Lucent RFTG-m-XO
Briefly:
Leave it running for at least 24hrs.
The 15MHz will slowly get on freq.
Countup is available on 1pps socket.
more when I have time
Hi Phil,
Would appreciate additional info please.
I'm trying a 24 hour run now with the XO unit just in case I never let it
run long enough previously. Also it's all buttoned-up just in case some
external RF source was disturbing it previously. The only connections are
24 VDC & the antenna.
The Fault & No GPS lamps are on & there is NO 15 MHz present on the front
panel SMA connector. With a scope I see no activity on J5.
Interestingly, the 5 VDC for the antenna comes from the daughter board, NOT
the GPS receiver. This verified by measuring 5 VDC on the TNC connector
with the GPS receiver unplugged. I guess this allows them to sense an
antenna fault. I tried various dummy loads (resistors) to simulate from
about 10-80 ma antenna loads. The fault lamp never extinguished.
Maybe I really have a faulty XO unit??
Are the RS-485 connections on J5 2-wire or 4-wire?? Has anybody managed to
make any sense of the data &/or commands??
REMartinson, N1VQR
-----Original Message-----
From: time-nuts-bounces@febo.com [mailto:time-nuts-bounces@febo.com] On
Behalf Of Phil Staton
Sent: Thursday, February 01, 2007 6:53 PM
To: time-nuts@febo.com
Subject: [time-nuts] Lucent RFTG-m-XO
Briefly:
Leave it running for at least 24hrs.
The 15MHz will slowly get on freq.
Countup is available on 1pps socket.
more when I have time
time-nuts mailing list
time-nuts@febo.com
https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
I do not recall if you mentioned this before or not, but did you probe the
OCXO itself to make sure it was sending out 10 MHz (or close to that)? Is
your 24V power supply able to supply enough amps?
The Motorola's expect an antenna to draw power within a certain range. It's
possible that they simply shunted that current to keep the false-alarms to a
minimum and used power from the secondary board and allow a wider range of
current draw, maybe not even monitoring the current.
Jason
I'm trying a 24 hour run now with the XO unit just in case I never let it
run long enough previously. Also it's all buttoned-up just in case some
external RF source was disturbing it previously. The only connections are
24 VDC & the antenna.
The Fault & No GPS lamps are on & there is NO 15 MHz present on the front
panel SMA connector. With a scope I see no activity on J5.
Interestingly, the 5 VDC for the antenna comes from the daughter board,
NOT
the GPS receiver. This verified by measuring 5 VDC on the TNC connector
with the GPS receiver unplugged. I guess this allows them to sense an
antenna fault. I tried various dummy loads (resistors) to simulate from
about 10-80 ma antenna loads. The fault lamp never extinguished.
Maybe I really have a faulty XO unit??
Are the RS-485 connections on J5 2-wire or 4-wire?? Has anybody managed
to
make any sense of the data &/or commands??
REMartinson, N1VQR
Thanks for the quick replay.
Yes the 10 MHz directly at the oscillator output is about 60 mHz high (I
adjusted it several days ago, it was close even before), plenty close enough
I would think. Unit only needs 410 mA when warmed up, power supply is 3 amp
so no prob.
Sure wish I knew what the fault was, I suspect if I had a way of
monitoring/controlling the unit via the RS-485 buss the info might be
available. It seems the XO unit does not spew data out the 485 port, it
waits for an interrogation????? I see no activity with a scope.
REMartinson
-----Original Message-----
From: time-nuts-bounces@febo.com [mailto:time-nuts-bounces@febo.com] On
Behalf Of Jason Rabel
Sent: Friday, February 02, 2007 11:08 AM
To: 'Discussion of precise time and frequency measurement'
Subject: Re: [time-nuts] Lucent RFTG-m-XO
I do not recall if you mentioned this before or not, but did you probe the
OCXO itself to make sure it was sending out 10 MHz (or close to that)? Is
your 24V power supply able to supply enough amps?
The Motorola's expect an antenna to draw power within a certain range. It's
possible that they simply shunted that current to keep the false-alarms to a
minimum and used power from the secondary board and allow a wider range of
current draw, maybe not even monitoring the current.
Jason
I'm trying a 24 hour run now with the XO unit just in case I never let it
run long enough previously. Also it's all buttoned-up just in case some
external RF source was disturbing it previously. The only connections are
24 VDC & the antenna.
The Fault & No GPS lamps are on & there is NO 15 MHz present on the front
panel SMA connector. With a scope I see no activity on J5.
Interestingly, the 5 VDC for the antenna comes from the daughter board,
NOT
the GPS receiver. This verified by measuring 5 VDC on the TNC connector
with the GPS receiver unplugged. I guess this allows them to sense an
antenna fault. I tried various dummy loads (resistors) to simulate from
about 10-80 ma antenna loads. The fault lamp never extinguished.
