Re: [time-nuts] Racal-Dana 1992 switches
Had the same trouble!!! bought a junk racal unit (they have several models) for $10 & stole the switches from it!!! Sad way to send a unit to the scrap BIN!!!
The unit is EXCELLENT & well worth the repair effort
Norm
---- David McGaw david@endor.com wrote:
Does anyone know of a source of push-button switches for the
Racal-Dana 1992? I have one that over half are bad. No luck from
Racal-Dana or their service house.
Thanks,
David
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I have a friend who has two of the surplus (telephone Co. ?) timing
receivers. That use a Motorola
(A111219115) GPS receiver and a ovenized 5 MHz oscillator
It has external connectors for 5 MHz., 1 PPS, -48Volts, RS232, and the
Antenna.
He has the matching Antenna which is marked 5 Volt and looks like it has
a helix inside.
What I want to do is get one of them running so I need to find the
correct commands to set the
Lat and Long. and read the status messages.
Anyone recognize this equipment?
Bill K7NOM
Can you get some photos so we can try to recognise it?
Rob K
-----Original Message-----
From: time-nuts-bounces@febo.com [mailto:time-nuts-bounces@febo.com] On
Behalf Of Bill Janssen
Sent: 10 March 2008 18:30
To: Discussion of precise time and frequency measurement
Subject: [time-nuts] Motorola GPS + 5 MHz oscillator ?
I have a friend who has two of the surplus (telephone Co. ?) timing
receivers. That use a Motorola
(A111219115) GPS receiver and a ovenized 5 MHz oscillator
It has external connectors for 5 MHz., 1 PPS, -48Volts, RS232, and the
Antenna.
He has the matching Antenna which is marked 5 Volt and looks like it has
a helix inside.
What I want to do is get one of them running so I need to find the
correct commands to set the
Lat and Long. and read the status messages.
Anyone recognize this equipment?
Bill K7NOM
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https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.
Bill,
This one of the old Motorola "Basic" receivers. Is it in a plastic box or an
aluminum one? Doesn't matter, just curious.
Many years ago I created a PDF version of the old VP command set which is
supported by the Basic. I think Jason Rabel has a copy on his website.
Jason, are you out there? Can't remember your URL.....
For instant gratification I would recommend you download TAC32 from Rick
Hambly's website:www.cnssystems.com (I think it is on the TAPR site too.
TAC32 will automatically go through all of the messages on power-up needed
to identify the receiver. Once you know that we can make a pretty good guess
on which commands it will support.
It's also a quick way to see if the receiver even functions.
Randy Warner
-----Original Message-----
From: time-nuts-bounces@febo.com [mailto:time-nuts-bounces@febo.com] On
Behalf Of Bill Janssen
Sent: Monday, March 10, 2008 11:30 AM
To: Discussion of precise time and frequency measurement
Subject: [time-nuts] Motorola GPS + 5 MHz oscillator ?
I have a friend who has two of the surplus (telephone Co. ?) timing
receivers. That use a Motorola
(A111219115) GPS receiver and a ovenized 5 MHz oscillator
It has external connectors for 5 MHz., 1 PPS, -48Volts, RS232, and the
Antenna.
He has the matching Antenna which is marked 5 Volt and looks like it has
a helix inside.
What I want to do is get one of them running so I need to find the
correct commands to set the
Lat and Long. and read the status messages.
Anyone recognize this equipment?
Bill K7NOM
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to
https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.
randy warner wrote:
Bill,
This one of the old Motorola "Basic" receivers. Is it in a plastic box or an
aluminum one? Doesn't matter, just curious.
Many years ago I created a PDF version of the old VP command set which is
supported by the Basic. I think Jason Rabel has a copy on his website.
Jason, are you out there? Can't remember your URL.....
For instant gratification I would recommend you download TAC32 from Rick
Hambly's website:www.cnssystems.com (I think it is on the TAPR site too.
TAC32 will automatically go through all of the messages on power-up needed
to identify the receiver. Once you know that we can make a pretty good guess
on which commands it will support.
It's also a quick way to see if the receiver even functions.
Randy Warner
Correct URL is:
http://www.cnssys.com/
Bruce
Thanks Bruce,
I guess I have been away from the GPS timing sector for too long. I'm sure I
will hear from Rick.......
