Just brainstorming here, but how about this un-conventional approach: Use a CSAC as a precise frequency reference for the LEA-6T. CSAC should operate at <0.12W, I know, that's a lot, but maybe just worth a try. To make the CSAC work, multiply the 10MHz up to the 26MHz the LEA uses. Then place a small antenna loop around the LEA part to injection-lock the internal 26MHz TCXO to the external antenna. That may work, or not. Or unsolder the LEA-6T metal shield, and remove the TCXO, and replace it with the externally generated stable 26MHz, then re-solder the shield. That's cheaper than buying 2000pcs reels from uBlox. It would be interesting to see how much more accurate the unit would become with a stable 26MHz rather than a low-cost 26MHz TCXO. AND: you can use the 1PPS output of the LEA-6T to actually discipline the CSAC to GPS :) bye, Said In a message dated 4/25/2012 11:42:52 Pacific Daylight Time, att...@kinali.ch writes:
The problem with most of those techniques is, that they are not available for the price the customer can afford. A dual frequency receiver costs a lot more than an of the shelf LEA6-T. Also these modules are usually build with larger power budgets in mind, e.g. the Trimble BD920 uses 1.3W typical, while the 0.3W max(!) of the LEA6-T already hurt us a lot. Using an external frequency reference is not possible with the LEA6-T. It would be possible to do that when using one of the GPS chipsets from u-blox, but therefor we would need to take at least a full reel (iirc 2000 pieces), which isnt exactly cost efficient. Beside, we would still need to use a TCXO, because there is not enough power available for an OCXO or even an MCXO. _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.