[time-nuts] SkyTraq PX1100T

[Nick Sayer]

I’ve been using the SkyTraq Venus838LPx-T module for some time now for my timing stuff. Well, between the supply chain and the Japanese oscillator fire it looks like SkyTraq is EOLing those. As a replacement, I’ve obtained a sample quantity of their recommended replacement, the PX1100T. One of the benefits of the changeover is that it has quad constellation support, and in my preliminary experiments, this seems to really help indoor reception.

Other differences from the 838 are that it supplies 3.3v antenna power, whereas the 838 required an external bias application (the benefit of which was that you could supply any reasonable voltage desired - the 838 had an input DC blocking cap). The recommended reset and BOOT_SEL pull-up from the 838 are also no longer required. Finally, this is a castellated edge board module rather than an LGA69 package.

I’ve set a couple up on Raspberry Pis as NTP servers so that I can watch them with cgps, and I’ve made a prototype of my GPS clock with one so I could figure out the necessary firmware deltas. Of course, those are not very demanding applications. I have one on a breakout board as well and might attempt to characterize the PPS jitter (as with the 838 it supports the PSTI,00 sawtooth correction message). I also have an order in for prototype boards for my OH300 based GPSDO.

I hope this doesn’t read too much like a press release or something. I’m not connected with SkyTraq other than being a customer. I just thought I’d come back from the wilderness and mention it on the off chance this hasn’t come up before.