Randy
-----Original Message-----
From: time-nuts-bounces@febo.com [mailto:time-nuts-bounces@febo.com] On
Behalf Of Bruce Griffiths
Sent: Monday, March 10, 2008 1:25 PM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] Motorola GPS + 5 MHz oscillator ?
randy warner wrote:
Bill,
This one of the old Motorola "Basic" receivers. Is it in a plastic box or
an
aluminum one? Doesn't matter, just curious.
Many years ago I created a PDF version of the old VP command set which is
supported by the Basic. I think Jason Rabel has a copy on his website.
Jason, are you out there? Can't remember your URL.....
For instant gratification I would recommend you download TAC32 from Rick
Hambly's website:www.cnssystems.com (I think it is on the TAPR site too.
TAC32 will automatically go through all of the messages on power-up needed
to identify the receiver. Once you know that we can make a pretty good
guess
on which commands it will support.
It's also a quick way to see if the receiver even functions.
Randy Warner
Correct URL is:
http://www.cnssys.com/
Bruce
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and follow the instructions there.
Guys,
I need to come up with a 0db little splitter to route 1 antenna into 2 GPS
receivers. To keep the isolation up I want to use an active splitter instead
of a passive one. I suppose I could use a passive splitter followed by two
LNA's (one to each receiver), but I would then have to add a lot of
attenuation to knock the signal back down. I suppose it would work, but the
noise factor sure wouldn't be optimum.
Does anyone out there know of a single/dual IC solution to this? Everything
I have found LNA wise is in the 10-30 dB range. Note that this will be a
board mounted circuit and I don't have to worry about connectors, etc. I'm
hoping to find a little solution that I can cover with one of Laird's
standard shield cans.
Thanks,
Randy Warner
randy warner wrote:
Guys,
I need to come up with a 0db little splitter to route 1 antenna into 2 GPS
receivers. To keep the isolation up I want to use an active splitter instead
of a passive one. I suppose I could use a passive splitter followed by two
LNA's (one to each receiver), but I would then have to add a lot of
attenuation to knock the signal back down. I suppose it would work, but the
noise factor sure wouldn't be optimum.
Does anyone out there know of a single/dual IC solution to this? Everything
I have found LNA wise is in the 10-30 dB range. Note that this will be a
board mounted circuit and I don't have to worry about connectors, etc. I'm
hoping to find a little solution that I can cover with one of Laird's
standard shield cans.
Thanks,
Randy Warner
Randy
The only solution that springs to mind is to amplify split/attenuate
amplify attenuate.
If one uses low noise amplifiers and maintains a net gain before the
output attenuator then the noise figure can be kept reasonably low.
This requires an input amplifier followed by a splitter and possibly an
attenuator followed by an amplifier with an output attenuator for each
of the 2 splitter outputs.
The output attenuators will also increase the isolation by a few dB.
Bruce
randy warner wrote:
Guys,
I need to come up with a 0db little splitter to route 1 antenna into 2 GPS
receivers. To keep the isolation up I want to use an active splitter instead
of a passive one.
Randy,
For a long time I used a passive splitter made from a swap meet $1 MCL
(minicircuits) 1 to 2 GHz splitter / combiner. Isolation of these is
good, around 30 dB, and the extra 3 dB loss will not be noticed in the
majority of cases. This one had SMAs all round and DC continuity
through from the A and B ports to the Common. I blocked one path to DC
with a 100 pF SM capacitor. If you need the Rx connected to the blocked
path to think it is feeding an antenna a series R and L combination with
a 220 Ohm R will fool the Rx in question.
I really would not think you will need any gain. For more than two
receivers though I would recommend the hp / symmetricom (?) 4 and 8 way
active splitters that can be found on eBay. If you did want gain there
are a lot of MMICs that will do the job.
I've given it away a while back so can't give you any further details,
but for two receivers this worked well for me. For my growing collection
of gps units here I now need more than two...
Dan
In message 47D5AFD9.5030206@xtra.co.nz, Bruce Griffiths writes:
I need to come up with a 0db little splitter to route 1 antenna into 2 GPS
receivers. To keep the isolation up I want to use an active splitter instead
of a passive one.
I have no idea if it is feasible at GPS frequencies, but two common-gate
amplifiers both feeding of the input might be workable.
--
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Never attribute to malice what can adequately be explained by incompetence.