[time-nuts] LeoNTP PPS output to PC DB9 input

[Brent Gordon]

Hello Anthony,

Those cables will NOT work.  The BNC connectors are 75 Ohms, which will 
damage the 50 Ohm connector on the server.

Yes, pin1 is DCD.  You might need level shifting, but probably not.

For the cable, just buy a cheap BNC cable and a DE-9 (sometimes 
erroneously called DB-9) connector.  Cut one end off of the cable, strip 
the outer jacket back a couple of centimeters, unravel then twist the 
braid, strip the white insulation back about 2 millimeters, and put some 
heat shrink on the braid so about 2 mm is showing.  Solder the center 
conductor to pin one and the braid to pin five.  Put a hood or some tape 
over the connector and you're done.

Brent

On 5/28/2019 9:28 PM, Anthony Dunne wrote:
> Hi Everyone
>
> I am hoping one of you may be able to help with a specific problem?
>
> Some time ago, I purchased the excellent LeoNTP time server available here:- https://store.uputronics.com/index.php?route=product/product&path=60_70&product_id=92
>
> It serves network time via NTP over Ethernet primarily but it also has PPS/1Mhz/10Mhz via a female BNC connector on the rear.
>
> I would like to connect the BNC output to a DB9 Serial input (female) on a machine running FreeBSD (pfSense) to provide PPS reference/accuracy to the NTPD running there.
>
> Firstly would this work?
>
> Secondly, my dilemma is the pin-out.
>
> I believe on the DB9 pin 1 is DCD (the actual pulse) and pin 5 is the ground. Is this correct?
>
> Could I use a cable such as this:- http://www.l-com.com/multimedia/eng_drawings/CTL4CAD.pdf
>
> even though pin five is not connected or would I need to use something like this:- http://www.l-com.com/multimedia/eng_drawings/CTL5CAD.pdf
>
> and make sure the pin 5/plug 5 is grounded in some way?
>
> Alternatively, is there a simpler way to achieve the goal?
>
> Sorry if this is vague but I would really appreciate some help on this :)
>
> Thank-you in advance
>
>
>
> Anthony
> New South Wales
> Australia
>
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