[time-nuts] GPS antenna??

Dennis Czelusniak czelusniakd at yahoo.com
Tue Apr 9 08:14:58 EDT 2013


I dont know? Maybe the obvious solution is to go well in advance, and see if the GPS works in the building. It would be much easier to resolve your problem if you knew if you actually have one.
 
Dennis

From: "time-nuts-request at febo.com" <time-nuts-request at febo.com>
To: time-nuts at febo.com 
Sent: Tuesday, April 9, 2013 7:47 AM
Subject: time-nuts Digest, Vol 105, Issue 27

Send time-nuts mailing list submissions to
    time-nuts at febo.com

To subscribe or unsubscribe via the World Wide Web, visit
    https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
or, via email, send a message with subject or body 'help' to
    time-nuts-request at febo.com

You can reach the person managing the list at
    time-nuts-owner at febo.com

When replying, please edit your Subject line so it is more specific
than "Re: Contents of time-nuts digest..."


Today's Topics:

  1. Re: GPS antenna?? (Grant Hodgson)
  2. Re: GPS antenna?? (Azelio Boriani)
  3. Re: GPS antenna?? (Bob Camp)
  4. Re: GPS antenna?? (Bob Camp)
  5. Re: Trimble SVeeSix -- was DATUM 9390-52054    Grief    again...
      (Rob Kimberley)
  6. Re: GPS antenna?? (Rob Kimberley)


----------------------------------------------------------------------

Message: 1
Date: Tue, 09 Apr 2013 09:27:38 +0100
From: Grant Hodgson <grant at ghengineering.co.uk>
To: time-nuts at febo.com, time-nuts-request at febo.com
Subject: Re: [time-nuts] GPS antenna??
Message-ID:
    <20130409092738.94222kn3697iyozk at webmail.ghengineering.co.uk>
Content-Type: text/plain; charset=ISO-8859-1; DelSp="Yes";
    format="flowed"

Alan

As has already been stated by others, if the purpose of the GPS signal  
is for a GPSDO, then putting an active patch next to a SW facing  
window should work fine.  No need to re-radiate.  You only need to  
receive 1 satellite in order to get a timing signal - more satellites  
will give better (lower) jitter/ADEV, but if you just want an accurate  
frequency source for a counter or signal generator then the setup you  
describe should be fine.

If that's the case, then it might be worth taking a Rubidium source as  
a higher-performance back-up than the GPSDO in holdover, although some  
GPSDOs are more equal than others in holdover performance.

regards
Grant

Quoting time-nuts-request at febo.com:
>
> Hi all an interesting problem you may have encountered, I want to use a GPS
> frequency standard inside a building with no opening windows (opening
> windows are known as air conditioning in the UK :-))  )
> This is part of a two day amateur microwave conference so we should have the
> expertise.
>
> I intend to try and pass the signal through a a double glazed glass window
> unit (hopefully not metalised) using a couple of patch antennas. The outer
> GPS antenna is active so will need  a 5v supply via an inserter. Inner patch
> active, outer patch passive to avoid problems of feedback. Main antenna can
> be shielded from the "coupling" either physically or with a slab of
> absorber.
>
> Has anyone tried this?.... does it work?.....any gotchas?
>
> Thanks
> Alan
> G3NYK
>
>
>



------------------------------

Message: 2
Date: Tue, 9 Apr 2013 11:56:42 +0200
From: Azelio Boriani <azelio.boriani at screen.it>
To: Discussion of precise time and frequency measurement
    <time-nuts at febo.com>
Subject: Re: [time-nuts] GPS antenna??
Message-ID:
    <CAL8XPmMto=O4j=A=eEB8YGR7uTaWHe1FLZi10pehu0Y1YHQFWA at mail.gmail.com>
Content-Type: text/plain; charset=ISO-8859-1

One satellite, OK, but before a GPSDO can use 1 satellite it must have the
normal satellite visibility to complete the autosurvey (usually 10K seconds
long). You can enter the exact lat/lon, if available, and start the 1
satellite operation (known as position hold mode) at once but, usually,
surveyed coordinates of a new antenna installation are not available.

