[time-nuts] Lucent RTGm-II-XO Slow Acquisition

Jerry jsternmd at att.net
Tue Aug 28 14:42:51 UTC 2012

Hi Tom,

Thanks for replying.   I recently got a pair RFTGm-II-Rb and RFTGm-II-XO for
an  inexpensive price (less than a T-bolt).  They appear late versions but I
have not opened them up to get a version or date estimate.

I came across the manual and software for these many years ago (~2005) from
a website (now defunct) when I was searching for literature on an ATT RFG-RB
standard I acquired for my ham radio workbench.  I could not get the
software to work with the ATT but it works great for the RFTGm's on Windows
Vista with compatibility mode set for Win XP (SP2).  

Based on your feedback I thinkthe issue may be my Symmetricom antennae which
I mounted for my T-bolt inside the peak of my attic (it was fast, easy and
only some plywood and asphalt shingle between it and open sky :-).
Yesterday we had some substantial overcast skies and maybe that plus my
inside location (plus 70' of RG-8x) and the Lucent needing a bit more signal
just was a bad combination.  This morning under clear skies, I rebooted
everything and within 30 minutes the RFTGm-II-Rb and RFTGm-II-XO were
GPS-locked and working as a pair per the manual.  I was pleasantly surprised
reading the manual to find that in contrast to some messages on this
reflector, the manual says that both the Rb and XO are each GPS disciplined
by comparing the phase shift between their 1pps signals. The default is that
the Rb is the primary standard while the XO is periodically used to verify
and update further disciplining.  Only issue for me then is the 10Mhz TP
output from the RFTGm-II-Rb is a square wave not sine but I am searching for
the best solution to convert this. If you have some suggestion - much
appreciated !

Let me know if you want me to send you copies of the RFTG manual and Windows


-----Original Message-----
From: time-nuts-bounces at febo.com [mailto:time-nuts-bounces at febo.com] On
Behalf Of Tom Knox
Sent: Tuesday, August 28, 2012 1:33 AM
To: Time-Nuts
Subject: Re: [time-nuts] Lucent RTGm-II-XO Slow Acquisition

Hi Jerry ;
I assume you mean RFTGm-II-XO. The cell sites usually had an Andrew 26dB
antenna with a real short coax run. They also had a 40dB antenna option if
needed. Unless you have a long coax run the Symmetricom ant should be ideal.
I don't think the RFTGm-II-XO lock as quickly the Thundebolt but yours
sounds like something is not right. Does the software allow you to set mask
angle and PDOP? It could be set to high and be ignoring Sats. It also could
possibly be set for a past fixed location.  I have a few
RFTGm-II-XO/RFTGm-II-RB combos but have never played with the software.
Where did you find your software? And do you have a manual?
Thomas Knox

> From: jsternmd at att.net
> To: time-nuts at febo.com
> Date: Tue, 28 Aug 2012 00:28:27 -0400
> Subject: [time-nuts] Lucent RTGm-II-XO Slow Acquisition
> I have a RTGm-II-XO and it takes quite some time to acquire the 
> minimum 4 satellites.  Using the same Symmetricom antenna with my 
> Thunderbolt, it acquires 6-8 satellites in 15-20 mins while the 
> RTGm-II-XO takes 60 minutes and sometimes much longer where I have 
> power cycled it to get it out of warm-up.  On power-up, the red alarm goes
off within 15mins as programmed.
> I have preset my GPS coordinates using the RS-422 interface and Lucent 
> software and set the coax length as well. The antenna voltage is 
> correct at 4.9vdc and the antenna is drawing about 25 ma.  The Lucent 
> software shows correct XO voltages per the manual.  Any advice
> jerry
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