[time-nuts] Component level 1:2 splitter

Dan Rae danrae at verizon.net
Mon Mar 10 18:23:24 EDT 2008


randy warner wrote:

>Guys,
>
>I need to come up with a 0db little splitter to route 1 antenna into 2 GPS
>receivers. To keep the isolation up I want to use an active splitter instead
>of a passive one.
>
Randy,
For a long time I used a passive splitter made from a swap meet $1 MCL 
(minicircuits) 1 to 2 GHz splitter / combiner.  Isolation of these is 
good, around 30 dB, and the extra 3 dB loss will not be noticed in the 
majority of cases.  This one had SMAs all round and DC continuity 
through from the A and B ports to the Common.  I blocked one path to DC 
with a 100 pF SM capacitor.  If you need the Rx connected to the blocked 
path to think it is feeding an antenna a series R and L combination with 
a 220 Ohm R will fool the Rx in question.

I really would not think you will need any gain.  For more than two 
receivers though I would recommend the hp / symmetricom (?) 4 and 8 way 
active splitters that can be found on eBay.  If you did want gain there 
are a lot of MMICs that will do the job.

I've given it away a while back so can't give you any further details, 
but for two receivers this worked well for me. For my growing collection 
of gps units here I now need more than two...

Dan






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