On Tue, Apr 9, 2013 at 10:27 AM, Grant Hodgson <grant at ghengineering.co.uk>wrote:

> Alan
>
> As has already been stated by others, if the purpose of the GPS signal is
> for a GPSDO, then putting an active patch next to a SW facing window should
> work fine.  No need to re-radiate.  You only need to receive 1 satellite in
> order to get a timing signal - more satellites will give better (lower)
> jitter/ADEV, but if you just want an accurate frequency source for a
> counter or signal generator then the setup you describe should be fine.
>
> If that's the case, then it might be worth taking a Rubidium source as a
> higher-performance back-up than the GPSDO in holdover, although some GPSDOs
> are more equal than others in holdover performance.
>
> regards
> Grant
>
> Quoting time-nuts-request at febo.com:
>
>>
>> Hi all an interesting problem you may have encountered, I want to use a
>> GPS
>> frequency standard inside a building with no opening windows (opening
>> windows are known as air conditioning in the UK :-))  )
>> This is part of a two day amateur microwave conference so we should have
>> the
>> expertise.
>>
>> I intend to try and pass the signal through a a double glazed glass window
>> unit (hopefully not metalised) using a couple of patch antennas. The outer
>> GPS antenna is active so will need  a 5v supply via an inserter. Inner
>> patch
>> active, outer patch passive to avoid problems of feedback. Main antenna
>> can
>> be shielded from the "coupling" either physically or with a slab of
>> absorber.
>>
>> Has anyone tried this?.... does it work?.....any gotchas?
>>
>> Thanks
>> Alan
>> G3NYK
>>
>>
>>
>>
> ______________________________**_________________
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to https://www.febo.com/cgi-bin/**
> mailman/listinfo/time-nuts<https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts>
> and follow the instructions there.
>


------------------------------

Message: 3
Date: Tue, 9 Apr 2013 06:47:32 -0400
From: Bob Camp <lists at rtty.us>
To: Discussion of precise time and frequency measurement
    <time-nuts at febo.com>
Subject: Re: [time-nuts] GPS antenna??
Message-ID: <B7EFF990-AD44-4A71-B7ED-BAE67E2C9A54 at rtty.us>
Content-Type: text/plain; charset=us-ascii

Hi

If this is a modern building, there may be some pretty good GPS location data associated with it. If you can find that data and if you can find the building plans you might be able to come up with a pretty good location for the window.

Yes that's a lot of if's and a lot of work.

Bob

On Apr 9, 2013, at 5:56 AM, Azelio Boriani <azelio.boriani at screen.it> wrote:

> One satellite, OK, but before a GPSDO can use 1 satellite it must have the
> normal satellite visibility to complete the autosurvey (usually 10K seconds
> long). You can enter the exact lat/lon, if available, and start the 1
> satellite operation (known as position hold mode) at once but, usually,
> surveyed coordinates of a new antenna installation are not available.
> 
> On Tue, Apr 9, 2013 at 10:27 AM, Grant Hodgson <grant at ghengineering.co.uk>wrote:
> 
>> Alan
>> 
>> As has already been stated by others, if the purpose of the GPS signal is
>> for a GPSDO, then putting an active patch next to a SW facing window should
>> work fine.  No need to re-radiate.  You only need to receive 1 satellite in
>> order to get a timing signal - more satellites will give better (lower)
>> jitter/ADEV, but if you just want an accurate frequency source for a
>> counter or signal generator then the setup you describe should be fine.
>> 
>> If that's the case, then it might be worth taking a Rubidium source as a
>> higher-performance back-up than the GPSDO in holdover, although some GPSDOs
>> are more equal than others in holdover performance.
>> 
>> regards
>> Grant
>> 
>> Quoting time-nuts-request at febo.com:
>> 
>>> 
>>> Hi all an interesting problem you may have encountered, I want to use a
>>> GPS
>>> frequency standard inside a building with no opening windows (opening
>>> windows are known as air conditioning in the UK :-))  )
>>> This is part of a two day amateur microwave conference so we should have
>>> the
>>> expertise.
>>> 
>>> I intend to try and pass the signal through a a double glazed glass window
>>> unit (hopefully not metalised) using a couple of patch antennas. The outer
>>> GPS antenna is active so will need  a 5v supply via an inserter. Inner
>>> patch
>>> active, outer patch passive to avoid problems of feedback. Main antenna
>>> can
>>> be shielded from the "coupling" either physically or with a slab of
>>> absorber.
>>> 
>>> Has anyone tried this?.... does it work?.....any gotchas?
>>> 
>>> Thanks
>>> Alan
>>> G3NYK
>>> 
>>> 
>>> 
>>> 
>> ______________________________**_________________
>> time-nuts mailing list -- time-nuts at febo.com
>> To unsubscribe, go to https://www.febo.com/cgi-bin/**
>> mailman/listinfo/time-nuts<https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts>
>> and follow the instructions there.
>> 
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.



