Hal Murray hmurray at megapathdsl.net
Would you please say more? Or post pictures?
Where did you find a 200 ms PPS pulse?
The circuitry I added takes the narrow positive going timing pulse
(2V/25us) on pin 2 of the surface mounted Lucent 1141 IC (U5)
near the DB25 output connector on the main
There really is nothing much to this modification. The Z3801A is already
designed to easily work on either interface, but most units are configured
for RS-422 as the default. It takes perhaps a half-hour to remove a few
zero-ohm SMD resistors and solder in a header strip. The simple
On 03/31/2012 08:11 AM, Hal Murray wrote:
There really is nothing much to this modification. The Z3801A is already
designed to easily work on either interface, but most units are configured
for RS-422 as the default. It takes perhaps a half-hour to remove a few
zero-ohm SMD resistors and
Has anyone figured out the other modifications possible?
About 10 years ago I added a true ~200ms PPS LED to existing holes in the
circuit board on the front panel plus a BNC connector to bring the same TTL
level signal out the back of the unit.
___
-nuts-boun...@febo.com] On
Behalf Of Hal Murray
Sent: Friday, March 30, 2012 11:12 PM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] HP Z3801A Sale
There really is nothing much to this modification. The Z3801A is
already
designed to easily work on either
On 3/31/12 8:21 AM, Eric Lemmon wrote:
Hal,
The beauty of the header strips is that the Z3801A can easily and quickly be
converted back to RS-422 in the future, without having to partially
dismantle the unit and do more soldering- again.
true, but you have to remove the board from the case
On 3/31/12 3:24 PM, Hal Murray wrote:
jim...@earthlink.net said:
I can't see ever changing mine back. I could see going in and modifying it
to put a USB/serial dongle inside, so it would have a USB jack on it, since
serial ports are become less common.
I have several USB-Serial dongles.
procedure
is described and illustrated here:
www.ad6a.com/Z3801A.html
73, Eric Lemmon WB6FLY
-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On
Behalf Of Larry McDavid
Sent: Friday, March 30, 2012 8:44 PM
To: Timenuts
Subject: [time-nuts] HP Z3801A
On 3/30/12 8:43 PM, Larry McDavid wrote:
On 2/16/2012 Brad Stockdale announced here on Time-Nuts that he had a HP
Z3801A GPSDO for sale. I corresponded with Brad several times and he
reported that he sold one Z3801A to a list member and that this unit had
been modified to provide RS-232 rather
