[time-nuts] Questions on Nortel Trimble NTBW50AA GPSTM

Clay Autery cautery at montac.com
Wed Aug 10 15:25:44 EDT 2016

1) Need a 24 VDC power supply.  Am considering just buying an Astron
VLS-35M Adjustable Voltage/Current supply (5-32V/1.5A to limit) since I
don't own a variable power supply yet, this is a linear, and the same
size package as my RS-70M.  I can worry about a dedicated supply later
if I decide to keep this GPSTM after I finish modding/testing it.

Anyone have any recommendations to the contrary?  Why?

2) Need to bring the PPS out from the TP in this article: 
https://www.i3detroit.org/wiki/Nortel_GPSTM  The article shows a buffer
circuit being used to accomplish this...  Need help locating a datasheet
on the Motorola chip used...  It's obsolete and I need to find a pin
compatible replacement...

Or, I need to find another buffer schematic/plan,

Or, alternatively....  has anyone ever tried pulling the 1pps out and
hooking it to the 9.8 MHz driver (severing the drive line to it and
jumpering in the 1pps)?  The 9.8MHz and the 10MHz signal out ports SEEM
to use identical driver/buffer circuits on this board...  Seems like a

Preferably, I find the Motorola chip, copy the buffer circuit and move

I'm pretty new at this, so any help is appreciated, and not slapping me
about for "not knowing" stuff is greatly appreciated!  :)


Clay Autery, KY5G
MONTAC Enterprises
(318) 518-1389

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