[time-nuts] Trimble SVeeSix -- was DATUM 9390-52054 Grief again...

Robert Atkinson robert8rpi at yahoo.co.uk
Sun Apr 7 17:49:07 UTC 2013


Hi Nigel,
I've had a couple of early Placers and am fairly sure it was a SVee6 but it was some time ago. I bought it surplus in the USA in 1998. I may still have one up in the attic. I'll go and dig.

Robert G8RPI.




________________________________
 From: "GandalfG8 at aol.com" <GandalfG8 at aol.com>
To: time-nuts at febo.com 
Sent: Sunday, 7 April 2013, 18:37
Subject: Re: [time-nuts] Trimble SVeeSix -- was DATUM 9390-52054 Grief again...
 
Hi Robert,

You need to be careful on this one.

I've never owned a Placer 400, so can't be 100% sure, but whilst  I have 
seen it suggested that it contained an SVeeSix I've have also  seen at least 
one quite emphatic comment, from a not very happy  user, stating that it's 
definitely not an SVeeSix, but that there was a  firmware upgrade available 
for the Placer 400 at one time to  make it SVeeSix compatible, whatever that 
might imply.

What I can confirm is that the version that's more generally available on  
Ebay, the Placer 450, consists of a single board inside the housing that  
integrates a GPS receiver with the control section.
I discovered this the hard way after I bought a couple, and expecting  them 
to contain one of the usual Trimble GPS modules with  a separate PCB for 
the control section, silly me:-)

Quite what the GPS section of that board might be derived from I don't  
know, but it would seem very unlikely that it's going to be a drop in  
replacement for a standard module.

Nigel
GM8PZR



In a message dated 07/04/2013 17:47:40 GMT Daylight Time,  
robert8rpi at yahoo.co.uk writes:

Hi,
IIRC the early Trimble Placer vehicle tracking GPS receivers  used the 
SVee6 and SVee8. I think the Placer 400 used  the SVee6. These  units turn up on 
ebay etc at very low cost.

Robert  G8RPI.




________________________________
From:  "GandalfG8 at aol.com" <GandalfG8 at aol.com>
To: time-nuts at febo.com  
Sent: Sunday, 7 April 2013, 8:53
Subject: [time-nuts] Trimble SVeeSix  -- was DATUM 9390-52054 Grief again...

The Trimble TNL 22880-B was  indeed the original SV6, or SVeeSix as  
Trimble 
chose to call it, I  have just confirmed this from a photo I took some  
time 
ago, and of  which I can supply a copy if required.

The SVeeSix manual from 1992 is  here.....
http://rapidshare.com/files/446743737/Trimble_SveeSix.pdf

and  a much smaller, optimised version,  here......
http://rapidshare.com/files/446744995/Trimble_SveeSix_Optimised.pdf

Thanks  for these should be directed to Rob Kimberley on the list who  
provided the original printed copy.

This original SVeeSix was  approx 4 x 3.5 inches and was  eventually 
replaced by the SVeeEight  of similar appearance and  again the same size.
The SVeeSix Plus and  SVeeEight Plus were the same modules mounted  in 
metal 
boxes.
The  SVeeEight Plus manual from 2000 is available on the Trimble ftp   site.

I know of at least one application where an SVeeEight PCB module  has been  
used as a drop in replacement for an SVeeSix, the Rapco  1804M GPS 
frequency  
standard, albeit using the opposite serial port,  but don't know if this 
was 
an "out of the box" drop in or whether the port  needed to be configured  
first.

The smaller, 1.8 x 3.3 inches,  version of the SVeeSix is  the SVeeSix-CM3 
embedded module, and the  1997 manual for that is also on  the Trimble ftp 
site in the  manuals/CM3 folder.

It's possible that an SVeeSix-CM3 could be  configured as an SVeeSix  
replacement but I've not investigated this,  both the SVeeSix and SVeeEight 
came  
fitted with 1 or 2 standard  serial ports on DB9 connectors, the 
SVeeSix-CM3 
used  an 8 pin header  with I/O at TTL  levels.

Regards

Nigel
GM8PZR



In a message  dated 06/04/2013 23:10:28 GMT Daylight Time, biwa at att.net  
writes:

(Note:  additional information about the receiver  module has been  added.)

Burt

Gang,

You will  remember several months ago I  had some stranges that I 
thought were  related to a defective Vectron  oscillator in one of my 
DATUM  9390-52054.  That turned out to be a  the internal switching  
power supply so I replaced it with an external  Cisco unit.   I've done 
this in three units, two are mine and one  belongs to Stu,  K6YAZ.

Well, I now have a different grief in one of my   units.  It had been 
cooking along swell with no problem ever since  I  replaced the power 
supply.  This morning I notice that one of  my  units had the lock and 
tracking lights out.  The display  said that  the signal level was low 
and there were no usable  satellites.  The 10  MHz output is also about 
20 or more dB  low.  I assumed the power  supply is all right because 
the  display was working and it said it was  9-E9, not so good, but  
working - sorta.  I swapped antennas and the  good Datum was  happy so 
I know the antenna is ok.  when I got inside  I checked  the power 
supply rails and they're within .05 Volts of where  they  should 
be.  There is 5 Volts on the GPS module and there is  4.96  Volts on 
the antenna Type-N connector (measured with the  antenna line  
disconnected.)  Power cycling the DATUM did not  resolve the  problem.

Does anyone know if the symptoms above will  occur if the 10  MHz 
oscillator is defective?  I can understand  it not tracking or not  
locked, but could this cause the receiver to  not see or indicate any  
satellites?  Since I only have two of  these units on line, I'm very  
reluctant to start swapping modules  because I would be without any  
working reference, so I need to keep  one up and running.  Both of my  
units are on a UPS, and  according to the clocks in the kitchen, the  
bedroom, and the old  VCR, we've not had a power interruption.

I do  not recognize the  GPS receiver module, but it has the following 
number on  it:   TNL 22880-B.  I have the schematics for the overall 
DATUM   9390-25054, but the GPS module in just a block.  By the way, 
the  GPS  block on the DATUM overall schematic is marked, "SV6 /  
(TANS)".  I  suspect this means something noteworthy.

Any  guidance would be  appreciated.

Thanks,

Burt

Burt I.  Weiner  Associates
Broadcast Technical Services
Glendale,  California   U.S.A.
biwa at att.net
www.biwa.cc
K6OQK  

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