[time-nuts] 58517A external SMC power versus PORT1 power

Christopher Hoover ch at murgatroid.com
Mon Feb 26 13:37:39 EST 2007

On 26 Feb 2007, John Ackermann N8UR <jra at febo.com> wrote:
> I started working on my 58517A splitter yesterday.  After looking at the
> board, I don't think installing a simple 0-ohm shunt to the GPS port is
> the right way to enable "thru" power.  If you do that, port 1 will go
> directly to a bunch of bypass capacitors, and I doubt you'll see any
> signal there.  What probably needs to be installed is an RF choke of
> some sort.  That'll let the DC through without shunting the signal to
> ground.

What you say is correct -- an SMD RFC in 1206 does seem like the right thing
and the shunt is clearly wrong.

I don't recall why I thought the shunt was correct.  It did work.  I can
only guess that there was sufficient reactance at L1 on the injected DC to
prevent killing the RF.

I've since switched over to SmartSplitter's.

-- Christopher.

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