Maybe I really have a faulty XO unit??
Are the RS-485 connections on J5 2-wire or 4-wire?? Has anybody managed
to
make any sense of the data &/or commands??
REMartinson, N1VQR
time-nuts mailing list
time-nuts@febo.com
https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
On Fri, Feb 02, 2007 at 10:07:45AM -0600, Jason Rabel wrote:
The Motorola's expect an antenna to draw power within a certain range. It's
possible that they simply shunted that current to keep the false-alarms to a
minimum and used power from the secondary board and allow a wider range of
current draw, maybe not even monitoring the current.
There is a 4 input 8 bit A/D chip on the mezzanine board as well as
a 16 bit A/D chip present only on the mezzanine boards of the XOs. It
would seem likely that one port of this chip reads the antenna current
and maybe another the various lamp and temp outputs of the LPRO/OCXO.
--
Dave Emery N1PRE, die@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."
Over the weekend I left the XO unit running for 38 hours, with it installed
in its "house" (No probing). The GPS receiver was tracking satellites at
the start and also at the end of the run as verified by monitoring J5-2
w/VisualGPS. The Fault & No GPS LEDs never went out. I'm about to conclude
that I have a defective unit and will order another unless anyone has any
further suggestions (PLEASE)?
I see at least John A., Jim M., & Phil S. have working XO units. I have
just reviewed all the emails on the RFTG units and believe I have tried all
the previous suggestions. Any additional secrets to share???
Bob Martinson, N1VQR
-----Original Message-----
From: time-nuts-bounces@febo.com [mailto:time-nuts-bounces@febo.com] On
Behalf Of Phil Staton
Sent: Thursday, February 01, 2007 6:53 PM
To: time-nuts@febo.com
Subject: [time-nuts] Lucent RFTG-m-XO
Briefly:
Leave it running for at least 24hrs.
The 15MHz will slowly get on freq.
Countup is available on 1pps socket.
more when I have time
time-nuts mailing list
time-nuts@febo.com
https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
On Feb 6, 2007, at 11:27 AM, Robert E. Martinson wrote:
I'm about to conclude that I have a defective unit and will order
another unless anyone has any further suggestions (PLEASE)?
Did you have the RB connected via the crossover cable and 10 MHz
cable as described in previous emails?
Jim
Those who maintain that its OK to use 75 ohm GPS antenna cable should read:
http://tf.nist.gov/timefreq/general/pdf/1380.pdf
Bruce
Thanks for the quick responses, Jim & Phil!
No, I was running the XO unit all by itself. My guess is that the XO should
be able to run all by itself??? I have previously run with the XO & the RB
interconnected (J5 & 10 MHz Ref). Not for 24 hours, but at least over
night, but No GPS stayed ON on both units, Fault was ON only on the XO.
Previously I have seen no activity on any pins of J6 on the XO, will check
again & also check J6 on the RB unit. Maybe I really do have a serious
fault??
Am I correct in assuming that the data continuously streams out of each J6
connector without any interrogation being sent from a PC??
Bob Martinson, N1VQR
-----Original Message-----
From: time-nuts-bounces@febo.com [mailto:time-nuts-bounces@febo.com] On
Behalf Of Jim Miller
Sent: Tuesday, February 06, 2007 4:55 PM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] Lucent RFTG-m-XO
On Feb 6, 2007, at 11:27 AM, Robert E. Martinson wrote:
I'm about to conclude that I have a defective unit and will order
another unless anyone has any further suggestions (PLEASE)?
Did you have the RB connected via the crossover cable and 10 MHz
cable as described in previous emails?
Jim
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On Feb 6, 2007, at 7:24 PM, Robert E. Martinson wrote:
No, I was running the XO unit all by itself. My guess is that the
XO should
be able to run all by itself???
Perhaps they can, perhaps they can't, but why not prove them in their
intended configuration before attempting to use a non-standard setup?
I have previously run with the XO & the RB
interconnected (J5 & 10 MHz Ref). Not for 24 hours, but at least over
night, but No GPS stayed ON on both units, Fault was ON only on the
XO.
"NO GPS" has always extinguished on mine after a half hour or so.
Previously I have seen no activity on any pins of J6 on the XO,
will check
again & also check J6 on the RB unit. Maybe I really do have a
serious
fault??
Data does not immediately appear after power up. It takes a while
(15 minutes
or more) to start coming out.
Am I correct in assuming that the data continuously streams out of
each J6
connector without any interrogation being sent from a PC??
That is correct - no interrogation is necessary. The data comes out
gratuitously at 1 second intervals at 9600 8N1 via differential
signalling
on pins J6-5,9.
Note also that J6 1PPS and SMA 15MHz outputs are not present on a
unit that
assumes a STDBY mode after completing its warmup.
73 de JIM N8ECI