------------------------------

Message: 4
Date: Tue, 9 Apr 2013 07:25:02 -0400
From: Bob Camp <lists at rtty.us>
To: Discussion of precise time and frequency measurement
    <time-nuts at febo.com>
Subject: Re: [time-nuts] GPS antenna??
Message-ID: <877E660D-8352-40E1-930A-6E70F90753B1 at rtty.us>
Content-Type: text/plain; charset=us-ascii

Hi

One other possibility is that we are talking about "illuminating" a fleet of devices.

Bob

On Apr 8, 2013, at 11:18 PM, Mark Spencer <mspencer12345 at yahoo.ca> wrote:

> I'll be curious to hear more details from Alan (the original poster.)  I agree it's not a slam dunk that the device in question is a GPSDO that supports hold over.
> 
> I also agree with Bill that we may be missing some details regarding this matter.
> 
> 
> Re: [time-nuts] GPS antenna?? 
> Bob Camp Mon, 08 Apr 2013 15:57:11 -0700 
> 
> Hi
> 
> I'm not sure that the "real" application here is a GPSDO. If it is, then 
> holdover may well be the easy answer.
> Bob
> 
> 
> 
> 
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.



------------------------------

Message: 5
Date: Tue, 9 Apr 2013 12:44:22 +0100
From: "Rob Kimberley" <robkimberley at btinternet.com>
To: "'Discussion of precise time and frequency measurement'"
    <time-nuts at febo.com>
Subject: Re: [time-nuts] Trimble SVeeSix -- was DATUM 9390-52054    Grief
    again...
Message-ID: <000401ce3517$96e6a160$c4b3e420$@btinternet.com>
Content-Type: text/plain;    charset="us-ascii"

You need to be careful as Nigel says as Datum had special SVeeSix units from
Trimble in the early days which were specifically modified for timing. 

Rob Kimberley

-----Original Message-----
From: time-nuts-bounces at febo.com [mailto:time-nuts-bounces at febo.com] On
Behalf Of GandalfG8 at aol.com
Sent: 07 April 2013 18:37
To: time-nuts at febo.com
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  

_______________________________________________
time-nuts  mailing  list -- time-nuts at febo.com
To unsubscribe, go to  
https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow  the  instructions  there.

_______________________________________________
time-nuts  mailing list -- time-nuts at febo.com To unsubscribe, go to
https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the  instructions  there.
_______________________________________________
time-nuts mailing  list -- time-nuts at febo.com To unsubscribe, go to
https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the  instructions there.
_______________________________________________
time-nuts mailing list -- time-nuts at febo.com To unsubscribe, go to
https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.




------------------------------

Message: 6
Date: Tue, 9 Apr 2013 12:47:00 +0100
From: "Rob Kimberley" <robkimberley at btinternet.com>
To: "'Discussion of precise time and frequency measurement'"
    <time-nuts at febo.com>
Subject: Re: [time-nuts] GPS antenna??
Message-ID: <000501ce3517$f25ffd20$d71ff760$@btinternet.com>
Content-Type: text/plain;    charset="us-ascii"

Alan,

I used to do a lot of my Datum demos with customers with antennae up against
a window as outside access wasn't available. 

Usually worked OK, unless as you say, the glass is metalised.
Rob

-----Original Message-----
From: time-nuts-bounces at febo.com [mailto:time-nuts-bounces at febo.com] On
Behalf Of Alan Melia
Sent: 08 April 2013 18:00
To: time-nuts measurement
Subject: [time-nuts] GPS antenna??

Hi all an interesting problem you may have encountered, I want to use a GPS
frequency standard inside a building with no opening windows (opening
windows are known as air conditioning in the UK :-))  ) This is part of a
two day amateur microwave conference so we should have the expertise.

I intend to try and pass the signal through a a double glazed glass window
unit (hopefully not metalised) using a couple of patch antennas. The outer
GPS antenna is active so will need  a 5v supply via an inserter. Inner patch
active, outer patch passive to avoid problems of feedback. Main antenna can
be shielded from the "coupling" either physically or with a slab of
absorber.

Has anyone tried this?.... does it work?.....any gotchas?

Thanks
Alan
G3NYK 

_______________________________________________
time-nuts mailing list -- time-nuts at febo.com To unsubscribe, go to
https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.




------------------------------

_______________________________________________
time-nuts mailing list
time-nuts at febo.com
https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts

End of time-nuts Digest, Vol 105, Issue 27
******************************************


More information about the time-nuts mailing list