[time-nuts] GPS time module

[SAIDJACK at aol.com]

Sorry in advance guys,
 
I could not resist doing a short comparison between our LC_XO module and  
this new Selig/RF-Suisse 1x1 module. Please excuse this blatantly biased  
comparison:
 
The Selig module is slightly larger, and consumes about the same amount of  
power as the LC_XO (TCXO version), and basically provides a similar set of  
signals. It is however about twice as expensive, has an 8-week lead-time 
versus  from-stock delivery, and there are other differences:
 
* 20 channel GPS without WAAS/SBAS (Selig) versus 50 channels with  
WAAS/SBAS (LC_XO)
 
* 1us time pulse accuracy (Selig) versus +/-25ns time pulse accuracy typ.  
(LC_XO)
 
* Washing not approved (Selig) versus washing approved (LC_XO)
 
* Selig requires an antenna cable to be plugged into the bottom of the PCB, 
 then the module is soldered onto a customer PCB. Thus if the antenna cable 
 becomes loose, it cannot be plugged back into the connector. LC_XO: 
antenna feed  via the solder pins from carrier PCB
 
* Selig I/O: Status LED and requirement to program for an I2C slave  
register, no NMEA or control command interface for GPSCon, GPSD, or Z38xx  etc 
versus LC_XO: two NMEA outputs (RAW NMEA and Binary from uBlox GPS), JLT  NMEA 
commands with custom commands, and SCPI control interface for third-party  
software
 
* Selig 60,000 feet altitude limit versus 164,000 feet for LC_XO
 
* Power requirement: Selig: 5V versus LC_XO 3.3V (LC_XO will provide 5V  
from internal DC switcher that can be used externally on carrier PCB)
 
* Phase Noise: about the same between both units
 
* ADEV: Selig slightly better at around 20s, LC_XO better above 1000s  
(LC_XO short-term ADEV can be significantly improved in stable environments by  
setting the time-constant of the loop to longer time frames)
 
* Selig module options: GPS or no GPS versus LC_XO module options: TCXO,  
OCXO, and external 1PPS input with auto-switchover to internal GPS  receiver
 
* Firmware updates: Selig does not provide customer update mechanism versus 
 LC_XO can be easily updated with various firmware versions available for  
customer download from the website without any website log-in etc.
 
* Selig TCXO stability: +/-100ppb from -20C to +70C versus +/-75ppb from 0C 
 to 60C or +/-25ppb from 0C to +60C (OCXO version)
 
Selig/RF-Suisse offering this form factor is a welcome event as it  
validates the form factor in itself.
 
I am however not seeing too many advantages for the Selig part in  
comparison especially at about twice the cost, am I missing something?
 
bye,
Said
 
 
In a message dated 10/29/2013 14:54:51 Pacific Daylight Time,  
lstoskopf at cox.net writes:

Sorry if  already  posted:

http://www.saelig.com/COMCR/COMCR002.htm