Hi Volker
One possibility, as I found with one of these recently, is that your
oscillator has aged such that the required EFC voltage for 10MHz output is now
outside the range provided by the board.
The EFC behaviour can be tracked if Lady Heather is enabled from switch on
and the DAC
Whilst on second thoughts it does seem a bit odd that this oscillator has
passed 10MHz and still not locking this might be linked to the alarms being
generated at around 5.6 volts as per my previous comment, even though the
EFC voltage at the extreme does, theoretically at least, seem to be
...thanks, Bob, it seems to be the oscillator, that is at it's limit, it
cannot tune to 10 MHz at full EFC voltage, see new thread (started by Mark).
Volker
Am 24.01.2014 01:09, schrieb Bob Camp:
Hi
That’s a cell phone base station board. It’s got a bunch of outputs, some of
which are
Thanks so much, Nigel, for this very interesting mail.
Yes, the voltages are exactly as my ones. And yes, I've removed the
oscillator, already. I then removed the thermal isolation from the osc,
as well as the label, in slight hope for a hidden tuning screw. Of
course, there isn't any.
I, too,
In a message dated 24/01/2014 17:06:43 GMT Standard Time,
ail...@t-online.de writes:
Thanks so much, Nigel, for this very interesting mail.
Yes, the voltages are exactly as my ones. And yes, I've removed the
oscillator, already. I then removed the thermal isolation from the osc,
as well
Volker,
I have also a Trimble Nortel NTG550AA and fortunately it works very well
from the beginning. I have a downloaded manual and some other info that
I can send you if interested.
And one word of caution: if you observe the cable that goes from the
main board to the small interface board,
time-nuts-boun...@febo.com on behalf of
EB4APL eb4...@cembreros.jazztel.es
Sent: Friday, January 24, 2014 2:27 PM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] Nortel GPSDO osc age alarm
Volker,
I have also a Trimble Nortel NTG550AA and fortunately it works very
Ignacio,
thanks for your message. Answeres within the text:
And one word of caution: if you observe the cable that goes from the
main board to the small interface board, you will see that one of the
connectors is reversed so be careful if you make a custom one for your
cabinet, do it in the
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] Nortel GPSDO osc age alarm
Volker,
I have also a Trimble Nortel NTG550AA and fortunately it works very well
from the beginning. I have a downloaded manual and some other info that
I can send you if interested
On 1/24/14 11:57 AM, Volker Esper wrote:
Nice! I didn't know that. But what a number, 300... Why such a
digital-hostile factor? Why not 256 or 512?
Volker
Am 24.01.2014 20:51, schrieb tmil...@skylinenet.net:
9.8304 MHz divided by 300 is 32,768 Hz.
Feed that to an electronic clock and you
Oukaay - I should've known... Thanks, Jim!
Am 24.01.2014 21:12, schrieb Jim Lux:
On 1/24/14 11:57 AM, Volker Esper wrote:
Nice! I didn't know that. But what a number, 300... Why such a
digital-hostile factor? Why not 256 or 512?
Volker
Am 24.01.2014 20:51, schrieb tmil...@skylinenet.net:
In a message dated 24/01/2014 21:48:27 GMT Standard Time,
ail...@t-online.de writes:
New ways of RF design - see photo ;-)
-
Definitely the last word in high rise developments:-)
And glad to hear you got it sorted.
Ok, I put three 1N4148 in series between
9.8304 MHz output, an odd frequency used by the cell tower equipment
9.8304 MHz is 8 x 1.2288 MHz which is the CDMA PN chip rate
a rather fundamental frequency to the CDMA phone system
Zim
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Hi!
I bought a Trimble/Nortel GPSDO
http://www.ebay.de/itm/300933951405?ssPageName=STRK:MEWNX:IT_trksid=p3984.m1497.l2648
and Lady Heather's now tells me that everything is alright - except
- DAC 6.04V
- OSC BAD
- osc age alarm
The rectangle 10MHz output signal (J5) shows a signal at about
Hi
That’s a cell phone base station board. It’s got a bunch of outputs, some of
which are related to the cell network it was built for rather than 10MHz. I’d
bet your 9.8 MHz output is one of those. They are DDS based so there likely is
some range of possible outputs.
The age alarm is not
The OSC age alarm says the oscillator EFC control voltage is getting near to
its programmed limit. The DAC alarm says that the EFC dac setting is it is at
the limit. I suspect that your oscillator EFC input is bad. I've seen this on
a couple of boards.
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