[time-nuts] Nortel GPSTM TP13 positive or negative?

[Taka Kamiya]

I was fortunate enough to buy Nortel GPSTM at very good prices.  This is a distant cousin of Thunderbird as far as I know.  However, it being CDMA clock source, it's second pulse output is actually once every 2 seconds.  According to various Internet sources, TP13 on board is 1 PPS.
I measured TP13 and it actually IS 1 PPS.  However, this test point is giving negative logic.  Normally +5V and it goes to 0V every 2 seconds.
Manual does not say anything about this being PP2S (with a bar on top).  

Has anyone noticed this or am I doing something wrong????
I cascaded two inverters (74AC04) and have used two gates to provide boost to obtain normally 0V and goes to 5V every 1 second.  It works but I am baffled.  Can anyone tell me what I am seeing is actually the way it is?

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(Mr.) Taka Kamiya
I'm stuck in a wormhole....  Hello, worms!