to
> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.
>






More information about the time-nuts mailing list