[time-nuts] HP Z3805A com port and monitoring questions

David I. Emery die at dieconsulting.com
Sat Oct 20 02:19:03 EDT 2012

On Thu, Oct 18, 2012 at 12:47:30AM -0500, Edgardo Molina wrote:
> Dear David,

> Yes, I bought the same unit as you. I will come back to you tomorrow
> with some serial number information. 

	I found mine is a DTE with TXD on pin 2... RXD on pin 3.

	Seems to like 9600,8,n,1

	Have it working under a XP virtual machine on this laptop with
the K8CU GPS receiver control program.   Seems to work OK...
no stats on performance yet.

	Mine has a Motorola 6 channel GPS rx in it - not a Furuno 16

	In the same shipment  I also ordered one of the Samsung branded
Symmetricom GPSes that does have the Furuno 16 channel receiver.
K8CU GPSCON reports it has a GT-80 and shows 16 channels.  It has
a Symmetricom OCXO, looks MTIish... but not MTI.  Mounted on a
doubler board - outputs 10 MHz.   Looking inside the receiver
is a Furuno GT8031F.

	I'm sort of wondering if I could upgrade the GPS in my close to
NOS HP z3805 box (would obviously require using the Samsung version of
the firmware) from the Samsung box... not clear how much (other than
TRIAM and WAAS) that might buy me or whether it would be worth it.

	Though I am sure you know all this, you certainly should be able
to find the port pins with a DVM or scope - mine outputs about -8 volts
on TXD and RXD floats about 0.2 volts positive.   I did find I need a
null modem cable to connect it up to a regular serial port (for this
test a keyspan HS-19 USB serial port).

	I'm not exactly sure what Said Jackson has and sings the praises
of.  Fluke.l has been selling a few Samsungs and has one advertised that
I guess is similar to mine but with an explicit MTI 260.

	I presume Said has units with the 10811-60165 rather than the
MTI-260... I'm curious which oscillator  he is finding those stability
and phase noise specs on - I'm looking to upgrade the reference to some 
microwave LO chains and would like a nice box with that performance.

	I'm not sure when he bought his or what age they are. 
Apparently some of the  HP branked z3805s must have had the Furuno
receiver module.

	There is also tommy_chou who has some Samsung z8505As with
the 10811 DOCXO... not sure what GPS these have.

	Appear to be 3 sellers with similar ex-Korea CDMA stuff...
tommy_chou,  our familiar fluke.1 and yixunhk.

> you are able to connect to your unit, please advise. None of the
> combinations I got in past emails worked. It must be cable or serial
> port, or blame it on the operator. I will update this thread with more
> information tomorrow. 

	I have found the obvious pilot error issues with things like
hyperterminal - the box should respond to a *CLS command with scpi > and
to an *IDN? command with the serial number.   I did find (silly me) that
hyperterminal  defaults to DCD flow control on and you have to say no
flow control before it will see anything from the ports on the box. This
is because DCD comes out off with the Null modem cable I was using.

	Basic stuff.

> I will be getting new toys to play around during the weekend. I will
> comment in a separate thread as soon as they are delivered to me. I wish
> to correspond with someone having the same equipment nowadays ; )

  Dave Emery N1PRE/AE, die at dieconsulting.com  DIE Consulting, Weston, Mass 02493
"An empty zombie mind with a forlorn barely readable weatherbeaten
'For Rent' sign still vainly flapping outside on the weed encrusted pole - in 
celebration of what could have been, but wasn't and is not to be now either."

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