[time-nuts] Nortel Trimble NTBW50AA GPSTM 10MHz Oscillator GPSDO

[Bob kb8tq]

Hi

> On Jul 5, 2015, at 1:52 AM, skipp Isaham via time-nuts <time-nuts at febo.com> wrote:
> 
> re: Nortel Trimble NTBW50AA GPSTM 10MHz Oscillator GPSDO 
> 
> Hello to the Group, 
> 
> An admitted late arrival to the group here. My initial time system launch revolved around 
> using a Trimble Thunderbolt. 
> 
> But used Trimble Thunderbolts for sale don't appear to be as plentiful as they once were 
> and the current prices I see on Ebay seem a bit high. 
> 
> Another option is an auction listing for the Nortel Trimble NTBW50AA GPSTM 10MHz 
> Oscillator GPSDO, aka Nortel NTBW50AA GPSTM GPS Timing Module offered for 
> $159 US (plus shipping). 
> 
> Would anyone be able and willing to provide an opinion regarding the Nortel NTBW50AA 
> modules compared to a Thunderbolt? Per an Ebay auction description, does the Nortel 
> Module work well with Lady Heather? 
> 

The GPSTM will work to a limited degree with Lady Heather. The TBolt will let you modify and 
save the control loop parameters. The GPSTM will not let you modify them. 

The GPSTM comes with any of a wide variety of OCXO’s. Some are better than others. Tom 
has plots on his site of four of them. None of the GPSTM OCXO’s are as good as the TBolt 
OCXO for phase noise. Some of them are a bit better on temperature stability. The phase noise
is masked by the noise of the digital stuff. The stability has little effect in normal operation.

ADEV of an un-tuned GPSTM is similar to an un-tuned TBolt. With careful tuning (possibly involving
board mods) the TBolt ADEV can be quite a bit better. 

The GPSTM will run off of a single supply and is insensitive to supply stability. The TBolt works best
with a linear regulated supply on the +12V line. 

Lots of differences, none of them may matter much in your application …...

Bob


> What I really need right now is the only 10MHz output. If I can get a comparable 10MHz 
> output from the Nortel modules, fine. Else I continue on a quest to locate one or two 
> more Thunderbolts. 
> 
> Or I'd appreciate any suggestions regarding other brands/modules comparable to a 
> Trimble Thunderbolt. 
> 
> Thank you in advance for your replies. 
> 
> Regards, 
> 
> skipp 
> 
> skipp025 at yahoo dot com 
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